Semiconductor apparatus

1. A semiconductor apparatus, comprising:

a semiconductor substrate;

a front electrode being in contact with a front surface of the semiconductor substrate;

a rear electrode being in contact with a rear surface of the semiconductor substrate;

a first peripheral insulating film;

a plurality of first peripheral conducting films;

a second peripheral insulating film; and

a plurality of second peripheral conducting films,

wherein

the semiconductor substrate comprises a device region and a peripheral region,

in a plan view along a thickness direction of the semiconductor substrate, the device region overlaps a contact face between the front electrode and the semiconductor substrate, and the peripheral region is located around the device region,

the device region comprises a semiconductor device being configured to pass electric current between the front electrode and the rear electrode,

the peripheral region comprises:

a plurality of guard rings being of a p-type, exposed in the front surface, and having an annular shape surrounding the device region; and

a drift region being of an n-type and separating the guard rings from each other,

the first peripheral insulating film is located on the front surface in the peripheral region,

each of the first peripheral conducting films is located on the first peripheral insulating film, and having an annular shape overlapping the corresponding guard ring in the plan view along the thickness direction,

the second peripheral insulating film is located on each of the first peripheral conducting films,

each of the second peripheral conducting films is located on the second peripheral insulating film, located so as to overlap a part of the corresponding first peripheral conducting film in the plan view along the thickness direction, and has a thickness greater than a thickness of each of the first peripheral conducting films,

each of the second peripheral conducting films is connected to the corresponding first peripheral conducting film via a first contact hole,

each of the second peripheral conducting films is connected to the corresponding guard ring via a second contact hole, and

a center of at least one of the second contact holes is located on an inner side with respect to a center line of the guard ring connected to the at least one second contact hole, the center line defining a center of the guard ring in a width direction.

2. The semiconductor apparatus of claim 1 , wherein

each of the guard rings comprises a linear portion extending straight in the plan view along the thickness direction and a corner portion extending in a curve in the plan view along the thickness direction, and

the second contact holes are located in positions overlapping the linear portions in the plan view along the thickness direction and are not located in positions overlapping the corner portions in the plan view along the thickness direction.

3. The semiconductor apparatus of claim 1 , wherein

the semiconductor substrate comprises a main region being of the p-type, being in contact with the front electrode, and separated from each of the guard rings by the drift region, and

a clearance between the main region and the guard ring located on an innermost side is smaller than each clearance between adjacent guard rings.

4. The semiconductor apparatus of claim 1 , wherein, among clearances between adjacent guard rings, each clearance increases as it is positioned on an outer side.

5. The semiconductor apparatus of claim 1 , wherein among widths of the guard rings, each width increases as it is positioned on an outer side.