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  • 1.
    Anderås, Emil
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Arapan, Lilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Thin Film Plate Wave Resonant Sensor for Pressure and Gravimetric Measurements2011In: Procedia Engineering 25, Eurosensors XXV: Proc. Eurosensors XXV, September 4-7, 2011, Athens, Greece, Elsevier, 2011, p. 571-574Conference paper (Refereed)
    Abstract [en]

    Thin film plate acoustic resonators (FPAR) devices operating in the lowest order symmetric Lamb wave mode (S0),the first order asymmetric Lamb wave mode (A1) and the first order symmetric Lamb wave mode (S1), propagatingin c-oriented aluminum nitride (AlN) membranes on Si were fabricated and tested for their sensitivities to pressureand mass. Systematic data on frequency shifts versus rigid mass (layer) thickness and ambient pressure variations arepresented for the different Lamb wave resonances. Further the ability to work in liquid environment of the S0, A1 andS1 modes, respectively, has been tested in view of Bio-sensor applications.

  • 2.
    Anderås, Emil
    et al.
    St Jude Medical, Cardiovascular Division, Uppsala.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Lamb wave resonant pressure micro-sensor utilizing a thin-film aluminium nitride membrane2011In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 21, no 8, p. 085010-Article in journal (Refereed)
    Abstract [en]

    In this work, pressure sensitivities of aluminium nitride (AlN) thin film plate acoustic resonators (FPAR) operating at the lowest-order symmetric (S0), the first-order asymmetric (A1) as well as the first-order symmetric (S1) Lamb modes are theoretically and experimentally studied in a comparative manner. The finite element method analysis has also been performed to get a further insight into the FPAR pressure sensitivity. The theoretical predictions are found to be in good agreement with the experiment. The S0 Lamb mode is identified as the most pressure-sensitive FPAR mode, while the A1 and S1 modes are found to be much less sensitive. Further, the S0 and the A1 modes exhibit almost equal temperature sensitivities, which can be exploited to eliminate the temperature drift by comparing the resonance frequencies of the latter two modes.

  • 3.
    Anderås, Emil
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Tilted c-Axis Thin-Film Bulk Wave Resonant Pressure Sensors With Improved Sensitivity2012In: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 12, no 8, p. 2653-2654Article in journal (Refereed)
    Abstract [en]

    Aluminum nitride thin film bulk wave resonant pressure sensors employing c- and tilted c-axis texture, have been fabricated and tested for their pressure sensitivities. The c-axis tilted FBAR pressure sensors demonstrate substantially higher pressure sensitivity compared to its c-axis oriented counterpart. More specifically the thickness plate quasi-shear resonance has demonstrated the highest pressure sensitivity while further being able to preserve its performance in liquid environment.

  • 4.
    Arapan, Lilia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Alexieva, Gergana
    Dept of Solid State Physics and Microelectronics, University of Sofia, Bulgarien.
    Avramov, Ivan D
    Georgy nadjakov Institute of Solid State Physics, Sofia,Bulgarian Academy of Sciences.
    Radeva, Elisaveta
    Georgy Nadjakov Institute of Solid State Physics, Sofia, Bulgarian Academy of Sciences.
    Strashilov, Vesseline
    University of Sofia.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Highly Mass-Sensitive Thin Film Plate Acoustic Resonators (FPAR)2011In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 11, no 7, p. 6942-6953Article in journal (Refereed)
    Abstract [en]

    The mass sensitivity of thin aluminum nitride (AlN) film S0 Lamb wave resonators is theoretically and experimentally studied. Theoretical predictions based on modal and finite elements method analysis are experimentally verified. Here, two-port 888 MHz synchronous FPARs are micromachined and subsequently coated with hexamethyl-disiloxane(HMDSO)-plasma-polymerized thin films of various thicknesses. Systematic data on frequency shift and insertion loss versus film thickness are presented. FPARs demonstrate high mass-loading sensitivity as well as good tolerance towards the HMDSO viscous losses. Initial measurements in gas phase environment are further presented.

  • 5.
    Arapan, Lilia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Anderås, Emil
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Sensitivity Features of Thin Film Plate Acoustic Wave Resonators2011In: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 11, no 12, p. 3330-3331Article in journal (Refereed)
    Abstract [en]

    Thin film plate acoustic resonators devices operating in the lowest order symmetric Lamb wave mode (S0) in coriented aluminum nitride (AlN) membranes on Si were fabricated and tested for their sensitivities to pressure and mass as well as for their ability to work in liquid environment.

  • 6.
    Arapan, Lilia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Avramov, Ivan
    Inst Solid State Physics, Bulgarian Academy of Sciences.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Thin film plate acoustic resonators for integrated microwave power oscillator applications2011In: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 47, no 7, p. 452-453Article in journal (Refereed)
    Abstract [en]

    Two-port film plate acoustic resonators (FPAR) devices operating on the lowest order symmetric Lamb wave mode (S0) in C-oriented AlN membranes on Si were fabricated and tested for their power handling capabilities in a feedback-loop power oscillator circuit. The FPAR was operated at an incident power level of 24 dBm for several weeks without performance degradation. Its flicker noise constant was calculated from close-in phase noise data as αR=2.1×10^−36/Hz. The results indicate that IC-compatible S0 FPARs are well suited for integrated microwave oscillators with thermal noise floor (TNF) levels below −175 dBc/Hz.

