Terepenic Series-Pyrogallol Resins and Their Application to Chemical Amplification Resists

Abstract

A series of pyrogallol-terpenic series (PTR) have been synthesized by the reaction of pyrogallol with terpenic series compounds, such as rosin, α-pinene and limonene. The conditions of the synthesis reactions and the characteristics of products have been investigated.
In order to improve the properties of PTR, the reactions of PTR with formalin have been carried out in acidic condition resulting in a series of pyrogallol-terpene-formalin resis (PTFR-A) which show high softening points. PTR and PTFR-A can be applied to:
1) Practical binder resins of general positive resists.
2) Raw resins to be esterified by 2, 1, 5-naphthoquinone diazide sulfonate.
3) Acidolysis type positive chemical amplification resists after cyclohexyl chloroformation have been introduced into them.
In alkalinous condition the reaction between PTR and formalin produces a series of resins (PTFR-B) having hydroxymethyls, for example pyrogallol-limonene-formalin resin. They can be used as negative chemical amplification resists, because they are cured after first irradiation to UV light under existence of photoinduced acid precursor and then heated.