Microstructural analysis of an epitaxial AlN thick film/trench-patterned template by three-dimensional reciprocal lattice space mapping technique

Abstract

Three-dimensional (3D) lattice plane microstructures were investigated at local regions in an epitaxial AlN thick film grown on a trench-patterned AlN/sapphire template. A 3D reciprocal lattice space mapping technique combined with cross-sectional X-ray microdiffraction using an appropriate Bragg reflection quantitatively revealed the inhomogeneity of the lattice structures in the AlN film without loss of spatial resolution. The results showed a strong correlation of the lattice plane tilt/twist and variations with respect to the void configuration, the patterning structure of the template, and the dislocation morphologies confirmed by transmission electron microscopy.

Synchrotron radiation microbeam X-ray diffraction for nondestructive assessments of local structural properties of faceted InGaN/GaN quantum wells

“…To this end, microscopic XRD techniques based on synchrotron radiation (SR) seem promising. [12][13][14][15][16][17] In this Letter, we describe the experimental results of nondestructive structural analyses of multifaceted structures by SR microbeam XRD with a sub-µm spatial resolution. A comparison with the spatially resolved optical characterization results supports the results of microbeam XRD analyses.…”

Quantitative analysis of lattice plane microstructure in the growth direction of a modified Na-flux GaN crystal using nanobeam X-ray diffraction

“…Nanobeam X-ray diffraction (nanoXRD) measurement using high-brilliance synchrotron sources is an attractive means for investigating local crystal structure due to its beam size, which can be focused to several hundred nanometers. 14,15,[25][26][27][28][29][30] In addition, a recently developed three-dimensional reciprocal space mapping technique (or ω-2θ-j mapping in angular space) using a two-dimensional detector allows simultaneous measurement of both lattice plane tilt and twist. In this study, we have performed position-dependent ω-2θ-j mapping by nanoXRD measurement to elucidate local lattice plane microstructures including lattice plane tilt, twist, and spacing around the GSB and coalescence boundary in the modified Na-flux GaN crystal.…”

Analysis of inverse-piezoelectric-effect-induced lattice deformation in AlGaN/GaN high-electron-mobility transistors by time-resolved synchrotron radiation nanobeam X-ray diffraction

“…The drain and source electrodes were short-circuited to simplify the electric field distribution in the gate region, that is, we used the long-gate HEMT device as a diode in the present experiments. Threedimensional (3D) ω-2θ-j mapping was performed for the diffraction; 23) to quantify the 2θ value corresponding to the lattice spacing, the measured 3D diffraction profiles were integrated over the ω (lattice tilting) and j (lattice twisting) directions to obtain one-dimensional 2θ profiles. The strain resolution calculated on the basis of the pixel size of the detector and the distance between the sample and the detector was ∼1.15 × 10 −4 .…”