Reliability aspects of laser programmable redundancy: infrared vs. green, polysilicon vs. silicide

Abstract

The laser explosion of memory redundancy target links has been simulated and temperature evolution profiles produced. The subsequent analysis suggests the following order starting with the most reliable: (1) polysilicon links with infrared laser; (2a) polysilicon links with green laser; (2b) silicide-polysilicon links with infrared laser; and (3) silicide-polysilicon links with green laser. Lower-melting point silicide (e.g. TiSi/sub 2/) is shown to hold some advantage over high-melting-point silicide (e.g. TaSi/sub 2/) as a target material. This advantage, however, is not enough to elevate it over polysilicon links in the reliability rank order.<>