Optimization of SiO.sub.2 film conformality in atmospheric pressure chemical vapor deposition

A method of forming a thin oxide film on a surface of a substrate comprising the steps of:

• providing a reaction chamber with an injector having at least two outer injection ports, a central injection port between said outer injection ports, and at least two separation ports between said outer injection ports and said central injection port, and a deposition area below said outer injection ports, said central injection port and said separation ports;
• positioning said substrate in said reaction chamber opposite said outer injection ports and said central injection ports;
• and
• coupling said central injection port to a source of ozone;
• coupling said outer injection ports to a source of an organosilicon precursor chemical reagent;
• coupling said separation ports to a source of an inert gas;
• injecting ozone through said central injection port to supply ozone to said reaction chamber in a substantially uniform concentration across said deposition area, and
• during said step of injecting ozone, separately injecting said inert gas through said separation ports and said chemical reagent through said outer injection ports so that the substantially uniform concentration of said ozone mixes with said chemical reagent in said reaction chamber between the substrate and said injector to deposit a substantially uniform film on the surface of the substrate.