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`Docket No.: P200896US00
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`AMENDMENTS TO THE CLAIMS
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`This listing of claims replaces all prior versions of claims in the application.
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`Listing of Claims:
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`1. (Original) A nitride semiconductor device, comprising:
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`a substrate having a first main surface and a second main surface which face in opposite
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`directions;
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`a first nitride semiconductor layer of a first conductivity type provided above the first
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`main surface;
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`a second nitride semiconductor layer of a second conductivity type provided above the
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`first nitride semiconductor layer,
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`the second conductivity type being different from the first
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`conductivity type;
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`a first opening which penetrates through the second nitride semiconductor layer to the
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`first nitride semiconductorlayer;
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`an electron transport layer and an electron supply layer provided, in that order from a side
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`on which the substrate is located, above the second nitride semiconductor layer and on an inner
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`surface ofthe first opening;
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`a gate electrode provided above the electron supply layer and covering the first opening;
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`a second opening at a position distanced from the gate electrode, the second opening
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`penetrating through the electron supply layer and the electron transport layer to the second
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`nitride semiconductorlayer;
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`a source electrode provided in the second opening and connected to the second nitride
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`semiconductorlayer;
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`a drain electrode provided on a second main surface-side of the substrate;
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`Application No.: 17/026,849
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`Docket No.: P200896US00
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`a third opening at an outermost edge part in a plan view ofthe substrate, the third opening
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`penetrating through the electron supply layer and the electron transport layer to the second
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`nitride semiconductor layer; and
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`a potential fixing electrode provided in the third opening, the potential fixing electrode
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`being connected to the second nitride semiconductor layer and in contact with neither the
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`electron transport layer nor the electron supply layer.
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`2. (Original) The nitride semiconductor device according to claim 1,
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`wherein in a plan view ofthe substrate, the third opening has an annular shape extending
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`along an entirety of the outermost edgepart.
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`3. (Original) The nitride semiconductor device according to claim 2,
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`wherein in a plan view of the substrate, the potential fixing electrode has an annular
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`shape extending along an entirety of the outermost edgepart.
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`4. (Original) The nitride semiconductor device according to claim 1,
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`wherein a planar shape of the substrate is a quadrangle, and
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`the potential fixing electrode is provided as a plurality of island shapes, each located on a
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`corresponding oneofsides of the substrate in a plan view ofthe substrate.
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`5. (Original) The nitride semiconductor device according to claim 1,
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`wherein the potential fixing electrode is electrically connected to the source electrode via
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`a conductive wiring layer.
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`Application No.: 17/026,849
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`Docket No.: P200896US00
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`6. (Original) The nitride semiconductor device according to claim 1, further comprising:
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`a fourth opening provided in the outermost edge part outward of the potential fixing
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`electrode and penetrating through the second nitride semiconductor layer to the first nitride
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`semiconductorlayer.
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`7. (Original) The nitride semiconductor device according to claim 6, further comprising:
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`a high-resistance region provided on a bottom surface of the fourth opening and having a
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`resistance higher than a resistance ofthe first nitride semiconductorlayer.
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`8. (New) Thenitride semiconductor device according to claim 1, wherein
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`a bottom part of the second opening and a bottom part of the third opening are at a same
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`height.
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