Simulation and application of the distorted ZOLZ patterns from dislocations in Si

The previously reported distorted zeroth-order fringes in a bright-field Tanaka pattern from a dislocated region in silicon have been computer simulated and the experimental and the many-beam calculated patterns agree well. Calculations are carried out for nine distinct cases of edge, screw and 60° dislocations in a silicon crystal. The general usefulness of the distortion of the ZOLZ pattern in determining geometrical properties of a dislocation is discussed.