초록 ▼

A semiconductor material, such as elemental silicon, is deposited on heated rod-shaped mandrels from a reactive gas stream capable of pyrolytically depositing silicon wherein the gas stream is regulated in such a manner that the silicon deposition rate remains constant per cubic centimeter of mandre

A semiconductor material, such as elemental silicon, is deposited on heated rod-shaped mandrels from a reactive gas stream capable of pyrolytically depositing silicon wherein the gas stream is regulated in such a manner that the silicon deposition rate remains constant per cubic centimeter of mandrel surface throughout the deposition process.

대표청구항 ▼

In a process for depositing elemental silicon from a reactive gas comprised of a mixture of a halogen silane and hydrogen whereby the reactive gas flows through a reaction housing containing a heated mandrel on which silicon is deposited from such gas and wherein the deposition rate of silicon onto

In a process for depositing elemental silicon from a reactive gas comprised of a mixture of a halogen silane and hydrogen whereby the reactive gas flows through a reaction housing containing a heated mandrel on which silicon is deposited from such gas and wherein the deposition rate of silicon onto the mandrel surface varies during a course of the deposition process, the improvement comprising: chronologically maintaining a relatively constant temperature at the mandrel surface and maintaining a relatively constant composition within the reactive gas; varying the reactive gas through-put past the mandrel in such a manner that the deposition rate of silicon onto the mandrel surface remains substantially constant throughout the deposition process, said deposition rate being selected at the beginning of the deposition process in relation to the surface unit area of the mandrel and in relation to a unit time, so that the deposition rate of silicon per unit area of mandrel surface and per unit time is maintained so as to be at least 0.1 gram per square centimeter per hour and less than about 0.5 gram per square centimeter per hour; and monitoring the concentration of a hydrogen halide in an exhaust gas flowing from the reaction housing and genErating a signal based on such concentration and feeding said signal to a control means for the supply of reactive gas which is in communication with the reaction housing so as to regulate the flow rate of reaction gas past the mandrel in such a manner that the concentration of said hydrogen halide in the exhaust gas remains chronologically substantially constant.