Semiconductor device

A semiconductor device, comprising:

• a semiconductor substrate;
• an active region formed on a front surface of the semiconductor substrate;
• a termination structure portion formed on the front surface of the semiconductor substrate and surrounding a periphery of the active region, to thereby form a boundary line on the front surface between the active region and the termination structure portion;
• and
• a third semiconductor region, a first semiconductor region, an intermediate region, and a second semiconductor region, formed in the termination structure portion and concentrically surrounding the boundary line on the front surface in this order, wherein
• the second semiconductor region surrounds the first semiconductor region, an impurity concentration of the second semiconductor region being lower than an impurity concentration of the first semiconductor region,
• the third semiconductor region has an impurity concentration that is different from the impurity concentration of the first semiconductor region, and
• the intermediate region is sandwiched between, and in contact with, the first and second semiconductor regions, the intermediate region including a plurality of first subregions and a plurality of second subregions that are alternately placed along a path in parallel to the boundary line on the front surface between the active region and the termination structure portion, an impurity concentration of each first subregion being the same as that of the first semiconductor region, an impurity concentration of the second subregions being the same as that of the second semiconductor region, each of the first and second subregions having two parallel side surfaces, which are respectively in direct contact with the first and second semiconductor regions.