| 摘要 |
PROBLEM TO BE SOLVED: To prevent an IGBT element from breaking in a reverse bias being applied effectively, by forming the IGBT and a pn diode composed of a p-type impurity diffused region and an n-type impurity diffused region in the same chip. SOLUTION: Since a p-type impurity diffused region 12 used as an anode region is a deep diffusion layer whose impurity concentration is high, it is possible to make the on-voltage of a pn diode low. Consequently, it becomes possible to turn the pn diode on at a comparatively high speed, when a reverse bias voltage is applied to an IGBT. In this way, a horizontal pn diode of low on-resistance and low on-voltage is formed in a semiconductor chip having an IGBT construction. Namely, it becomes possible to prevent the IGBT element from breaking by causing a current to flow into the pn diode preferentially, when a reverse bias is applied to the IGBT by malfunctioning in operation by providing the IGBT and the pn diode in the same chip together. |
