Analysis of Modified Williamson-Hall Plots on GaN Layers

Williamson–Hall (W-H) analysis is often used to separate the lateral coherence length (LCL) broadening and dislocation broadening on the ω−scan with a Lorentzian distribution. However, besides the LCL broadening and dislocation broadening, curvature also can broaden the ω−scan peak. Usually, the ω−scan can be described by a Pseudo-Voigt (P-V) function more precisely than a Lorentzian function. Based on the P-V fit peak profile, we modify the W-H plots. Both LCL broadening and curvature broadening can be eliminated from (00l) ω-scans plots simultaneously, and a reliable tilt can be obtained. This method is a good complementary for the existing method, but is more convenient. Although we focuse on GaN layers, the results are applicable to a wide range of other materials having mosaic structures.