Hi, Alaa

Thanks for the specification. I guess my wafer cannot survive very
high temperature annealing, since there is photoresist coating. I
think coating both side of the wafer is a good idea, if the stress in
wafer is of concern. However, in my case, nickel film applies the
stress to the photoresist coating directly, I am looking for methods
to prevent photoresist peeling off from the wafer, by the nickel film.

Wei


>
>
> ---------- 已转发邮件 ----------
> From: "A.ALLOUCH" 
> To: General MEMS discussion 
> Date: Mon, 01 Mar 2010 12:02:08 +0100
> Subject: Re: [mems-talk] photoresist peeled off during Ni e-beam deposition
> Hi, Wei
>
> the wafer annealing is a very hot "hard bake" (500°c for Pyrex 7740 i.e)
> and it allow a very good organization for particles inside the wafer,
> but the main cause of the stress is the difference in expansion between
> your wafer and the deposited layer ( Ni), then to avoid the stress, it's
> recommanded to deposit on the both side of your wafer.
>
> I hope to be useful,
>
>
> Alaa

--
Wei Tang
Department of Materials Science and Engineering, UCLA
Cell: 310-357-0158
Website: http://tangweipku.googlepages.com