Patent · US Active

Method for in-situ aberration measurement of optical imaging system in lithographic tools

US8035801B2 · kind B2 · utility

0Cited by

8References

14Claims

0Family size

Assignee

SHANGHAI MICRO ELECTRONICS EQUIPMENT (GROUP) CO., LTD · CN

Inventors

Fan Wang · Shanghai, CN
Mingying Ma · Shanghai, CN
Xiangzhao Wang · Shanghai, CN

Key dates

Filing date	Dec 25, 2006
Grant date	Oct 11, 2011
Priority date	—
Expiry date	Apr 10, 2028

Classification

Technology area (CPC G)Physics
CPC primaryG03F7/706
WIPO fieldOptics
WIPO sectorInstruments

Abstract

A method for in-situ aberration measurement in an optical imaging system of lithographic tools. According to the method, a reticle pattern is imaged to form an imaged pattern by transmitting beams through a reticle via the optical imaging system. The imaged reticle pattern is shaped to have plural groups of imaged linewidths. The plural groups of imaged linewidths are measured using either of an image sensor, a CD-SEM and a microscope by modifying the intensity distribution at an exit pupil plane of the optical imaging system. The asymmetry and ununiformity of the imaged linewidths are calculated. Aberrations of the optical imaging system are calculated.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.