Glass passivated gold diffused SCR pellet and method for making

A method for manufacturing semiconductor controlled rectifiers having a preselected distribution of an auxiliary impurity therein, said method comprising the steps of:

• providing a wafer of semiconductor material that defines two major surfaces and includes four layers of alternating p-type and n-type conductivities that define three p-n junctions substantially parallel to said major surfaces;
• thermally growing a layer of oxide on one of said major surfaces of said wafer;
• selectively removing said oxide from a plurality of preselected portions of said one major surface to form windows;
• diffusing an auxiliary impurity through said windows into said wafer in a preselected distribution, wherein said auxiliary impurity is selected to be one which stimulates carrier recombination in semiconductor devices;
• covering said windows by applying a protective coating at a relatively low temperature;
• selectively removing more of said oxide from other preselected portions of said one major surface to form intersecting elongated openings in said oxide which separate said windows and separate said wafer into a plurality of semiconductor controlled rectifiers;
• etching grooves into said wafer at said other preselected portions, wherein said grooves intersect at least one of said p-n junctions;
• and
• passivating said junctions by coating said grooves with glass.