Triac with gold diffused boundary

A method for fabricating a plurality of bilateral thyristor pellets on a single wafer comprising the steps of:

• providing a wafer of semiconductor material defining two major surfaces and selectively diffused with impurities so as to form a plurality of portions, each portion comprising a first conductive region and a second conductive region;
• applying a mask to one of said major surfaces, wherein said mask defines openings at the boundaries between said first conductive regions and said second conductive regions;
• diffusing an auxiliary impurity through said openings, wherein said auxiliary impurity stimulates carrier recombination at said boundaries;
• masking said openings at a temperature low enough that no significant migration of said auxiliary impurity takes place;
• forming new openings in said mask where intersecting grooves that will separate said portions are to be formed;
• forming grooves in said new openings;
• coating said grooves with glass;
• and
• subdividing said wafer between said portions.