Patent ID: 7109131
Filing Date: 2006-09-19
Classification: H01L

Abstract:
1. A method of selectively oxidizing one material with respect to another material formed on one or more semiconductor substrates, comprising: generating in a torch chamber a mixture of steam comprising approximately 10% to 30% steam and the balance hydrogen by flowing hydrogen and oxygen into said torch chamber; contacting the one or more semiconductor substrates in a process chamber with said mixture of steam at a temperature in the range of approximately 700 to 850° C. to form an oxide layer selectively on the one material; sensing existence of a flame with a flame sensor positioned in said torch chamber and close to a flame combustion region within said torch chamber, an output signal of said flame sensor being coupled directly to a process controller; if said output signal fails to indicate the existence of a flame in said torch chamber within a programmable amount of time, interrupting the flow of hydrogen to said torch chamber and starting high flow rate dilution with an inert gas; detecting leaks in said processing chamber with a pressure sensor positioned in said processing chamber and if said pressure sensor detects a leak in said processing chamber, interrupting the flow of hydrogen to said torch chamber; combusting any unreacted hydrogen which passes through said torch and processing chambers; and in the event of an electrical power failure, extracting any unreacted hydrogen from said torch and processing chambers and diluting it with nitrogen to below hazardous levels.