Electromagnetic wave detector, electromagnetic wave detector array, and manufacturing method of electromagnetic wave detector
An electromagnetic wave detector includes a semiconductor substrate, a first insulating film disposed on the semiconductor substrate and formed so as to expose a part of the semiconductor substrate, a first electrode disposed on the first insulating film, a two-dimensional material layer having a joint part forming a Schottky junction with the semiconductor substrate in a part of the semiconductor substrate, the two-dimensional material layer extending from the joint part to the first electrode over the first insulating film, a second electrode in contact with the semiconductor substrate, and a control electrode disposed at least partly around the joint part in plan view to form a Schottky junction with the semiconductor substrate.
1 . An electromagnetic wave detector comprising:
a semiconductor substrate;
a first insulating film disposed on the semiconductor substrate and formed so as to expose a part of the semiconductor substrate;
a first electrode disposed on the first insulating film;
a two-dimensional material layer having a joint part forming a first Schottky junction with the semiconductor substrate in a part of the semiconductor substrate, the two-dimensional material layer extending from the joint part to the first electrode over the first insulating film;
a second electrode in contact with the semiconductor substrate; and
a control electrode disposed at least partly around the joint part in plan view to form a second Schottky junction with the semiconductor substrate,
wherein the two-dimensional material layer has a portion that extends over an upper surface of the first insulating film to the first electrode and is in contact with the first insulating film,
the two-dimensional material layer and the control electrode are disposed such that a depletion layer formed as a result of the connection of a depletion layer of the second Schottky junction to a depletion layer formed in the first Schottky junction when the first Schottky junction is reverse-biased covers an entire interface of the first Schottky junction, and
the control electrode is disposed all around the joint part in plan view.
2 . The electromagnetic wave detector according to claim 1 , wherein the control electrode is not in contact with the two-dimensional material layer.
3 . The electromagnetic wave detector according to claim 1 , wherein the control electrode is in contact with the two-dimensional material layer.
4 . An electromagnetic wave detector comprising:
a semiconductor substrate;
a first insulating film disposed on the semiconductor substrate and formed so as to expose a part of the semiconductor substrate;
a first electrode disposed on the first insulating film;
a two-dimensional material layer having a joint part forming a first Schottky junction with the semiconductor substrate in a part of the semiconductor substrate, the two-dimensional material layer extending from the joint part to the first electrode over the first insulating film;
a second electrode in contact with the semiconductor substrate; and
a control electrode disposed at least partly around the joint part in plan view to form a second Schottky junction with the semiconductor substrate,
wherein the two-dimensional material layer has a portion that extends over an upper surface of the first insulating film to the first electrode and is in contact with the first insulating film,
the two-dimensional material layer and the control electrode are disposed such that a depletion layer formed as a result of the connection of a depletion layer of the second Schottky junction to a depletion layer formed in the first Schottky junction when the first Schottky junction is reverse-biased covers an entire interface of the first Schottky junction, and
the two-dimensional material layer is disposed so as to cover the control electrode with the first insulating film interposed between the two-dimensional material layer and the control electrode.
5 . The electromagnetic wave detector according to claim 1 , wherein the control electrode is disposed in a region where the control electrode does not overlap the two-dimensional material layer in plan view.
6 . The electromagnetic wave detector according to claim 1 , wherein the control electrode is connected to a ground node.
7 . The electromagnetic wave detector according to claim 1 , wherein the control electrode is electrically connected to the first electrode.
8 . The electromagnetic wave detector according to claim 7 , further comprising a pn diode including a cathode electrode electrically connected to the control electrode and an anode electrode electrically connected to the first electrode.
9 . The electromagnetic wave detector according to claim 1 , further comprising:
a first power supply to apply a voltage between the first electrode and the second electrode; and
a second power supply to apply a voltage to the control electrode.
10 . The electromagnetic wave detector according to claim 1 , further comprising
a second insulating film disposed between the semiconductor substrate and the control electrode, wherein
the control electrode forms a Schottky junction with the semiconductor substrate with the second insulating film interposed between the control electrode and the semiconductor substrate.
11 . The electromagnetic wave detector according to claim 1 , wherein a material of the control electrode includes metal.
12 . An electromagnetic wave detector array comprising a plurality of electromagnetic wave detectors according to claim 1 , wherein
the plurality of electromagnetic wave detectors are arranged side by side in at least either a first direction or a second direction.
13 . A manufacturing method of an electromagnetic wave detector, comprising:
preparing a semiconductor substrate;
forming a control electrode to form a first Schottky junction with the semiconductor substrate;
forming an insulating film on the semiconductor substrate, the insulating film exposing a part of the semiconductor substrate;
forming a first electrode on the insulating film;
forming a second electrode in contact with the semiconductor substrate; and
forming a two-dimensional material layer having a joint part forming a second Schottky junction with the semiconductor substrate in a part of the semiconductor substrate, the two-dimensional material layer extending from the joint part to the first electrode over the insulating film, wherein
the forming a two-dimensional material layer causes the control electrode to be disposed at least partly around the joint part in plan view,
the two-dimensional material layer has a portion that extends over an upper surface of the first insulating film to the first electrode and is in contact with the first insulating film,
the two-dimensional material layer and the control electrode are disposed such that a depletion layer formed as a result of the connection of a depletion layer of the second Schottky junction to a depletion layer formed in the first Schottky junction when the first Schottky junction is reverse-biased covers an entire interface of the first Schottky junction, and
the control electrode is disposed all around the joint part in plan view.
14 . The electromagnetic wave detector according to claim 2 , wherein the two-dimensional material layer is disposed so as to cover the control electrode with the first insulating film interposed between the two-dimensional material layer and the control electrode.
15 . The electromagnetic wave detector according to claim 1 , wherein the two-dimensional material layer is disposed so as to cover the control electrode with the first insulating film interposed between the two-dimensional material layer and the control electrode.
16 . The electromagnetic wave detector according to claim 2 , wherein the control electrode is disposed in a region where the control electrode does not overlap the two-dimensional material layer in plan view.