We avoid wet chemistry when at all possible. The plasma chemistries we use for this are either SF6, at low power, high pressure, and high flows, which works reasonably well - but will slightely etch oxides and resist (somewhere betwen 20 and 50:1, depending on the settings), and have a down vs undercut rate of something like 2:1 at best. But what works much better is XeF2 systems - you can get almost zero oxide and resist etch. Contact Xactix at xactix.com. Its a bit slower etch rate, but more like 1:1 down vs undercut. Xuzhengyi wrote: > > Dear all: > > I am now doing an experiment which need to etch the silicon without attacking Al. The alkaline etchants that we usually adopted in MEMS, TMAH and KOH, could not satisfy the requirement. I heard that some organic material can do this job, can anyone here provide me the information? Or advise me other effective solutions? Anything you provided will be highly appreciated! > > Thanks > > Daniel > > ************************************************************ > Daniel Xu (Xu zhengyi) > ------------------------------------------------------------ > Ph.D candidate > State Key Laboratories of Transducer Technology > Shanghai Institute of Microsystem & Information Technology > Chinese Academy of Sciences > 865 Changning Road > Shanghai 200050 > China > ------------------------------------------------------------ > Tel: 86-21-62511070 ext. 8607 > FAX: 86-21-62513510 > email:xzy@mail.sim.ac.cn > ************************************************************ > _______________________________________________ > mems-talk@memsnet.org mailing list: to unsubscribe or change your list > options, visit http://fab.mems-exchange.org/mailman/listinfo/mems-talk > Hosted by the MEMS Exchange, providers of MEMS processing services. > Visit us at http://www.mems-exchange.org/ -- Tom Rust Nanochip Inc Box 13249 Oakland, CA 94661 (510) 339-6263 (510) 339-9636 FAX (510) 912-4662 cell http://www.nanochip.com