Design and Lithographic Characteristics of Alicyclic Fluoropolymer for ArF Chemically Amplified Resists

摘要

We designed a novel alicyclic fluoropolymer, poly[3-hydroxy-4-(hexafluoro-2-hydroxyisopropyl)tricyclodecene], as an ArF (193 nm) chemically amplified resist. This fluoropolymer has a hexafluoroisopropanol group as an alkaline soluble unit and a hydroxyl group for improving adhesion. This polymer also exhibited a high transparency of 93%/150 nm at 193 nm, high thermal stability (355℃), and a good adhesion to a Si substrate compared with a poly(norbornene) with a hexafluoroisopropanol group. The etching rate of our developed fluoropolymer for CF_4 gas was 1.29 times that of the KrF resist. Moreover, a chemically amplified positive resist comprising an ethoxymethyl-protected polymer and a photoacid generator achieved a 110 nm line-and-space pattern with an ArF exposure.