Dear All, I am trying to etch Si with Al as DRIE mask and using LF substrate bias pulses. I got Si grass everywhere and was explained to be due to micromasking of Al (sputtering and redeposition) The problem disappears if RF continuous substrate bias is used. But I need to use the LF to overcome notching effect. Has anyone succeeded before an etch with Al and LF without having Si grass? Any process suggestions will be appreciated. Thanks in advance, Yasser Sabry Doctorante ESIEE Cité Descartes, 2 Bd Blaise Pascal, F-93162 Noisy-le-Grand Cedex, FRANCE +33604488624