Transistor device and manufacturing method thereof

A transistor device, comprising a gate, a gate insulator, and a drift region stacked with a body region in a first direction,

• wherein the gate comprises a top surface, a bottom surface arranged opposite to the top surface, and a side surface between the top surface and the bottom surface, the bottom surface is in the first direction of the top surface, the gate insulator covers the bottom surface and at least a portion of the side surface of the gate, the gate insulator comprises a sidewall and a bottom, the body region covers a portion of the sidewall of the gate insulator, and the gate insulator is extended from the surface of the drift region facing the body region to the drift region along the first direction;
• wherein the body region comprises a first subregion, a second subregion and a third subregion arranged sequentially along a second direction, the second direction is perpendicular to the first direction and pointing to a direction away from the gate insulator, wherein an average carrier concentration in the first subregion and an average carrier concentration in the third subregion are greater than an average carrier concentration in the second subregion;
• wherein the transistor device further comprises a dopant concentration rising region in the drift region and located aligning with the second subregion along the first direction, the average dopant concentration of the doped substance of the second conductive type in the dopant concentration rising region is greater than the average dopant concentration of the doped substance of the second conductive type in the drift region.