Boule shaping of single crystal silicon carbide by wire electrical discharge machining

Wire electric discharge machining (WEDM) has proven to be a useful technology in the processing of semiconductor materials for micro-electronics and MEMS applications. The technology has been shown to reduce processing costs by improving material utilization, eliminating defects, and simplifying the manufacturing process. The intent of this investigation was to apply WEDM to the shaping of a single-crystal silicon carbide (SiC) boule with the goal of reducing the cost associated with boule shaping. In micro-electronic systems, SiC has been shown to be well suited for applications in extreme operating conditions such as high-temperature or adverse chemical environments. SiC is a material of very high hardness, which means it is a difficult material to machine by mechanical means. SiC is an important material for the future of electronic devices, but the use of SiC is limited by the difficulty and high cost associated with production of SiC substrates.;This work presents the results of an investigation in using a wire electric discharge machine to shape a boule of single crystal nitrogen-doped silicon carbide into a O76.2 mm circular disc with a thickness of about 14 mm that can subsequently be sliced into thin wafers for further processing. A new method was developed for shaping a boule by WEDM that produces no damage to the machined surface of the material, simultaneously machines the reference flat into the boule without the necessity of additional manufacturing processes, and also results in continuous large cutoff pieces that can be recycled.