Abstract: During the integrated circuit manufacturing process, ultra-precision grinding based on the principle of wafer rotation grinding is an important method in flattening of silicon wafers and in back-thinning of the completed device wafers, but the surface/subsurface damage is generated inevitably in ground silicon wafers. The subsurface damage distribution in ground silicon wafer has great significance in analyzing the reason of wafer bow/warp and determining the wafer removal thickness of subsequent process. Using the angle cross-section microscopy, the subsurface damage distributions in different crystal orientations and radial locations of silicon wafers ground with wafer rotation grinding method are investigated, and the effect of spark-out process on the subsurface damage distribution is analyzed. The experiment results show that in the ground wafer without spark-out process, the subsurface damage depth in <110> crystal orientation is larger than that in <100> crystal orientation and the subsurface damage depth increases along the radical direction from the centre to the edge; but in the ground wafer with spark-out process, the subsurface damage depths in different crystal orientations and radial locations are almost the same. And the subsurface damage depth in ground silicon wafers with spark-out process is significantly smaller than that without spark-out process.

Key words: Diamond wheel, Grinding, Silicon wafers, Subsurface damage