Laser tool for programming programmable logic arrays and repairing VLSI chips

Abstract

Very large scale integration (VLSI) presents difficult design and development problems due to the ease with which errors creep into the process. It can require several passes through the design and development cycle to eliminate the errors. A laser tool has been developed that makes connections between two levels of metallization separated by an insulator on a VLSI chip. A programmable logic array (PLA) was developed in conjunction with the laser tool. The PLA is programmed to perform a complex logic function by means of the laser tool. A short movie shows the tool in operation programming a PLA. The PLA contains the equivalent of 600 circuits worth of logic, which can be programmed in a few minutes. It is thus possible to construct a complex system with a relatively few PLA modules in a short time. © 1982 Optical Society of America