Tetrahydropyranyl (THP) protected poly (p-hydroxystyrene) (PHS) was synthesized and its acid-catalysed thermal deprotection utilized in the design of an alkali developable, positive phOtoresist system incorporating chemical amplification. The solubility of THP-PHS films mixed with the appropriate onium salt photo acid generators in alkaline developers increases upon exposure to deep u.v. radiation and subsequent heating. A resist composed of THP-PHS and bis(tert-butylphenyl)iodonium triflate resolves 0.35/~m line-and-space patterns using a KrF excimer laser (248 nm) stepper (20 mJ cm 2).
Посилання на статтю:
Tetrahydropyranyl protected polyhydroxystyrene for a chemically amplified deep u.v. resist / Nobuaki Hayashi, Takumi Ueno, Simon Hesp, Minoru Toriumiand Takao Iwayanagi* // Polymer. – 1992. – Vol 33. – P. 1583-1588.