Method of determining a time to clean a low pressure chemical vapor deposition (LPCVD) system

摘要

A method for accurately determining a time to clean a LPCVD system is disclosed, in which gas flow readings of the gas supplying source from a mass flow meter (MFM) are recorded during the depositing process. The gas flow volume of the gas supplying source read from the MFM decreases as the congestion in the vacuum route of the LPCVD system increases. Based on the established relationship, an accurate time for cleaning the LPCVD system can be determined, so as to avoid product defects due to an excessive deposition.