A method of producing semiconductor bodies with an extremely low-resistance substrate

摘要

1,126,338. Manufacturing semi-conductor devices. TELEFUNKEN PATENTVERWERTUNGS G.m.b.H. 5 Nov., 1965 [19 Dec., 1964], No. 46986/65. Heading H1K. In making semi-conductor devices one face of a semi-conductor wafer is provided with an insulating layer (for example a thermally grown oxide layer) and on this is deposited a supporting stratum (for example of polycrystalline semi - conductor material) to strengthen the wafer in subsequent processing. The free face of the wafer is now etched (or lapped) to a predetermined thickness and a high conductivity monocrystalline or polycrystalline layer of semi-conductor material deposited on the new surface. The supporting stratum is removed, for example with an etch which is stopped by the insulating layer. The original body may contain two layers differing in resistivity-that nearer the insulated surface being an epitaxial layer of relatively high resistivity. The deposited semi-conductor layer of high conductivity may be given a variation of resistivity across its thickness with the lowest resistivity at the free surface and the variation may be continuous or in discrete steps. Further processing is used to form a transistor in which the collector zone includes the high conductivity layer and the contiguous part of the body.