Patent GB-1017119-A (GB)
Title: Improvements in or relating to the manufacture of semiconductor materials
Inventor: STERLING HENLEY FRANK
IPC: C01B33/02
Filed: 1964-05-06
Abstract: A semi-conductor material, which includes a significant impurity element or significant impurity elements of opposite conductivity type and which is made by decomposing a gaseous hydride of the semi-conductor element simultaneously with a gaseous hydride of the or one of the impurity element or elements of a decomposition zone, the gaseous hydride of the or each impurity element being generated in situ at or near to the decomposition zone, may be made by epitaxial deposition of the hydrides on to a heated substrate in the decomposition zone.  The semi-conductor material and the substrate may be in single crystal form and may be of the same material.  The decomposition zone may be bounded by a decomposition chamber, the generation of the or each impurity hydride either occurring at or near to the entrance to the chamber, when the semi-conductor element hydride may be supplied to the chamber separately from the supply of the or each impurity hydride, the latter being carried into the chamber by a stream of hydrogen gas, or occurring within the chamber, when only the semi-conductor element hydride may be supplied to the chamber from an external source.  The or each impurity element may be at an elevated temperature. The hydride of the or each impurity element may be generated by a process utilizing electrical power, for example by the reaction between atomic hydrogen and a body comprising the impurity element or a compound thereof, by electrolysis of a fused salt of the impurity element using inert electrodes, or by electrolysis of an electrolyte using electrodes of the impurity element, and the rate of generation of the hydride may be controlled by varying the electrical power to the generation means.  The Specification details sources and preparations of the atomic hydrogen.  The semi-conductor material may be, for example, silicon or germanium; the impurity element may be, for example, arsenic, antimony or phosphorus, or boron, aluminium or gallium.  Fully described and illustrated examples are given of the production of semi-conductor material containing boron and arsenic as impurity elements by deposition of silicon on silicon substrates, the impurity element hydrides being generated near to the entrance to, and within, the decomposition chamber.ALSO:A semi-conductor material which includes a significant impurity element or significant impurity elements of opposite conductivity type is made by decomposing a gaseous hydride of the semi-conductor element simultaneously with a gaseous hydride of the or one of the impurity element or elements at a decomposition zone, the gaseous hydride of the or each impurity element being generated in situ at or near to the decomposition zone. The decomposition zone may be bounded by a decomposition chamber, the generation of the or each impurity hydride either occurring at or near to the entrance to the chamber, when the semi-conductor element hydride may be supplied to the chamber separately from the supply of the or each impurity hydride, the latter being carried into the chamber by a stream of hydrogen gas, or occurring within the chamber, when only the semi-conductor element hydride may be supplied to the chamber from an external source.  The or each impurity element may be at an elevated temperature.  The hydride of the or each impurity element may be generated by a process utilizing electric power, for example by the reaction between atomic hydrogen and a body comprising the impurity element or a compound thereof, by electrolysis of a fused salt of the impurity element using inert electrodes, or by electrolysis of an electrolyte using electrodes of the impurity element. The atomic hydrogen may be made by subjecting molecular hydrogen to controlled electric sparking, for example between electrodes comprising the impurity element, when the electrodes may include a material compatible with the electrode material for lowering its resistivity, to controlled ultra-violet radiation, to an electric glow discharge, or by passing molecular hydrogen over a heated filament. The source of the atomic hydrogen may be the hydrogen carrier gas or hydrogen produced by the decomposition of the hydride of the semi-conductor element.  The rate of generation of the gaseous impurity element hydride may be controlled by varying the electric power to the generation means.  The semi-conductor material may be made by epitaxial deposition of the hydrides on to a heated substrate in the decomposition zone.  The semi-conductor material and the substrate may be in single crystal form and may be of the same material.  The semi-conductor material may be, for example, silicon, the impurity element may be, for example, arsenic, antimony or phosphorus, or boron, aluminium or gallium.  Fully described and illustrated examples are given of the production of silicon semi-conductor material containing boron and arsenic as impurity elements, the impurity element hydrides being generated near to the entrance to, and within, the decomposition chamber.