Morphological characterization of 325 mesh-grinding-induced defects on silicon wafer surface

Abstract

This article details how various mechanical defects resulting from 325-mesh grinding for wafer thickness reduction influence the mechanical stability of chips individually diced from silicon wafers after more fine grinding. It was found through SEM, AFM, and TEM examinations that 325-mesh grinding-induced defects can survive on wafer surfaces even after 3000-mesh fine grinding, thereby deteriorate the reliability of diced chips. Through AFM and TEM examinations of fractured surfaces of silicon chips diced from 325-mesh grinded wafers, it was found that a phase boundary between silicon locally melted by grinding-induced friction and original silicon can be generated during 325-mesh grinding. This phase boundary was investigated to survive after 3000-mesh fine grinding up to a thickness of 2 μm in order to reduce chip fracture reliability. However, this work shows that 325-mech grinding induced phase boundaries besides deep scratch marks can be effectively removed in order to increase chip fracture possibility after 3000-mesh fine grinding up to a thickness of 10 μm.