GB1447380A - Apparatus for the epitaxial growth of material from the liquid phase - Google Patents

Abstract

1447380 Epitaxial growth on a substrate INTERNATIONAL BUSINESS MACHINES CORP 15 Nov 1973 [20 Nov 1972] 52957/73 Heading BIS Apparatus for the epitaxial growth of a material on a substrate from two solutions comprises a chamber rotatable about a shaft means for supporting a substrate within the chamber e.g. on a lid, and a wall within the chamber defining a treatment zone around the substrate supported in the chamber and serving to separate the two solutions from one another. The wall is arranged so that in operation of the chamber by rotation about the shaft, one of the solutions is constrained within the treatment zone at a first angular position, the other solution is constrained within the chamber at a second angular position and no solution is constrained within the treatment zone at a third angular position. A ridge formed on the interior of the chamber and extending parallel to the shaft may be provided to assist wetting of a plurality of substrates as the chamber is rotated. The axial shaft may be hollow to allow the passage of gaseous substances. Several internal arrangements for the wall are described. In the figure shown the representation has the cylinder rolled out into the plane of the drawing i.e. the front face 7 and end face 8 of the cylindrical chamber appears in the drawing as vertical straight lines on the left and right side respectively. The two solutions 'A' and 'B' are arranged so that 'A' can wet substrate 4 in zone 9 while at the same time solution 'B', separated from the solution 'A' is in an open channel 10. After completion of a revolution both solutions are exchanged so that solution 'B' contacts the substrate whilst solution 'A' is in channel 10. Separation walls 12, 13 extend radially to a height of about one third the diameter of the the cylinder and confine zone 9. Although walls 14 and 15, are shown centrally disposed they could be offset. The channel 10 which penetrates wall 13 has its mouth arranged above transverse rim 6. The thickness of the layer deposited is determined by the rate of revolution of the chamber. Specified 'A' solutions are gallium with minor amounts of Al and Te dissolved in GaAs and GaP dissolved in Ga and doped with sulphur. Specified 'B' solutions are Ga mixed with Al and Te in different proportions to the 'A' solution above dissolved in GaAs and GaP in Ga doped with zinc. Exemplified substrates are (III)-orientated GaP and (III)-oriented GaAs.