Acid amplified resists represent a major development in lithography in
the last few years. It is recognized that for precise CD control with
these resists in device manufacturing, it is required that the proces
sing environment be free of any basic contaminants. Top coat protectio
n of the resist films in conjunction with rigorous exclusion of basic
chemical vapors in the work area has been recommended to minimize the
effects of environmental contaminants. Another important variable in d
etermining the resist performance is the effect of substrate chemistry
which has received little attention in the literature. This paper pro
vides an understanding of these effects and gives a general method to
circunmvent the problem.