Patent ID: 8087427

Claim:
A vapor phase growth apparatus comprising: a first flow path used to supply a chamber with a hydride gas as required for vapor phase epitaxial film formation on or above a wafer being received in the chamber, said first flow path including a series combination of two-stage valves; a second flow path configured to supply into said chamber a ClF 3 gas for cleaning of inside of said chamber; a third flow path configured to exhaust a residual gas within said chamber; a pressure switch being provided between said series combination of two-stage valves; a valve configured to control flow of the ClF 3 gas in said second flow path; and a control device configured to control flow of the hydride gas in the first flow path, one of said series combination of two-stage valves of said first flow path being controlled to close, and then another one of said series combination of two-stage valves of said first flow path being controlled to close after said hydride gas had been drained away from within an inside space of said first flow path including a space of the first flow path between said series combination of two-stage valves, to control said valve of said second flow path to open after said series combination of two-stage valves had been closed after said hydride gas had been drained away from within the inside space of said first flow path, and then to control said valve of said second flow path to close for preventing supplying of the ClF 3 gas when said pressure switch detects a change of an increase by the hydride gas which flows through one of said series combination of two-stage valves, in pressure of the space of the first flow path between said series combination of two-stage valves during supplying the ClF 3 gas into said chamber by the second flow path.