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US 5,962,877 AGranted
Inverter apparatus having improved switching element
AssigneeHitachi, Ltd.
InventorsNaoki Sakurai, Masahiro Nagasu
Life of this patent
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Abstract
An inverter with an improved semiconductor device is provided having a pn junction composed of a first semiconductor layer made of a first conductivity type semiconductor and a second semiconductor layer made of a second conductivity type semiconductor having a wider band-gap than that of the first semiconductor layer.
Claims8
An inverter apparatus comprising:
- a pair of direct current terminals;
- a plurality of alternating current terminals, wherein the number of said alternating current terminals is equal to a phase number of alternating current outputs of the inverter apparatus;
- and
- a plurality of inverter units connected between said pair of direct current terminals, wherein the number of said inverter units is equal to a number of said alternating current outputs, including two serially connected arms, each of said arms having a circuit of a switching element connected in parallel with a diode whose polarity is inverse to that of said switching element, wherein mutual connection points of said arms are connected to said respective alternating current terminals, respectively,
- said switching element comprising:
- a first semiconductor layer formed of a first conductivity type semiconductor,
- a second semiconductor layer formed of a second conductivity type semiconductor, adjoining said first semiconductor layer,
- a third semiconductor layer formed of said first conductivity type semiconductor, said third semiconductor layer being formed in said second semiconductor layer, and
- a fourth semiconductor layer formed of said second conductivity type semiconductor, formed in said third semiconductor layer,
- wherein a band-gap of said second conductivity type semiconductor used for forming the second semiconductor layer is larger than a band-gap of said first conductivity type semiconductor used for forming said first semiconductor layer.
7 more elements
An inverter apparatus comprising:
- a pair of direct current terminals;
- a plurality of alternating current terminals, wherein the number of said alternating current terminals is equal to a phase number of alternating current outputs of the inverter apparatus;
- and
- a plurality of inverter units connected between said pair of direct current terminal, wherein the number of said inverter units is equal to a number of said alternating current outputs, including two serially connected arms, each of said arms having a circuit of a switching element connected in parallel with a diode whose polarity is inverse to that of said switching element, wherein mutual connection points of said arms are connected to said respective alternating current terminals, respectively;
- said switching element comprising:
- a first semiconductor layer formed of a first conductivity type semiconductor,
- a second semiconductor layer formed of a second conductivity type semiconductor, adjoining said first semiconductor layer,
- a third semiconductor layer formed of said first conductivity type semiconductor, said third semiconductor layer being formed in said second semiconductor layer,
- a fourth semiconductor layer formed of said second conductivity type semiconductor, formed in said third semiconductor layer,
- a first main electrode contacting said first semiconductor layer,
- a second main electrode contacting said fourth semiconductor layer, and
- an insulated gate electrode provided on said third semiconductor layer,
- wherein a band-gap of said second conductivity type semiconductor used for forming the second semiconductor layer is larger than a band-gap of said first conductivity type semiconductor used for forming said first semiconductor layer.
10 more elements
An inverter apparatus comprising:
- a pair of direct current terminals;
- a plurality of alternating current terminals, wherein the number of said alternating current terminals is equal to a phase number of alternating current outputs;
- and
- a plurality of inverter units connected between said pair of direct current terminal, wherein the number of said inverter units is equal to a number of said alternating current outputs, including two serially connected arms, each of said arms having a circuit of a switching element connected in parallel with a diode whose polarity is inverse to that of said switching element, wherein mutual connection points of said arms are connected to said respective alternating current terminals, respectively;
- said switching element comprising:
- a first semiconductor layer formed of a first conductivity type semiconductor,
- a second semiconductor layer formed of a second conductivity type semiconductor, adjoining said first semiconductor layer,
- a third semiconductor layer formed of said first conductivity type semiconductor, said third semiconductor layer being formed in said second semiconductor layer,
- a fourth semiconductor layer formed of said second conductivity type semiconductor, formed in said third semiconductor layer,
- a first main electrode contacting said first semiconductor layer,
- a second main electrode contacting said fourth semiconductor layer, and
- a control electrode contacting said third semiconductor layer,
- wherein a band-gap of said second conductivity type semiconductor used for forming the second semiconductor layer is larger than a band-gap of said first conductivity type semiconductor used for forming said first semiconductor layer.
10 more elements
An inverter apparatus comprising:
- a pair of direct current terminals;
- a plurality of alternating current terminals, wherein the number of said alternating current terminals is equal to a phase number of alternating current outputs;
- and
- a plurality of inverter units connected between said pair of direct current terminal, wherein the number of said inverter units is equal to a number of said alternating current outputs, including two serially connected arms, each of said arms having a circuit of a switching element connected in parallel with a diode whose polarity is inverse to that of said switching element, wherein mutual connection points of said arms are connected to said respective alternating current terminals, respectively;
- said switching element comprising:
- a first semiconductor layer formed of a first conductivity type;
- a second semiconductor layer formed of a second conductivity type semiconductor adjoining the first semiconductor layer,
- means formed in said second semiconductor layer for providing carriers as major carriers to said second semiconductor layer;
- and
- means for injecting said carriers as major carriers of said second semiconductor layer into said first semiconductor layer during an ON-state of the semiconductor device,
- wherein a band-gap of said second conductivity type semiconductor used for forming the second semiconductor layer is larger than a band-gap of said first conductivity type semiconductor used for forming said first semiconductor layer.
8 more elements
Dependencies are inferred from the claim text.