Semiconductor device including power MOSFET and peripheral device and method for manufacturing the same
AssigneeDenso Corporation
InventorsShoichi Yamauchi, Yasushi Urakami
Life of this patent
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Abstract
First and second trenches are formed on an n+ type substrate at a power MOSFET formation region and a peripheral device formation region, respectively. An n− type epitaxial film, a p type epitaxial film, and an n+ type epitaxial film are deposited on the substrate and in the trenches, and then flattening is performed. As a result, an n− type region is provided in the second trench of the peripheral device formation region. Then, a p type well layer is formed in the n− type region by ion-implantation. Accordingly, a power MOSFET and a peripheral device can been formed at the power MOSFET formation region and the peripheral device formation region easily.
Claims11
A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type having a main surface that includes a power MOSFET formation region having a first trench for forming a power MOSFET thereon and a peripheral device formation region having a second trench for forming a peripheral device thereon, the semiconductor substrate surrounding the first trench being as a drain of the power MOSFET;
- a well layer of a second conductivity type disposed in the second trench of the peripheral device formation region;
- wherein the MOSFET includes:
- a drift region of a first conductivity type disposed in the first trench and having an impurity concentration lower than that of the semiconductor substrate;
- a base region of the second conductivity type formed in the drift region and extending from the main surface in a perpendicular direction with respect to the main surface;
- and
- a source of the first conductivity type formed in the base region and extending from the main surface in the perpendicular direction.
A semiconductor device comprising:
- a first conductivity type semiconductor substrate;
- a power MOSFET formed in the semiconductor substrate at a power MOSFET formation region, the power MOSFET including a drain that is composed of the semiconductor substrate;
- a peripheral device formed in the semiconductor substrate at a peripheral device formation region;
- and
- a semiconductor region surrounding the peripheral device to separate the peripheral device from the semiconductor substrate, and having an impurity concentration lower than that of the semiconductor substrate;
- wherein the MOSFET includes;
- a drift region of a first conductivity type disposed in the first trench and having an impurity concentration lower than that of the semiconductor substrate;
- a base region of the second conductivity type formed in the drift region and extending from the main surface in a perpendicular direction with respect to the main surface;
- and
- a source of the first conductivity type formed in the base region and extending from the main surface in the perpendicular direction.
Dependencies are inferred from the claim text.