If TEOS is the Si precursor for PECVD SiO2 deposition will be conformal. SiH4 as a Si precursor will result in a much less conformal deposition. Roger Shile -----Original Message----- From: mems-talk-bounces+rshile=nanoink.net@memsnet.org [mailto:mems-talk-bounces+rshile=nanoink.net@memsnet.org] On Behalf Of Gabriel Puebla-Hellmann Sent: Tuesday, November 20, 2012 8:37 AM To: 'General MEMS discussion' Subject: [mems-talk] 2 micron dielectric pillars Hi, I need 2 micron high dielectric pillars with somewhat sloped sidewalls for a project involving post deposition, lateral dimensions are 6 by 8 microns. I'm currently using PECVD silicon oxide, which gives good slopes, but due to the conformal nature of the deposition, also flags (see SEM image), even with an undercut of more than 5 microns. Does anyone have an alternative suggestion? Or a way of getting rid of the flags/making the PECVD more directional? Unfortunately, a post deposition wet-etching does not really work, 10 s in 20:1 BHF already removes the entire structure. The oxide quality is low as the PECVD is running at a low temp (120 deg) process to avoid resist melting/glass transition. Thanks for your input, Gabriel ************************************************************** Gabriel Puebla-Hellmann ETH Zuerich Laboratory for Solid State Physics Quantum Device Lab HPF D5 Schafmattstr. 16 8093 Zurich Switzerland Tel: +41 44 633 71 24 www.qudev.ethz.ch ************************************************************** _______________________________________________ Hosted by the MEMS and Nanotechnology Exchange, the country's leading provider of MEMS and Nanotechnology design and fabrication services. Visit us at http://www.mems-exchange.org Want to advertise to this community? See http://www.memsnet.org To unsubscribe: http://mail.mems-exchange.org/mailman/listinfo/mems-talk _______________________________________________ Hosted by the MEMS and Nanotechnology Exchange, the country's leading provider of MEMS and Nanotechnology design and fabrication services. Visit us at http://www.mems-exchange.org Want to advertise to this community? See http://www.memsnet.org To unsubscribe: http://mail.mems-exchange.org/mailman/listinfo/mems-talk