SEMICONDUCTOR DEVICE AND METHOD FOR DRIVING SAME

摘要

Provided are: a semiconductor device which is reduced in average forward voltage drop and provides a rectifying element having lower loss; and a method for driving the semiconductor device. A semiconductor device which has a diode structure wherein a p-type layer (7), an i layer (1) and an n-type layer (2) are sequentially formed between an anode electrode (9) and a cathode electrode (3). This semiconductor device is provided with a second n-type layer (8) that is formed on the anode electrode (9) side in parallel with the p-type layer (7), and is also provided with a gate driving circuit (10) that selects the p-type layer (7) or the second n-type layer (8) on the anode electrode (9) side during the forward bias. A gate electrode (5) has a trench structure (4) that is in contact with the p-type layer (7), a second p-type layer (6) and the second n-type layer (8), and an insulating layer (4a) and an electrode are provided within the trench. The gate electrode (5) forms a p-type or n-type channel in the trench surface in accordance with the gate voltage applied thereto from the gate driving circuit (10).