Patent · US Expired

Dark field target design system for alignment of semiconductor wafers

US4880309A · kind A · utility

14Cited by
5References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 14, 1987
Grant dateNov 14, 1989
Priority date
Expiry dateApr 14, 2007

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03F9/7076
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A dark field target design system for alignment of semiconductor wafers is disclosed. The system utilizes improved target designs which provide for improvement in the alignment of semiconductor wafers.

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