RF-MBE growth of cubic InN nano-scale dots on cubic GaN

Abstract

This paper reports the first successful growth and structural control of cubic InN (c-InN) nano-scale dots. The samples were grown on MgO (001) substrates by RF-N2 plasma molecular beam epitaxy (RF-MBE). Cubic GaN (c-GaN) underlayers with a thickness of 500nm were grown on the substrates followed by the growth of a few nm-thick InN under various conditions. The formation of InN dots aligned along the 〈110〉 directions were confirmed by atomic force microscopy (AFM). X-ray diffraction (XRD) measurements suggested the cubic zincblende lattice structure of the obtained InN dots. The area density and size of c-InN dots were well controlled by adjusting the growth conditions such as the substrate temperature and the In flux, and a very high dot density of 2.2×1011cm−2 was successfully obtained at a growth temperature of 470°C and an In flux of 7.0×10−5Pa.