This　work　systematically　investigates　the　electrical　properties　and　device　physics　in　short-channel　indium　tin　oxide　(ITO)　field-effect　transistors　(FETs).　A　150-nm-channel-length　device　was　fabricated　using　semiconducting　ITO　as　the　active　channel　layer.　The　fabricated　transistors　demonstrated　normallyoff　operation　with　a　threshold　voltage　of　0.1　V　at　100　pA∗W/L　standard,　a　subthreshold　swing　of　68　mV/dec,　a　transconductance　of　223　μS/μm　at　Vds　=　0.5　V,　and　a　high　on-state　current　of　602　μA/μm　at　Vds　=　1　V.　Furthermore,　a　physical　device　model　incorporating　actual　process　parameters　was　developed　using　the　SILVACO　TCAD　platform.　High-fidelity　matching　of　the　transfer　and　output　characteristics　with　experimental　data　was　achieved　by　establishing　a　density　of　states　model　specific　to　amorphous　oxide　semiconductors.　Positive　and　negative　bias　stress　tests　were　conducted　to　evaluate　the　reliability　degradation　under　bias　stress　and　to　analyze　the　threshold　voltage　shift　mechanisms.　The　results　indicate　that　electron　trapping　at　the　insulator/channel　interface　is　the　dominant　factor　contributing　to　the　negative　threshold　voltage　drift.　This　work　provides　a　theoretical　foundation　for　optimizing　the　device　performance　and　reliability　mechanisms　in　amorphous　oxide　transistors,　offering　critical　insights　for　advancing　highperformance　oxide　semiconductor　electronics.　©　2025　IEEE.