Initial Stages of Epitaxial Growth of GaP on Si with AsH₃ Preflow

A previous paper reported that when GaP epilayers are grown on Si substrates, an As-stabilized surface made by AsH 3 preflow before growth prevents many defects from generating at the GaP/Si interface, and that consequently, the crystalline quality of GaP epilayers is markedly improved. This letter describes the AsH 3 preflow effect on the initial stages of GaP epitaxial growth. The relative ease with which As or P atoms are absorbed onto Si surfaces is observed using X-ray photoelectron spectroscopy. Although preflow before GaP growth causes As or P atoms to absorb onto Si surfaces, As atoms are absorbed more easily than P atoms. The initial stages of GaP epitaxial growth on Si substrates with and without AsH 3 preflow are investigated using high-resolution scanning electron microscopy and transmission electron microscopy. This confirms that AsH 3 preflow suppresses island growth, allowing GaP epilayers to grow two-dimensionally, and also reduces the GaP-Si interfacial energy.