On the identification of trap location in AlGaN/GaN HEMTs during electrical stress

Location and properties of traps generated in AlGaN/GaN high electron mobility transistors submitted to electrical stress was studied using an integrated electrical and optical methodology. A spatial and spectral electroluminescence study reveals traps generated during both OFF- and ON-state stress to be located in the gate and access region close to the drain side of the gate edge, while UV-light assisted detrapping analysis in conjunction with photoluminescence illustrate these dominant traps located mostly within an AlGaN subsurface layer.