Semiconductor device

A semiconductor device comprising:

• a semiconductor switching element that includes:
• a drift layer of a first conductivity type;
• a body region of a second conductivity type disposed above the drift layer;
• an impurity region of the first conductivity type disposed in a surface layer portion of the body region within the body region and having an impurity concentration higher than that of the drift layer;
• a plurality of trench gate structures disposed in a plurality of gate trenches that are arranged in a stripe shape and extend along one direction as a longitudinal direction with a depth reaching the drift layer through the body region from the impurity region, each of the plurality of trench gate structures having a double gate structure in which a shield electrode, an intermediate insulation film and a gate electrode layer are sequentially stacked in a corresponding gate trench via an insulation film;
• a high-concentration layer of the first or second conductivity type disposed on a side opposite to the body region with respect to the drift layer, and having an impurity concentration higher than that of the drift layer;
• an interlayer insulation film disposed above the plurality of trench gate structures, the body region, and the impurity region;
• an upper electrode electrically connected to the body region and the impurity region through a contact hole that is formed in the interlayer insulation film to be connected to the body region and the impurity region;
• a gate wiring connected to the gate electrode layer through a contact hole that is formed in the interlayer insulation film to be connected to the gate electrode layer;
• a shield wiring connected to the shield electrode through a contact hole that is formed in the interlayer insulation film to be connected to the shield electrode;
• and
• a lower electrode electrically connected to the high-concentration layer, wherein
• the upper electrode, the gate wiring and the shield wiring are electrically isolated from each other,
• a part including both ends in the longitudinal direction of the plurality of gate trenches is referred to as an outer peripheral part,
• a part inside of the outer peripheral part is referred to as a cell part,
• in the cell part, the body region and the impurity region are disposed to constitute the semiconductor switching element,
• the plurality of gate trenches includes an end trench disposed at an outermost end and in which the shield electrode is embedded without the gate electrode layer,
• the shield electrode includes, in the outer peripheral part, a shield liner that has a portion extending outward beyond the gate electrode layer and protruding outward beyond the plurality of gate trenches in the longitudinal direction of the plurality of gate trenches, and a portion protruding outward beyond the end trench in a direction intersecting with the longitudinal direction of the plurality of gate trenches and extending along the longitudinal direction of the plurality of gate trenches,
• the gate wiring is disposed at a center position in the longitudinal direction of the plurality of gate trenches, and extends in the direction intersecting with the longitudinal direction of the plurality of gate trenches,
• the upper electrode includes a first upper electrode portion and a second upper electrode portion that are disposed on opposite sides of the gate wiring, and
• the shield wiring is disposed in at least one of a first position between the first upper electrode portion and the gate wiring or a second position between the second upper electrode portion and the gate wiring, and extends in the direction intersecting with the longitudinal direction of the plurality of gate trenches.