Yes, it is that orange stuff, but it is ceric ammonium NITRATE. I agree with Ned about etch rate. The recipe we use is as follows: 20 g Ce(NH4)2 (NO3)6 3.5 mL CH3COOH and adding H2O till 100 mL Eowin. ________________________________ Från: Ned FlandersTill: General MEMS discussion Skickat: ons 20 juli 2011 3:40:45 Ämne: Re: [mems-talk] Cr wet etching Correction: I meant ceric ammonium NITRIDE etchant. Which also contains perchloric acid. That orange stuff, in other words. m