  • 7.
    Arapan, Lilia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    An intermode-coupled thin-film micro-acoustic resonator2012In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 22, no 8, p. 085004-Article in journal (Refereed)
    Abstract [en]

    A novel concept for the development of thin-film micro-acoustic resonators based on the coupling between different plate acoustic modes was demonstrated. The basic principles for the design and fabrication of intermode-coupled plate acoustic wave resonators on c-textured thin AlN films were presented and first experimental proof of coupling between laterally propagating waves and BAW was demonstrated. The experimental results demonstrate that the grating-assisted intermode coupling can be employed in high-frequency resonators inheriting the low dispersive nature of the S0 mode in combination with the energy localization in the plate bulk typical for the fundamental thickness shear resonance.

  • 8.
    Arapan, Lilia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Alexieva, Gergana
    Dept of Solid State Physics and Microelectronics, University of Sofia.
    Strashilov, Vesseline
    Dept of Solid State Physics and Microelectronics, University of Sofia.
    Avramov, Ivan
    Georgy Nadjakov Institute of Solid State Physics, Sofia, Bulgarian Academy of Sciences.
    Radeva, Ekaterina
    Georgy Nadjakov Institute of Solid State Physics, Sofia, Bulgarian Academy of Sciences.
    Polymer coated thin film plate acoustic resonators (FPAR) for gas sensing applications2011In: 2011 Joint Conference of the IEEE International Frequency Control Symposium and European Frequency and Time Forum Proceedings, San Fransisco, CA, USA, 2011Conference paper (Refereed)
    Abstract [en]

    Mass sensitivity of thin aluminum nitride (AlN) film S0 plate wave resonators is theoretically and experimentally studied. Here, two-port 888MHz synchronous thin film plate acoustic resonators (FPAR) are micromachined and subsequently coated with plasma-polymerized hexamethyldisiloxane (pp-HMDSO) thin films of various thicknesses. Systematic data on frequency shift and insertion loss versus film thickness are presented in a comparative manner. Measurements in gas phase environment are further presented in a comparative manner.

  • 9.
    Avramov, Ivan
    et al.
    Bulgarian Academy of Sciences.
    Arapan, Lilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Strashilov, Vesseline
    University of Sofia.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    IC-compatible Power Oscillators Using Thin Film Plate Acoustic Resonator (FPAR)2009In: Proceedings 2009 IEEE International Ultrasonics Symposium, 2009Conference paper (Refereed)
    Abstract [en]

    In this study, two-port 880MHz FPAR devicesoperating on the lowest order fast symmetric Lamb wave mode(S0) in c-oriented AlN membranes on Si, were fabricated andsubsequently tested for their power handling capabilities in afeedback-loop power oscillator circuit. The S0 Lamb waves wereexcited and detected by a classical two-port resonator structure,as in Rayleigh SAW (RSAW) resonators. Incident power levels ofup to 24 dBm (250 mW) for the FPARs were provided by a high powersustaining amplifier in the loop. No measurable performance degradation was observed. The results from this study indicate that IC-compatible S0 FPAR devices can dissipate orders of magnitude higher RF-power levels than their RSAWcounterparts on quartz and are well suited for integrated microwave power oscillators with thermal noise floor (TNF) levelsbelow -175 dBc/Hz.

  • 10.
    Bjurström, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Rosén, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Dependence of the Electromechanical Coupling on the Degree of Orientation of c-Textured Thin AlN Films2003In: IEEE Ultrasonics Symposium, Honolulu, Hawaii, USA, 2003, 2003Conference paper (Refereed)
  • 11.
    Bjurström, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Wingqvist, Gunilla
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Design and Fabrication of Temperature Compensated Liquid FBAR Sensors2006Conference paper (Refereed)
  • 12.
    Bjurström, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Wingqvist, Gunilla
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Temperature compensation of liquid FBAR sensors2007In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 17, no 3, p. 651-658Article in journal (Refereed)
    Abstract [en]

    In this work we demonstrate a practically complete temperature compensation of the second harmonic shear mode in a composite Al/AlN/Al/SiO2 thin film bulk acoustic resonator (FBAR) in the temperature range 25 °C–95 °C. The main advantages of this mode are its higher Q value in liquids as well as its higher frequency and hence higher resolution for sensor applications. For comparative reasons the non-compensated fundamental shear mode is also included in these studies. Both modes have been characterized when operated both in air and in pure water. Properties such as Q value, electromechanical coupling, dissipation and sensitivity are studied. An almost complete temperature compensation of the second harmonic shear mode was observed for an oxide thickness of 1.22 µm for an FBAR consisting of 2 µm thick AlN and 200 nm thick Al electrodes. Thus, the measured temperature coefficient of frequency (TCF) in air for the non-compensated fundamental shear mode (1.25 GHz) varied between −31 and −36 ppm °C−1 over the above temperature range while that of the compensated second harmonic shear mode (1.32 GHz) varied between +2 ppm °C−1 and −2 ppm °C−1 over the same temperature interval. When operated in pure water the former type shows a Q value and coupling coefficient, k2t, around 180 and 2%, respectively, whereas for the second harmonic these are 230 and 1.4%, respectively.

