An alloy-diffuse silicon high current transistor with fast-switching possibilities

A method is described for the fabrication of a high-power silicon transistor capable of operating at case temperatures exceeding 100°C. Large-area transistors can be produced having uniform base widths of a few ten-thousandths of an inch. The base is established by the diffusion of impurities from a double-doped alloyed contact on the surface of the silicon. This device gives a common emitter current gain of greater than 30 at 10 amperes collector current and can dissipate 100 watts if the case temperature is held below 55°C. In addition it has constant common emitter current gain out to 200 kc, Hence this technique produces a power device combining both good current gain and frequency characteristics.