Studies on photoresists derived from SI cyclized copolymers.

A series of styrene-isoprene copolymers (SI copolymers) have been synthesized from styrene and isoprene. The styrene- isoprene cyclized copolymers (SI cyclized copolymers) have been synthesized by proper cyclization of the obtained copolymers. Through the regulation of ether additives, the copolymers contain different 1, 4-copolymer content and 3, 4-copolymer content. The relative content of 3, 4-copolymer and 1, 4-copolymer in SI copolymers is calculated by data of IR and 1H NMR spectra and the cyclization process is monitored by IR spectra. In this paper, we discuss the influence of various factors on the copolymerization, the cyclization and the products in detail. The minimum quantity of exposure energy required Emin of the phatoresists prepared by SI cyclized copolymers is about 9.7mJ/cm2. The resistance of the photoresist to acids and plasma etching is better than that of cyclized polyisoprene photoresist.