Semiconductor device and method for manufacturing same

A method for manufacturing a semiconductor device including a trench-type semiconductor switching element having a trench gate structure, the method comprising:

• preparing a substrate having a high impurity concentration layer with a first conductive type or a second conductive type and a drift layer arranged on one surface side of the high impurity concentration layer, having the first conductive type and having an impurity concentration lower than the high impurity concentration layer;
• forming a plurality of trench gate structures by forming a plurality of trenches with one direction as a longitudinal direction in the drift layer, and arranging a gate electrode layer in each of the plurality of trenches via an insulation film;
• forming a body region having the second conductive type on the drift layer between the plurality of trenches;
• forming a first impurity region having the first conductive type with an impurity concentration higher than the drift layer in a surface portion of a part of the body region in the body region;
• forming an interlayer insulation film on the trench gate structure, the body region, and the first impurity region;
• forming a contact hole connected to the body region and the first impurity region in the interlayer insulation film;
• forming an upper electrode electrically connected to the first impurity region and the body region through the contact hole;
• and
• forming a lower electrode electrically connected to the high impurity concentration layer, wherein:
• the forming of the contact hole includes:
• forming a first contact hole connected to the first impurity region;
• and forming a second contact hole connected to a portion of the body region in which the first impurity region is not formed, the method further comprising:
• after forming the first contact hole, ion implanting a first conductive type impurity using the interlayer insulation film as a mask to form the first conductive type contact region in the first impurity region;
• forming a contact trench, exposing the first conductive type contact hole on a side surface of the contact trench, and exposing the body region on a bottom of the contact trench by etching the first impurity region including the first conductive type contact region through the first contact hole using the interlayer insulation film as a mask;
• and
• after forming the second contact hole, ion implanting a second conductive type impurity using the interlayer insulation film as a mask to form a second conductive type contact region in the body region.