Abstract
To reduce kerf loss and wafer thickness, wire electric discharge machining (W-EDM) has been studied as a new method for slicing of polycrystalline silicon ingots. The EDM-affected layer with wire material on the sliced surface formed during W-EDM must be removed. In this study, a blasting process was applied to remove the affected layer. Aluminum oxide and silicon carbide grains 10 – 40μm in mean diameter were used as the blasting media. The results indicated that blasting with WA#1000 abrasive could remove the affected layer and also make the wafer surface smoother than that sliced with a multi-wire saw. Energy dispersive X-ray analysis indicated elimination of contamination by elements such as copper and oxygen on the blasted wafer. The etch rate of the blasted wafer was higher than that before blasting, and this result supported those of element analysis. A solar cell was fabricated from blasted silicon wafer sliced by W-EDM.
