Try a oxide etching as a pre-step; native oxide and organic junk inhibits Si etching; also make sure to use a dilute TMAH solution, hight temperature and sonication if possible. On Fri, Jul 25, 2008 at 10:18 PM, Muk Mei Yuwrote: > Hi, > > Did anyone encounter 'etch initiation' failure for Si etch in TMAH solution > before? Some refer etch initiation failure as passivation of Si during > etching which prohibits etching of Si. Si presents un-etched after the whole > process. What are the casues of this phenomenon? Any measures to help > mitigate this defect? > > Thanks, > Muk -- _fm