Hi,

Please take look at this picture:
http://picasaweb.google.com.tw/ccjmc1977/Switch#5417217340388044546

As can be clearly seen in the picture, these black spots are
unwanted deposition (4000 A - 5000 A-thick) which were produced during
etching PMMA (1 um -thick) using O2 RIE. The RIE tool we were using is
Oxford 80 Cloey. Does anyone know what these black spots are  and how can I
avoid and remove them?

Thanks

CC