Laser coding of bipolar read-only memories

Author

North, James C. ; Weick, Walter W.

Volume

11

Issue

4

fYear

1976

fDate

8/1/1976 12:00:00 AM

Firstpage

500

Lastpage

505

Abstract

Laser beam coding of high-speed bipolar silicon integrated circuit memories is described. Coding is accomplished by the selective vaporization of Ti-Pt links connecting the contact pads of each memory cell to Ti-Pt-Au bit lines. Vaporized link resistances of >10/SUP 9/ Ω can be consistently obtained, with no melting of the adjacent gold patterns. Parameters that have been found to be relevant to the link vaporization process are described including the number of laser pulses per link, beam spot size, thickness of the gold metallization, and pulse energy. The laser coding process is especially useful for applications where relatively small numbers of chips of each of many codes are needed, since only one photolithographic mask set is required.

Keywords

Digital integrated circuits; Laser beam applications; Monolithic integrated circuits; Read-only storage; Semiconductor storage devices; digital integrated circuits; laser beam applications; monolithic integrated circuits; read-only storage; semiconductor storage devices; Gold; Laser beam cutting; Laser beams; Metallization; Optical pulses; Pulsed laser deposition; Read only memory; Semiconductor laser arrays; Silicon; Temperature;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/JSSC.1976.1050766

Filename

1050766