Surface and subsurface microstructure properties of monocrystalline silicon cut by electroplated diamond wire saw

Monocrystalline silicon (mono-Si) is an important application material in photovoltaic and microelectronic chips. The mono-Si bricks or rods are cut into wafers using diamond wire saw, and the surface and subsurface microstructure properties of wafers are key concerns in the slicing process. This paper conducted experiments on cutting mono-Si using electroplated diamond wire saw, with feed speed, wire speed, and the cut specimen size as influencing factors, and single factor and orthogonal experiments were designed. Then the influence of three factors on the mono-Si wafer surface and subsurface microstructure properties was studied. The research results indicate that within the range of experimental parameters in this paper, the generation of mono-Si wafer surface is the result of materials brittle and ductile removal. In addition to slender grooves and brittle pits, there are typical wavy saw marks on sawed surface that approximate the distribution of a sine function curve, and the height difference between the peaks and valleys (PV) of the waviness changes with the values of three factors. Residual median cracks cause wafer subsurface damage (SSD), and there are also residual lateral cracks that have not fully expanded and removed the material. Increasing wire speed and decreasing feed speed and specimen length will reduce the PV value.The parameter that has the greatest impact on the PV value is the feed speed, followed by the specimen length and wire speed. SSD exhibits the same pattern of change. The research results provide experimental basis for a deeper understanding of the surface and subsurface microstructure characteristics of electroplated diamond wire sawed mono-Si wafers and optimizing process parameters and improving the wafer quality.