Influence of polarization Coulomb field scattering on the electrical properties of normally-off recessed gate AlGaN/GaN metal–insulator–semiconductor high-electron-mobility transistor with ALD-Al2O3 gate dielectric stack

•Normally-off recessed gate AlGaN/GaN MIS-HEMTs with ALD-Al2O3 gate dielectric stack was fabricated.•The effect mechanism of PCF scattering on electrical properties of normally-off recessed gate AlGaN/GaN MIS-HEMTs was studied and clarified.•For the region underneath the gate, the increase in VGS resulted in an increase in ΔρG andn2DEG, moreover, the effect of n2DEG for PCF scattering is more significant thanΔρG.•For the gate-source region and gate-drain region, the parasitic resistance changes with VGS owing to the effect of PCF scattering, moreover, the effect of PCF scattering on the RS_CH is stronger thanRD_CH.•This study perfects the carrier transport model of normally-off recessed gate AlGaN/GaN MIS-HEMTs and provides a new theoretical foundation for the device of this type to improving the electron mobility and reducing parasitic resistance.