Thermal strain analysis considering in-plane anisotropy for sputtered AlN on <i>c</i>- and <i>a</i>-plane sapphire under high-temperature annealing

High-temperature annealing of sputtered AlN (Sp-AlN) using a face-to-face configuration is novel technique that has attracted considerable attention because it can reduce the threading dislocation density Sp-AlN to 107 cm−2. However, drawbacks such as cracking, residual stress, and wafer curvature remain high temperature 1700 °C. We previously developed thermal strain analysis model uses an elastic multilayer system describe behavior on sapphire under high-temperature annealing. In this study, we expand consider in-plane anisotropy. By performing curvature, strain, energy c-plane grown c- a-plane sapphire, our calculation successfully approximates experimental results, even for anisotropic structure. The proposed is, therefore, useful quantitative evaluation contribute engineering AlGaN-based deep-ultraviolet light-emitting diodes.