Hello Ian, Your wafers are not bonding because you do not have any current flow. Try these tips: 1. Clean the Borofloat in an RCA clean. For some reason Pyrex comes in very clean but Borofloat is usually dirty. 2. Make sure that you actually have voltage at the bond chucks. Many tools will read a voltage potential even if there is not a connection to the chucks. If you are using stainless steel chucks it is common for them to warp, this can cause them to not make contact with electrode that passes current to the chuck. If you are using SiC chucks you should give them a overnight dip in RCA, the Na build up will prevent current flow. The resistance across a 200mm SiC should be 5k or less. 3. When the bond process is running can you see a blue glow around the wafers or chucks? The blue glow is a plasma that is generated when you apply a voltage in a vacuum. Try lowering the vacuum below 1e-3mbar or above 40mbar. An anodic bond works really well at atmosphere. If you have bubbles in the bond it is usually due to colliding bond fronts. If this is the case lower the voltage to slow down the bond front and help push out the air as it moves across the wafer. If you see half moon cracks or circular cracks in the glass this is caused by trapped air that cracked the glass, vented, and bonded. Lowering the voltage will help. Your recipe looks fine for a starting point. Clean the glass, check the voltage, and move the chamber pressure out of the plasma range and you can move on to your next challenge of getting rid of Na pitting on the glass. Good luck Brad Johnson Sales Application Engineer DJK Global US Distributor, Semiconductor Inspection Systems 2447 W. 12th St. - Suite 6, Tempe, AZ 85281 480-968-3343 Ext 112 office 602-501-4413 cell bjohnson@djksemi.com http://www.djksemi.com -----Original Message----- From: ShengYi Hsiao [mailto:d927729@oz.nthu.edu.tw] Sent: Thursday, March 06, 2008 1:30 AM To: mems-talk@memsnet.org Subject: [mems-talk] fialed in borofloat-si bonding? Hi everybody. Does anyone have experience in bonding borofloat glass to silicon wafer? I am using recipe of 1000V and 400degree celcuse in vaccume environment, however, after applying that bonding condition for an hour, the glass and the wafer still not being bonded. Only same weak connection randomly happened, which results the interfering pattern. The wafers can easily be separated. Does anyone know the bonding condition for borofloat glass and Si? the FAIL experiment records are : voltage : 1000V temperature: 400C pressure: 9mtorr bonding: 1 hr bonding current: 0.02mA (form starting to the end) ....WHY? Charge: 0~6e-2 (form starting to the end) Any help would be greatly appreciated. Greetings, IAN Hsiao.