I believe the gas rate of oxygen is crucial. There is a maximum depostion rate
when you change the oxygen gas rate at given temperature. I think you have to
try
by yourself because different LPCVD is DIFFERENT.

> I already deposit SiO2 at 950 C, so i don't think annealling will be
>necessary.
>Which LPCVD temperature do you use ?
>Do you have any suggestion (gas flows) in order to obtain an high deposition
>rate ?