Bidirectional AC switching device with MOS-gated turn-on and turn-off control

A bidirectional semiconductor switching device, comprising:

• a semiconductor substrate;
• a first device terminal and a second device terminal on said substrate;
• a first semiconducting device region of first conductivity type in said substrate;
• a second semiconducting device region of second conductivity type in said substrate, said second device region forming a P-N junction with said first device region;
• a bipolar junction transistor in said substrate for providing non-regenerative conduction in a forward direction from said second device terminal to said first device terminal, said bipolar junction transistor having a base in said first device region and a collector in said second device region;
• a first field effect transistor in said substrate, electrically connected in series between said first device region and said first device terminal;
• a thyristor in said substrate for providing regenerative conduction in a forward direction from said first device terminal to said second device terminal, said thyristor having a first emitter in said second device region;
• and
• a second field effect transistor in said substrate, electrically connected in series between said second device region and said first device terminal.

A semiconductor switching device, comprising:

• a semiconductor substrate having first and second opposing faces and a drift region of first conductivity type therein;
• a first semiconducting layer of second conductivity type on said drift region;
• a second semiconducting layer of first conductivity type on said first semiconducting layer, opposite said drift region;
• a first device terminal on the first face and electrically contacting said second semiconducting layer;
• first and second trenches in said substrate, at the first face, said first and second trenches extending through said first and second semiconducting layers;
• a first semiconducting well of second conductivity type in said drift region, at the second face;
• a second semiconducting well of first conductivity type in said first semiconducting well and forming a P-N junction therewith;
• a second device terminal on the second face and electrically contacting said first and second semiconducting wells.

A semiconductor switching device, comprising:

• a semiconductor substrate having first and second opposing faces;
• a first device terminal on the first face;
• a second device terminal on the second face;
• a first semiconducting device region of first conductivity type in said substrate;
• a second semiconducting device region of second conductivity type adjacent said first device region and forming a P-N junction therewith in said substrate;
• a third semiconducting device region of second conductivity type adjacent said first device region and forming a P-N junction therewith in said substrate, and wherein said first device region extends between said second and third device regions and wherein said third device region ohmically contacts said second device terminal at the second face;
• a fourth semiconducting device region of first conductivity type adjacent said third device region and forming a P-N junction therewith in said substrate, said fourth device region ohmically contacting said second device terminal at the second face;
• a first insulated-gate field effect transistor in said substrate, said first insulated-gate field effect transistor having a drain in said first device region and a source electrically contacting said first device terminal;
• and
• a second insulated-gate field effect transistor in said substrate, said second insulated-gate field effect transistor having a drain in said second device region and a source electrically contacting said first device terminal;
• wherein said first, second, third and fourth semiconducting device regions comprise a thyristor having a first emitter in said second semiconducting device region and a second emitter in said fourth semiconducting device region;
• and
• wherein said first, second and third semiconducting device regions comprise a bipolar junction transistor having an emitter in said third semiconducting device region and a collector in said second semiconducting device region.

A switching device, comprising:

• a semiconducting substrate;
• a first device terminal on said semiconducting substrate;
• a second device terminal on said semiconducting substrate;
• a thyristor in said semiconducting substrate, said thyristor comprising a pair of regeneratively coupled P-N-P and N-P-N bipolar junction transistors;
• a first field effect transistor in said substrate, electrically connected in series between a base of one of said pair of bipolar junction transistors and said first device terminal;
• and
• a second field effect transistor in said substrate, electrically connected in series between an emitter of said one of said pair of bipolar junction transistors and said first device terminal.