  • 13.
    Enlund, Johannes
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Martin, David M.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    FBAR sensor array for in liquid operation2010In: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 10, no 12, p. 1903-1904Article in journal (Refereed)
    Abstract [en]

    This letter discusses the design of thickness shear mode thin-film bulk acoustic resonator (FBAR) sensor array for in liquid operation with respect to minimizing the observed Q-degradation and crosstalk.

  • 14.
    Enlund, Johannes
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Martin, David
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yanchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Analysis of Q-degradation and Cross-Talk in BAW Sensor Arrays Operating in Conductive Liquid Media2009Conference paper (Refereed)
  • 15.
    Enlund, Johannes
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Martin, David
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Solidly mounted thin film electro-acoustic resonator utilizing a conductive Bragg reflector2008In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 141, no 2, p. 598-602Article in journal (Refereed)
    Abstract [en]

    A new design of a solidly mounted resonator (SMR) that utilizes an all-metal Bragg reflector eliminating thus the need for a bottom electrode is proposed. In this configuration, the role of the bottom electrode is taken by the Bragg reflector rendering the resonator “combined electrode-Bragg reflector SMR”. The main advantages of the proposed design are the substantially reduced electrode resistance (and hence higher Q), the utilization of the full piezoelectric coupling at high frequencies as well as expected improvement in power handling capabilities due to lower dissipation and improved heat conductivity. Resonators with the classical and the new design have been fabricated and evaluated. The measurements indicate that indeed the resonators with the new design demonstrate improved performance.

  • 16.
    Enlund, Johannes
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics.
    Electric Field Sensitivity of Thin Film Resonators Based on Piezoelectric AlN thin films2006Conference paper (Refereed)
  • 17.
    Johansson, Linda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Enlund, Johannes
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Johansson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Wiklund, M
    Dept of Applied Physics, Albanova/KTH , Stockholm.
    Yantchev, Ventislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Surface acoustic wave-induced precise particle manipulation in a trapezoidal glass microfluidic channel2012In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 22, no 2, p. 025018-Article in journal (Refereed)
    Abstract [en]

    Surface acoustic wave (SAW) excitation of an acoustic field in a trapezoidal glass microfluidic channel for particle manipulation in continuous flow has been demonstrated. A unidirectional interdigital transducer (IDT) on a Y-cut Z-propagation lithium niobate (LiNbO3) substrate was used to excite a surface acoustic wave at approximately 35 MHz. An SU8 layer was used for adhesive bonding of the superstrate glass layer and the substrate piezoelectric layer. This work extends the use of SAWs for acoustic manipulation to also include glass channels in addition to prior work with mainly poly-di-methyl-siloxane channels. Efficient alignment of 1.9 mu m polystyrene particles to narrow nodal regions was successfully demonstrated. In addition, particle alignment with only one IDT active was realized. A finite element method simulation was used to visualize the acoustic field generated in the channel and the possibility of 2D alignment into small nodal regions was demonstrated.

  • 18.
    Johansson, Linda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Enlund, Johannes
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Johansson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Surface acoustic wave induced particle manipulation in a PDMS channel: principle concepts for continuous flow applications2012In: Biomedical microdevices (Print), ISSN 1387-2176, E-ISSN 1572-8781, Vol. 14, no 2, p. 279-289Article in journal (Refereed)
    Abstract [en]

    A device for acoustic particle manipulation in the40 MHz range for continuous-flow operation in a 50 μm wide PDMS channel has been evaluated. Unidirectionalinterdigital transducers on a Y-cut Z-propagation lithiumniobate wafer were used to excite a surface acoustic wavethat generated an acoustic standing wave inside the microfluidicchannel. It was shown that particle alignment nodeswith different inter-node spacing could be obtained,depending on device design and driving frequency. Theobserved inter-node spacing differed from the standard halfwavelengthinter-node spacing generally employed in bulkacoustic transducer excited resonant systems. This effectand the related issue of acoustic node positions relative thechannel walls, which is fundamental for most continuousflow particle manipulation operations in channels, wasevaluated in measurements and simulations. Specificapplications of particle separation and alignment wherethese systems can offer benefits relative state-of the artdesigns were identified.

  • 19.
    Katardjiev, Ilia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bjurström, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Wingqvist, Gunilla
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Enlund, Johannes
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Martin, David
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Recent advances in the thin film electroacoustic technology2006Conference paper (Refereed)
  • 20.
    Katardjiev, Ilia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Recent developments in thin film electro-acoustic technology for biosensor applications2012In: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 86, no 5, p. 520-531Article, review/survey (Refereed)
    Abstract [en]

    The article reviews recent developments of the thin film electro-acoustic (TEA) technology in view of the design and fabrication of micro-acoustic transducers for biosensor applications. The use of the TEA technology leads to transducer miniaturisation, compatibility with the IC technology, possibility for multiplexing, decrease in fabrication cost, reduction of consumables, mass fabrication, etc. Focus lies on the design, fabrication and evaluation of the transducer performance in liquid media as judged by electro-acoustic behaviour and ultimately by mass and viscosity resolution. The analysis draws the conclusion that the thickness excited quasi-shear thin film bulk acoustic resonator technology is far ahead in its development with regard to other alternative approaches in terms of both performance and level of maturity. Consequently, the main aspects of the quasi-shear thin film bulk acoustic resonator (FBAR) technology from film synthesis and fabrication through to performance evaluation and demonstration are reviewed in detail.

