Serif mask design for correcting severe corner rounding and line end shortening in lithography
US6127071A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 22, 1999 |
| Grant date | Oct 3, 2000 |
| Priority date | — |
| Expiry date | Jun 22, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/36
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A photolithographic mask for conducting illumination from a light source onto a semiconductor surface during a microlithographic manufacturing process. The mask includes a line end portion of a width w and including two corners, each corner defining a respective region for locating one or more serifs for correcting severe corner rounding and line end foreshortening effects caused by the optical diffraction during the optical imaging process. For aerial image/resist pattern modeled as a convolution or the square of a convolution between the photomask and an intensity/amplitude kernel function having an effective range r in x and y directions, and under a condition that w<r<2w, a hanging square serif of a size w.times.w is provided attached to a respective corner within a corner region. For the condition of 2nw<r.ltoreq.2(n+1)w, with n=1, 2, . . . , each corner region includes an associated (n+1) serifs, each being linearly aligned along line-end extension line and spaced apart from an adjacent serif by a distance w, with each of the first n serifs being square and of a width w, and the (n+1).sup.th serif being a rectangle of a length w and a width min(r-2nw, w). When the intensity/a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.