Figure 1

Antiphase domains in GaP on Si substrates. (a) Ball and stick model illustrating the formation and annihilation of antiphase boundaries (APBs) in GaP grown on a (001) Si, (1.) APBs parallel to (110) due to sub-lattice occupation disorder, (2.) APBs along the {111}Si due to monoatomic steps, (3.) annihilation of APBs along (111) and (110) and (4.) annihilation of APBs due to diatomic steps. (b) Plan-view secondary electron image and (c). Plan-view backscattered electron image both acquired at a sample tilt of 70° from the same region of the surface of a 70 nm GaP film grown on an (001) Si substrate (miscut < 0.1°). The inset shows areas marked with a red dot and a purple dot which may well be regions with two orientations corresponding to a difference in the location of cation atoms (eg. Ga) and anion atoms (P) in the two sub-lattices as expected in the case of APDs.