SEMICONDUCTOR DEVICE AND POWER CONVERSION DEVICE

According to an embodiment of the present invention, a semiconductor device includes a first region, a second region, a third region, and a gate region. The first region is of first conductive type and formed on a surface layer on one main surface side of the semiconductor substrate. The second region is of second conductive type and formed in a different region of the surface layer from the first region. The third region is formed between the first region and the second region on the surface layer, and has a predetermined impurity concentration distribution. The gate region is formed at one end of the third region through a gate oxide layer. The third region includes a first change region of the impurity concentration distribution corresponding to a position of the gate region.