High resolution X-ray diffraction analyses of ion-implanted GaN/AIN/Si heterostructures

High resolution triple-axis X-ray diffraction has been used to characterize the effects of nitrogen ion implantation into thin (15 nm and 55 nm) A1N buffer layers on the resultant structural quality of nominally 2 mu m epitaxial GaN layers grown on silicon substrates. The GaN symmetric (0002) and the asymmetric (101 (1) over bar4) and (101 (1) over bar5) Bragg reflections shows that in all cases, the extent of the off-peak kinematic diffuse scattering was reduced when growth was performed on the ion-implanted A1N buffer layers. Analysis of the log I - log q dependence of the kinematic intensity shows linear behavior but with slopes changing from -4.3 to -3.7 (in the case of the (0002) reflection) in the unimplanted and ion-implanted buffer layers, respectively, indicating a change in the defect character in the layers. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.