Bill "Flow TEOS round the resist.." At what temperature was it done ? Deposition of oxide from TEOS needs a high temperature ~375 C. Using ozone/TEOS it would still need at least 300 C. For a planarizing deposit the temperature is higher. It does not reflow like BPSG. mateen Bill Moffat wrote: > > The image reversed pillars resist thermal flow like silylated resist does. > First expose the pillar regions. Then image reverse using ammonia technique, > dozens of papers on this technique. Then flood expose remaining resist, this > is the exposure level that determines the pillar wall angle. Any angle 22 > degrees +/- from vertical is easily achievable. Then develop away the newly > exposed resist leaving the original exposed and reversed pillars. This resist > is more resistant to thermal flow. Flow TEOS around the resist. Then CMP or > back lap off the hillocks over the pillars. This exposes the tops of the > pillars and they can be removed with simple Oxygen plasma giving vertical side > walls down to the contacts. Contact me by phone and I will walk through any > variations and details of reversal down to 800 angstrom lines and spaces. I > think in later production they used spin on glass. This process is one we > tried to do in the 80's called the lost contact process but we etched and the > contacts got bigger so we had no benefit. With the reversal approach this > gave a 40% reduction in chip size and a 60% increase in speed. I think. My > phone number if you want to hear more details is 408 954 8353. Bill > > -----Original Message----- > From: mmf [mailto:mmf@soton.ac.uk] > Sent: Friday, May 17, 2002 1:11 PM > To: mems-talk@memsnet.org > Subject: Re: [mems-talk] PDMS pillar shape > > Bill, > > "Then flowing TEOS around the reversed image photo resist he defined > contacts with vertical side walls..." > > How did he do it? > > mateen > _______________________________________________ > 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.mems-exchange.org/ > _______________________________________________ > 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.mems-exchange.org/