A method of forming a silicon oxide layer is described. The method first deposits a silicon-nitrogen-and-hydrogen-containing (polysilazane) film by radical-component chemical vapor deposition (CVD). The polysilazane film is converted to silicon oxide by exposing the polysilazane film to humidity at low substrate temperature. The polysilazane film may also be dipped in a liquid having both oxygen and hydrogen, such as water, hydrogen peroxide and or ammonium hydroxide. These conversion techniques may be used separately or in a sequential combination. Conversion techniques described herein hasten conversion, produce manufacturing-worthy films and remove the requirement of a high temperature oxidation treatment. An ozone treatment may precede the conversion technique(s).