| 摘要 |
870,347. Semi-conductor devices. WESTERN ELECTRIC CO. Inc. Oct. 9, 1958 [Oct. 28, 1957], No. 32259/58. Class 37. Semi-conductor devices comprising bodies of germanium or silicon or germanium-silicon alloy are treated by being wetted with an aqueous solution of hydrogen peroxide and then baked in an atmosphere containing oxygen. When devices which comprise rectifying junctions are thus treated their reverse currents are reduced and, in the case of transistors, current amplification is increased. The necessary concentration of hydrogen peroxide is at least 10% and is preferably 30%. The temperature for the baking step is preferably between 100‹ C. and the lowest melting-point of any alloy in the device being treated. Baking may take place in air and should continue for at least 15 minutes; one hour is preferred. A short treatment with an etchant which includes hydrofluoric acid and nitric acid may advantageously precede the peroxide dip. If inorganic salts are formed on the surface of the device during the baking step, the device should be rinsed in deionized water during or after the bake; if the latter, a subsequent drying step is necessary. The Specification contains examples of the results produced by the treatment of PNP germanium transistors comprising lead-indium alloyed pellets, nickel wire electrodes attached thereto, and antimony-coated base-plates; also of an NPN germanium transistor comprising lead-arsenic pellets and a gold-coated base-plate. |
