Dear Virginia, what is wrong with the H2O2? It should not attack Al as it will passivate it first and gold should be also inert. Other option (not wet) might be SF6 plasma or XeF2 vapors. In case you are interested to try out the latest one, why do not just send us your samples and we will etch them for you free of charge. It is normal service we offer to out clients to try outs (few samples, not hundreds of wafers, of course). Best Regards Pavel ===== Pavel Neuzil CTO SiMEMS Pte Ltd __________________________________________________ Do you Yahoo!? Yahoo! Tax Center - File online, calculators, forms, and more http://tax.yahoo.com