  • 21.
    Katardjiev, Ilia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    A Passive Radio Triggered Switch with ID Functionality2012Patent (Other (popular science, discussion, etc.))
  • 22.
    Katardjiev, Ilia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Recent advances in the thin film electro-acoustic technology2012Conference paper (Refereed)
  • 23.
    Katardjiev, Ilia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Shear mode TFBARs2007Conference paper (Refereed)
  • 24.
    Lin, Chih-Ming
    et al.
    Berkeley Sensor and Actuator Center (BSAC), University of California, Berkeley, CA 94709, USA.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Chen, Yung-Yu
    3Department of Mechanical Engineering, Tatung University, Taipei 10452, TAIWAN.
    Pisano, Albert
    Univ Calif Berkeley, Berkeley Sensor & Actuator Ctr, Berkeley, CA 94720 USA; Univ Calif Berkeley, Dept Mech Engn, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA.
    Micromachined One-Port Aluminum Nitride Lamb Wave Resonators Utilizing the Lowest-Order Symmetric Mode2013In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 23, no 1, p. 78-91Article in journal (Refereed)
    Abstract [en]

    The characteristics of one-port aluminum nitride (AlN) Lamb wave resonators utilizing the lowest symmetric (S0) mode with electrically open, grounded, and floating bottom electrode configurations are theoretically and experimentally investigated. The finite element analysis (FEA) is performed to take an insight into the static capacitance characteristics of the AlN Lamb wave resonators with various bottom surface conditions. The theoretical results predict that the floating bottom electrode efficiently reduces the static capacitance in the AlN thin plate and then promotes an efficient improvement in the effective coupling coefficient. Experimentally the AlN Lamb wave resonator without a bottom electrode exhibits a loaded quality factor (Q) as high as 3033 at its series resonance frequency, 948.1 MHz, but a low effective coupling coefficient of 0.18%. On the contrary, the Lamb wave resonator with an electrically floating bottom electrode shows an effective coupling coefficient up to 1.05% but a low loaded Q of 850 at its series resonance frequency, 850.3 MHz. In contrast to the floating bottom electrode, the Lamb wave resonator with an electrically grounded bottom electrode shows a smaller effective coupling coefficient of 0.78% and a similar loaded Q of 800 at the series resonance frequency, 850.5 MHz.

  • 25.
    Lin, Chih-Ming
    et al.
    Department of Mechanical Engineering, Berkeley, University of California,.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Felmetsger, Valery
    OEM Group.
    Pisano, Albert
    Department of Mechanical Engineering, Berkeley, University of California,.
    Characteristics of AlN Lamb wave resonators with various bottom electrode configurations2011In: Frequency Control and the European Frequency and Time Forum (FCS), 2011 Joint Conference of the IEEE International, San Francisco, USA, 2011, p. 1-5Conference paper (Refereed)
    Abstract [en]

    The characteristics of aluminum nitride (AlN) Lamb wave resonators utilizing the lowest symmetric (S0) mode with grounded, floating, and open bottom surface configurations are theoretically and experimentally investigated. The Lamb wave resonator without the bottom electrode exhibits a quality factor (Q) as high as 2,573 but a low effective coupling of 0.18% at 949.7 MHz. On the contrary, the Lamb wave resonator with a floating bottom electrode shows an effective coupling of 1.05% but a low Q of 850 at 850.3 MHz because the imperfect interface between the AlN plate and bottom electrode usually degrades the Q. Limited by the larger static capacitance, in contrast to the floating bottom electrode, the Lamb wave resonator with a grounded bottom electrode shows a smaller effective coupling of 0.78% and a low Q of 800 at 850.5 MHz. These results suggest that the resonator with a floating bottom surface is suitable for filter applications, whereas that with an open bottom surface is preferred for sensor and oscillator applications.

  • 26.
    Martin, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Enlund, Johannes
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Olsson, Jorgen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Thick Silicides Synthesised With Smooth Surface for Integrated TFBAR Applications2008In: 2008 European Frequency and Time Forum, Toulouse, France, 2008Conference paper (Refereed)
  • 27.
    Martin, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Enlund, Johannes
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Olsson, Jörgen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Optimisation of a smooth multilayer Nickel Silicide surface for ALN growth2007Conference paper (Refereed)
  • 28.
    Martin, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Enlund, Johannes
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Olsson, Jörgen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Optimisation of a smooth multilayer Nickel Silicide surface for ALN growth2008In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 100, no 4, p. 042014-Article in journal (Refereed)
    Abstract [en]

    For use in thin film electroacoustic (TEA) technology a few hundred nanometrethick nickel silicide (NiSi) electrode would need to be fabricated. A complete fabrication process for the formation of over 200 nm thick silicide films has been optimised for use as an electroacoustic electrode. Optimisation of silicidation temperature and identification of the mono phase of silicide is demonstrated. Thick electrodes are formed by depositing multilayers of silicon and nickel pairs onto silicon (Si) substrates before rapid thermal annealing. The numbers of multilayers and relative material thicknesses are optimized for both surface roughness and electrical resistivity. The growth of textured aluminium nitride (AlN) has been investigated on the optimised surfaces.

