Acid-Catalyzed Reactions of Tetrahydropyranyl-Protected Polyvinylphenol in a Novolak-Resin-Based Positive Resist

Abstract

This paper deals with an acid-catalyzed reaction mechanism of a polymeric dissolution inhibitor of a novolak-resin-based positive chemical amplification resist system. This resist system consists of a novolak matrix resin, tri(methanesulfonyloxy)benzene as an acid generator, and tetrahydropyranyl-protected polyvinylphenol (THP-M) as a polymeric dissolution inhibitor. The acid-catalyzed deprotection products of THP-M in the resist film are detected and their subsequent acid-catalyzed reactivities are evaluated. It is found that tetrahydropyranyl group are exchanged between THP-M and the matrix to yield a strong dissolution inhibitor, causing negative tone behavior at the overexposure dose. High-resolution patterns (0.3-µm contact holes) are achieved with high sensitivity (2.4 µC/cm2 at 50 kV).

Investigation of Deep UV Resists by NMR. Residual Casting Solvents, Chemistries, and PAG Decomposition in Film.

“…Existence of side reactions and the cleanness of deprotection reactions have been largely ignored, although some resist systems have been shown, through model reactions in solution, to produce byproducts. 8 One reason for the lack of such information is that the commonly employed IR technique is too insensitive to detect small amounts of foreign structures. Side reactions in the resist film could reduce the dissolution rate, contrast, sensitivity, etc.…”

Temperature‐Triggered Functionalization of Polymers

“…Initially, hemiacetal type protecting groups drew immediate attention to the field of photoresists because these groups could be used as a chemically amplified photoresist arising from their autocatalytic deprotection behavior in the presence of photoacid generators. Tetrahydropyranyl (THP) [15][16][17] and acyclic alkoxy-ethyl groups [18] were among the early screened protecting groups for polyhydroxystyrene (PHS) in photoresist applications. While polymers protected with t-butyl groups show high thermal stability but low acid decomposition efficiency, THP-protected polymers exhibited high acid decomposition efficiency but low thermal stability.…”

Influence of solubility switching mechanism on resist performance in molecular glass resists

“…16,17 In an attempt to circumvent some of the problems with the dihydropyran deprotection product of THPE-THP, THPE-EE was synthesized in the hope that the deprotection product could more easily be volatilized and would not be as reactive toward polymerization as the dihydropyran produced from the THPE-THP. It did not consistently form good films, even when HMDS was used to prime the silicon substrate surface.…”