Semiconductor device, and method for manufacturing the same
AssigneeRohm Co., Ltd.
InventorYuki Nakano
Life of this patent
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Abstract
A semiconductor device (A1) includes a semiconductor layer having a first face with a trench (3) formed thereon and a second face opposite to the first face, a gate electrode (41), and a gate insulating layer (5). The semiconductor layer includes a first n-type semiconductor layer (11), a second n-type semiconductor layer (12), a p-type semiconductor layer (13), and an n-type semiconductor region (14). The trench (3) is formed so as to penetrate through the p-type semiconductor layer (13) and to reach the second n-type semiconductor layer (12). The p-type semiconductor layer (13) includes an extended portion extending to a position closer to the second face of the semiconductor layer than the trench (3) is. Such structure allows suppressing dielectric breakdown in the gate insulating layer (5).
Claims16
A semiconductor device comprising:
- a semiconductor layer having a first face provided with a trench and a second face opposite to the first face;
- a gate electrode provided in the trench;
- and
- an insulating layer provided in the trench so as to insulate the semiconductor layer and the gate electrode from each other;
- wherein the semiconductor layer includes a first semiconductor layer of a first conductivity type, and a second semiconductor layer of a second conductivity type opposite to the first conductivity type,
- wherein the trench is formed so as to penetrate through the second semiconductor layer and to reach the first semiconductor layer,
- wherein the second semiconductor layer includes a close portion closer to the second face of the semiconductor layer than the trench is,
- wherein the semiconductor layer further includes a semiconductor region formed around the trench,
- wherein a recessed portion is provided at the first semiconductor layer, the second semiconductor layer, or the semiconductor region, and
- wherein the close portion and the recessed portion are disposed so as to overlap in a widthwise direction perpendicular to a depthwise direction of the trench.
A method of manufacturing a semiconductor device, the method comprising:
- forming a trench and a recessed portion on a surface of a semiconductor substrate;
- forming an insulating layer in the trench;
- forming a gate electrode stacked on the insulating layer in the trench;
- irradiating the recessed portion with ions thereby forming a first semiconductor region of a conductivity type different from a conductivity type of the semiconductor substrate, the first semiconductor region being located close to a bottom portion of the recessed portion;
- and
- irradiating the surface of the semiconductor substrate with ions thereby forming a second semiconductor region of a conductivity type different from the conductivity type of the semiconductor substrate;
- wherein the first and the second semiconductor regions are connected with each other, and
- wherein the trench penetrates through the second semiconductor region.
Dependencies are inferred from the claim text.