The　effects　of　different　kinds　of　interface　treatment　on　the　characteristic　of　AlGaN/GaN　MIS-HEMTs　were　studied　in　this　paper.　N2　and　NH3　plasma　pretreatment　were　used　to　improve　the　interface　quality.　The　results　show　that　N2　plasma　pretreatment　could　reduce　the　current　collapse　of　devices.　By　optimizing　the　time　of　N2　plasma　pretreatment,　it　was　found　that　the　dynamic　characteristic　of　devices　with　10　min　the　pretreatment　was　improved,　while　that　of　30　min　was　degraded.　As　a　gate　dielectric　intercalation　layer,　the　annealed　AlN　interlayer　can　effectively　improve　the　dynamic　characteristic　of　the　device.　The　Vth　hysteresis　was　decreased　from　411　mV　to　111　mV,　and　the　device　current　collapse　factor　was　reduced　from　42.04　to　4.76　after　under　OFF-state　VD　stress　of　900.　©　2019,　Science　Press.　All　right　reserved.