Hello,

Thanks again!

The edge bead exist on the SU-8 layer, and I checked samples to find out the
stiction happens at or around the edge bead.

And the humidity is not very different from before when stiction rarely
happen, it is about 65-74%.

By the way, there is  no edge bead remove facility in my spin-coater. Could
anybody show me a simple measure to remove edge bead?


On Fri, Oct 24, 2008 at 2:45 AM, Suzanne Scullen Ericson <
[email protected]> wrote:

> I have also observed parameters of the mask aligner having a great effect
> on
> stiction.  Not only is the leveling/contact force important but also the
> parallelism of contact.  If the approach of the substrate into the mask is
> not level then a "scrubbing" action can occur which will tear the resist.
>
> Where are you noting the resist is sticking to the mask?  Along the highest
> spots?  Leveling of the resist surface is important for making clean
> contact.  Minimize the edge bead.
>
> Also, there are "Mask Protection Layers"; a hydrophobic Teflon-like
> coatings
> that really do repel the resist stiction.  I know Bill Moffat of Yield
> Engineering mentioned it as something you might consider. Image Technology
> [SUSS MicroTec] also offers masks with MPT coating applied.

--
Best Regards,

郑瑞麟

Ruilin Zheng

Address:
Pen-Tung Sah MEMS Research Center,
Xiamen University, Xiamen,361005,
P.R.China