Resist system based on the cationic photocrosslinking of poly(4‐hydroxystyrene) and polyfunctional electrophiles

J. T. Fahey, K. Shimizu, Jean Frechet*, N. Clecak, C. G. Willson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

New resist systems based on acid‐catalyzed, electrophilic aromatic substitution are described. These new resists show high sensitivity to deep UV and E‐beam radiation with values approaching 2 mJ/cm2 and 2 μC/cm2, respectively. The resists are based on a three component system consisting of poly(4‐hydroxystyrene), a polyfunctional, low molecular weight, latent electrophile, and a photoactive onium salt used as an acid generator. Irradiation of the resist film produces a latent image of acid dispersed in the matrix. During the postbaking step the photo‐generated acid reacts with the latent polyfunctional electrophile and releases a reactive carbocationic intermediate with concomitant liberation of acetic acid. The carbocationic intermediate then reacts with neighboring phenolic moieties in a crosslinking reaction. The substitution reaction liberates a proton, making the process catalytic in nature, thus incorporating the concept of chemical amplification. These highly sensitive materials can be used as nonswelling negative multipurpose resists that function in deep‐UV, x‐ray or E‐beam modes. © 1993 John Wiley & Sons, Inc.

Original languageEnglish (US)
Pages (from-to)1-11
Number of pages11
JournalJournal of Polymer Science Part A: Polymer Chemistry
Volume31
Issue number1
DOIs
StatePublished - Jan 1 1993

Keywords

  • E‐beam
  • UV
  • carbocationic
  • chemical amplification
  • crosslinker
  • photocrosslinking
  • photoresist
  • poly(p‐hydroxystyrene)
  • radiation‐sensitive
  • thin‐film chemistry
  • triarylsulfonium salt
  • x‐ray

ASJC Scopus subject areas

  • Polymers and Plastics
  • Organic Chemistry
  • Materials Chemistry

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