Patent · US Expired

Optical system and method for the production of micro-structured components by microlithography

US7317508B2 · kind B2 · utility

1Cited by

2References

29Claims

0Family size

Assignee

Carl Zeiss SMT GmbH · DE

Inventors

Daniel Kraehmer · Aalen, DE
Wilhelm Ulrich · Aalen, DE

Key dates

Filing date	Nov 24, 2004
Grant date	Jan 8, 2008
Priority date	—
Expiry date	Dec 23, 2025

Classification

Technology area (CPC G)Physics
CPC primaryG03F7/70966
WIPO fieldOptics
WIPO sectorInstruments

Abstract

An optical system of a microlithographic exposure apparatus comprises at least one optical element (L1 to L16, 15, 16, 24) having a locally varying birefringence direction distribution that is caused by stress-induced birefringence and is at least substantially rotationally symmetrical. At least one birefringent correcting element (K1, K2; K′) is made of a crystal having a location independent birefringence direction distribution that is at least substantially rotationally symmetrical. The crystal has a crystal lattice orientation that is oriented such that its birefringence direction distribution is at least substantially perpendicular to the locally varying birefringence direction distribution of the at least one optical element (L1 to L16, 15, 16, 24).

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