The electrochemical potential caused be the metal/semiconductor
     interface may lead very slight etching/dissolution of the polysilicon
     in HF.

     You could try to release the structures in a lower concentration HF.

     Michael Pedersen
     Knowles Electronics


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Subject: No subject given
Author:  "Glen Smith"   mems-cc@ISI.EDU at
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Date:    01/28/2000 1:16 AM



In the presence of chrome/gold, discoloration of the polysilicon layers is
seen when releasing the MUMPS devices in 49% HF.

Anyone out there with an explaination and a possible solution?

Thanks

Glen
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