AlGaN based MEMS structures

Al_xGa_1-xN solid solutions were heteroepitaxially grown on 3C-SiC(111)/Si(111) pseudo substrates fabricated by low pressure chemical vapour deposition. Free standing doubly-clamped resonator bars and cantilevers were fabricated from these Al_xGa_1-xN layers. The resonance frequencies of the microelectromechanical structures were measured using electrostatic excitation and vibrometry at ambient conditions. The obtained resonance frequencies allowed a self consistent determination of the Young's modulus of the Al_xGa_1-xN layers and the residual strain in the free standing structures.