| 摘要 |
757,805. Coating by vapour deposition. GENERAL ELECTRIC CO. Aug. 20, 1953 [Aug. 20, 1952], No. 23008/53. Class 82(2). [Also in Group XXXVI] In a method of making P-N junction units a layer of semiconductor containing donor or acceptor impurity, is condensed from the vapour on to one or more preferably polished and etched surfaces of a monocrystalline semiconductor body of the opposite conductivity type. A suitable N or P type semiconductor material is evaporated from a quartz or beryllium oxide crucible 14 into a vacuum chamber 10 in which semiconductor wafers 16 of opposite conductivity type, with surfaces masked to give a deposit on the required area only, are symmetrically mounted about a hole in the crucible lid 12, the duration of vaporisation controlling the layer thickness. The deposit is a dull amorphous one if the wafer is at a low temperature, finely crystalline if it is hotter. When the volatility of the semiconductor and activator impurity differ greatly they are vaporised from separate crucibles. Ge and Si are specified as suitable semiconductor materials, and Sb, As, P, A1, Ga, In, Zn as donors and acceptors respectively. Photocells and transistors made from such junction units are described (see Group XXXVI). Specification 728,129 [Group XXXVI] is referred to. |
