I had used KOH and HNA in my experiment.But I can't get a satisfied result to use nickel mask in KOH and photoresist mask in HNA.Waht's a convenient material for mask? ----- Original Message ----- From:To: Sukanta ; General MEMS discussion Sent: Thursday, June 26, 2003 3:56 PM Subject: Re: [mems-talk] help for silicon etching > There are many chemical processes for etching silicon available in the literature. Depending on masking material if any that is being used and the rate of silicon etch you are looking for we use to use an HF/Acetic/Nitric acid. The reaction is very strong with good exhaust required to prevent exposure to the operator but is will etch silicon. Bob Henderson