Hi, Just to share some lab results. When I diluted XeF2 (1.5 torr) with
about 8 torr of N2, the etch rate was lower, but quite uniform for features
from 0.1 to 1mm. Thanks, Junjun

On Tue, Feb 24, 2009 at 8:08 PM, xudehui0108  wrote:

> Hi junjun wu, I also found that the etch rate decreases as the feasure size
> decreases when I did XeF2 etching. However, the etch rate decreases very
> fast as the feaure size decreases if the feature size is under certain
> value. On the other hand, the etch rate decreases slow as the feaure size
> decreases if the feature size is over certain value. I think it is maybe due
> to that XeF2 is more easy to reach the silicon surface and SiF4 is more easy
> to pump out as the feature size increase.
>
> It's difficult to obtain uniform etch rate on different feature size on the
> same surface using XeF2. But you can carefully arrange the etch windows to
> get a uniform etching.
>
>
> 2009-02-25
>
> xudehui0108

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Junjun Wu
Twin Creeks Technologies
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