Role of threading dislocation structure on the x-ray diffraction peak widths in epitaxial GaN films

Abstract

The Oxford-Diamond In Situ Cell for studying chemical reactions using time-resolved X-ray diffraction Rev. Sci. Instrum. 83, 084101 (2012) Synchrotron-based ultrafast x-ray diffraction at high repetition rates Rev. Sci. Instrum. 83, 063303 (2012) Shortening x-ray pulses for pump-probe experiments at synchrotrons J. Appl. Phys. 109, 126104 (2011) High-pressure and high-temperature x-ray diffraction cell for combined pressure, composition, and temperature measurements of hydrides Rev. Sci. Instrum. 82, 065108 (2011) High resolution short focal distance Bent Crystal Laue Analyzer for copper K edge x-ray absorption spectroscopy Rev. Sci. Instrum. 82, 063106 (2011) Additional information on Appl. Phys. Lett.

The influence of nitridation time on the structural properties of GaN grown on Si (111) substrate

“…The influence of the nitridation time on the structural properties of a GaN epilayer Heteroepitaxial thin films with a large lattice-mismatch with respect to the substrate in turn form a mosaic structure of slightly misoriented sub-grains [18,19,22], which is characterized by the nucleation of slightly misoriented islands and the coalescence of these islands towards a smooth surface. The mosaic structure of the epilayers is determined by the size and angular distribution of the mosaic blocks.…”

“…The mosaic structure of the epilayers is determined by the size and angular distribution of the mosaic blocks. The vertical and lateral correlation lengths, heterogeneous strain, and degree of mosaicity as expressed by the tilt and twist angles are important parameters in characterizing the quality of the epitaxial films with a large lattice mismatch to the substrate [17,19,22]. The mosaic blocks are assumed to be slightly misoriented with respect to each other.…”

“…Large lattice mismatch with respect to the substrate commonly causes high dislocation densities in heteroepitaxial thin films [18][19][20][21]. These types of structures are often described by the model of mosaic crystals [20,22].…”

Lattice-matched HfN buffer layers for epitaxy of GaN on Si

“…3 For GaN-onsapphire, it is recognized that the asymmetric rocking curve actually shows better correlation with the threading dislocation density. 19 Asymmetric rocking curve widths of 10 arcmin for the (10-12) reflection 15 interfaces. 20 The large amplitude of the oscillations attests to the high interface quality.…”

Electronic-grade GaN(0001)/Al2O3(0001) grown by reactive DC-magnetron sputter epitaxy using a liquid Ga target

“…Also, in conventional GaN growth methods the film thickness is commonly a few micrometers, which is dictated by the need to bury the defects generated in the seed/buffer layer. 20 In the present work no buffer layer was used, yet the defect density is low close to the interface ͑see Fig. 2͒ compared to CVD-grown films where low temperature GaN or AlN buffer layers are used to confine most of the defects within the first 200-300 nm.…”