| 摘要 |
A method for etching semiconductor fusions to change their electrical characteristic, especially to reduce the firing current of thyristor fusions, to a predetermined desired value is disclosed. The etching is accomplished by subjecting fusions comprised of a body of semiconductor material, for example, silicon, including an anode emitter region therein and an anode electrode affixed thereto, an anode base region, a cathode base region and a gate electrode affixed thereto, and a cathode emitter region having a cathode electrode affixed thereto, to a plasma etchant comprising a mixture of CF4 and a carrier gas such for example, nitrogen, for a predetermined time interval. Following this etching cycle the firing current of the fusions is measured. Any fusions having a firing current in excess of the desired value at the end of the first etching cycle are subjected to another etching cycle to further reduce the firing current. The etching and measurement cycle is repeated for a predetermined number of cycles. Any fusions having a firing current in excess of the desired value after the predetermined number of etch cycles are scraped.
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