In　this　paper,　a　new　structure　of　SiC-base　trench-gate　MOSFET　protected　by　vertical　field　plate　is　proposed.　Compared　with　conventional　trench　gate　MOSFET,　a　deep　trench　connected　to　the　source　is　added.　The　source　trench　is　filled　with　polysilicon　and　acts　as　a　vertical　field　plate.　Under　blocking　state,　the　depletion　charge　between　trenches　is　coupled　with　the　vertical　field　plate,　which　can　modify　the　electric　field　distribution　near　the　gate　oxide　corner.　Lower　field　strength　in　gate-oxide　is　the　guarantee　for　long-term　reliable　operation　of　the　device.　In　order　to　investigate　the　effect　of　charge-coupling,　double　doped　epitaxial　drift　region　is　selected.　The　doping　concentration　of　first　epi-layer　is　lower　than　that　of　second　eip-layer.　The　bottom　of　the　deep　source　trench,　that　is,　the　end　of　vertical　field　plate,　falls　at　the　junction　for　the　two　epitaxial　layer.　The　static　characteristics　are　simulated　for　both　conventional　trench　gate　and　dual　trench　dual　epitaxy　new　structures　by　using　Sentaurus　TCAD.　Simulation　results　show　that　the　new　structure　with　double　trenches　and　double　epitaxy　has　higher　Baliga＇s　figures　of　merit　(FOM)　Also,　under　the　blocking　state,　the　maximum　electric　field　in　gate　oxide　can　be　lower　than　5MV/cm.　That　is　desirable　for　the　long-term　operation　reliability　of　the　gate.　©　2022　Association　for　Computing　Machinery.