Characteristics of m-Plane InN Films Grown on ZnO Substrates at Room Temperature by Pulsed Laser Deposition

Abstract

We have grown single-crystal m-plane (1100) InN films on m-plane (1100) ZnO substrates at low substrate temperatures by the use of pulsed laser deposition. X-ray diffraction and electron back-scattered diffraction measurements have revealed that pure m-plane InN grows at substrate temperatures below 300 °C. The full width at half maximum values of the X-ray rocking curves for m-plane InN grown at room temperature (RT) are as low as 0.12 and 0.12° with X-ray incidence directions normal to [0001] and [1120], respectively. Grazing-incidence X-ray reflectivity measurements have revealed that interfacial layers of greater than 5 nm in thickness are formed in the samples grown at temperatures above 300 °C, while no interfacial layers are formed between InN and ZnO at RT. The suppression of interfacial reactions by reducing the growth temperature down to RT is probably the reason for the improvements in crystalline quality that are observed.