THEORY OF THE (1(2)UNDER-BAR-10) PRISMATIC STACKING-FAULT IN GAN

The atomic and electronic structure for a (1210) prismatic stacking fa ult in GaN is calculated from first principles. The fault vector is 1/ 2[1011]. Such a fault is believed to occur when GaN is grown on sapphi re or SiC, and may originate when basal plane stacking faults fold ont o the prism plane. We find that the boundary is heavily reconstructed, but that the atoms remain fourfold coordinated, with no wrong bonds o r dangling bonds present. Despite the existence of distorted four-memb ered rings of bonds at the boundary, the fault does not induce deep st ates inside the gap. The calculated stacking fault energy is 72 meV/An gstrom(2). (C) 1998 American Institute of Physics.