Direct measurement of lateral macrostep velocity on an AIN vicinal surface by transmission electron microscopy

Lateral macrostep motion on a vicinal AIN surface is experimentally characterized by the threading dislocation behaviors in an AIN film via transmission electron microscopy (TEM). TEM observations of the macrostep-induced dislocation bending and kink formation offer a new way to directly measure the lateral velocity of macrostep motion. The lateral macrostep velocity is found to be inversely proportional to the macrostep height, which agrees with the crystal growth theory. The surface diffusion length of an Al adatom on the vicinal AIN surface is approximately 6.8 nm, as estimated from the relationship between the lateral velocity and the height of the macrosteps. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4721656]