Improvements in or relating to the production of semi-conductor arrangements

摘要

A plurality of semi-conductor devices is produced by placing semi-conductor bodies on a metallic support in an atmosphere of a gaseous compound of the semi-conductor, heating to join the bodies to the support and to decompose the compound to deposit a semi-conductor layer on the bodies which are then separated by cutting the support. Fig. 1 shows a reaction chamber with a molybdenum support 24 carrying semi-conductor discs 23. The support is heated by direct current, or alternatively by induction "loss angle" or radiation. In the production of a rectifier, P-type silicon discs of low resistivity are placed on a molybdenum plate, etched and heat treated in hydrogen, and a P-type, 2m , 3 ohm. cm. layer is deposited on the discs from an atmosphere of hydrogen, silicon chloroform and boron bromide or another boron halogenide. A low resistivity, 10m , N-type layer is then deposited on the P-layer and a molybdenum plate or gauze joined to the N-type layer. Fig. 4 shows a transistor similarly produced comprising a low resistivity P-type layer 7 on molybdenum plate 6, a higher resistivity (5 ohm. con.), 1m , P-type layer 8, a high resistive (50 ohm. con.) P or N or intrinsic layer 9, a 0,5 ohm. con. 5m , N-type layer 10 and a very low resistivity, 50m , P-type layer 11. A low melting point metal plate 12 is joined to layer 11. Layer 8 constitutes the collector, layer 10 the base and layer 11 the emitter. The base support 6 may be of gauze and may first be silicized and may consist of tantalum, carbon or a supported iron layer instead of molybdenum. Deposition of the various layers may be restricted by masking to form, for example, an upwardly decreasing cross section, and layers other than the first may be produced by alloying or diffusion. Germanium may be used in place of silicon, deposition being obtained by using germanium tetrachloride or germanium chloroform. Phosphorus and boron are favoured impurities.