This phenomena is known in the semiconductor (hillocks) - caused by aluminum stressing and relieving stress. Slightly better with 1% Si inside but almost impossible to get rid of it. Replace the aluminum with another metal. Shay -----Original Message----- From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On Behalf Of Xin Yan Sent: Monday, March 05, 2012 4:02 PM To: General MEMS discussion Subject: [mems-talk] Al grass on the 7740 glass Hi everyone, the process flow as follows, 1 etch cavity on the 7740 glass 2 deposit 200nm Al layer on the cavity of 7740 glass, 3 anodic bonding process with silicon, 400 degreeC, 800V the problem: we always find the Al grass on the al layer after the anodic bonding, the Al grass dimension: about 2~3um long, and with a diameter of 200nm the quantity of grass is not too much , but it cause the device short circuit. have somebody met this problem before? what's the source of this phenomenon? Any suggestions would be appreciated! -- Yan Xin _______________________________________________ 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