  • 29.
    Martin, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Smith, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Olsson, Jörgen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Thick NiSi Electrodes for AlN Electroacoustic Applications2009In: Electrochemical and solid-state letters, ISSN 1099-0062, E-ISSN 1944-8775, Vol. 12, no 5, p. H182-H184Article in journal (Refereed)
    Abstract [en]

    Theuse of thick NiSi electrodes in electroacoustic resonators allows front-endintegration with integrated circuit technology. Problems are identified in theformation of thick nickel silicide (NiSi) electrodes via a singledeposition of Ni onto blank Si wafers. An alternative fabricationprocess based on the deposition and silicidation of a multilayerfilm is presented. The films were found to have lowresistivity and smooth surfaces, with the layered structure preserved evenafter silicidation. Textured piezoelectric films of (002) wurtzite AlN demonstrateda diffraction-peak width that narrows to 3.5° when deposited ona thick 10 pair NiSi film.

  • 30.
    Martin, David
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Electronics.
    Yantchev, Ventsislav
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Electronics.
    Katardjiev, Ilia
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Electronics.
    Thin Film Electro-Acoustic Devices Utilising Buried Electrodes2005In: Proc. 2005 Gigahertz Symp., Uppsala, Sweden, October 2005, 2005Conference paper (Other academic)
  • 31. Mirea, T.
    et al.
    DeMiguel-Ramos, M.
    Clement, M.
    Olivares, J.
    Iborra, E.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    AlN Solidly Mounted Resonators for High Temperature Applications2014In: 2014 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS), 2014, p. 1524-1527Conference paper (Refereed)
    Abstract [en]

    Monitoring under harsh environments, particularly high temperatures (> 600 degrees C), is on high demand nowadays. Applications such as gas control in propulsion systems or fire detection in early stages are good examples. During the last decades, materials and devices have been extensively investigated for these applications. Few have proven thermal and chemical stability. Among the most used devices are surface acoustic wave (SAW) resonators using a langasite (LGS) substrate. Their main disadvantage is related to their transducer topology. Their long and narrow electrode strips are subjected to destructive agglomeration. In order to solve this problem, solidly mounted bulk resonators (SMR) are here proposed as an alternative. They provide rigidity, high performance and large electrodes. Here we investigate the performance of SMR devices after annealing under vacuum condition at 700 degrees C for a cumulative time of 24h. SMRs are composed of porous-SiO2/Mo Bragg mirrors and Ir or Mo electrodes. Their performance shows and initial overall improvement with subsequent stabilization. Q(p)xk(eff)(2) in the order of 72 are achieved. Further investigations on full dielectric Bragg mirrors will be performed. With this initial study we demonstrate that SMRs can be a good alternative to SAWs for high temperature applications.

  • 32. Mirea, Teona
    et al.
    Iborra, Enrique
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Microacoustic in-liquid sensors based on thin AlN films: A comparative study2014In: 2014 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS), 2014, p. 659-662Conference paper (Refereed)
    Abstract [en]

    We present a novel low-cost and low-power MEMS gas sensor concept based on an ultrasonic resonance cavity. The sensor consists of a capacitive micromachined ultrasonic transducer (CMUT) embedded to an acoustic resonance cavity. The sensor operation was demonstrated with carbon dioxide CO2 and methane CH4, the lowest resolvable concentrations are about 10 - 20 ppm - a competitive result with the existing commercially available CO2 sensors. In addition, the sensor is able to measure gas concentration and humidity independently, and thus can be used as a combo sensor for gas concentrations and humidity.

  • 33. Mirea, Teona
    et al.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Influence of liquid properties on the performance of S-0-mode Lamb wave sensors: A theoretical analysis2015In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 208, p. 212-219Article in journal (Refereed)
    Abstract [en]

    Sensors based on thin film electroacoustic (TEA) devices have emerged as a promising alternative to quartz crystal microbalance and surface acoustic wave devices, in view of sensibility, miniaturization and easy integration. TEA devices include quasi-shear film bulk acoustic resonators (QS-FBAR) and S-0 mode Lamb wave resonators (S-0-LWR) based on AlN films. Despite the work done on the application of TEA devices as in-liquid biological and chemical sensors, a theoretical framework for S-0-LWRs properly describing their sensing mechanisms is still needed. Here we validate a finite element analysis model on QS-FBARs and study the sensing mechanisms of S-0-LWRs in liquid media. We show that S-0-LWRs can sense changes in the dielectric permittivity of the liquid and demonstrate different sensitivities to viscosity and density. A complementary assessment of the S-0-LWRs losses, dependent in a non-specific manner on the square root of the density viscosity product, provides the ability to discriminate density from viscosity changes on the entire device surface. Finally, with an S-0-LWR optimization study we show that resolution improves with the decrease of the membrane thickness; however, a trade-off between sensitivity, quality factor and membrane fragility has to be considered.

