DETECTION OF A POINT-DEFECT IN A SILICON SINGLE-CRYSTAL BY A SUBTRACTION METHOD USING HIGH-RESOLUTION TRANSMISSION ELECTRON-MICROSCOPY

The contrast of high-resolution transmission electron-microscope (HRTE M) images of silicon single crystals in [<(1)over bar 10>] orientation containing a pair of single [111] vacancies tetrahedrally bonded (div acancy), triple divacancy clusters in two orientations and an intersti tial single Si atom has been calculated The displacement of atoms arou nd a point defect are deduced by extrapolating the distortion around a stacking-fault tetrahedron (SFT). The small contrast changes and disp lacements of the images of atoms in the crystal containing a point def ect are revealed by finding the difference between the computed image of the point defect and that from the perfect crystal. The visibility of the images and the possibility of the detection of point defects ar e also discussed.