Patent ID: 7109132

Claim:
A high-density plasma CVD process comprising the steps of: a) preparing a semiconductor substrate; b) loading the semiconductor substrate into a process chamber; c) injecting first main process gases including a silicon source gas, an oxygen gas, a nitrogen free chemical etching gas and a hydrogen gas into the process chamber to generate a high density plasma over the semiconductor substrate and to simultaneously form a silicon oxide layer on the semiconductor substrate; d) injecting second main process gases into the process chamber after the injection of the first main process gases, wherein the second main process gases include a silicon source gas, an oxygen gas, a nitrogen free chemical etching gas, a hydrogen gas and a helium gas; and e) injecting third main process gases into the process chamber after the injection of the second main process gases, wherein the third main process gases include a silicon source gas, an oxygen gas and a hydrogen gas, wherein the semiconductor substrate is heated to a temperature in a range of about 550° C. to about 700° C.