Direct atomic observation of Ge/(001)Si interfaces by image processing methods in high-resolution electron microscopy

We have established some useful methods of direct observation Ge/(001)Si interfaces by high-resolution electron microscopy. A real-time optical Fourier transform apparatus is employed for coma-free alignment of the objective lens in the microscope. The digital image processing techniques such as band-pass filtering, deconvolution and pseudo-colouring are shown to be effective for obtaining structural information from the high-resolution electron microscope image. The possibility of high precision alignment of beam and crystal is demonstrated through the analysis of effects of lens and crystal tilts on the simulated images. The validity of the resolved Ge/(001)Si interface structure is also confirmed by multi-slice image simulations.