Quantitative assessment of subsurface damage depth in silicon wafers based on optical transmission properties

As a nondestructive evaluation method, laser scattering has been applied for subsurface damage measurement in silicon wafers. Previous results showed that laser scattering can detect and distinguish subsurface damage of different depths. However, quantitative correlation between scatter data and subsurface damage depth has not been established. This paper presents an analysis on how to use the 'skin depth' to correlate optical scattering data obtained at different wavelengths with subsurface damage depth in silicon wafers. The results clearly demonstrate that subsurface damage depth in silicon wafers can be quantitatively assessed by the laser scattering nondestructive evaluation method.