Design of high-resolution positive-working photoresist

Abstract

Factors which improve the resolution of a positive-working photoresist composed of a naphthoquinonediazide and a novolac resin are discussed. Control of the dissolution rate of the resist film into the developer is essential to improve the resolution. The relationship between the dissolution rate and the chemical structures of the matrix resin and the photoactive compound is discussed. It is also shown that the photobleaching phenomenon of the photoactive compound helps to increase the resolution and the term “internal contrast-enhanced lithography (CEL) effect” is introduced.