Residual stress measurement of the ground wafer by stepwise corrosion and Raman Spectroscopy

The residual stress on ground wafer surface layer are detected by stepwise corrosion and Raman Spectroscopy. The corrosion depth is measured by scanning white light interferometric. The results show that the ground wafer surface layer mainly present compressive stress. For rough ground wafer, the compressive stress layer thickness is about 45 nm, the compressive stress transform to tensile stress when the corrosion depth is more than 45 nm. For fine ground wafer, the compressive stress layer thickness is about 65 nm, the compressive stress transform to tensile stress when the corrosion depth is more than 65 nm. The compressive stress layer depth of rough ground wafer is smaller than that of fine ground wafer. The main reasons for generation of residual stress are phase and elastic-plastic deformation.