| 摘要 |
692,250. Rectifiers. WESTERN ELECTRIC CO., Inc. March 4, 1952 [March 7, 1951], No. 5624/52. Class 37. [Also in Groups II and XL (b)] To produce a layer of semi-conductve material of one conductivity type on a body of semi-conductive material of opposite conductivity type, the body is mounted in a chamber through which passes the vapour of a compound of semi-conductive material including an impurity material characteristic of the one conductivity type, and the chamber is heated to decompose the vapour to deposit the layer required. Germanium discs 28 of nconductivity are mounted in a chamber 11; a mass 27 of germanium of p-type conductivity, e.g. containing 1 per cent gallium, is placed at the entrance to the chamber and is treated with hydrogen, from inlet pipes 12, 13 and iodine vapour, from iodine 26 in heated chamber 10; germanium iodides are formed, and the temperature of the chamber 11 is controlled by heating coils 20, 21, 22 to produce a temperature gradient as shown in Fig. 2, so that germanium of p-type conductivity is deposited on the discs 28. Suitable impurities are indium, aluminium or boron. Instead of iodine, use may be made of bromine or chlorine. The discs may be of p-type conductivity and the layer of n-type conductivity. Further layers of appropriate conductivity type may be added. Silicon may be used instead of germanium. |
