A process model of wafer thinning by diamond grinding
This paper is to develop and investigate a wafer thinning process model (WTPM) to integrate the wafer thickness into set-up parameters and predict total thickness variation (TTV) of ground wafers with modification of the wafer grinding process model (WGPM) developed previously. Due to the variation of wafer thickness during diamond grinding, the WTPM can be used to estimate the TTV after wafer thinning process. Experiments have been performed on a G&N nano grinder MPS-940 to demonstrate its feasibility of silicon wafer thinning. Results have been obtained that the TTV is less than 3 μm for two sets of tests of wafer thickness of 600–700 μm and 700–800 μm as compared with the desired TTV of 0 μm from simulation of the developed WTPM with certain set-up of tilting angles. Therefore, the WTPM has been verified in this study and further used for forecasting the limitation of wafer thinning with different wafer thickness.
Source: Journal of Materials Processing Technology