Strain field imaging on Si/SiGe(001)-(2×1) surfaces by low-energy electron microscopy and scanning tunneling microscopy

We show that ultrahigh-vacuum low-energy electron microscopy and scanning tunneling microscopy can be used to image residual uniaxial strain fields on (001) surfaces of SiGe heterostructures. We find that the surface crosshatch morphology on these films is highly correlated with large spatial variations in the residual uniaxial strain fields, confirming the importance of local strain fields in the formation of crosshatch.