Studies of Novel Copolymers for Deep-UV Photoresists. I. Synthesis and Properties of Poly(Styrene-co-Silicon-containing maleimide)

Abstract

ABSTRACT:Soluble copolymers of trimethyl (4-(N-maleimido) phenoxy) silane (TMMS) with styrene-series monomers were synthesized by radical polymerization in toluene at 70 C using 2, 2 0 -azobisisobutyronitrile (AIBN)as initiator. The comonomer reactivity ratios were calculated by the conventional Fineman-Ross and Kelen-Tüdos methods and a nonlinear least-squares Tidwell-Mortimer method. The glass transition temperatures (T g s) and thermal degradation of copolymers were determined by differential scanning calorimetric (DSC) and thermo-gravimetric analysis (TGA) methods, respectively. The comonomer reactivity ratio of TMMS with styrene was changed from a alternating to middle type between alternating and ideal copolymerization for the side-chain of TMMS and the deactivators of styrene. The curves of T g s versus the different compositions of the above synthesized styrene-maleimide copolymers matched the modified Johnston's equation as increasing the affect of weight ratio on alternating-segment, and exhibited an S-shaped curve of deviation in comparison with the Fox's equation. The maleimide-segments and styrene-segments within these copolymers were completely compatible and the thermal stability and flame retardancy of polystyrene could be enhanced simultaneously via the introduction of silicon-containing maleimide.

Studies of silicon-containing maleimide polymers. Part II: Synthesis and properties of poly(styrene-co-brominecontaining maleimide).

“…The copolymerization behavior of truly alternating styrenemaleic anhydride copolymer has already been reported by many researchers [23][24][25][26]. But, the silicon-containing AM systems are still rarely seen in literature [27,28].…”

Synthesis of N‐Substituted Maleimides and Poly(styrene‐co‐N‐maleimide) Copolymers and Their Potential Application as Photoresists

“…Another example has been shown by Shu et al. [ 13 ] Silicon containing poly(styrene‐ co ‐ N ‐maleimide) copolymers were synthesized by radical polymerization and their structure, and thermal properties were studied for chemically amplified DUV photoresist applications.…”

“…[11] The resulting positive tone photoresists showed good thermal stability as well as good adhesion on a silicon substrate while patterns of 0.8 μm could be obtained. Another example has been shown by Shu et al [13] Silicon containing poly(styrene-co-N-maleimide) copolymers were synthesized by radical polymerization and their structure, and thermal properties were studied for chemically amplified DUV photoresist applications.…”