SEMICONDUCTOR DEVICE

To provide a semiconductor device including a low concentration layer into which controllable carrier injection is performed.SOLUTION: A semiconductor device comprises a first conductive-type first semiconductor layer, a second conductive-type second semiconductor layer, a second conductive-type third semiconductor layer. The second semiconductor layer and the third semiconductor layer are provided on the first semiconductor layer. The second semiconductor layer includes a recess formed by selectively removing its part and an outer edge surrounding the recess. The third semiconductor layer is disposed so as to be separated from the second semiconductor layer in a first direction along a first boundary between the first semiconductor layer and the recess of the second semiconductor layer. A second conductive-type impurity distribution in the vicinity of the first boundary in a second direction crossing the first direction is approximately the same as a second conductive-type impurity distribution in the second direction in the vicinity of a second boundary between the outer edge and the first semiconductor layer. The second conductive-type impurity distribution in the second direction in the vicinity of the second boundary is approximately the same as a second conductive-type impurity distribution in the second direction in the vicinity of a third boundary between the first semiconductor layer and the third semiconductor layer.SELECTED DRAWING: Figure 1 【課題】低濃度層へのキャリア注入を制御できる半導体装置を提供する。【解決手段】半導体装置は、第１導電形の第１半導体層と、第２導電形の第２半導体層と、第２導電形の第３半導体層と、を備える。前記第２半導体層および前記第３半導体層は、前記第１半導体層上に設けられる。前記第２半導体層は、その一部を選択的に除去したリセス部と、前記リセス部を囲む外縁部と、を有する。前記第３半導体層は、前記第２半導体層の前記リセス部と前記第１半導体層との間の第１境界に沿った第１方向において前記第２半導体層から離間して配置される。前記第１境界と交差する第２方向における前記第１境界近傍の第２導電形不純物分布は、前記外縁部と前記第１半導体層との間の第２境界近傍における前記第２方向の第２導電形不純物分布と略同一であり、前記第２境界近傍における前記第２方向の第２導電形不純物分布は、前記第１半導体層と前記第３半導体層との間の第３境界近傍における前記第２方向の第２導電形不純物分布と略同一である。【選択図】図１