Acid generation and deprotecting reaction by diphenyliodonium 9,10‐dimethoxyanthracene‐2‐sulfonate in a novolak positive photoresist based on chemical amplification

Publisher Website
Google Scholar
Abstract
In a positive photoresist composed of diphenyliodonium 9,10‐dimethoxyanthracene‐2‐sulfonate as a novel photoacid generator, bisphenol A protected with tertbutoxycarbonyl group as a dissolution inhibitor, and a novolak resist matrix, the efficiency of photo‐acid generation and deprotective reaction were investigated by means of UV‐visible and IR spectroscopies. The quantitative measurement of photogenerated acid by using the acid‐sensitive dye exhibited 0.18 as the quantum yield of acid generation in novolak resin film. The lithographic evaluation of this system as a chemically amplified resist was studied. The catalytic chain length for the acid‐catalyzed deprotection step was determined as about 100 when 10 min post‐exposure bake (PEB) at 80°C was given. The sensitivity and the resolution as a positive resist are 180 mJ/cm2 and higher than 1 μm, respectively under the PEB conditions mentioned above.