Semiconductor device with switch electrode and gate electrode and method for switching a semiconductor device

A semiconductor device, comprising:

• a semiconductor substrate comprising an emitter region of a second conductivity type, a drift region of a first conductivity type, a body region of the second conductivity type and a source region of the first conductivity type, the drift region being formed between the emitter and the body region, and the body region being formed between the drift and the source region;
• at least a first trench structure extending from the source region at least partially into the drift region, the first trench structure comprising at least a gate electrode arranged next to the body region and at least a switch electrode arranged at least in portions next to the drift region, wherein the switch and gate electrodes are electrically insulated from each other in the trench structure;
• a common gate driver, the common gate driver being electrically connected to the switch electrode;
• and
• at least one retardation element, wherein the gate electrode is electrically connected to the common gate driver via the retardation element.

A power semiconductor unit, comprising:

• semiconductor device, comprising:
• a semiconductor substrate comprising an emitter region of a second conductivity type, a drift region of a first conductivity type, a body region of the second conductivity type and a source region of the first conductivity type, the drift region being formed between the emitter and the body region, and the body region being formed between the drift and the source region;
• and
• at least two trench structures extending from the source region at least partially into the drift region, the trench structures being arranged laterally spaced from each other and forming a mesa structure therebetween, wherein each of the trench structures comprises at least a gate electrode arranged next to the body region and at least a switch electrode arranged at least in portions next to the drift region, wherein the switch and gate electrodes are electrically insulated from each other in the trench structure;
• wherein the drift region comprises a vertical extension LDrift between the body and the emitter region, wherein a lower end of the switch electrode extends into the drift region to a length L of not more than 0.2*LDrift.

A semiconductor device, comprising:

• a semiconductor substrate comprising an emitter region of a second conductivity type, a drift region of a first conductivity type, a body region of the second conductivity type and a source region of the first conductivity type, the drift region being formed between the emitter and the body region, and the body region being formed between the drift and the source region;
• at least a first trench structure extending from the source region at least partially into the drift region, the first trench structure comprising at least a gate electrode arranged next to the body region and at least a switch electrode arranged at least in portions next to the drift region, wherein the switch and gate electrodes are electrically insulated from each other in the trench structure;
• a first pad structure electrically connected to the gate electrode;
• and
• a second pad structure electrically connected to the switch gate and insulated from the first pad structure.

A method for switching a semiconductor device, comprising:

• providing a semiconductor device comprising an emitter region of a second conductivity type, a drift region of a first conductivity type, a body region of the second conductivity type and a source region of the first conductivity type, the drift region being formed between the emitter and the body region, and the body region being formed between the drift and the source region, wherein the semiconductor device further comprises at least a first trench structure extending from the source region at least partially into the drift region, the first trench structure comprising at least a gate electrode arranged next to the body region and at least a switch electrode arranged at least in portions next to the drift region, wherein the switch and gate electrodes are electrically insulated from each other in the trench structure;
• bringing the semiconductor device into an on-state by applying a first on-voltage of a second polarity to the gate electrode to generate a conductive channel in the body region and by applying a second on-voltage of the second polarity to the switch electrode;
• and
• bringing the semiconductor device into an off-state by applying a first off-voltage to the switch electrode before applying a second off-voltage to the gate electrode, wherein the first and second off-voltages are selected from zero voltage or voltages of first polarity.