Finite Element Analysis on Soft-Pad Grinding of Wire-Sawn Silicon Wafers

Abstract

Silicon is the primary semiconductor material used to fabricate microchips. The quality of microchips depends directly on the quality of starting silicon wafers. A series of processes are required to manufacture high quality silicon wafers. Surface grinding is one of the processes used to flatten the wire-sawn wafers. A major issue in grinding of wire-sawn wafers is the reduction and elimination of wire-sawing induced waviness. Several approaches (namely, combination of grinding and lapping, reduced chuck vacuum, soft-pad, and wax mounting) have been proposed to address this issue. Finite element analysis modeling of these approaches was conducted and the results were published earlier. It was shown that soft-pad grinding was a very promising approach since it was very effective in reducing the waviness and very easily adopted to conventional grinding environment. This paper presents a study of finite element analysis on soft-pad grinding of wire-sawn silicon wafers, covering the mechanisms of waviness reduction and the effects of pad material properties.