A method for forming a silicon oxide layer over a substrate disposed in a high density plasma substrate processing chamber. The method includes flowing a process gas that includes a silicon-containing source, an oxygen-containing source and a fluorine-containing source into the substrate processing chamber and forming a plasma from said process gas. The substrate is heated to a temperature above 450.degree. C. during deposition of said silicon oxide layer and the deposited layer has a fluorine content of less than 1.0 atomic percent.