Process for the production of semiconductor bodies

摘要

A process for producing a semi-conductor body having a region of reduced cross-section comprises placing a stencil plate 2 on the semi-conductor body 1 to cover the region of the body the cross-section of which is to be reduced and heating the surface of the body covered by the plate in the presence of a reaction gas consisting of or containing a halogen-containing compound to a temperature such that semi-conductor material is removed from the surface and deposited on the side of the plate adjacent the body, which side is relatively cooler than the body, by a chemical transfer reaction, the surface of the body in the region covered by the plate being sufficiently rough to permit the reaction gas to diffuse between the surface and the plate and to establish the required temperature difference between the surface and the plate. Examples are of transferring Si from a body at 1100 DEG C. using SiHCl3 and H2, of transferring Ge using GeCl4 and H2, and of transferring GaAs using GaCl and H2. Using a continuous flow of gas there is, in addition to the transfer of material as indicated at 6, 7, 8, Fig. 2, deposition of semi-conductor material from gas at positions 9 and 10 not covered by the stencil. This deposition can be doped by adding doping agents to the gas so as to obtain a p-n-junction. The additional deposition can be prevented either by using only a predetermined quantity of gas in a closed system or by using HCl with a carrier gas either as a continuous flow or in a closed system. The stencil plate may be of the same semi-conductor material as the semi-conductor body or be such coated on SiC or graphite or may be of high purity graphite. It may have a plurality of openings and be used to produce solid body circuits. Fig. 3 (not shown) illustrates a semi-conductor body having zones 13, 14 of different conductivity, e.g. produced by diffusing doping material into the body. The transfer reaction is carried out to expose a p-n-junction, Fig. 4 (not shown). Several such junctions may be exposed in a body having several junctions. The bodies may be cut to provide several assemblies, their surfaces are metallized and electrodes joined thereto.ALSO: A process for producing a semi-conductor body having a region of reduced cross-section comprises placing a stencil plate 2 on the semi-conductor body 1 to cover the region of the body the cross-section of which is to be reduced and heating the surface of the body covered by the plate in the presence of a reaction gas consisting of or containing a halogen-containing compound to a temperature such that semi-conductor material is removed from the surface and deposited on the side of the plate adjacent the body, which side is relatively cooler than the body, by a chemical transfer reaction, the surface of the body in the region covered by the plate being sufficiently rough to permit the reaction gas to diffuse between the surface and the plate and to establish the required temperature difference between the surface and the plate. Examples are of transferring Si from a body at 1100 DEG C. using SiHCl3 and H2, of transferrin Ge using GeCl4 and H2, and of transferring GaAs using GaCl and H2. Using a ocntinuous flow of gas there is, in addition to the transfer of material as indicated at 6, 7, 8 (Fig. 2), deposition of semi-conductor material from gas at positions 9 and 10 not covered by the stencil. This deposition can be doped by adding doping agents to the gas so as to obtain a PN junction. The additional deposition can be prevented either by using only a predetermined quantity of gas in a closed system or by using HCl with a carrier gas either as a continuous flow or in a closed system. The stencil plate may be of the same semi-conductor material as the semi-conductor body or be such coated on SiC or graphite or may be of high purity graphite. It may have a plurality of openings and be used to produce solid body circuits.