X-ray scattering techniques for the measurement of InP substrates

The application of X-ray scattering techniques to InP and InAs substrates is presented. Applications focus on double crystal X-ray topography (imaging) and reciprocal space scans. Both types of substrates have shown dramatic improvements in crystalline quality and wafer size over the past few years. The topographic measurements display large area images of variations in both lattice dilations (strain) and lattice tilts. Low angle boundaries, precipitates, and dislocations are readily imaged over the entire wafer. Images taken at different rocking curve positions provide information about crystallographic defects and "rocking topographs" provide quantitative information about long range deformation in the substrates. The reciprocal space scans presented here demonstrate the sensitivity of triple axis rocking curves to subsurface damage in both InP and InAs.