Insulated gate semiconductor device and method for producing the same
First Claim
1. An insulation gate type semiconductor device including a body region which is positioned on an upper surface inside a semiconductor substrate and is a first conductive type semiconductor;
- and a drift region which is in contact with the downward of the body region and is a second conductive type semiconductor;
comprising;
a first trench portion group passing through the body region in the thickness direction of the semiconductor substrate, positioned in a cell area, and each gate trench of the first trench portion group internally incorporating a first gate electrode;
first floating regions enclosed by the drift region and surrounding a bottom portion of at least one trench portion in the first trench portion group, which is the first conductive type semiconductor;
a second trench portion group passing through the body region in the thickness direction of the semiconductor substrate, positioned in a terminal area surrounding the cell area, and formed to be annular so as to surround the cell area when being viewed from above; and
second floating regions enclosed by the drift region and surrounding a bottom portion of at least one trench portion in the second trench portion group, which is the first conductive type semiconductor;
wherein the semiconductor device is adapted such that electric field strength peak at two places in the semiconductor substrate in a thickness direction;
at a PN junction between the first or second floating regions and the drift region; and
at a PN junction between the body region and the drift region;
wherein a second gate electrode is internally incorporated in at least the innermost positioned trench portion in the second trench portion group;
wherein a lower end of the second gate electrode in the second trench portion group is equal to a lower end of the first gate electrode in the first trench group in a position in the substrate in the thickness direction.
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Accused Products
Abstract
The invention has an object to provide an insulation gate type semiconductor device and a method for producing the same in which high breakdown voltage and compactness are achieved. The semiconductor device has a gate trench and a P floating region formed in the cell area and has a terminal trench and a P floating region formed in the terminal area. In addition, a terminal trench of three terminal trenches has a structure similar to that of the gate trench, and the other terminal trenches have a structure in which an insulation substance such as oxide silicon is filled. Also, the P floating region 51 is an area formed by implanting impurities from the bottom surface of the gate trench, and the P floating region is an area formed by implanting impurities from the bottom surface of the terminal trench.
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Citations
8 Claims
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1. An insulation gate type semiconductor device including a body region which is positioned on an upper surface inside a semiconductor substrate and is a first conductive type semiconductor;
- and a drift region which is in contact with the downward of the body region and is a second conductive type semiconductor;
comprising;a first trench portion group passing through the body region in the thickness direction of the semiconductor substrate, positioned in a cell area, and each gate trench of the first trench portion group internally incorporating a first gate electrode; first floating regions enclosed by the drift region and surrounding a bottom portion of at least one trench portion in the first trench portion group, which is the first conductive type semiconductor; a second trench portion group passing through the body region in the thickness direction of the semiconductor substrate, positioned in a terminal area surrounding the cell area, and formed to be annular so as to surround the cell area when being viewed from above; and second floating regions enclosed by the drift region and surrounding a bottom portion of at least one trench portion in the second trench portion group, which is the first conductive type semiconductor; wherein the semiconductor device is adapted such that electric field strength peak at two places in the semiconductor substrate in a thickness direction;
at a PN junction between the first or second floating regions and the drift region; and
at a PN junction between the body region and the drift region;wherein a second gate electrode is internally incorporated in at least the innermost positioned trench portion in the second trench portion group; wherein a lower end of the second gate electrode in the second trench portion group is equal to a lower end of the first gate electrode in the first trench group in a position in the substrate in the thickness direction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- and a drift region which is in contact with the downward of the body region and is a second conductive type semiconductor;
Specification