Method to match exposure tools using a programmable illuminator
US8351037B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 2010 |
| Grant date | Jan 8, 2013 |
| Priority date | — |
| Expiry date | Feb 14, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70525
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Programmable illuminators in exposure tools are employed to increase the degree of freedom in tool matching. A tool matching methodology is provided that utilizes the fine adjustment of the individual source pixel intensity based on a linear programming (LP) problem subjected to user-specific constraints to minimize the difference of the lithographic wafer data between two tools. The lithographic data can be critical dimension differences from multiple targets and multiple process conditions. This LP problem can be modified to include a binary variable for matching sources using multi-scan exposure. The method can be applied to scenarios that the reference tool is a physical tool or a virtual ideal tool. In addition, this method can match different lithography systems, each including a tool and a mask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.