Imaging of strain from deep trenches using X-Ray Diffraction Imaging (XRDI)

X-Ray Diffraction Imaging (XRDI) is used to non-destructively image strain in Si associated with deep trench isolation in high voltage devices. The XRD images show that there is dark contrast associated with deep trenches which is indicative of strain and defects in a material. Using defect etching, it is shown that there is a tendency for higher dislocation densities in regions where there is dark contrast in the XRD image. These results suggest that XRD imaging can be a useful tool for optimizing layout and processes for devices with deep trench isolation.