Subsurface damage distribution in silicon wafers ground with wafer rotation grinding method

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 crystal orientation is larger than that in 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. © 2013 Journal of Mechanical Engineering.