Thanks everybody for your different answers.

Indeed it seems to be very difficult to etch titanium in an anisotropic way at
such depths. I have seen a paper from the Nat. Laboratory of nano/micro
technologies in China claiming that they were able to etch titanium up to 200µm
with a SU-8 etch mask, I think I'll ask them how they do.

I was wondering how precise is an etching generally speaking? Can we control the
depth we want to achieve with a precision of 1 µm? How that is affect the
structure?

Best regards,

Helene.

> Date: Wed, 27 Jan 2010 00:19:02 +0100
> From: wangfeiustc@gmail.com
> To: mems-talk@memsnet.org
> Subject: Re: [mems-talk] Titanium etching
>
> Hi,
>
> I am afraid that ion beam etching won't work for 300um. It would be
> nice if you can deposite the Titanium with some kind of mould to get a
> vertical slope. Otherwise, no etchant would give you a vertical
> profile even for a few microns.
>
> Best regards,
> Fei
>
> 2010/1/26, leiwangsdu :
> > Dear helene viatge
> >
> > I used the EDTA wet etch for titanium film. But you know that wet
> > etching is isotropic
> > and tilted sidewalls were always obtained. If you need vertical sidewalls,
> > maybe you can try
> > the ion beam etching (milling).
> >
> > Yours sincerely,
> >
> > Lei Wang