Hi Morten

Thanks for sharing your process. I'm wondering if your setup causes
problems with stiction? I mean moisture induced stiction for the
released MEMS parts. Thanks

Best
Leo

On Tue, Feb 3, 2009 at 11:10 AM, Morten Aarøe  wrote:
> HF vapour etching is isotropic, so etching square 10µm x 10µm holes 10µm
> deep is not possible. What you would get is at best a 20µm circular hole.
>
> I'm currently using this process to release fragile MEMS structures with
> some success. It should be noted, that the only thing you need is a
> container of 40% HF and a way to suspend your wafer above it (etch-side
> down) in a fumehood- I use a PTFE/Teflon cylindrical shell with a slightly
> smaller internal diameter than my wafer, which any workshop can make. The
> etch rate is about 200nm/minute. We use 1.5µm AZ resist, but I can't tell
> you if that's the best solution. It seems OK for 10µm etches though.
>
> // Morten

Xiaoguang "Leo" Liu
Birck Nanotechnology Center,
Purdue University,
1205 W.State Street, West Lafayette, IN, 47906 USA
[email protected]