SIMULATION OF ELASTIC-NETWORK RELAXATION - ISLANDS IN SEMICONDUCTOR HETEROJUNCTIONS

The results of a computer simulation for islands in semiconductor stra ined heterojunctions are presented. The atomic positions are individua lly calculated by means of a minimization procedure of the total elast ic energy, evaluated within Keating's model. Results obtained for Ge/S i and InAs/ GaAs systems differ substantially from the ones obtained v ia the macroscopic theory, which largely overestimates the elastic rel axation energy. The results are applied to evaluate the critical thick ness corresponding to undislocated island nucleation in epitaxial stra ined heterostructures.