Patent GB-991370-A (GB)
Title: Semi-conductor material and method of manufacture
IPC: H01L29/73
Filed: 1961-10-13
Abstract: A plurality of semi-conductor bodies coated with at least one layer of a single crystal semi-conductor having a different conductivity and separated by a transition region, are formed simultaneously by a process in which semi-conductor wafers are supported in sockets in a reaction chamber and heated in the vapour comprising semi-conductor atoms and active impurity atoms. The semi-conductor materials may be Si, Ge, SiC, GeAs, InP, GaP, <PICT:0991370/C1/1> InSb, and the active impurity atoms may be B, Al, Ga, P, As and Sb.  The decomposable vapour comprises a halide of the semi-conductor material and the active impurity in a carrier gas of hydrogen, e.g. SiHCl3, SiCl4, SiBr4, GeCl4, BCl3 and PCl3.  In the case of Si a silane may be used. As shown in Fig. 1, semi-conductor wafers 14 are mounted in sockets 13 on electrically heated supports 12 in a sealed reaction chamber 10.  The decomposable vapours are supplied to the chamber via inlet 22 and nozzle 19 and exhausted via conduit 21.  The supports 12 may be made of Si, SiC, C, Ta, Mo or Nb. The crystallographic plane of the surface of the wafer to be treated is preferably the [III] plane and is prepared by grinding, polishing and etching.  The wafers 14 are heated to about 1250 DEG  C., hydrogen is then introduced to clean the wafers and then the decomposable vapour is introduced.  In the case of SiHCl3 vapour the wafers should not exceed 1170 DEG  C. Several layers of semi-conductor material may be formed by repeating the procedure and introducing sufficient decomposable vapours. Alternatively, after forming a first layer of N-type silicon (Si + P) on N + silicon wafer a P layer may be diffused into the N layer by decomposition of BCl3 vapour in hydrogen to form a NPlN transistor (Fig. 4, not shown).  Further treatment, e.g. with vapour containing arsenic can produce N regions in the P layer.ALSO:A plurality of semi-conductor bodies coated with at least one layer of a single crystal semi-conductor having a different conductivity and separated by a transition region, are formed simultaneously by a process in which semi-conductor wafers are supported in sockets in a reaction chamber and heated in the vapour comprising semi-conductor atoms and active <PICT:0991370/C6-C7/1> impurity atoms.  The semi-conductor materials may be Si, Ge, SiC, GaAs, InP, GaP, InSb, and the active impurity atoms may be B, Al, Ga, P, As and Sb.  The decomposable vapour comprises a halide of the semi-conductor material and the active impurity in a carrier gas of hydrogen e.g. SiHCl3, SiCl4, SiBr4, GeCl4, BCl3 and PCl3.  In the case of Si a silane may be used. As shown in Fig. 1 semi-conductor wafers 14 are mounted in sockets 13 on electrically heated supports 12 in a sealed reaction chamber 10. The decomposable vapours are supplied to the chamber via inlet 22 and nozzle 19 and exhausted via conduit 21.  The supports 12 may be made of Si, SiC, C, Ta, Mo or Nb. The crystallographic plane of the surface of the wafer to be treated is preferably the [111] plane and is prepared by grinding, polishing and etching.  The wafers 14 are heated to about 1250  DEG C., hydrogen is then introduced to clean the wafers and then the decomposable vapour is introduced.  In the case of SiHCl3 vapour the wafers should not exceed 1170  DEG C. Several layers of semi-conductor material may be formed by repeating the procedure and introducing sufficient decomposable vapours. Alternatively after forming a first layer of N type silicon (Si + P) on N + silicon wafer a P layer may be diffused into the N layer by decomposition of BCl3 vapour in hydrogen to form a NP1N transistor, Fig. 4 (not shown).  Further treatment e.g. with vapour containing arsenic can produce N regions in the P, layer.