Hi!

I did not try wet etch. I am concerned about the anisotropy. I am
using PMMA A4 950ml. Its around 180nm thick. I dont know whether a
thicker PMMA will resolve my patterns. My pattern is photonic crystal
structure with 217 nm circles.

Thanks all
satish

On 4/10/08, Oakes Garrett <G.Oakes@evgroup.com> wrote:
> Have you tried a buffered oxide etch (BOE)?
>
> http://en.wikipedia.org/wiki/Buffered_Oxide_Etch
>
> Best Regards,
> Garrett Oakes
>