Semiconductor device and method of manufacturing semiconductor device

A semiconductor device comprising:

• a semiconductor layer having a partitioned region partitioned by a trench;
• a field insulating layer which is formed on a main surface of the semiconductor layer at an interval from the trench toward an inner side of the partitioned region and covers the partitioned region;
• a trench insulating layer formed at least in the trench;
• an intermediate region annularly formed between the field insulating layer on the main surface of the semiconductor layer and the trench insulating layer;
• and
• a bridge insulating layer which is formed in the intermediate region and connects the field insulating layer and the trench insulating layer,
• wherein the bridge insulating layer has a bridge buried portion buried in the main surface of the semiconductor layer, wherein
• the trench insulating layer includes a trench inner covering portion covering an inner wall of the trench, and a field covering portion drawn out from the trench inner covering portion to the main surface of the semiconductor layer and connected to the field insulating layer via the bridge insulating layer,
• the field covering portion has a first buried portion buried in the main surface of the semiconductor layer,
• the field insulating layer has a second buried portion buried in the main surface of the semiconductor layer, and
• the bridge buried portion, the first buried portion, and the second buried portion are formed by a single buried portion which is integrally continuous in a direction along the main surface of the semiconductor layer.