I've seen the same thing before when using Cr as a mask for LPCVD oxide. In my case, it appeared that some of the oxide was sputtered off and coated the Cr. A quick HF or BHF dip removed the oxide, and the Cr could then be stripped in CR-14 or CR-7. --Kirt Williams ----- Original Message ----- From: "Ho Yin Chan"To: Sent: Sunday, April 27, 2008 9:49 PM Subject: [mems-talk] Chromium removal > Hi all, > > Currently, I am etching PECVD oxide using standard RIE and Cr is the > masking layer. However, I found that I cannot remove the Cr mask using > Cr etch after going through the RIE process. I am wondering if there > is anything happened on the Cr surface. I'd like to see if you could > give me some suggestions on how to remove the top Cr layer. Thanks