  • 34.
    Moreira, Milena
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bjurström, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Aluminum scandium nitride thin-film bulk acoustic resonators for wide band applications2011In: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 86, no 1, p. 23-26Article in journal (Refereed)
    Abstract [en]

    Piezoelectric c-textured Al(1-x)ScxN thin films, where the Sc relative concentration, x, varies in the range 0-0.15 have been studied in view of radio frequency (RF) electro-acoustic applications. Thin film bulk acoustic wave resonators (FBARs) employing these films were fabricated and characterized as a function of the Sc concentration for the first time. The measured electromechanical coupling is found to increase by as much as 100% in the above concentration range. The results from this work underline the potential of the c-textured Al(1-x)ScxN based FBARs for wide band RF applications.

  • 35.
    Moreira, Milena
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bjurström, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Efficient RF voltage transformer with bandpass filter characteristics2013In: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 49, no 3, p. 198-199Article in journal (Refereed)
    Abstract [en]

    A microwave bandpassfilter with a large ratio between the output andthe input impedance has been designed and fabricated. Consequently,it functions both as a voltage transformer and a bandpassfilter, or trans-filter for brevity. It represents a two-port micro-acoustic resonatoremploying Lamb waves in a thin piezoelectric AlNfilm grown ontoa Si carrier substrate with a centre frequency of around 887 MHz.The transfilter has a transformer ratio of 10 and a voltage efficiencyof over 80%. The component has a small size ( < 0.5 mm2) and isshown to sustain power levels of 250 mW. It can be used in avariety of cases where both voltage amplification and frequencyfilter-ing are required. Examples include: charge pumps in RFID tags,energy scavenging, remotely triggered switches, wake-up radios inwireless networks, stand-by units in home electronics etc.

  • 36.
    Moreira, Milena De Albuquerque
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bjurström, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Synthesis and characterization of highly c-textured Al(1-x)Sc(x)N thin films in view of telecom applications2012In: More than moore: Novel materials approaches for functionalized silicon based microelectronics, 2012, p. 012014-Conference paper (Refereed)
    Abstract [en]

    Wurtzite AlN is a piezoelectric material with excellent electro-acoustic properties and is used for the fabrication of high frequency thin film micro-acoustic components, most notably filters, duplexers, resonators, etc. Its moderate electromechanical coupling coefficient (k(t)(2)) of 6%-7% is insufficient for applications requiring larger bandwidths. Recent theoretical and experimental studies indicate that AlN alloyed with Sc exhibits a substantially higher piezoelectric constant than pure AlN. This study aims at determining the main electro-acoustic parameters of Al(1-x)Sc-(x) N in view of large bandwidth applications. To this end, highly c-textured Al(1-x)Sc(x) N thin films have been synthesized with relative Sc concentrations of up to 0,15. Subsequently, FBAR resonators were fabricated and characterized as a function of the Sc content. It is seen that k(t)(2) increases linearly with the latter to a value of 12% for a Sc concentration of x=0,15, while the Q value decreases from 739 to about 348 in the same concentration range. Likewise, the TCF varies from -35,9ppm/degrees C to -39,8ppm/degrees C, while the dielectric constant increases from epsilon=10 to a value of 14,1 for x=0,15. Finally, the relative dielectric losses are seen to increase by approximately a factor of two.

  • 37.
    Plessky, Victor
    et al.
    CNRS, FEMTO ST, France.
    Ballandras, Sylvain
    Freq'N'Sys, France.
    Grigorievsky, Valery
    RAS, Fryazino, Russia.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    3th type of FBARs?2013In: Proc. 2013 IEEE Int. Ultrasonic Symposium (IUS), 2013Conference paper (Refereed)
    Abstract [en]

    Different « layered structures » were proposed in the past combining the advantageous features of substrates (e.g. low SAW attenuation in sapphire) and high quality of piezoelectric (e.g. AlN) films for the development of acoustic wave guides. Unfortunately, the achievable electromechanical coupling constant K2 is in most cases very small. Meanwhile in FBARs AlN films excited in thickness mode demonstrated K2 > 6%. We propose here a transducer structure comprising: 1) a substrate suitable for propagation of surface acoustic waves in the X-direction with low loss, 2) a metal layer deposited on said substrate and 3) micro-acoustic transducers (resonators) created in the form of piezoelectric (AlN, ZnO, etc.) bars or ridges with cross-section dimension in X-direction smaller than a half wavelength of any acoustic wave in the substrate material at operation frequencies and having top conducting electrodes. The thickness of the piezoelectric layer is close to λp /4 or λp /2 of the bulk wave excited in said transducers/resonators. Said transducers being placed periodically and separated (centre-to-centre) by a distance in the X-direction smaller than 1/2 wavelength of any acoustic wave in the substrate material are connected to the balanced source of voltage +/- V/2. We have simulated both cases. The principal results are that the resonator grating always provides larger coupling factors than the solid layer one, and that a mode can occur exhibiting a coupling of at least 4.2% depending on the layer thickness. In this mode the resonances in narrow FBARs are coupled through the substrate. Actually a new type of FBAR is described, wherein the isolation from the substrate is provided by destructive interference of the radiated bulk waves because of the resonators periodicity < λBulk /2. The coupling can be easily adjusted. The mode we see may be treated as not a SAW, but as a vibration in a system of coupled FBARs

