From jennyhu at stanford.edu  Mon Sep  1 22:59:54 2008
From: jennyhu at stanford.edu (Jenny Hu)
Date: Mon, 1 Sep 2008 22:59:54 -0700
Subject: Selectively Etching Al over GaAs
Message-ID: <000901c90cc1$1f27e720$5d77b560$@edu>

Hi Wet Bench GaAs Users,

 

 I have patterned resist over 100nm Aluminum over GaAs, and I would like to
etch the aluminum without etching the GaAs beneath.  It seems most chemicals
that etch Al (H3PO4, HCl, KOH, NaOH) also etch GaAs.

I tried etching using AL-11 etchant at 40C, but my GaAs surface was also
etched and the surface was roughened. The timing was very hard to control,
so I wasn't able to stop at exactly the Al/GaAs interface.  I tried a lower
temperature, but I was still not able to remove my sample in time.   

 

Does anyone have any experience with this?  Any suggestions would also be
very helpful.

 

Thank you very much for your help.

 

Sincerely,

Jenny Hu

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://snf.stanford.edu/pipermail/wbgaas-hpl/attachments/20080901/0b9f6d2e/attachment.html>