X‐ray diffraction studies of Al_xGa_1−xN (0≤x≤1) ternary alloys grown on sapphire substrate

Abstract

Purpose

The purpose of this paper is to report the structural properties of Al_xGa_1−xN (0≤x≤1) grown on sapphire substrate by means of X‐ray diffraction (XRD) technique. The main purpose of this work was to investigate the effects of Al(x) composition to the structural and microstructural properties of Al_xGa_1−xN ternary alloy such as the crystalline quality, crystalline structure and lattice constant c.

Design/methodology/approach

Al_xGa_1−xN thin films with wurtzite structure in the composition range of 0≤x≤1 are used in this study. The compositions of the samples are calculated using Vegard's law and verified by energy dispersive X‐ray analysis. The samples are then characterized by means of XRD rocking curve (RC) and phase analysis.

Findings

Investigation revealed that the full width half maximum (FWHM) of RC increase with the increase x value. This indicates that the crystalline quality of the samples deteriorate with the increase of Al compositions. The best fit of the non‐linear interpolation of the FWHM of the (002) diffraction RC data suggested that a maximum disorder should be expected in this mixed crystals system when the composition x≈45 percent.

Originality/value

This paper provides valuable information on the effect of Al compositions to the structural characteristics of Al_xGa_1−xN alloy system. The availability of information about maximum disorder of Al composition in Al_xGa_1−xN (0≤x≤1) alloy system provides useful reference in device fabrications where researchers are able to choose correct alloy composition in order to fabricate good quality devices.

Citation

Sha Shiong, N., Chin Guan, C., Hassan, Z. and Abu Hassan, H. (2011), "X‐ray diffraction studies of Al_xGa_1−xN (0≤x≤1) ternary alloys grown on sapphire substrate", Microelectronics International, Vol. 28 No. 2, pp. 44-48. https://doi.org/10.1108/13565361111127359