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.