Hi Chengzhengxi, It is often a good idea to use about 20% v/v of CF4 with the oxygen to etch polyimide (at least thats what I assume you mean by PI) cleanly. -Michael On Thu, Jul 7, 2011 at 9:39 AM, chengzhengxiwrote: > Hi, > > How do I strip off thin flim that remained after a PI that contained > silicon and was etched by oxygen plasma? > > I used some kind PI that contained Si as sacrifical layer. When i released > the microstrure in oxygen plasma, I found that a layer of thin film remained > on the substrate that could not be etched by oxygen plasma. > > Is there any way to get rid of that thin film? or strip that layer of thin > film off by some kind of solution? > > chengzhengxi