Semiconductor device with suppressed decrease in breakdown voltage of an insulation film and manufacturing method of the same

A semiconductor device comprising:

• a semiconductor substrate in which a semiconductor element is provided;
• and
• an insulation film provided on the semiconductor substrate,
• wherein
• the semiconductor substrate comprises a first portion and a second portion which has a thickness thinner than a thickness of the first portion, wherein an upper surface of the second portion is positioned lower than an upper surface of the first portion,
• a recess extending in a thickness direction of the semiconductor substrate is provided on the upper surface of the second portion located at a position where the first portion and the second portion adjoin each other,
• the insulation film extends over from the first portion to the second portion, and fills the recess,
• a plurality of field limiting rings is provided in the second portion,
• the field limiting ring which is nearest to the first portion is provided below the recess,
• the field limiting rings are of a first conductivity type,
• a trench is provided in the upper surface of the first portion,
• a first region of the first conductivity type is provided in a vicinity of a bottom surface of the trench,
• a second region of a second conductivity type exists between the field limiting ring which is the nearest to the first portion and the first region,
• the bottom surface of the trench is located lower than a bottom surface of the recess, and
• a distance from the bottom surface of the trench to the bottom surface of the recess in the thickness direction of the semiconductor substrate is shorter than a distance from the bottom surface of the recess to the upper surface of the second portion.