Changes in edge shape during silicon wafer polishing: Roll-off and roll-up formation

Abstract

The edge shape of a silicon wafer is crucial for optimal device manufacturing. In polishing processes, it is necessary to form wafers into either a flat or roll-up shape, depending on the specific requirements of the process. However, the conventional process typically results in a roll-off shape. This study identifies the factors that influence a change in the edge shape during polishing. Polishing experiments were conducted to examine the effects of the initial edge shape and contact state between the wafer and polishing pad on the removal distribution. An approach for adjusting the resulting edge shapes was proposed.