I dont agree with the loss of mechanical and electrical and physical properties using silicon- initial diffusions are often done at 1200 C without degredation of the base product if the environment is clean. The biggest issue is the potential for unwanted doping if the environment is not clean- We use a 9hour 900 C in Nitrogen and also a 2 hour 1200 C in O2 anneal of NTD float zone Silicon without any degredation of the base product and this product withstands a subsequent 14 hour 1200 degree Al difussion with less than a 3% change in the product resistiivity. The key is to keep any mechanical or envrionment contaminants from contacting the product as even handling ingot or wafers with tainted gloves or tweesers can cause unwanted spot doping of product. Normal Oxidation of Silicon has a normal stop point as the Si is partially consumed during the process. Longer and thicker oxides using wet or dry Thermal oxidation methods can be obtained but can take hundreds of hours in the best environment to obtain. Ken robtdavis@charter.net wrote: > As with most materials science questions there are conditions for everything. I can list several obstacles to your quest, high temperature metallization reactions with the silicon, SiO2 formation the film will be flawed unless the oxidizing environment controlled and the loss of mechanical, electrical and physical properties. Several of the oxides of silicon are unique crystal structures that may or may not be compatible with your poly or single crystal silicon substrate.... to list a few > > I would like to be more positive but that is why we use Silicon Carbide for high temperature electronics. > > Robert Davis > > > > _______________________________________________ > 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/ > -- Kmbh Associates 47 Rocket Circle Rancho Cordova, CA 95742 U S A 510-714-5055 Efax- 510 217 4421 or 561 658 6136 High Purity Float Zone and Specialty CZ Silicon for Power, IR and Mirror Optics, Optoelectronics, MEMS, SOI, and other Semiconductor applications. Service in SOI, Polishing SSP and DSP. Quartz, Glass, Pyrex and Borofloat Wafer Supply. Anodic Bonding. SOG, SOS.