| 摘要 |
1360073 Electroluminescence WESTERN ELECTRIC CO Inc 29 Nov 1971 [30 Nov 1970 10 May 1971] 55273/71 Heading C4S [Also in Division H1] The operating life of a Ga-containing PN junction light-emitting device is increased by thermally oxidizing the semi-conductor body in an aqueous oxidizing medium to form a film 16 of gallium oxide at least 100 Š and baking the device to expel excess moisture from the film 16. The device may emit coherent or non-coherent light, and suitable semi-conductor materials are GaP, GaAs, GaAsP, GaAlAs, AlGaP, InGaAs and InGaP. The GaP device shown comprises an N-type substrate 11 on which are formed, by liquid phase epitaxy or diffusion, a Te-doped N-type layer 12 and a Zn and O-doped P-type layer 13. The device is bonded to a header by a Si-Au preform and a Be-Au electrode 15 is provided on the layer 13. The gallium oxide film 16 is formed, after etching and rinsing, by immersion in an aqueous H 2 O 2 solution. Oxide formation is enhanced by the presence of a noble metal catalyst, either in the solution or bonded to the semi-conductor, e.g. as one of the electrodes, and excess moisture is driven off by heating at progressively higher temperatures up to 150-350‹ C. An additional glassy layer 17 of SiO 2 improves the passivating properties of the gallium oxide film 16. The invention may also be applied to PNPN light-emitting devices. Boiling water may also be used as the oxidizing medium. Telephone and other uses are disclosed. |
