durusmail: mems-talk: Re: problems of release/etching process
Re: problems of release/etching process
Re: problems of release/etching process
Kenneth A. Honer
1998-11-17
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: zhanglq@itsvr.sim.ac.cn
>
> Tel: +86-21-625-11070 ext. 8603
>
>


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