Patent ID: 7182819

Claim:
A method for cleaning a chamber of semiconductor device manufacturing equipment comprising: supplying cleaning gas into the chamber to start a cleaning process; detecting an intensity of a wavelength for the cleaning gas; fixing a valve to control a pressure in the chamber at a predetermined position when the intensity of the wavelength exhibits a predetermined condition, wherein the predetermined condition is that the intensity of the detected wavelength is higher then a predetermined value and substantially constant for a predetermined duration; detecting the pressure in the chamber during a time period while the intensity of the wavelength exhibits the predetermined condition, wherein detecting the pressure in the chamber during a time period is performed during about 10% of a cleaning time, wherein the cleaning time is the time from when the cleaning process starts to when the intensity of wavelength is settled at the predetermined value; and stopping the supply of the cleaning gas into the chamber to complete the cleaning process when the detected pressure meets a predetermined criterion.