Patent · US Expired

Reflection type photomask with phase shifter

US5190836A · kind A · utility

11Cited by
1References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 12, 1991
Grant dateMar 2, 1993
Priority date
Expiry dateMar 12, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03F1/26
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A reflection type photomask includes a substrate, and a reflecting surface formed on the substrate and including a first region and a second region which have a relative height difference. Due to the concavo-convex structure of the reflecting surface, a light reflected from the first region and a light reflected from the second region have a predetermined phase difference which may be used effectively to form a pattern on a photoresist layer.

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