Hello, Mr Ken,

I appreciate your proposal very much, and I'll try the vaper-etch process in the
coming days which I 've once considered but never expected to achieve in a
simple
setup instead of a special device. By the way, your guess is right that I did
use
SiO2 layers as sacrificial layers. PSG layers may be better, but I had no choice
since the PSG deposition system of our lab had retired for a long time.

Thanks for your helpful advice.

Yours,
Liuqiang Zhang


Kenneth A. Honer wrote:

> Hello,
>
> >From your description, I am assuming you use SiO2 as a sacrificial layer.
> Without Critical point drying, your best bet is to use HF vapor. You will
> need to suspend your sample above a container of concentrated HF. This setup
> needs to be in a fume hood, obviously. However, it is best if the beaker of
> HF and the sample are both under a larger, inverted, beaker in the fume hood.
> BE VERY CAREFUL HANDLING CONCENTRATED HF.
>
> Hope that helps,
> Ken
>
> > Dear colleague,
> >
> > I am working on the processing of a MEMS-based infrared image device,
> > everything goes through well but the release of the device. Here are
> > the problems: first, since the micro-machined structures are very
> > flimsy, I couldn't stir the resolution violently, thus bubbles arising
> > in the etching process of SiO2 not only prevented the uniform etching
> > but also destroyed the structures; second, as I haven't a
> > supercritical desiccator or a squeezing drier, after removing of the
> > sacrificial layers, the suspending structure always corrupted because
> > of the capillary forces.
> >
> > Are there any good ideas on the release/drying process? Your help is
> > highly appreciated.
> >
> > Best regards.
> >
> > Liuqiang Zhang, Ph.D. Candidate,
> >
> > State Key Laboratories of Transducer Technology,
> >
> > Shanghai Institute of Metallurgy, Academia Sinica
> >
> > Email: [email protected]
> >
> > Tel: +86-21-625-11070 ext. 8603
> >
> >