The influence of material properties on the wire sawing process of multicrystalline silicon

The influence of material properties on the cutting efficiency of multicrystalline silicon was investigated for bricks taken from different positions of industrial-scale G5 multicrystalline silicon ingots in a diamond wire sawing process. It is shown, that bricks from diverse ingot positions reveal significant differences regarding the forces in feed direction when exactly the same process conditions are applied. Higher forces in feed direction imply a stronger bowing of the wire web developing during the process and therefore indicate a lower cutting efficiency. The size of silicon nitride and silicon carbide precipitates in the material are identified as the main factor for the cutting efficiency. The findings show the potential to optimize industrial wafering processes regarding process time or wire consumption.