A. Yamaguchi et al., SELF-DEVELOPING CHARACTERISTICS OF SI CONTAINING POLYMERS AND THEIR APPLICATION TO X-RAY-LITHOGRAPHY, Journal of the Electrochemical Society, 143(2), 1996, pp. 657-665
The self-development characteristics of Si containing polymers were in
vestigated with the objective of applying these polymers to the surfac
e-imaging process in x-ray lithography. Polymers containing Si atoms i
n their backbones or substitutents were studied in detail; UV and Four
ier transform infared spectra were used to study their reaction to sof
t xrays. The polymers exhibited postive-tone characteristics when expo
sed to x-rays. Their self-development sensitivity and oxygen reactive
ion etching (O-2-RIE) resistance were measured to estimate the feasibi
lity of their use in lithography. Polysilanes and polystyrene showed l
ow self-development sensitivity while polymethacrylates showed high se
nsitivity. All of these polymers have O-2-RIE resistance high enough f
or application as surface-imaging resists. The films remaining after s
elf-development were characterized by estimating their durability agai
nst solvents, their thermal desorption spectra, and their x-ray photoe
lectron spectra. A polymethacrylate derivative was found to be the mos
t promising Of the polymers; it was applied to pattern replication usi
ng dry development. The results show that Si containing polymers are f
undamentally feasible for the postive-tone dry processes.