Recycling of silicon kerfs from wafer sawing

摘要

There is provided a method of cutting a silicon ingot and recycling residual material, comprising the steps of:
a) cutting a Si ingot using carbon-containing particles as abrasive material such that Si wafers and a residual material comprising Si kerfs and carbon-containing particles are obtained;
b) purifying the residual material such that purified Si kerfs and carbon-containing particles are obtained; and
c) adding the purified Si kerfs and carbon-containing particles to a reduction process producing Si,
the method being characterized in that the carbon-containing particles added in step a) is contains less than 0.25 ppm (w/w) boron and less than 0.5 ppm (w/w) phosphorus.