摘要 |
1,066,165. Semi-conductor devices. DEUTSCHE AKADEMIE DER WISSENSCHAFTEN ZU BERLIN. Aug. 6, 1965, No. 33753/65. Heading H1K. A metal layer is formed on a P-type semiconductor body and lithium is deposited on the layer, the body then being heated to simultaneously temper the metal layer and diffuse lithium into the body to form an N-region and ohmic contact thereon. Suitable semi-conductors are silicon, germanium, and gallium arsenide. Suitable metals are nickel, silver, gold, and aluminium. In an embodiment a 400 ohm. cm. P-type silicon wafer is cleaned ultrasonically in trichloroethylene, etched in hydrofluoric acid, and boiled several times in deionised water before it is nickeled in a hot chemical bath. The nickel is coated with lithium by vapour deposition and the body heated to 600‹ C. After slow cooling the main faces of the wafer are masked and nickel is etched from the edges. The process is completed by a wash in trichloroethylene. |