DISLOCATION GENERATION MECHANISMS FOR GAP ON SI GROWN BY METALORGANIC CHEMICAL-VAPOR-DEPOSITION

Dislocation generation mechanisms for GaP on Si substrates by metalorganic chemical vapor deposition are described. Dislocations are not observed at the GaP/Si interface when the layer thickness is less than 90 nm. The presented high resolution transmission electron microscopy shows two kinds of dislocations with the extra-half plane in the GaP layer and Si substrate. These observations predict that the misfit dislocations are formed at the growth temperature while the dislocations with the extra-half plane in the GaP layer are formed during the cooling process, owing to the difference of the thermal expansion.