| 摘要 |
PROBLEM TO BE SOLVED: To provide a bipolar rectifying element which has high breakdown voltage, is little in leakage current, and is superior in reverse recovery characteristics. SOLUTION: This bipolar element comprises a trench-type insulating electrode 7 containing a conductor 6 enclosed with an insulating film 5 in a plurality of trenches, provided on one main face of a semiconductor base body in addition to a structure of a conventional MPS diode. An interval between respective sidewalls of the trenches is 1.6 times or less as much as a width of a depletion region caused from the trench having no confronting sidewalls. A distance from a p-n junction interface between an anode region 3 and a drift region 2 to a bottom part of the trench along the sidewall of the trench is set to be 1.5 to 2 times or more in comparison to that between the sidewalls. This structure operates as an combination of a Schottky diode and a p-n junction in a forward bias, and a cathode electric field is prevented by a trench type insulating electrode in reverse bias and does not affect the vicinities of a Schottky junction and the p-n junction. Therefore, the leakage current from the schottky junction is decreased, thereby attaining a high breakdown voltage. |
