We routinely use CHF3/O2 RIE for oxide etch, with a gas flow of 50 sccm CHF3
and 2 sccm O2. The etch rate is about 30 nm /min but is decreasing if you do
a long etch and use resist mask due to polymerization. The rate is also
dependent on the deposition condition of TEOS.

Long


On 9/17/07, deepa sree  wrote:
>
>   Hello All:
>     I am having difficulty in etching a silicon oxide layer that I
> deposited in a Plasma therm system with Silane and Nitrous oxide. Thickness
> is about 8000 A. It etches really fast (about 30 seconds) in 5:1 BOE, but
> doesn't etch at all in a dry etch system. I am using Oxygen and CHF3 for
> etching. I have tried various gas ratios, power and pressure settings, but I
> am not able to etch this layer. I need to use a dry etch for my application.
> Any suggestions about etch or deposition is appreciated.
>      Thanks
>   Deepa