Fixed Abrasive Diamond Wire Saw Slicing of Single Crystal SiC Wafers

Abstract

This paper investigates the slicing of single crystal SiC with a fixed abrasive diamond wire. A spool-to-spool rocking motion diamond wire saw machine using a 0.22 mm nominal diameter diamond wire with electroplated bond and 20 μm average size diamond grit is used. The effect of wire downfeed speed on wafer surface roughness and subsurface damage is first investigated. The surface marks due to the loose diamond and stagnation of the wire during the change in wire cutting direction are studied. A scanning acoustic microscope is explored as a non-destructive evaluation method to identify the level of subsurface damage. Another set of tests investigates the effects of using a new diamond wire on the cutting forces and surface roughness. Scanning electron microscopy (SEM) is applied to examine the machined surfaces and the diamond wire wear. This study demonstrated the feasibility of fixed abrasive diamond wire cutting of SiC wafers and the usage of a scanning acoustic microscope to study the machining subsurface damage.