Identifying Interface States in AlInN/GaN Heterostructure by Photocurrent Method

In order to assess the residual leakage current mechanisms in electronic devices based on AlInN/GaN heterostructures, defect states were investigated by photocurrent method based on a metal-semiconductor-metal structure device. As a result, a continuous distribution of defect levels from 56 to 110 meV below the conduction band of GaN was identified at the AlInN/GaN interface by analyzing photocurrent spectra under different bias voltages and photogenerated carrier transport based on the simulation of electric field distribution. These interface states filled with electrons at zero bias can release electrons at reverse bias and provide a path of gate leakage.