MANUFACTURE OF HOLLOW BODIES OF SEMICONDUCTOR MATERIAL

摘要

1320416 Hollow semi-conductor bodies SIEMENS AG 1 Oct 1970 [6 April 1970] 46633/70 Heading C1A Hollow semi-conductor bodies open at least at one end are made by depositing semiconductor material on to a heated carrier body of different material from a gaseous reaction mixture of a compound of the semi-conductor and a reducing gas until a sufficiently thick layer has been built up and then removing the carrier body from the hollow body so formed, the rate of deposition being such that prior to a layer of 2-5 Á in thickness being built up the amount of semi-conductor material deposited per unit area and time is from 1/100 to ¢ of the amount deposited per unit area and time during the remainder of the deposition step. The semi-conductor may be Si, SiC, Ge, GaAs or InSb. Si may be deposited from mixtures of H 2 with SiHCl 3 , SiH 2 Cl 2 or SiCl 4 . When Si is deposited the initial rate of deposition may be 0À002 g.-0À1 g. Si/cm.2h. and then, after the layer of 2-5 Á has been formed, the rate may be increased to 0À05-0À2 g. Si/cm.2h. This rate of deposition may be achieved by passing the following gas mixtures over the heated carrier body: (a) SiHCl 3 /H 2 with a mol. ratio of 0À02- 0-2 at 1200‹ C., (b) SiCl 4 /H 2 with a mol. ratio of 0À005-0À05 at 1200‹ C., and (c) SiH 2 Cl 2 /H 2 with a mol. ratio of 0À05-0À5, preferably at a rate of 0À05-2À5 l./cm.2h. prior to the formation of the 2-5 Á layer and then at approx. 5 l./cm.2h. thereafter. The temp. of the carrier body may be decreased by 20‹ C./mm. of surface deposited. A hydrogen halide, e.g. HCl, or an inert gas may be included within the reaction mixture.