Hello, You may also use " Apiezon " vacuum grease. Easy to remove using acetone. However, be sure that the 50% etch rate variation is not due to chamber heating, or chamber conditioning : is etch rate is changing smoothly with the number of wafers, or "randomly" from wafer to wafer ? Good luck Florent GRECO CEA - LETI - Département Optronique - Service Laboratoire Infra Rouge 17 rue des Martyrs 38054 Grenoble cedex 9 FRANCE Tel : 33 (0)4 38 78 25 97 Fax : 33 (0)4 38 78 51 67 mailto:florent.greco@cea.fr -----Message d'origine----- De : mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] De la part deKarin Buchholz Envoyé : mardi 30 novembre 2004 08:44 À : mems-talk@memsnet.org Objet : [mems-talk] RIE - keep Temp constant Dear mems talkers, we have a RIE chamber with temperature control of the 3" carrier wafer. Since we are just using waferpieces we just place these on top of the carrier wafer. It seems now that these small pieces do not have proper thermal contact to the chuck, so the temperature of the sample is not constant from etch to etch and the etch rate also varies by 50per cent... Do you have any suggestions how to provide good thermal contact? The manufacturer suggested Fomblin vaccuum oil, but it is impossible to remove it from the samples after etching... I appreciate any help! Have a nice day, Karin -- Dipl.-Ing. Karin Buchholz Walter Schottky Institut Technische Universitaet Muenchen _______________________________________________ MEMS-talk@memsnet.org mailing list: to unsubscribe or change your list options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk Hosted by the MEMS Exchange, providers of MEMS processing services. Visit us at http://www.memsnet.org/