Patent ID: 7604010

Claim:
A method for using a film formation apparatus for a semiconductor process, the method comprising: performing cleaning inside a reaction chamber of the film formation apparatus to remove a by-product film deposited inside the reaction chamber, while supplying a cleaning gas into the reaction chamber, and setting the interior of the reaction chamber at a temperature and a pressure to cause the cleaning gas to react with the by-product film, the by-product film having been deposited inside the reaction chamber by performing film formation of forming a film on a target substrate by use of TEOS (Si(C 2 H 5 Q) 4 ) inside the reaction chamber; monitoring a concentration of ethanol generated due to etching of the by-product film by the cleaning gas and contained in exhaust gas from the reaction chamber in a predetermined period of the cleaning; comparing a measurement value of the concentration of the ethanol with a preset value, and thereby determining an end point of the cleaning; and finishing the cleaning based on the end point.