Patent · US Expired

Enhanced illuminator for use in photolithographic systems

US6842223B2 · kind B2 · utility

74Cited by
7References
25Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 11, 2003
Grant dateJan 11, 2005
Priority date
Expiry dateApr 11, 2023

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03F7/701
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

Methods and apparatus for enabling both isolated and dense patterns to be accurately patterned onto a wafer are disclosed. According to one aspect of the present invention, an illumination system that is suitable for use as a part of a projection tool includes an illumination source and an illuminator aperture. The illuminator aperture has a center point and an outer edge, and also includes a first pole and a second pole. The first pole is defined substantially about the center point, and the second pole is defined substantially between the first pole and the outer edge of the first pole. The illumination source is arranged to provide a beam to the illuminator aperture.

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