Photolithographic Evaluation of Deep UV Resist Materials for Maskmaking Applications

摘要

This paper discusses methods used for photoresist selection and etch processing for laser mask patterning tool characterization. A major requirement of a deep ultraviolet (DUV) resist is that it has a storage capability of more than 90 days. This means the material does not have to be coated on demand to deliver exceptional lithographic performance. Process difficulties in the development and implementation of an advanced DUV maskmaking solution and how they are being addressed is also described. The purpose of this paper is to provide a look at the resist, develop, and etch processes being developed at Etec Systems, Inc. for DUV maskmaking applications. Key topics are etch characterization and resist process optimization at 257 nm associated with the migration to DUV from Mine manufacturing environments and turning from wafer to mask patterning applications. The paper also shows results of work being done to assess alternative resist chemistries in an attempt to maintain a precoated mask blank option for mask shop use. The paper points out issues to be considered when moving from diazoquinone (DNQ) chemistry to chemically amplified resists (CAR) processing in a mask manufacturing environment.