Semiconductor device and method for fabricating the same

摘要

A lower resist film, which is made of PMMA for EB exposure and has a thickness of about 200 nm, is applied onto a substrate, and then an upper resist film to be exposed to i-rays is applied on the lower resist film. Thereafter, a mixed layer, in which the upper and lower resist films are mixed, is formed in the interface between the upper and lower resist films. Next, the upper resist film, except for the head-forming region thereof, is exposed to i-rays and developed, thereby forming an upper-layer opening. And then the mixed layer and a leg-forming region of the lower resist film are exposed to EB and developed, thereby forming a lower-layer opening having an upper part like a taper progressively expanding upward.