Aged hydrogen silsesquioxane for sub-10 nm line patterns
2016 (English)In: Microelectronic Engineering, ISSN 0167-9317, E-ISSN 1873-5568, Vol. 163, 105-109 p.Article in journal (Refereed) Published
Hydrogen silsesquioxane (HSQ) has been used as a negative tone resist in electron beam lithography to define sub-10 nm patterns. The spontaneous polymerization in HSQ usually called aging in this context, sets a restricted period of time for a vendor-warranted use in patterning such small features with satisfactory line-edge roughness (LER). Here, we study the effect of HSQ aging on sensitivity and LER by focusing on exposing line patterns of 10 nm width in various structures. The results show that the 10 nm lines are easily achievable and the LER of the patterned lines remains unaltered even with HSQ that is stored 10 months beyond the vendor-specified expiration date. However, an increasingly pronounced decrease with time of the threshold electron dose (D-th), below which the line width would become less than 10 nm, is observed. After the HSQ expiration for 10 months, the 10 nm lines can be manufactured by reducing D-th to a level that is technically manageable with safe margins. In addition, the inclusion of a prebaldng step at 220 degrees C to accelerate the aging process results in a further reduced D-th for the 10 nm lines and thereby leads to a shortened writing time. The time variation of D-th with respect to the vendor-specified production date of HSQ is found to follow an exponential function of time and can be associated to the classical nucleation-growth polymerization process in HSQ.
Place, publisher, year, edition, pages
2016. Vol. 163, 105-109 p.
Electron beam lithography (EBL); Hydrogen silsesquioxane (HSQ); 10 nm wide resist lines; Aging effect; Line edge roughness (LER); Prebaking
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-300188DOI: 10.1016/j.mee.2016.06.011ISI: 000381837300015OAI: oai:DiVA.org:uu-300188DiVA: diva2:951023
FunderSwedish Foundation for Strategic Research , ICA 12-0047 SE13-0033Swedish Research Council, 2014-5588 2014-5591Göran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of Technology, GG 1459BCarl Tryggers foundation , CTS14-527