Patent GB-996287-A (GB)
Title: Methods of producing thin films of semiconductor materials
IPC: C23C16/00
Filed: 1961-09-21
Abstract: <PICT:0996287/C1/1> A layer of semi-conducting material is produced on a substrate by mounting the latter and a transfer body of semi-conducting material not more than 10 microns apart in an atmosphere comprising a halogen-containing gas, heating the two bodies, the substrate being at 10-100 DEG  C. less than the transfer body, which thereby gives a thin coating by vapour deposition on the substrate. The epitaxial layer formed is of the same crystalline orientation as the substrate, preferably a (III) type, and they may be the same or different materials, e.g. as substrate N- and P-type Si, P-type Ge, and as transfer material N-type Si, P-type GaAs, and P-type Ge.  A quartz tube 10 is supplied with a halogen-containing gas, e.g. halogens, HCl or SiCl4 and a diluent gas, e.g. H, N, He, or A, which is drawn off at exit 19. The substrate 20 is in contact with transfer material 21, and heat is applied by an element 24 to establish a temperature gradient during vaporisation.  When the two surfaces are in contact and the transfer body has a geometric pattern cut more than 10 m  deep on its surface, a replica of the pattern is produced on the substrate, eliminating the need for masking the substrate. Specification 972,511 is referred to.ALSO:<PICT:0996287/C6-C7/1> A layer of semi-conductive material is produced on a substrate by mounting the substrate and a transfer body of the semi-conductive material not more than 10 microns apart in an atmosphere comprising a halogen-containing gas; heating the bodies while maintaining the substrate at a temperature of from 10-100 DEG C. less than the temperature of the transfer body, so that semi-conductive material from the transfer body is transferred to the surface of the substrate by vapour deposition.  The semi-conductive epitaxial layer formed has the same crystalline orientation as that of the substrate, preferably a (111) crystallographic orientation, and may be the same or different materials. e.g. as substrates n- and p-type Si, p-type Ge, and as transfer materials n-type Si, p-type GaAs, and p-type Ge.  In an embodiment of the invention quartz tube 10 is supplied with halogen-containing gas, e.g. HCl, and a diluent gas H2, which may also be N2, He or A; the diluted HCl being exhausted through exit tube 19. Substrate 20 is in contact with a supporting body of the transfer material 21, the whole being mounted on pedestal 22 sealed in the base of the quartz tube by O-ring 23; the unit is heated by a two-coil induction heater 24 to a temperature dependent upon the melting point of the materials chosen, preferably just below the melting point of the lowest melting component thus establishing a temperature gradient during the vapour transfer operation.  When the surface of the transfer body is in contact with the substrate and has an indented portion of a desired geometric shape cut more than 10m  deep, a replica of that pattern is produced on the substrate eliminating the need for masking of substrates. Silicon tetrachloride, halogens, and other halogen acids are an alternative halogen-containing gas. Specification 972,511 is referred to.