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US 11,600,722 B2Granted
Semiconductor element and semiconductor device
AssigneeFuji Electric Co., Ltd.
InventorTakeyoshi Nishimura
Life of this patent
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Abstract
Provided are a semiconductor element and a semiconductor device capable of achieving on-resistance reduction and miniaturization. The semiconductor element is used in a semiconductor switch for protecting an electric circuit, and includes a semiconductor substrate SB, a MOS transistor Tr provided on the semiconductor substrate SB, and a source electrode SE provided on a front surface 2a side of the semiconductor substrate SB. The MOS transistor Tr includes an n-type source region 8 connected to the source electrode SE, an n-type drift region 21 arranged away from the source region 8, and a p-type well region 31 arranged between the source region 8 and the drift region 21. The source region 8 is interposed between the source electrode SE and the well region 31.
Claims21
A semiconductor element comprising:
- a semiconductor substrate including a support substrate of a first conductivity type and a semiconductor layer of the first conductivity type formed on one surface of the support substrate, the support substrate having a higher concentration of impurities of the first conductivity type than the semiconductor layer;
- an active region on the semiconductor layer and comprising a field effect transistor, the field effect transistor comprising:
- a first electrode on one surface side of the semiconductor substrate;
- an electrode region of the first conductivity type connected to the first electrode,
- a drift region of the first conductivity type arranged away from the electrode region,
- a well region of a second conductivity type arranged between the electrode region and the drift region, the drift region being under the well region,
- a source region of the first conductivity type on the well region,
- a trench penetrating through the well region from a front surface of the electrode region,
- a gate insulating film arranged in the trench and covering a bottom face and a side face of the trench,
- a gate electrode embedded in the trench via the gate insulating film, a part of the gate electrode being drawn out onto the semiconductor layer covered with the gate insulating film,
- a first body diode between the drift region and the well region, and
- a second body diode between the well region and the electrode region, the first body diode and the second body diode being connected in series to each other, and a forward direction of the first body diode being reverse to a forward direction of the second body diode;
- an outer peripheral portion surrounding the active region and being outside of the electrode region, the outer peripheral region comprising:
- a gate wire electrically connected to the gate electrode and surrounding the active region,
- a channel stopper region on the outer peripheral region, the channel stopper region and the well region having mutually the same depth from a front surface of the semiconductor layer,
- a local oxidation of silicon (LOCOS) film surrounding the active region, and
- a field plate electrically separated from the gate electrode and fixed at a different potential than the gate electrode;
- and
- a resurf region to straddle the active region and the outer peripheral region, a depth of the resurf region from the front surface being deeper than the depth of the well region from the front surface.
16 more elements
A semiconductor element comprising:
- a field effect transistor including:
- an active region comprising:
- a first body diode formed between a drift region and a well region of the field effect transistor and connected to a drain of the field effect transistor, the first body diode comprising the drift region and the well region, and
- a second body diode formed between a well region and an electrode region of the field effect transistor and connected to a source of the field effect transistor, the second body diode comprising the well region and the electrode region,
- wherein a forward direction of the first body diode is reverse of a forward direction of the second body diode, and the first body diode and the second body diode are connected in series to each other;
- an outer peripheral region surrounding the active region and comprising:
- a gate wire electrically connected to the gate electrode and surrounding the active region,
- a channel stopper region on the outer peripheral region, the channel stopper region and a well region of the active region having mutually the same depth from a front surface of the field effect transistor,
- a local oxidation of silicon (LOCOS) film surrounding the active region, and
- a field plate electrically separated from a gate electrode of the active region and fixed at a different potential than the gate electrode;
- and
- a resurf region to straddle the active region and the outer peripheral region, a depth of the resurf region from the front surface being deeper than the depth of the well region from the front surface.
9 more elements
Dependencies are inferred from the claim text.