  • 38. Plessky, Victor
    et al.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Two Resonances of Different Nature in STW Resonators With Aperture-Weighted Metallization2015In: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, ISSN 0885-3010, E-ISSN 1525-8955, Vol. 62, no 4, p. 766-770Article in journal (Refereed)
    Abstract [en]

    In a narrowband 2-port resonator on 37 degrees-cut quartz with Al electrodes (h(Alu) = 100 nm) exploiting surface transverse waves (STW), we have observed parasitic ripples which have been attributed to transverse modes unusually situated on the left side of the main resonance. To suppress these modes, we have used metallization coefficient weighting across the aperture, with more metal in the middle and reduced metallization close to the busbars. The parasitic modes indeed disappeared, but at significantly higher frequency, we have found an additional strong response which does not exist in a resonator with uniform electrode metallization. 3-D simulations showed that the structure has another very different mode, with the wave propagating mainly along the edge of the busbars, but excited with the interdigital electrode system.

  • 39.
    Plessky, Victor
    et al.
    CNRS, FEMTO ST, France.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Ballandras, Sylvain
    Freq|n|Sys, France.
    Grigorievsky, Valery
    RAS, Russia.
    Surface Transverse Wave (STW) resonators on langasite2013In: Proc. 2013 IEEE Int. Ultrasonic Symposium, Prague, Chech, 2013Conference paper (Refereed)
    Abstract [en]

    The Surface Transverse Waves (STW) cut of langasite (LGS), Euler angles (0°, 22°, 90°), provides temperature stable delay of STW with coupling coefficient a few times larger than that of 36° rotated Y-cut of quartz which also supports STW. It was expected that, as in the case of quartz, one can get excellent Q-factor resonators based on low loss shear surface acoustic waves (STW). Such resonators are in great demand for high temperature sensors and for this application Platinum (Pt) electrodes are necessary. However, recent attempts to develop such resonators resulted in mediocre Q factors of the order of 1000 rather than the expected Q>10000 in the 434 MHz ISM frequency range. In this paper we show that for a thickness of Pt (h/λ close to 2%) on this cut of LGS there is no wave-guiding, which means that the STW energy is radiated into the busbars. This effect can be explained by the concave shape of the slowness curve for SAW in the bus-bar area due to a large increase in the wave velocity with deviation of the propagation direction from 0Z axis. The use of thicker Pt layers, (yielding a relative thickness h/λ in excess of 3%) makes the phase velocity of STW in the periodic grating at resonance drop below the wave velocity of all types of waves propagating under the bus-bars due to the high reflectivity of the electrodes, establishing the usual wave-guiding conditions.

  • 40.
    Salut, Roland
    et al.
    CNRS France.
    Gesset, Celine
    CEA France.
    Saada, Samuel
    CEA France.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Fabrication of GHz range Oscillators stabilized by nano-carbon-diamond-based surface acoustic resonators2009In: Proceedings 2009 International IEEE Ultrasonics Symposium, 2009Conference paper (Refereed)
  • 41. Strashilov, V
    et al.
    Yantchev, Ventsislav
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Electronics.
    Surface Transverse Waves: Properties, Devices and Analysis2005In: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, ISSN 0885-3010, E-ISSN 1525-8955, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, ISSN 0885-3010, Vol. 52, no 5, p. 812-821Article in journal (Refereed)
  • 42.
    Uzunov, Ivan
    et al.
    Technical University of Sofia.
    Gajdajiev, Dobromir
    Microelectronic Technologies Department at Smartcom Bulgaria AD.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    FBAR filter with asymmetric frequency response and improved selectivity and passband width2011In: Proceedings of the 18th International Conference - Mixed Design of Integrated Circuits and Systems, MIXDES 2011, 2011, p. 596-601Conference paper (Refereed)
    Abstract [en]

    The paper is dedicated to improving the frequency response of FBAR filters by replacing some of the single FBARs with two resonators connected in parallel. The method is applied for the basic lattice filter architecture and its modification with twice fewer number of FBARs. The conditions that must satisfy the resonator parameters are derived by theoretical considerations and computer simulations.

  • 43.
    Wingqvist, Gunilla
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Andersson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Lennartsson, Christian
    iv. Applied Physics, Dep. Physics, Chemistry and Biology, Linkoping University, Linkoping, Sweden.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Lloyd Spetz, Anita
    Div. Applied Physics, Dep. Physics, Chemistry and Biology, Linkoping University, Linkoping, Sweden.
    On the applicability of high frequency acoustic shear mode biosensing in view of thickness limitations set by the film resonance2009In: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 24, no 11, p. 3387-3390Article in journal (Refereed)
    Abstract [en]

    The IC-compatible thin film bulk acoustic resonator (FBAR) technology has made it possible to move the thickness excited shear mode sensing of biological layers into a new sensing regime using substantially higher operation frequencies than the conventionally used Quartz Crystal Microbalance (QCM). The limitations of the linear range set by the film resonance using viscoelastic protein films are here for the first time addressed specifically for FBARs operating at 700MHz up to 1.5GHz. Two types of protein multilayer sensing were employed; one utilizing alternating layers of Streptavidin and Biotinated BSA and the other using stepwise cross-linking of fibrinogen with EDC/NHS activation of its carboxyl groups. In both cases the number of protein layers within the linear regime is well above the number of protein layers usually used in biosensor applications, further verifying the applicability of the FBAR as a biosensor. Theoretical calculations are also presented using well established physical models to illustrate the expected behavior of the FBAR sensor, in view of both the frequency and the dissipation shifts.

