Investigation of interdiffusion in thin films of ZnO/ZnCdO grown by molecular beam epitaxy

Abstract

Rutherford backscattering spectrometry (RBS) was used to determine the composition, uniformity, impurity, and elemental depth profiles of Zn, Cd, and O in ZnCdO/ZnO thin film deposited on differently oriented Al2O3 substrates using molecular beam epitaxy technique. For the films deposited under the same condition, it was observed that the variation of Zn/Cd/O ratios is dependent on substrate orientation and highly depends on the growth parameters. The composition and thickness variation, in relationship with two different substrates orientations, were explored with RBS, scanning electron microscopy, and photoluminescence measurements. It was found that ZnCdO films deposited on r- oriented ZnO buffers exhibit much less surface roughness and intermixing after the rapid thermal processing annealing is less extensive.