I used to use silver as a plating base, and I can give you a warning about it:
Never use plasma O2 on silver, it forms a peroxide which is black and
almost flows
at room temperature.  Also, silver tarnish of several microns can form in
presence of sulfer.

     Jon Bernstein

At 05:12 PM 4/16/99 -0400, you wrote:
>Hi Folks-
>
>Does anyone have or know of any experience using silver thin films as masks
>for etching silicon in any of the common anisotropic etch processes,
>including KOH, TMAH, EDP or the Bosch/STS Deep RIE process?  [I need Ag on
>my finished device for an unrelated reason, but it would be very helpful if
>I could also use it as an etch mask.]
>
>I don't believe silver will be dissolved in any of the above, but I'm not
>sure how well thin films will hold up to extended etch times, temperatures,
>concentrations, etc.  Does an oxide form during the etch?  Can it be removed
>without damaging the remaining Ag or the Si?  I would be very interested in
>any first hand observations or recommendations for using Ag (or Au), before
>I try it myself.
>
>I have spent much of the last two days searching for an answer to this
>question with little luck.  Are there any good references that summarize
>etch rates for potential masking materials in various etchants, particularly
>metal masks?  One very nice table of several common ones was compiled by
>Kirt Williams, and can be found on BSAC's web site:
>
>http://www-bsac.eecs.berkeley.edu/db/etch.pdf
>
>Unfortunately this doesn't have the specific info I need.  I would welcome
>any other suggestions, and will gladly post a summary of any I receive.
>Thanks for your time.
>
>--
>Marc Straub
>Advanced Technology Development
>Visteon Automotive Systems, Ford Motor Company
>Dearborn, MI
>mstraub1@visteon.com
>
>




Jonathan Bernstein
MEMS Technology Center
Draper Labs, MS 37
555 Technology Square
Cambridge, MA 02139 USA

jbernstein@draper.com
Tel. (617) 258-2513
Fax  (617) 258-4238