The　large　numbers　of　high-energy　carriers　that　occur　in　semiconductor　devices　under　semi-on　state　conditions　can　cause　significant　device　degradation.　The　effects　of　different　stresses　on　the　electrical　and　trapping　characteristics　of　GaN-based　high-electron-mobility　transistors　(HEMTs)　are　investigated.　Test　results　for　GaN　HEMTs　under　semi-on　state　conditions　show　that　the　electrical　characteristics　of　these　devices　degrade　to　a　certain　extent　after　they　are　subjected　to　electrical　pulse　stress　cycles　with　different　drain　voltage,　frequencies,　and　duty　cycles;　a　degree　of　degradation　also　occurs　in　the　electrical　characteristics　of　the　devices　when　they　are　subjected　to　direct　current　electrical　stresses.　After　electrical　stress　is　applied,　the　absolute　amplitude　of　the　traps　in　the　device　increases,　thus　indicating　an　increase　in　the　trap　density.　The　results　show　that　voltage　is　the　main　driver　for　device　damage,　with　the　current　playing　an　accelerating　role　through　its　effects　on　device　temperature　or　by　supplying　hot　electrons;　therefore,　the　drain　voltage　has　the　most　significant　effect　on　device　degradation,　which　is　mainly　due　to　channel　high-energy　hot　electron　injection.　©　2024　Elsevier　Ltd