Abstract: A method of providing a reagent into a chemical process said provision being in the vapor phase and at a controlled mass flow rate wherein the method comprises:(a) providing a gas stream which contains a gaseous phase complexing agent for the reagent said complexing agent being provided at a controlled partial vapor pressure in said gas stream;(b) providing a primary source of the reagent in a reservoir which is connected to the gas stream via a diffusion path;(c) causing the gaseous phase complexing agent to diffuse into the reservoir at a mass flow rate controlled by its partial pressure in the gas stream;(d) causing the gaseous phase complexing agent in the reservoir to react with the primary source to generate a gaseous phase complex of the reagent and the gaseous phase complexing agent, said generation being, in the steady state, at a rate equivalent to the rate of inflow of said complexing agent;(e) causing the gaseous phase complex to diffuse out of the reservoir into the gas stream at a rate, in the s

Abstract: A method for the growth of a semi-conductor material on a substrate by vapour phase epitaxy, comprises establishing a gas flow in each of a plurality of ducts, and moving the substrate, in a single plane of movement, from one duct to another. Suitable apparatus for use in the method comprises a plurality of ducts; apparatus for establishing a gas flow along each duct; a substrate support member, on which there may be a groove for the location of a substrate; and apparatus for moving, e.g. rotating, the support member. In use, the substrate is exposed sequentially to at least two of the gas flows, e.g. to grow GaInAs on InP.

Abstract: A method of depositing a group III element--group V element compound or alloy on a hot substrate using a metal organic chemical vapor deposition procedure. Attempts to apply an MOCVD procedure to the production of a group III element--group V element compound from alkyl derivatives of group III elements which are strong Lewis acids and group V element hydrides have met with limited success. This is because the reactants react in the cold gas phase to form an involatile polymer which does not give the required product on the hot substrate. The present invention proposes modifying the alkyl derivative of the group III element to be a weaker Lewis acid. This can be achieved by either substituting an electron donating group for one of the alkyl groups bonded to the group III element or by combining the group III element alkyl derivative with an alkyl derivative of a group V element thereby forming a volatile compound.

Abstract: Semiconductor compounds which are alloys of group III-V compounds are grown by a liquid phase epitaxy method which includes heating growth apparatus in a reducing atmosphere while maintaining a solvent for the compound, a source of the group III-V compound and another element of the alloy separate from each other. After heating to reduce oxides, the element is added to the solvent, the source is brought into contact with the solvent and the resulting solution is brought into contact with a substrate to effect growth of the compound. Apparatus for carrying out the method is also described.