Switching device

A switching device comprising:

• a switching element that has a semiconductor substrate, a first electrode and a second electrode disposed on one surface of the semiconductor substrate, and a gate unit disposed between the first electrode and the second electrode on the one surface, and that makes a portion between the first electrode and the second electrode conductive by forming a channel region on the semiconductor substrate when a gate voltage exceeding a predetermined threshold voltage is applied to the gate unit;
• and
• a drive circuit that switches between ON and OFF of the switching element by applying the gate voltage to the gate unit of the switching element, wherein
• the semiconductor substrate includes a semiconductor-stacked body formed by having a first semiconductor layer and a second semiconductor layer stacked, has a hetero-junction interface at a junction portion between the first semiconductor layer and the second semiconductor layer, and uses a 2-dimensional electron gas layer generated in the hetero junction interface as the channel region,
• the switching element has a hole injecting unit that includes an injecting electrode directly connected to the semiconductor substrate,
• the drive circuit has an injection driving unit that injects holes from the hole injecting unit into the hetero junction interface by applying an injection voltage to the injecting electrode,
• the injection driving unit injects holes into the hetero-junction interface by applying the injection voltage to the injecting electrode, during a reset period that is set before a time point when the switching element is turned ON,
• the switching element has a pair of the gate units, and
• the injection driving unit uses a high-potential-side gate unit out of the pair of gate units, for the hole injecting unit.

A switching device comprising:

• a switching element that has a semiconductor substrate, a first electrode and a second electrode disposed on one surface of the semiconductor substrate, and a gate unit disposed between the first electrode and the second electrode on the one surface, and that makes a portion between the first electrode and the second electrode conductive by forming a channel region on the semiconductor substrate when a gate voltage exceeding a predetermined threshold voltage is applied to the gate unit;
• and
• a drive circuit that switches between ON and OFF of the switching element by applying the gate voltage to the gate unit of the switching element, wherein
• the semiconductor substrate includes a semiconductor-stacked body formed by having a first semiconductor layer and a second semiconductor layer stacked, has a hetero-junction interface at a junction portion between the first semiconductor layer and the second semiconductor layer, and uses a 2-dimensional electron gas layer generated in the hetero junction interface as the channel region,
• the switching element has a hole injecting unit that includes an injecting electrode directly connected to the semiconductor substrate,
• the drive circuit has an injection driving unit that injects holes from the hole injecting unit into the hetero junction interface by applying an injection voltage to the injecting electrode, and
• the hole injecting unit is provided in a plurality of number.

A switching device comprising:

• a switching element that has a semiconductor substrate, a first electrode and a second electrode disposed on one surface of the semiconductor substrate, and a gate unit disposed between the first electrode and the second electrode on the one surface, and that makes a portion between the first electrode and the second electrode conductive by forming a channel region on the semiconductor substrate when a gate voltage exceeding a predetermined threshold voltage is applied to the gate unit;
• and
• a drive circuit that switches between ON and OFF of the switching element by applying the gate voltage to the gate unit of the switching element, wherein
• the semiconductor substrate includes a semiconductor-stacked body formed by having a first semiconductor layer and a second semiconductor layer stacked, has a hetero-junction interface at a junction portion between the first semiconductor layer and the second semiconductor layer, and uses a 2-dimensional electron gas layer generated in the hetero junction interface as the channel region,
• the switching element has a hole injecting unit that includes an injecting electrode directly connected to the semiconductor substrate,
• the drive circuit has an injection driving unit that injects holes from the hole injecting unit into the hetero junction interface by applying an injection voltage to the injecting electrode, and
• the gate unit is provided in a pair, and the hole injecting unit is disposed between the pair of gate units.