| 摘要 |
PROBLEM TO BE SOLVED: To reduce switching loss at the time of turn-off.SOLUTION: A semiconductor device includes a first-conductivity-type first semiconductor region, a second-conductivity-type second semiconductor region, a first-conductivity-type third semiconductor region, a control electrode, an insulating film, a first electrode, a second electrode, and a second-conductivity-type fourth semiconductor region. The second semiconductor region is provided on the first semiconductor region. The third semiconductor region is provided on the second semiconductor region. The control electrode controls the conduction between the first semiconductor region and the third semiconductor region. The insulating film is provided between the control electrode and the second semiconductor region. The first electrode is electrically connected to the second semiconductor region and the third semiconductor region. The fourth semiconductor region is provided between the second electrode and the first semiconductor region. The fourth semiconductor region has a first portion having first impurity concentration and a first contact area as a contact area with the second electrode, and a second portion having second impurity concentration higher than the first impurity concentration and a second contact area smaller than the first contact area. |
