Crack damage control for diamond wire sawing of silicon: The selection of processing parameters

Fixed diamond wire sawing has been the most common technology to cut mono- and multi-crystalline silicon into wafers in the fields of photovoltaics and integrated circuits. The crack damage inevitably occurred in wire sawing is preventing the further reduction of wafer manufacturing cost due to wafer breakage and subsequent crack damage removal. This paper presents a numerical model to predict the processing parameters for a given expected crack damage depth of as-cut wafers, aiming to realize the control of crack damage. The model adopts a classic median-and-lateral crack system to describe the crack damage induced by the scratching of diamond abrasives randomly distributed on wire. The key processing parameter - the ratio of feed speed to wire speed - is determined by making the calculated crack damage depth equal to the expected value. The deflection/bow angle of wire is checked to avoid excessive end-cutting time and severe shape deviation of wafers. The established model is verified by wire sawing experiments using the processing parameters predicted by this model. The maximum relative error between experimental values and expected values of the crack damage depth is 5.26%. This model can be applied to the industrial crack damage control of as-cut wafers by the selection of processing parameters.

Automated summary

This paper presents a numerical model to predict processing parameters for cutting silicon wafers, aiming to control crack damage. The model involves checking the deflection/bow angle of the wire to avoid excessive damage and shape deviation.