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Organosilicate Polymer E-Beam Resists with High Resolution, Sensitivity and Stability



Christopher Soles, Richard Kasica, Hae-Jeong Lee, Jae H. Sim, Sung-Il Lee, Ki-Bum Kim, Hyun-Mi Kim, Do Y. Yoon


Hydrogen silsesquioxane (HSQ) is an attractive electron-beam (e-beam) resist for sub-20 nm lithography due to its high resolution, excellent line-edge-roughness (LER), and good plasma etch resistance. However, the sensitivity and long-term stability of HSQ need to be significantly improved to have HSQ resists adopted for volume manufacturing. Here we develop novel organosilicate e-beam resists with improved e-beam sensitivity and stability as an alternative to HSQ resists. Copolymers of norbornene ethyltrimethoxysilane (NETMS) with 1,2-bis(triethoxysilyl)ethane, synthesized via acidcatalyzed sol-gel reactions, show excellent e-beam sensitivity with ca. a six-fold reduction in the critical dose as compared with HSQ but poor LER characteristics. Terpolymers are then synthesized using pchloromethylphenyl trimethoxysilane (p-CMPTMS), NETMS and tetraethoxysilane (TEOS), which exhibit significant improvement in sensitivity as compared with previously reported materials, together with high resolution patterns and long-term stability. High resolution patterns of features as small as 20 nm with excellent LER are successfully fabricated employing organosilicate terpolymers using a 100 keV e-beam. The dose for patterning 20 nm lines is reduced from 4000 μC/cm2 for HSQ to 900 μC/cm2 for an optimized terpolymer resist. FT-IR measurements suggest that the main reason for the increased e-beam sensitivity is chain transfer reaction between the norbornene moieties, which provide an efficient cross-linking mechanism by the e-beam generated radicals.
Applied Organometallic Chemistry


lithography, pattering, electron beam, organosilicate, nanostructure


Soles, C. , Kasica, R. , Lee, H. , Sim, J. , Lee, S. , Kim, K. , Kim, H. and Yoon, D. (2013), Organosilicate Polymer E-Beam Resists with High Resolution, Sensitivity and Stability, Applied Organometallic Chemistry, [online], (Accessed April 14, 2024)
Created February 28, 2013, Updated February 10, 2023