Message-Id:Dear colleagues, We are etching thick film polyimides such as OCG Probimide 7005 with an oxygen plasma barrel etcher. We find that a thin dielectric layer remains following the oxygen plasma etch at temperatures as high as 150 C. Could anyone tell us what the nature of the remaining 20 to 50 nm film is and how we can selectively remove this film without etching underlying LTO and metal films. C. Sun Microelectronics Center NJIT e-mail: cxs3530@megahertz.njit.edu