Hi, Mike,

Thanks a lot for your info.
The ratio 100:1 you mentioned is ammonium fluoride : HF, right?
Thanks.

Best,
Jeff


On 12/15/05, Beggans Michael H IHMD  wrote:
> Hi Jeff,
>
> For 5nm the etch rate for even 100:1 HF is probably too high to be
> practical. 1 minute in 100:1 HF is enough to remove the native oxide on
> silicon and that can be as thick as 30 nm.
>
> You probably want to go to a plasma etch where the oxide etch rate is less
> than 1000 A/min.