Mike, Maybe they will be willing to sell you the material and you could apply it yourself? Shay -----Original Message----- From: mems-talk-bounces+shay=mizur.com@memsnet.org [mailto:mems-talk-bounces+shay=mizur.com@memsnet.org] On Behalf Of Mike Whitson Sent: Friday, January 06, 2012 4:35 PM To: General MEMS discussion Subject: Re: [mems-talk] Optical absorbing material Hi Dean, That's definitely interesting; unfortunately the surface in question is SiO2 - and it's on top of a finished CMOS chip, so I can't simply clear away the SiO2 to expose Si. This also means I have to keep an eye on thermal budget and minimize high-temperature processes. Does the grass formation depend on having single-crystal Si, or could it be formed in, say, a low-temp CVD poly-Si film deposited on top of my SiO2? (And you're correct; spin coating is not a true requirement. I'd mainly been thinking along the lines of various spinnable polymers like we'd used in the past, but something that could be deposited or fabricated and patterned with other standard fab equipment would likely be suitable too, as long as it doesn't involve high-temperature processing. I'm mainly ruling out things like laminated tapes, sprays, paints, and high-viscosity pastes which are used to blacken macro-scale components.) To Shay: Thanks for the suggestion; I'll contact those people to see if it might be possible to make something work. However, this project has some ITAR restrictions slapped on it, so sending my samples to Israel will involve significant paperwork. It's not impossible if they're truly a unique provider of an essential service, but it's a lot of hassle on my end. -Mike On Jan 5, 2012, at 14:43, Dean Hopkins wrote: > Hi Mike, would you consider "Black Silicon"? > > Anyone with a deep RIE system can treat your wafers to form a black silicon 'grass' on horizontal exposed silicon surfaces. The black silicon process is frequently used in tuning the process for best vertical sidewalls. > > * High broadband optical absorption. > I don't know the spectral range of absorption, but it is really black, black, black. > > * Spin coatable. > No, but is that a performance requirement or an artifact of the existing process sequence? > > * > Electrical resistivity as high as possible. > As etched the 'grass' is conductive, but a thin oxide or nitride layer can passivate it. > > * > Patternable. > Simple. Only open the areas you want to blacken to the RIE. > > * Long life. > As long lived as the silicon in the rest of the device. > > I think I might be able to intercede with a fab to get samples run, if you are interested. > > Best, > > Dean Hopkins _______________________________________________ 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