Monitor method of chemical vapor deposition process temperature

This invention provides a monitor method of chemical vapor deposition process temperature, which utilizes sub-atmospheric undoped silicate glass (SAUSG) as a temperature index. According to the invented method, a SAUSU film is formed onto a blanket wafer, comparison among deposition rate, standard deposition rate and standard deposition temperature is made to verify whether the temperature provided by the heat source is in accordance with the temperature on the surface of the wafer. Therefore, an undesired fast deposition rate due to low temperature and thus a film with poor gap fill capability can be prevented. Moreover, the invented method can be used as an index for replacing heating apparatus so that an effective heating quality can be provided.