Thin film deposition apparatus

Abstract

To suppress the deposition of thin films on exposed positions inside the process chamber and facilitate the selective deposition of good quality thin films with high productivity, disilane gas is introduced to a substrate heated by a heater inside a process chamber , and a silicon film is deposited only on the silicon surfaces of substrate by thermal CVD. A heat-reflecting plate , which is provided inside process chamber to reflect the heat radiated from substrate back to the substrate, is made of silicon with a silicon oxide film formed on its surface. Silicon atoms separate out and adhere to the surface of silicon oxide layer through the decomposition of disilane, but a reforming operation in which oxygen gas is introduced is performed between the film deposition processing of each substrate , whereby the Si atoms which exist in an isolated state with no Si—Si bonds between them are converted to silicon oxide. Accordingly, the conditions for selective deposition are continuously maintained at the surface of heat-reflecting plate , and the deposition of a silicon film is suppressed.