Patent ID: 7972649
Filing Date: 2011-07-05
Classification: C23C,H01L

Abstract:
1. A thin film formation method for forming a thin film comprising: providing a conductance valve on an exhaust path connecting a depressurizable processing chamber and a vacuum pump, arranging a processing object substrate inside the processing chamber, performing once or plural times a cycle including, using the chemical reaction to form the thin film on the substrate, supplying a predetermined gas into the processing chamber by a specified flow while exhausting the inside of the processing chamber; determining a reference value that is equal to a valve opening level of the conductance valve corresponding to a specified value of pressure inside the processing chamber by performing automatic pressure control during a preparation period before the film formation processing period starts; stopping the automatic pressure control and maintaining the valve opening level of the conductance valve at the reference value during the film formation processing period; variably controlling the valve opening level of the conductance valve by a pressure feedback method such that a detected value of the pressure inside the processing chamber matches the specified value; measuring the valve opening level of the conductance valve; and acquiring instantaneous values of the valve opening level of the conductance valve at fixed time intervals as sample values, and obtaining an average of n (n being a whole number) of the sample values.