Heteroepitaxy of InP on Si: Reduction of defects by substrate misorientation and thermal annealing

The results of a study of the effects of substrate misorientation and ex situ thermal annealing on the morphology, defect density, and low temperature photoluminescence (PL) emission of epitaxial films of InP grown on Si substrates are presented. InP films were grown by gas-source molecular beam epitaxy on both (100) oriented and (100) misoriented 4° towards the [011] Si wafers. InP films on misoriented substrates were mirror-like over the entire 3-in. wafer and exhibited a factor of 2 lower dislocation density than films on oriented substrates, as determined by double crystal x-ray diffraction and transmission electron microscopy (TEM). Thermal annealing resulted in a significant enhancement of the low temperature near band edge PL emission and a decrease in the density of dislocations and stacking faults. The best results obtained were for annealed films on misoriented substrates with an x-ray linewidth of 440 arcsecs, a TEM dislocation density of ∼2×108 cm2, a stacking fault density of ∼2×107 cm−2, and a PL linewidth of 6 meV.