Buried electrode electroacoustic technology for the fabrication of thin film based resonant components
2006 (English)In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 16, no 9, 1869-1874 p.Article in journal (Refereed) Published
A fabrication process for thin film electroacoustic devices utilizing buriedelectrodes is presented. A one-step lithography process has been developedto bury electrodes resulting in a planarized surface. The proposedtechnology is expected to bring about a number of benefits concerning theperformance of a variety of thin film electroacoustic devices. With respectto thin film plate acoustic resonators (FPAR), burying the reflectorelectrodes results in improved reflectivity and potentially lowersusceptibility to acousto-migration effects. It is also shown that employingthe proposed technology for the fabrication of both thin film bulk acousticresonators (FBAR) and thin film solidity mounted bulk acoustic resonators(SBAR) eliminates certain macro-structural defects in the piezoelectric filmwhich is a prerequisite for substantially improved device performance andhigher power handling capability. The buried electrode electroacoustic (EA)technology is demonstrated for a thin aluminium nitride (AlN) piezoelectricfilm with electrodes of both molybdenum (Mo) and tungsten (W). The latterhave been primarily chosen because of their high electroacoustic materialquality. Thin film resonant structures produced by this technology arecharacterized and their features are discussed.
Place, publisher, year, edition, pages
2006. Vol. 16, no 9, 1869-1874 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-88219DOI: 10.1088/0960-1317/16/9/016ISI: 000239774600035OAI: oai:DiVA.org:uu-88219DiVA: diva2:139719