25 August 1987 Mechanistic Study Of A Selective Gas-Phase Reactive Microlithographic System
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The gas-phase functionalization of poly(p-hydroxystyrene) (PPHS), prepared imagewise by the acid-catalyzed deprotection of poly(t-butoxycarbonyloxystyrene) (PBOCST) was investigated using a piezoelectric quartz crystal microbalance fitted inside a temperature- and pressure-controlled chamber. This apparatus allowed the real-time monitoring of the mass changes in the resist film during acid-catalyzed thermolysis of the t-butoxycarbonyl groups and subsequent vapor treatment with hexamethyldisilazane (HMDS). Effects of optical exposure, presilylation baking, vapor treatment conditions, and copolymerization with Tn-lowering acrylate esters were investigated and suggest the following: (1) Gas-phase fanctionalization rates are dependent on vapor treatment temperature and pressure, as well as other process variables that alter polymer chain mobility. (2) Rapid diffusion of HMDS takes place in the exposed areas due to the plasticization and increases in void space caused by the evolution of isobutylene and carbon dioxide during photoacid-catalyzed thermolysis of the pendant t-butoxycarbonyl groups. (3) Silicon incorporation appears to be initially reaction-rate limited due to the void space enhanced diffusion.
© (1987) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
T. B. Brust, T. B. Brust, S. R. Turner, S. R. Turner, } "Mechanistic Study Of A Selective Gas-Phase Reactive Microlithographic System", Proc. SPIE 0771, Advances in Resist Technology and Processing IV, (25 August 1987); doi: 10.1117/12.940314; https://doi.org/10.1117/12.940314

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