Characterization of in situ SiN_x thin film grown on AlN/GaN heterostructure by metal-organic chemical vapor deposition

摘要

We report an investigation of in situ SiN_x gate dielectric grown on AlN/GaN heterostructures by metal-organic chemical vapor deposition. It is revealed that the in situ SiN_x is Si-rich, with a N/Si ratio of 1.21 and a relatively high effective dielectric constant of ～8.3. The 7 ran in situ SiN_x film exhibited a large resistivity of ＞10~(14) Ω · cm and a breakdown field of 5.7 MV/cm. Furthermore, interface trapping effects in the in situ SiN_x/AlN/GaN heterostructures were investigated by frequency dependent conductance analysis.