Photoacid generation in chemically amplified resists: elucidation of structural effects of photoacid generators using new acid-sensitive dyes for monitoring acid generation

摘要

This paper focuses on all aspects of acid quantification in DUV resists using novel acid sensitive dyes. The design criteria for creating acid sensitive dyes are discussed and several new classes of dyes are described. Upon protonation, these molecules undergo a large bathochromic shift in the absorption maximum. This change in the UV absorption spectrum can readily be used to quantify acid generation spectrophotometrically. The utility of these new acid sensitive dyes will be demonstrated by quantifying the acid generating efficiency of different PAG classes. In this paper, the relationship between resist performance and PAG structure is studied for a series of DUV PAGs in which the structure of both the chromophore and the acid are varied. In addition, the sensitivity of these dyes is sufficiently high that trace amounts of acid lost from chemically amplified resists during exposure may be measured. Preliminary results of acid loss experiments on assorted DUV PAGs will also be presented.