I have done the following:
Ion mill the sapphire surface to ensure cleanliness.
Ion-mill deposit chromium as an adhesion layer (~200 A).
Ion-mill deposit nickel as an solderable layer (~1000 A).
Ion-mill deposit gold as an wetting layer (~200 A).
This was all done without breaking vacuum
I then soldered to this metallization, heating to about 250 C.
I saw no adhesion problems.

Kirt Williams, Ph.D.    consultant

----- Original Message -----
From: Mark Fuller 
To: General MEMS discussion 
Sent: Wednesday, August 13, 2003 10:52 AM
Subject: [mems-talk] Adhesion layer for sapphire?


> I am trying to get a good bond between Indium and sapphire.
> I am currently using sputtered Ti as an adhesion layer.
> The adhesion layer is failing in a following thermal cycle.
> Any suggestions as to what would work better?
>
> --
> Mark Fuller
> Microelectronics Fabrication Facility
> Washington State University
> Dana Hall 102
> Pullman, WA  99164-2711
> (509)335-1797
>
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