Patent ID: 7004012

Claim:
A method for estimating a thickness of an oxide layer formed on a wafer, the method comprising: providing an oxidizing system having an oxidizing chamber for forming an oxide layer on one or more substrates by flowing an oxidizing gas through said oxidizing chamber; placing a working wafer in said oxidizing chamber of said oxidizing system; performing an oxidizing process on said working wafer under a specified operating condition to form an oxide layer on said working wafer by flowing said oxidizing gas through said oxidizing chamber; measuring an oxygen concentration of said oxidizing gas exiting said oxidizing chamber; and estimating a thickness of said oxide layer according to said measured oxygen concentration and a previously determined relation between oxide layer thicknesses formed on test substrates placed in said oxidizing chamber and oxygen concentrations of gases exiting said oxidizing chamber in test runs of oxidizing processes performed on the test substrates under said specified operating condition.