Contamination control: removing small particles from increasingly large wafers

With the introduction of 450 mm wafers, which are considerably larger than the currently largest wafers of 300mm, handling with side grippers is no longer possible and backside grippers are required. Backside gripping increases the possible buildup of particles on the backside of the wafers with possible cross-contamination to the front-side. Therefore, regular backside cleaning is required. Three vacuum compatible cleaning methods were selected. Tacky rollers and highvoltage cleaning were selected for particles and plasma cleaning for molecular layers. A test-bench was designed and constructed implementing these three cleaning methods. The first experiments show promising results for the plasma cleaner and the tacky roller. © 2012 SPIE