  • 44.
    Wingqvist, Gunilla
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Arapan, Lilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yanchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Temperature Compensation of Thin Film Resonators utilizing the Lowest order Symmetric Lamb mode2008In: Proc. 2008 Int. IEEE Ultrason. Symp., 2008 Beijing, China, 2008Conference paper (Refereed)
  • 45.
    Wingqvist,, Gunilla
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Arapan, Lilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Temperature Compensation of Thin Film Resonators utilizing the Lowest order Symmetric Lamb mode2008Conference paper (Other academic)
    Abstract [en]

    Micromachined Thin film plate acoustic wave resonators (FPAR) utilizing the lowest order symmetric Lamb wave (S0) propagating in highly textured 2μm thick Aluminum Nitride (AlN) membranes have been successfully demonstrated[1]. However, a notable drawback of the proposed devices is their non-zero temperature coefficient of frequency (TCF) which lies in the range -20 ppm/K to –25 ppm/K. In this work temperature compensation of thin AlN film Lamb wave resonators is studied and demonstrated. Temperature compensation, while retaining at the same time the device electromechanical coupling, isexperimentally demonstrated. The zero TCF Lamb wave resonators are fabricated onto composite AlN/SiO2 membranes. Q factors of around 1400 have been measured at a frequency of around 755 MHz.

  • 46.
    Wingqvist, Gunilla
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Arapan, Lilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Micromachined thermally compensated thin film Lamb wave resonator for frequency control and sensing applications2009In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 19, no 3, p. 035018-Article in journal (Refereed)
    Abstract [en]

    Micromachined thin film plate acoustic wave resonators (FPAR) utilizing the lowest order symmetric Lamb wave (S0) propagating in highly textured 2μm thick Aluminum Nitride (AlN) membranes have been successfully demonstrated [1]. The proposed devices have a SAW-based design and exhibit Q factors of up to 3000 at a frequency around 900MHz as well as design flexibility with respect to the required motional resistance. However, a notable drawback of the proposed devices is non-zero temperature coefficient of frequency (TCF) which lies in the range -20 ppm/K to –25 ppm/K. Thus, despite the promising features demonstrated, further device optimization is required. In this work temperature compensation of thin AlN film Lamb wave resonators is studied and experimentally demonstrated. Temperature compensation while retaining at the same time the device electromechanical coupling is experimentally demonstrated. The zero TCF Lamb wave resonators are fabricated onto composite AlN/SiO2 membranes. Q factors of around 1400 have been measured at a frequency of around 755 MHz. Finally, the impact of technological issues on the device performance is discussed in view of improving the device performance.

  • 47.
    Wingqvist, Gunilla
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bjurström, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Liljeholm, Lina
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Shear mode AlN thin film electro-acoustic resonant sensor operation in viscous media2007In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 123, no 1, p. 466-473Article in journal (Refereed)
    Abstract [en]

    A shear mode thin film bulk acoustic resonator (FBAR) operating in liquid media together with a microfluidic transport system is presented. The resonator has been fabricated utilizing a recently developed reactive sputter-deposition process for AlN thin films with inclined c-axis relative to the surface normal with a mean tilt of around 30°. The resonator has a resonance frequency of around 1.2 GHz and a Q value in water of around 150. Sensor operation in water and glycerol solutions is characterized. Theoretical analysis of the sensor operation under viscous load as well as of the sensitivity and stability in general is presented. The theoretical predictions are compared with experimental measurements. The results demonstrate clearly the potential of FBAR biosensors for the fabrication of highly sensitive low cost biosensors, bioanalytical tools as well as for liquid sensing in general.

  • 48.
    Wingqvist, Gunilla
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bjurström, J.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Mass Sensitivity of Thin Film Resonator Device2007Conference paper (Refereed)
  • 49.
    Wingqvist, Gunilla
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Bjurström, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Thin film bulk acoustic resonators (FBARs) for biosensor applications2008Conference paper (Refereed)
  • 50.
    Wingqvist, Gunilla
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Mass sensitivity of multilayer thin film resonant BAW sensors2008In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 148, no 1, p. 88-95Article in journal (Refereed)
    Abstract [en]

    Abstract: A systematic study of the mass sensitivity and its dependence on the material's properties and thicknesses in composite multilayer Thin Film Bulk Acoustic Resonators (FBAR) is presented. The Mason transmission line model has been employed in combination with the acoustic energy balance principle for the determination of the FBAR mass sensitivity. The results have been experimentally verified. Further, the mass sensitivity dependence on various parameters has been studied and correlated with wave reflection and interference within the composite structure in addition to the well-known dependence on resonator acoustic impedance and operation frequency. The mass sensitivity for both the fundamental and the second harmonic mode of operation has been studied in view of their practical relevance. In particular, sensitivity amplification induced by the presence of an on-top deposited low acoustic impedance layer has been identified for the first harmonic and its potential applicability discussed in terms of gas and in-liquid sensing. Optimized structures for both sensing applications are suggested by considering the overall sensor resolution defined by both the mass sensitivity and the FBAR performance.

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