| 摘要 |
918,028. Semi-conductor devices; etching electrolytically. PHILIPS ELECTRICAL INDUSTRIES Ltd. Sept. 1, 1959 [Sept. 4, 1958], No. 29790/59. Classes 37 and 41. A method of making a semi-conductor device comprises alloying an acceptor material to an edge of a thin P-type zone and to the adjoining parts of a thicker N-type zone and subsequently electrolytically etching the assembly with the recrystallized material connected as anode. In the embodiment (Fig. 1) in which aluminium 4 is alloyed to the middle zone 2 and adjacent parts of the end zones 1, 3, of an NPN silicon body, a wire 5 of tungsten or molybdenum, to serve as an electrode, is introduced into the aluminium while it is molten. After cooling, the body is immersed in a solution of hydrofluoric acid and alcohol and an etching current passed between electrode 5 connected as anode and a platinum cathode in the solution until the configuration shown in Fig. 2 is attained with electrode 5 on a circular pillar 12 of P-type material. As an alternative a linear contact running along the length of the middle zone may be provided. |
