Dear Sharma ji,

There are many etchant for Alumina. The best one is the Potassium
Carbonate and Potassium bicarbonate mixture. This has been reported by
Team of IBM.

Another good etchant is mixture of Phosphoric acid H 3PO4 and Chromic
acid solution. To prepare this solution you can take 7 ml of
Phosphoric acid and add 4 gram of Cr2O3.

Or another way is to etch Alumina by NaOH and EDTA solution. Alternate
to NaOH is Tetramethylammonium hydroxide solution.

Bye the way, what type of Alumina you are using? Anodized Alumina or
Amorphous Alumina ceramic sheet? If it is Anodized Alumina, you can
find number of report / papers on this topic. Try sciencedirect or
scifinder for that....

HF will certainly not work.

Hope this will help you.

Best

Amit

> ---------- Forwarded message ----------
> From: jpt sharma 
> To: mems-talk@memsnet.org
> Date: Wed, 10 Oct 2007 08:57:07 -0700 (PDT)
> Subject: [mems-talk] Al2O3
> I am looking for the AL2O3 wet etch chemical. Can anyone suggest me the
chemical and vendor?

--
Dr. Amit Asthana
Brain-pool Scientist
Institute of Applied Chemistry and Biological Engineering
(IACBE), Polymer Derived Ceramic Material Lab,
Chungnam National University, 220 Kung-Dong, Yusung-Gu
Daejeon, 305-764, South Korea.
Phone: 042 821 8920 / 7684 (office)
Fax:     042 823 6665
Email: amitasthana4@gmail.com
          amitasthana4@yahoo.com