Method for lithography model calibration
US7488933B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 2006 |
| Grant date | Feb 10, 2009 |
| Priority date | — |
| Expiry date | Jul 11, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/705
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for separately calibrating an optical model and a resist model of lithography process using information derived from in-situ aerial image measurements to improve the calibration of both the optical model and the resist model components of the lithography simulation model. Aerial images produced by an exposure tool are measured using an image sensor array loaded into the exposure tool. Multiple embodiments of measuring aerial image information and using the measured aerial image information to calibrate the optical model and the resist model are disclosed. The method of the invention creates more accurate and separable optical and resist models, leading to better predictability of the pattern transfer process from mask to wafer, more accurate verification of circuit patterns and how they will actually print in production, and more accurate model-based process control in the wafer fabrication facility.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.