Patent ID: 7494943

Claim:
A method for using a film formation apparatus for a semiconductor process, the method comprising: applying process conditions of a film formation process for forming a thin film on a target substrate accommodated in a reaction chamber of the film formation apparatus, the process conditions including a preset film thickness of the thin film to be formed on the target substrate; applying a timing of performing a cleaning process for removing a by-product film deposited on an inner surface of the reaction chamber due to the film formation process, in accordance with the process conditions, the timing being defined by a threshold concerning a cumulative film thickness that is a value obtained by multiplying a number of repetitions of the film formation process by the preset film thickness, wherein the cumulative film thickness does not exceed the threshold where the film formation process is repeated N times (N is a positive integer), but exceeds the threshold where the film formation process is repeated N+1 times; performing first to Nth processes, each consisting of the film formation process, continuously without interposing the cleaning process therebetween; and performing the cleaning process after the Nth process and before an (N+1)th process consisting of the film formation process.