Semiconductor device
First Claim
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1. A semiconductor device, comprising:
- a semiconductor layer made of SiC;
a source region of a first conductivity type formed in the semiconductor layer, the source region forming a surface of the semiconductor layer;
a body region of a second conductivity type formed in the semiconductor layer, the body region being in contact with the source region from a side of a back surface of the semiconductor layer;
a drain region of a first conductivity type formed in the semiconductor layer, the drain region being in contact with the body region from the side of the back surface of the semiconductor layer;
a gate trench dug down in the semiconductor layer from the surface thereof, the gate trench passing through the source region and the body region and the deepest portion thereof reaching the drain region;
a gate insulating film formed on an inner surface of the gate trench;
a gate electrode embedded in the gate trench on the gate insulating film;
a source trench dug down in the semiconductor layer from the surface thereof, the source trench passing through the source region and the body region, and the deepest portion thereof reaching a first conductivity type part of the drain region; and
a conductive material embedded in the source trench, the conductive material having a first layer conforming to a side surface and a bottom surface of the source trench and a second layer formed on the first layer;
wherein the second layer includes at least a lower layer conforming to the first layer to define a space inside the source trench, and an upper layer embedded in the space.
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Abstract
The semiconductor device according to the present invention includes: a semiconductor layer made of SiC; an impurity region formed by doping the semiconductor layer with an impurity; and a contact wire formed on the semiconductor layer in contact with the impurity region, while the contact wire has a polysilicon layer in the portion in contact with the impurity region, and has a metal layer on the polysilicon layer.
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Citations
23 Claims
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1. A semiconductor device, comprising:
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a semiconductor layer made of SiC; a source region of a first conductivity type formed in the semiconductor layer, the source region forming a surface of the semiconductor layer; a body region of a second conductivity type formed in the semiconductor layer, the body region being in contact with the source region from a side of a back surface of the semiconductor layer; a drain region of a first conductivity type formed in the semiconductor layer, the drain region being in contact with the body region from the side of the back surface of the semiconductor layer; a gate trench dug down in the semiconductor layer from the surface thereof, the gate trench passing through the source region and the body region and the deepest portion thereof reaching the drain region; a gate insulating film formed on an inner surface of the gate trench; a gate electrode embedded in the gate trench on the gate insulating film; a source trench dug down in the semiconductor layer from the surface thereof, the source trench passing through the source region and the body region, and the deepest portion thereof reaching a first conductivity type part of the drain region; and a conductive material embedded in the source trench, the conductive material having a first layer conforming to a side surface and a bottom surface of the source trench and a second layer formed on the first layer; wherein the second layer includes at least a lower layer conforming to the first layer to define a space inside the source trench, and an upper layer embedded in the space. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A semiconductor device, comprising:
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a semiconductor layer made of SiC; a source region formed in the semiconductor layer, the source region forming a surface of the semiconductor layer; a body region formed in the semiconductor layer, the body region being in contact with the source region from a side of a back surface of the semiconductor layer; a drain region formed in the semiconductor layer, the drain region being in contact with the body region from the side of the back surface of the semiconductor layer; a gate trench dug down in the semiconductor layer from the surface thereof, the gate trench passing through the source region and the body region and the deepest portion thereof the drain region; a gate insulating film formed on an inner surface of the gate trench; a gate electrode embedded in the gate trench on the gate insulating film; a source trench dug down in the semiconductor layer from the surface thereof; and a conductive material embedded in the source trench, the conductive material having a first layer conforming to a side surface and a bottom surface of the source trench and a second layer formed on the first layer; wherein the first layer selectively forms an ohmic contact and a first junction with respect to the semiconductor layer, the first junction having a smaller junction barrier than the diffusion potential of a body diode intrinsic in the semiconductor device, and wherein the second layer includes at least a lower layer conforming to the first layer to define a space inside the source trench, and an upper layer embedded in the space. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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Specification