Characteristics of a Schottky Barrier Diode and the SiC Wafers Sliced by Wire Electrical Discharge Machining

The multi-wire electrical discharge slicing (multi-wire EDS), which is a brand-new method for fabricating wafers, is expected to considerably reduce the production cost of SiC wafers by decreasing in the width of kerf and kerf loss. We evaluated, for the first time, the influences of a wire electrical discharge machining (WEDM) on the SiC wafers based on experiments using WEDM equipped with a power supply of EDS. Although the analyses by transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) revealed that the WEDM influenced layer consists of a contamination layer including several kinds of metals and a layer having crystal defects was certainly formed near the wafer surfaces, the width of the influenced layers was only 3μm, and the layer could be easily removed by the grinding process. Furthermore, characteristics of Schottky barrier diodes (SBDs) fabricated with removing the influenced layer formed by WEDM are comparable to those fabricated with using conventional wafers.