An investigation of the Young's modulus of single-crystalline wurtzite indium nitride using an atomic force microscopy based micromechanical bending test

High quality single-crystalline wurtzite indium nitride (InN) thin film was first demonstrated to have a Young's modulus of 149 ± 5 GPa along a-axis using atomic force microscopy microbending test since the revision of InN energy gap. These released InN cantilever beams were examined to have ignorable in-plane residual stress using micro-Raman spectroscopy, where the E2 (high) mode at 490 cm−1 exists zero shift because of the perfect lattice match (8:9 commensurate) between InN and underneath aluminum nitride buffer. The experimental value of Young's modulus agrees well with a number of theoretical estimations ranging from 146 to 159 GPa.