Verfahren zur Herstellung von Halbleitereinrichtungen

777,403. Semi-conductor devices. WESTERN ELECTRIC CO., Inc. June 24, 1955 [June 29. 1954], No. 18339/55. Class 37. A semi-conductor device is manufactured by wetting the end faces of a closely-spaced pair of electrodes with molten semi-conductor material so that material is supported between them by surface tension, which freezes to form the semi - conductor body. In one example, a pair of electrodes 11 and 12 supported by insulator 13 (Fig. 1B) are dipped into a melt of germanium 17 in an inert atmosphere such as helium, hydrogen or nitrogen. The electrode assembly is then withdrawn by means 22, and the germanium suspended between the electrodes allowed to cool. The electrodes may comprise donor or acceptor material to produce bodies with P and N regions, and may be made non-wettable except for their end regions by carbonizing, oxidizing, glazing or silicone coating. The body may be directionally cooled by means of a temperature gradient so that a monocrystal is formed, and the conductivity may be varied by utilizing the different segregation coefficient of various donor and acceptor material. The electrode with the smallest end may be withdrawn first from the melt to provide directional cooling. The electrodes may be graded in size to control the cooling process. Three or more electrodes may be utilized in one assembly and withdrawn together from the melt, to provide a transistor with, for example, NPN regions. A tetrode transistor is also described. The regions of N or P type conductivity may alternatively be produced by a thermal diffusion process applied after the body has cooled; mass production may be effected by arranging electrodes assemblies in multiple, or on a continuous band, for dipping into the melt. The semi-conductor material may consist of germanium, silicon, germanium-silicon alloy, or compounds of elements of Group III and Group V; the electrodes may consist of molybdenum, tantalum or tungsten, the acceptors of copper, thallium, indium, boron, aluminium or gallium and donors of antimony, phosphorus, lithium, or arsenic. Specifications 748,414 and 769,673, [Group XI], are referred to.