Semiconductor device fabrication using a photomask with assist features
US6421820B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 13, 1999 |
| Grant date | Jul 16, 2002 |
| Priority date | — |
| Expiry date | Dec 13, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70441
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A semiconductor device can be fabricated using a photomask that has been modified using an assist feature design method (see e.g., FIG. 4A) based on normalized feature spacing. Before the device can be fabricated, a layout of original shapes is designed (402). For at least some of the original shapes, the width of the shape and a distance to at least one neighboring shape are measured (404). A modified shape can then be generated by moving edges of the original shape based on the width and distance measurements (406). This modification can be performed on some or all of the original shapes (408). For each of the modified shapes, a normalized space and correct number of assist features can be computed (410). The layout is then modified by adding the correct number of assist features in a space between the modified shape and the neighboring shape (412). This modified layout can then be used in producing a photomask, which can in turn be used to produce a semiconductor device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.