In order to machine the 300mm-400mm silicon wafer to the specifiedsurface roughness and flatness, ELID diamond grinding were employed inthis study to investigate its feasibility. Cast iron fiber reinforceddiamond wheels were used to grind silicon wafers and various ELIDparameters were systematically tested to examine their influences onthe grinding process. The results showed that, under the same grindingconditions, the obtained surfaces were characterized by (1) thickpoly/amorphous layer with occasionally deep-penetrated cracks, (2)thick amorphous layer (up to 250nm) with distributed dislocation loops(-300nm into the substrate), and (3) thin amorphous layer (up to 30nm)when (1) no ELID, (2) ELID with rather low peak voltage and currentand (3) ELID with high peak voltage and current were applied in thegrinding processes.