Hi Sven

Could you be more specific with your etching condition? Like your mask
material, HF concentration etc?

Best
Leo

On 10/19/07, Sven Holmström  wrote:
>
> Dear all,
>
> I try to do isotropic etching in quartz (fused silica, to be more
> precise) with HF. It has been very hard to mask, but recently I
> succeeded with the masking step. But then the profiles where quite
> different than suspected.
>
> The mask patterns are either straight lines or circular holes. I had
> expected the profiles to be similar to that of HNA etching in silicon,
> rounded pits that (in the case of the circular holes) expand as ever
> larger half spheres around the etch hole. But instead of this I see
> almost totally straight sidewalls and flat bottom.
>
> Can this be due to lack of agitation? When you lack agitation in HNA
> silicon etching you will get a flat bottom, but always somewhat
> rounded sidewalls.
>
> Can it be a material issue? Is there perhaps a very specific material
> requirement for isotropic quartz etching that I have missed?
>
--
Xiaoguang "Leo" Liu
Birck Nanotechnology Center,
Purdue University,
1205 W.State Street, West Lafayette, IN, 47906 USA
liu79@purdue.edu