POINT-DEFECT-INDUCED CRYSTAL-GROWTH - AN AB-INITIO STUDY

A novel mechanism for the growth on crystalline surfaces under low sup ersaturation, namely, induced by the presence of point defects, is pro posed and studied. More precisely, we use ab initio minimization techn iques to calculate the potential-energy surface for a series of adatom s sequentially deposited on the Si(100)2 x 1 surface in the presence, beneath the top layer, of a vacancy. We find that, indeed, this defect can act as a growth site for the crystal: the energy at the defect is about 1 eV lower than the lowest point of the perfect surface. Adatom s aggregate near the defect and form the nucleus of subsequent growth.