Spatially Resolved Analysis of Residual Strain in Semiconductor Single Crystal Wafers by Scanning Infrared Polariscopy and High Resolution X-Ray Diffraction

A comprehensive procedure as how to record the spatial distribution of residual strain and stress respectively, in semiconductor single crystal wafers by Scanning Infrared Polariscopy (SIRP) and High Resolution X-ray Diffraction (HRXD) is demonstrated. The SIRP based on the strain-induced birefringence is the most sophosticated method for the fast lateral mapping of combinations of the in-plane strain tensor components determined in transmission of the whole wafer. The HRXD adds the subsurface profile of the single tensor components of strain and stress in selected points of the wafer by analysing sets of diffraction lines of different penetration depths calculated according to the dynamic theory of X-ray scattering. The averaged strain and stress values extrapolated from the HRXD subsurface data correlate with the corresponding results of SIRP. The more general application of residual strain characterisation demonstrated on InP to other wafer materials is recommended.