50:25:37.5 mmol/L HF/NH4F/HNO3 at 25C gives a smooth ~13 nm / minute
in the borosilicate I use.

On Wed, Jun 8, 2011 at 1:13 AM, Ned Flanders  wrote:
> Hi all,
>
> I need to etch 100 nm of borosilicate glass. I used a diluted HF + HCl
> recepy - but it seems that when diluted, this doesn't create a very
> smooth etch surface. However, I cannot use it in a more concentrated
> form, as it has an etch rate of about 8 um/min and I need to control
> the etch depth with a higher degree of precision. I need 100 nm +/- 20
> nm
>
> Any suggestions?
>
> thanks
>
> m