Back to results
US 11,695,045 B2Granted
Silicon carbide semiconductor device and silicon carbide semiconductor circuit device
AssigneeFuji Electric Co., Ltd.
InventorsKeiji Okumura, Akimasa Kinoshita
Life of this patent
Estimating the term…
Abstract
In a silicon carbide semiconductor device and a silicon carbide semiconductor circuit device equipped with the silicon carbide semiconductor device, a gate leak current that flows when negative voltage with respect to the potential of a source electrode is applied to the gate electrode is limited to less than 2×10−11 A and the gate leak current is limited to less than 3.7×10−6 A/m2.
Claims22
A silicon carbide semiconductor device, comprising:
- a first-conductivity-type semiconductor layer of a first conductivity type and having a first main surface and a second main surface;
- a first semiconductor region of a second conductivity type selectively provided in a surface layer at the first main surface of the first-conductivity-type semiconductor layer;
- a second semiconductor region of the first conductivity type, the second semiconductor region being provided at the second main surface of the first-conductivity-type semiconductor layer;
- a third semiconductor region of the first conductivity type selectively provided on the first semiconductor region;
- a trench having a depth of about 1 μm to 2 μm from the first main surface of an active region of the silicon carbide semiconductor device;
- a gate insulating film provided at an inner wall of the trench and in contact with a region of the first semiconductor region between the first-conductivity-type semiconductor layer and the third semiconductor region;
- a gate electrode provided on an inner side of the gate insulating film in the trench, the first semiconductor region being provided on an outer side of the gate insulating film across from the gate electrode;
- a first electrode electrically connected to the first semiconductor region and the third semiconductor region;
- and
- a second electrode electrically connected to the second semiconductor region,
- wherein
- the gate insulating film has a total area in the active region of the silicon carbide semiconductor device so that when a negative voltage is applied to the gate electrode a gate leak current that flows is limited to less than 2×10−11A and the gate leak current is limited to less than 3.7×10−6A/m2,
- the negative voltage is negative relative to a potential of the first electrode, and
- a surface area of the active region is about 60% to 70% of the silicon carbide semiconductor device.
11 more elements
A silicon carbide semiconductor device comprising:
- a first-conductivity-type semiconductor layer of a first conductivity type and having a first main surface and a second main surface;
- a first semiconductor region of a second conductivity type selectively provided in a surface layer at the first main surface of the first-conductivity-type semiconductor layer;
- a second semiconductor region of the first conductivity type, the second semiconductor region being provided at the second main surface of the first-conductivity-type semiconductor layer;
- a third semiconductor region of the first conductivity type selectively provided on the first semiconductor region;
- a trench having a depth of about 1 μm to 2 μm from the first main surface of an active region of the silicon carbide semiconductor device;
- a gate insulating film provided at an inner wall of the trench and in contact with a region of the first semiconductor region between the first-conductivity-type semiconductor layer and the third semiconductor region;
- a gate electrode provided on an inner side of the gate insulating film in the trench, the first semiconductor region being provided on an outer side of the gate insulating film across from the gate electrode;
- a first electrode electrically connected to the first semiconductor region and the third semiconductor region;
- and
- a second electrode electrically connected to the second semiconductor region,
- wherein
- the gate insulating film has a thickness of at least approximately 72 nm in the active region of the silicon carbide semiconductor device so that when a negative voltage applied to the gate electrode is limited to −3V or higher relative to a potential of the first electrode,
- an electric field applied to the gate insulating film is limited to 0.42MV/cm or lower, and
- a surface area of the active region is about 60% to 70% of the silicon carbide semiconductor device.
11 more elements
Dependencies are inferred from the claim text.