Accurate statistical extraction of AlGaN/GaN HEMT device parameters using the Y-function

•Parameter extraction using Y-function based on drain current.•Statistical dispersion study of electrical parameters of HEMT-GaN devices.•Study verified over a large range of channel lengths for two normally-off HEMT GaN wafers. A new protocol based on Y-function is used for accurate statistical extraction of electrical parameters of High Electron Mobility Transistor (HEMT) devices for GaN technology. This protocol presented here is used for extraction of relevant electrical parameters such as oxide capacitance, threshold voltage, effective mobilities and access resistance. This study has been verified over a large range of channel lengths for two normally-off HEMT GaN wafers having different levels of access resistances.