Semiconductor device and manufacturing method thereof

A semiconductor device, comprising:

• a substrate;
• a drift region, located on the substrate;
• a drain-end doped region, located at one end of an upper surface of the drift region in a first direction;
• a well region, located at another end of the upper surface of the drift region, wherein said another end is opposite to the drain-end doped region in the first direction;
• a source-end doped region, located in the well region;
• a gate structure, which is located at the well region, and forms a channel region at a position from the well region to the drift region, wherein a channel direction of the channel region is the first direction of the drift region, the channel region is located between the source-end doped region and the drain-end doped region, and is in contact with the source-end doped region,
• wherein, the source-end doped region comprises at least one first doped region and at least one second doped region of opposite doping types, a doping type of the drift region is same with a doping type of the drain-end doped region, a doping type of said at least one first doped region is same with the doping type of the drain-end doped region, said at least one first doped region and said at least one second doped region are linearly distributed in a second direction and alternately connected, wherein the second direction is perpendicular to the first direction on the upper surface of the drift region, and each one of said at least one first doped region is located corresponding to the channel region,
• wherein the gate structure comprises at least one trench gate, each of which consists of a first portion and a second portion, the second portion has a sidewall surface in direct contact with the source-end doped region, an entire bottom surface of the first portion is in direct contact with the drift region, an entire bottom surface of the second portion is in direct contact with the well region, and the first portion and the second portion have upper surfaces flush with each other and have a same height,
• a bottom surface of the drain-end doped region and a contact surface, facing the drain-end doped region, of each said at least one trench gate, are in direct contact with the drift region.