Semiconductor device having super junction structure with varying width

A semiconductor device, comprising:

• a drift layer of a first conductivity type;
• a plurality of embedded parts embedded in the drift layer and being of a second conductivity type different from the first conductivity type, wherein the embedded parts are arranged with a first direction as a longitudinal direction and spaced from each other along a second direction that intersects the first direction;
• a plurality of body parts of the second conductivity type disposed corresponding to each of the embedded parts in a surface layer portion of the drift layer and connected to the corresponding embedded part;
• a source of the first conductivity type disposed in a surface layer portion of each of the body parts;
• a gate electrode disposed on a front surface of the drift layer at a position across every two adjacent body parts;
• and
• a drain layer of the first conductivity type connected to a bottom portion of the drift layer,
• wherein a width of each of the embedded parts in the second direction changes continuously along the first direction,
• each of the plurality of embedded parts is embedded in a trench, and the width of the each of the embedded parts changes along an entirety of a length of the trench, and
• the plurality of embedded parts extending into the drift layer in a third direction are connected to bottom portions of the body parts respectively, and the third direction is orthogonal to the first direction and the second direction.