High breakdown voltage wide band-gap MOS-gated bipolar junction transistors with avalanche capability
AssigneeCree, Inc.
InventorQingchun Zhang
Life of this patent
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Abstract
High power wide band-gap MOSFET-gated bipolar junction transistors (“MGT”) are provided that include a first wide band-gap bipolar junction transistor (“BJT”) having a first collector, a first emitter and a first base, a wide band-gap MOSFET having a source region that is configured to provide a current to the base of the first wide band-gap BJT and a second wide band-gap BJT having a second collector that is electrically connected to the first collector, a second emitter that is electrically connected to the first emitter, and a second base that is electrically connected to the first base.
Claims25
A high power wide band-gap MOSFET-gated bipolar junction transistor (“MGT”), comprising:
- a first wide band-gap bipolar junction transistor (“BJT”) having a first collector, a first emitter and a first base;
- a wide band-gap MOSFET having a source region that is configured to provide a current to the base of the first wide band-gap BJT;
- and
- a second wide band-gap BJT having a second collector that is electrically connected to the first collector, a second emitter that is electrically connected to the first emitter, and a second base that is electrically connected to the first base so that the second wide band-gap BJT is connected in parallel to the first wide band-gap BJT,
- wherein the second base is thinner than the first base.
A high power wide band-gap MOSFET-gated bipolar junction transistor (“MGT”), comprising:
- a first silicon carbide (“SiC”) bipolar junction transistor (“BJT”) having a collector, an emitter and a base;
- a first SiC MOSFET having a source region that is configured to provide a current to the base of the SiC BJT;
- and
- a second SiC BJT in parallel with the first SiC BJT, wherein the second SiC BJT provides a non-destructive avalanche current path within an active area of the MGT.
A high power wide band-gap MOSFET-gated bipolar junction transistor (“MGT”), comprising:
- an n-type bulk single crystal silicon carbide (“SiC”) substrate;
- an n-type SiC drift layer on the n-type conductivity bulk single crystal SiC substrate, the n-type drift layer having a first carrier concentration that is less than a second carrier concentration of the n-type SiC substrate;
- a patterned p-type SiC layer in the n-type SiC drift layer, the patterned p-type SiC layer including a base region and a source isolation region that includes a channel region that is spaced-apart from the base region;
- a patterned n-type SiC layer in the patterned p-type SiC layer, the patterned n-type SiC layer including a source region that is located in the source isolation region of the patterned p-type SiC layer and an emitter region in the base region of the patterned p-type SiC layer;
- an insulating layer on the source region, the channel region, and the n-type drift layer;
- a gate electrode on the insulating layer;
- and
- a collector contact on a surface of the SiC substrate opposite the n-type drift layer;
- an emitter contact on the emitter region of the patterned n-type SiC layer,
- wherein the source region is electrically connected to the base region,
- wherein the MGT further includes a second emitter region, and wherein the second emitter region extends deeper into the base region than does the first emitter region, and
- wherein a breakdown voltage of the MGT exceeds at least 5,000 volts.
Dependencies are inferred from the claim text.