SEMICONDUCTOR DEVICE, METHOD OF MANUFACTURING THE SAME AND POWER CONVERTER
First Claim
1. A semiconductor device, comprising:
- a first semiconductor layer that is configured to have one characteristic out of n-type and p-type characteristics;
a second semiconductor layer that is configured to have the other characteristic out of the n-type and p-type characteristics that is different from the one characteristic, and is stacked on the first semiconductor layer;
a third semiconductor layer that is configured to have the one characteristic and is stacked on the second semiconductor layer;
a trench that is formed from the third semiconductor layer to penetrate through the second semiconductor layer and to be recessed into the first semiconductor layer and is configured to include a side face and a bottom face;
a first insulator that is mainly made of a first insulating material, is provided as a film formed from the side face over the bottom face, and is configured to include a side face film portion formed on the side face and a bottom face film portion formed on the bottom face;
a second insulator that is mainly made of a second insulating material having a higher relative permittivity than relative permittivity of the first insulating material and is formed in at least a corner portion of an area defined by the side face film portion and the bottom face film portion; and
an electrode that is formed inside of the trench via the first insulator and the second insulator, whereina thickness Th1 of the second insulator in an area located in the corner portion is greater than a thickness Th2 of the second insulator in an area where the side face film portion is placed between the second insulator and the second semiconductor layer, whereinthe thickness Th1 denotes a thickness relative to a surface of the bottom face film portion andthe thickness Th2 denotes a thickness relative to a surface of the side face film portion.
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Accused Products
Abstract
An object is to effectively reduce electric field crowding in a trench MIS structure in a semiconductor device. The semiconductor device comprises a first semiconductor layer; a second semiconductor layer; a third semiconductor layer; a trench that is configured to include a side face and a bottom face; a first insulator that is mainly made of a first insulating material, is provided as a film formed from the side face over the bottom face and is configured to include a side face film portion and a bottom face film portion; a second insulator that is mainly made of a second insulating material having a higher relative permittivity than relative permittivity of the first insulating material and is formed in at least a corner portion of an area defined by the side face film portion and the bottom face film portion; and an electrode that is formed inside of the trench via the first insulator and the second insulator. A thickness Th1 of the second insulator in an area located in the corner portion, relative to a surface of the bottom face film portion is greater than a thickness Th2 of the second insulator in an area where the side face film portion is placed between the second insulator and the second semiconductor layer, relative to a surface of the side face film portion.
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Citations
18 Claims
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1. A semiconductor device, comprising:
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a first semiconductor layer that is configured to have one characteristic out of n-type and p-type characteristics; a second semiconductor layer that is configured to have the other characteristic out of the n-type and p-type characteristics that is different from the one characteristic, and is stacked on the first semiconductor layer; a third semiconductor layer that is configured to have the one characteristic and is stacked on the second semiconductor layer; a trench that is formed from the third semiconductor layer to penetrate through the second semiconductor layer and to be recessed into the first semiconductor layer and is configured to include a side face and a bottom face; a first insulator that is mainly made of a first insulating material, is provided as a film formed from the side face over the bottom face, and is configured to include a side face film portion formed on the side face and a bottom face film portion formed on the bottom face; a second insulator that is mainly made of a second insulating material having a higher relative permittivity than relative permittivity of the first insulating material and is formed in at least a corner portion of an area defined by the side face film portion and the bottom face film portion; and an electrode that is formed inside of the trench via the first insulator and the second insulator, wherein a thickness Th1 of the second insulator in an area located in the corner portion is greater than a thickness Th2 of the second insulator in an area where the side face film portion is placed between the second insulator and the second semiconductor layer, wherein the thickness Th1 denotes a thickness relative to a surface of the bottom face film portion and the thickness Th2 denotes a thickness relative to a surface of the side face film portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method of manufacturing a semiconductor device, the method comprising:
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forming a first semiconductor layer having one characteristic out of n-type and p-type characteristics, on a substrate; stacking a second semiconductor layer having the other characteristic out of the n-type and p-type characteristics that is different from the one characteristic, on the first semiconductor layer; stacking a third semiconductor layer having the one characteristic, on the second semiconductor layer; forming a trench that includes a side face and a bottom face by etching from the third semiconductor layer through the second semiconductor layer to the first semiconductor layer; forming a first insulator as a film formed from the side face over the bottom face by using a first insulating material, such that the first insulator includes a side face film portion formed on the side face and a bottom face film portion formed on the bottom face; forming a second insulator in at least a corner portion of an area defined by the side face film portion and the bottom face film portion by using a second insulating material having a higher relatively permittivity than relative permittivity of the first insulating material; and forming an electrode inside of the trench that the first insulator and the second insulator are formed in, wherein the forming the second insulator comprises making a thickness Th1 of the second insulator in an area located in the corner portion greater than a thickness Th2 of the second insulator in an area where the side face film portion is placed between the second insulator and the second semiconductor layer, wherein the thickness Th1 denotes a thickness relative to a surface of the bottom face film portion and the thickness Th2 denotes a thickness relative to a surface of the side face film portion. - View Dependent Claims (16, 17, 18)
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Specification