TEM analysis of an interface layer formed by the anti-surfactant treatment on a GaN template

Transmission electron microscope (TEM) analysis was performed for the anti-surfactant (AS)-treated interface of GaN thin films deposited by the metal-organic vapor-phase epitaxy method. It was revealed that the AS-treatment with supplying a gas-source of tetraethyl-silicon (TESi) forms an interface layer of about 1 nm thickness. The electron diffraction pattern for the interface layer shows a streak along [0 0 0 1] at about one-thrid positions between hkil=0  0 0 0 and 1¯21¯0. The point analysis of energy dispersive X-ray spectroscopy (EDS) confirmed that the interface layer contains a certain amount of silicon. These results revealed that the interface layer is a crystalline phase of silicon compound. The effect of the interface layer on the morphology of threading dislocations was also discussed in terms of coherency of the interface layer with GaN.