Semiconductor device and method for fabricating the same
US6051454A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Sep 10, 1998 |
| Grant date | Apr 18, 2000 |
| Priority date | — |
| Expiry date | Sep 10, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/95
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.