Patent · US Expired

Photomask used in fabrication of mask read only memory

US6139992A · kind A · utility

1Cited by
1References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 11, 1999
Grant dateOct 31, 2000
Priority date
Expiry dateJan 11, 2019

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH10B20/65
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A photomask used in a formation of a mask read only memory (mask ROM) device is provided. The photomask contains a bonding pad opening pattern and a code area opening pattern so that bonding pads and code areas are simultaneously formed in a more economical operation.

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