WE used to live with hillocks when we were trying advanced processing 2 layers of metal. Hey this was in the 80"s, did not have a cure but it caused a lot of metal to metal short problems. If you research aluminum hillock problems some one should have a solution by now. Bill Moffat ________________________________ From: mems-talk-bounces@memsnet.org on behalf of shay kaplan Sent: Sat 9/27/2008 12:31 AM To: Julie.Verstraeten@usherbrooke.ca; 'General MEMS discussion' Subject: Re: [mems-talk] "cavity" formation after annealing of evaporated aluminium on Si Julie, Sound like hillocks. It forms when heating evaporated aluminum because of the TCE differences. The aluminum expands gets detached from the surface causing the small bumps that remain when the sample is cooled. Shay