Patent · US Expired

Lithographic projection apparatus

US6384899B1 · kind B1 · utility

61Cited by
11References
14Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 2, 2000
Grant dateMay 7, 2002
Priority date
Expiry dateFeb 2, 2020

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03F9/7069
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

In an interferometric alignment system provides an alignment signal for reproducibly registering a reticle 10 with a wafer 12. The radiation from a laser 50, which is the illumination source for the interferometer, is modulated by a phase modulator 52 to eliminate spurious noise from the alignment signal.

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