Using double exposure effects during phase shifting to control line end shortening
US6566019B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 25, 2001 |
| Grant date | May 20, 2003 |
| Priority date | — |
| Expiry date | Nov 14, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/70
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
One embodiment of the invention provides a system that facilitates a semiconductor fabrication process to create a line end in a manner that controls line end shortening arising from optical effects, and is especially applicable in alternating aperture phase shifting. This system operates by positioning a first mask over a photoresist layer on a surface of a semiconductor wafer. This first mask includes opaque regions and transmissive regions that are organized into a first pattern that defines an unexposed line on the photoresist layer. The system then exposes the photoresist layer through the first mask. The system also positions a second mask over the photoresist layer on the surface of the semiconductor wafer. This second mask includes opaque regions and transmissive regions that are organized into a second pattern that defines an exposure region. This exposure region cuts through the unexposed line on the photoresist layer to create the line end in the unexposed line, without the optical line end shortening that arises from creating the line end with a single mask. The system then exposes the photoresist layer through the second mask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.