Trenched high breakdown voltage semiconductor device
First Claim
1. A high breakdown voltage semiconductor device comprising:
- a semiconductor substrate having first and second main surfaces opposite to each other and also having a plurality of trenches provided at said first main surface;
a first impurity region of a first conductivity type formed within a region of said semiconductor substrate sandwiched between one and another trenches of said plurality of trenches at a sidewall surface of said one trench;
a second impurity region of a second conductivity type formed within said region sandwiched between said one and another trenches at a sidewall surface of said another trench, and forming a pn junction together with said first impurity region;
a third impurity region of the second conductivity type formed closer to said first main surface than said first and second impurity regions;
a fourth impurity region of the first conductivity type formed on at least one of said first main surface and a sidewall surface of said one trench such that said fourth impurity region is disposed opposite to said first impurity region with said third impurity region disposed therebetween; and
a gate electrode layer opposite to said third impurity region, sandwiched between said first and fourth impurity regions, with a gate insulating layer disposed therebetween;
whereinsaid first impurity region has a distribution of concentration of an impurity diffused from a sidewall surface of said one trench; and
said second impurity region has a distribution of concentration of an impurity diffused from a sidewall surface of said another trench.
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Accused Products
Abstract
An n type diffusion region and a p type diffusion region are formed in a region sandwiched between trenches arranged at a first main surface of a semiconductor substrate. A p type well is formed in the n- and p-type diffusion regions nearer the first main surface. A source n+ diffusion region is formed at the first main surface within the p type well. A gate electrode layer is formed opposite to the p type well sandwiched between the n type diffusion region and the source n+ diffusion region with a gate insulating layer disposed therebetween. The n- and p-type diffusion regions each have an impurity concentration distribution diffused from a sidewall surface of a trench. Thus, a fine, micron-order pn repeat structure can be achieved with sufficient precision and a high breakdown voltage semiconductor device is thus obtained which has superior on-state voltage and breakdown voltage as well as fast switching characteristics.
279 Citations
20 Claims
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1. A high breakdown voltage semiconductor device comprising:
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a semiconductor substrate having first and second main surfaces opposite to each other and also having a plurality of trenches provided at said first main surface; a first impurity region of a first conductivity type formed within a region of said semiconductor substrate sandwiched between one and another trenches of said plurality of trenches at a sidewall surface of said one trench; a second impurity region of a second conductivity type formed within said region sandwiched between said one and another trenches at a sidewall surface of said another trench, and forming a pn junction together with said first impurity region; a third impurity region of the second conductivity type formed closer to said first main surface than said first and second impurity regions; a fourth impurity region of the first conductivity type formed on at least one of said first main surface and a sidewall surface of said one trench such that said fourth impurity region is disposed opposite to said first impurity region with said third impurity region disposed therebetween; and a gate electrode layer opposite to said third impurity region, sandwiched between said first and fourth impurity regions, with a gate insulating layer disposed therebetween; wherein said first impurity region has a distribution of concentration of an impurity diffused from a sidewall surface of said one trench; and said second impurity region has a distribution of concentration of an impurity diffused from a sidewall surface of said another trench. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A high breakdown voltage semiconductor device comprising:
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an SOI semiconductor substrate having first and second main surfaces opposite to each other, said SOI semiconductor substrate having a substrate arranged nearer said second main surface and a semiconductor layer arranged nearer said first main surface and insulated from said substrate, and also having a plurality of trenches provided at said first main surface; a first impurity region of a first conductivity type formed within a region of said semiconductor layer sandwiched between one and another trenches of said plurality of trenches at a sidewall surface of said one trench; a second impurity region of a second conductivity type formed within said region sandwiched between said one and another trenches at a sidewall surface of said another trench, and forming a pn junction together with said first impurity region; a third impurity region of the second conductivity type formed within said semiconductor layer; a fourth impurity region of the first conductivity type formed on at least one of said first main surface and a sidewall surface of said one trench such that said fourth impurity region is disposed opposite to said first impurity region with said third impurity region disposed therebetween; and a gate electrode layer opposite to said third impurity region, sandwiched between said first and fourth impurity regions, with a gate insulating layer disposed therebetween; wherein said first impurity region has a distribution of concentration of an impurity diffused from a sidewall surface of said one trench; and said second impurity region has a distribution of concentration of an impurity diffused from a sidewall surface of said another trench; a source electrode formed on said first main surface electrically connected with said third and fourth impurity regions and a drain electrode formed on said first main surface electrically connected with said first impurity region.
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Specification