Terahertz device, imaging device, and sensing device

Abstract

A terahertz device (A1, A2, A3, A31, A4, A5, A6, A7, A71, A8, A9) comprising: a terahertz element (7); a current limiting unit (2, 24, 25, 26) that is connected in series with the terahertz element (7); a first rectifying element (31) that is electrically connected in parallel with the terahertz element (7) between the terahertz element (7) and the current limiting unit (2, 24, 25, 26); and a second rectifying element (32) that is electrically connected in parallel with the terahertz element (7) and the first rectifying element (31) between the terahertz element (7) and the current limiting unit (2, 24, 25, 26), in a manner in which the forward direction thereof is the reverse from the forward direction of the first rectifying element (31).

Description

Terahertz devices, imaging devices and sensing devices

[0001] The disclosures disclosed herein relate to terahertz devices and to imaging and sensing devices using terahertz devices.

[0002] Terahertz devices have been disclosed that can perform large-capacity communication, information processing, imaging, sensing, and the like using a frequency range called the terahertz band, which has frequencies of 0.1 THz to 10 THz (see Patent Document 1, etc.).

[0003] Patent No. 7192188 [Summary]

[0004] There is a growing demand to provide better terahertz devices.

[0005] The terahertz device disclosed in this specification comprises a terahertz element, a current limiting unit configured to be electrically connected in series with the terahertz element, a first rectifying element configured to be electrically parallel to the terahertz element and connected between the terahertz element and the current limiting unit, and a second rectifying element configured to be electrically parallel to the terahertz element and the first rectifying element and connected between the terahertz element and the current limiting unit so that its forward direction is opposite to the forward direction of the first rectifying element.

[0006] FIG. 1 is a perspective view of a terahertz device according to a first embodiment. FIG. 2 is a plan view of the terahertz device shown in FIG. 1. FIG. 3 is a cross-sectional view of the terahertz device shown in FIG. 1. FIG. 4 is a schematic circuit diagram of the terahertz device according to the first embodiment. FIG. 5 is a schematic circuit diagram of a current limiting circuit, which is an example of a current limiting unit. FIG. 6 is a cross-sectional view of rectifying elements used as the first rectifying element and the second rectifying element. FIG. 7 is a diagram showing the current-voltage characteristics of the first rectifying element. FIG. 8 is a diagram showing an example of the current-voltage characteristics of a combined element combining the first rectifying element and the second rectifying element. FIG. 9 is a plan view of a terahertz chip B1. FIG. 10 is a partially enlarged view of region IX of the terahertz chip shown in FIG. 9. FIG. 11 is a cross-sectional view taken along line X-X shown in FIG. 10. FIG. 12 is a partially enlarged cross-sectional view of FIG. 11. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 9. FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 9. FIG. 15 is a cross-sectional view taken along line XV-XV in FIG. 9 . FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. 9 . FIG. 17 is a cross-sectional view taken along line XVII-XVII in FIG. 9 . FIG. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. 9 . FIG. 19 is a cross-sectional view taken along line XIX-XIX in FIG. 9 . FIG. 20 is a cross-sectional view taken along line XX-XX in FIG. 9 . FIG. 21 is a cross-sectional view taken along line XXI-XXI in FIG. 9 . FIG. 22 is a diagram showing the relationship between the input voltage of the terahertz device and the current flowing through the terahertz element. FIG. 23 is a diagram showing the relationship between the input voltage of the terahertz device and the voltage applied to the terahertz element. FIG. 24 is a plan view of a terahertz device A11 according to a first modified example. FIG. 25 is a plan view of a terahertz device A12 according to a second modified example. FIG. 26 is a cross-sectional view of a terahertz device according to the second embodiment. Fig. 27 is a plan view of a terahertz chip of a terahertz device of a third embodiment. Fig. 28 is a plan view of a terahertz device of a third embodiment. Fig. 29 is a circuit diagram of a terahertz device of a third embodiment. Fig. 30 is a plan view of a terahertz device of a third modified example. Fig. 31 is a plan view of a terahertz device of a fourth modified example. Fig. 32 is a circuit diagram of a terahertz device of a fifth modified example. Fig. 33 is a plan view of a terahertz device of a fourth embodiment.FIG. 34 is a plan view of a terahertz chip provided in the terahertz device of the fourth embodiment. FIG. 35 is a circuit diagram of the terahertz device of the fourth embodiment. FIG. 36 is a plan view of a terahertz device of a sixth modified example. FIG. 37 is a plan view of a terahertz device of a seventh modified example. FIG. 38 is a circuit diagram of a terahertz device of the fifth embodiment. FIG. 39 is a plan view of a terahertz chip B5 used in the terahertz device of the fifth embodiment. FIG. 40 is a plan view of a terahertz device of the sixth embodiment. FIG. 41 is a circuit diagram of a terahertz device of the sixth embodiment. FIG. 42 is a plan view of a terahertz device of an eighth modified example. FIG. 43 is a plan view of a terahertz device A of a ninth modified example. FIG. 44 is a plan view of a terahertz device of the seventh embodiment. FIG. 45 is a circuit diagram of a terahertz device of the seventh embodiment. FIG. 46 is a plan view of a terahertz device of a tenth modified example. FIG. 47 is a plan view of a terahertz device of an eleventh modified example. Fig. 48 is a circuit diagram of a terahertz device of a twelfth modified example. Fig. 49 is a plan view of a terahertz device of the eighth embodiment. Fig. 50 is a plan view of a terahertz chip provided in the terahertz device of the eighth embodiment. Fig. 51 is a circuit diagram of the terahertz device of the eighth embodiment. Fig. 52 is a plan view of a terahertz device of a thirteenth modified example. Fig. 53 is a plan view of a terahertz device of a fourteenth modified example. Fig. 54 is a circuit diagram of a terahertz device of the ninth embodiment. Fig. 55 is a plan view of a terahertz chip used in the terahertz device of the ninth embodiment. Fig. 56 is a schematic configuration diagram of a sensing device using a terahertz device. Fig. 57 is a schematic configuration diagram of an imaging device using a terahertz device.

[0007] [Detailed Description] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description, the terms "placed," "contacted," and "stacked" may be used. In this case, unless otherwise specified, this includes cases where "placed," "contacted," and "stacked" are directly placed, "contacted," and "stacked," as well as cases where "placed," "contacted," and "stacked" are indirectly placed through the intermediary of another member.

[0008] 1 is used as a reference, and the direction perpendicular to the surface on which the terahertz chip B1 of the wiring substrate 11 of the support 1 is arranged is defined as the Z direction. The direction perpendicular to the Z direction is defined as the X direction. The direction perpendicular to the Z direction and the X direction is defined as the Y direction. That is, in the terahertz device A1, the terahertz chip B1 is arranged on the XY plane of the wiring substrate 11. One side of the X direction is defined as the X1 side, and the opposite side is defined as the X2 side. Hereinafter, the arrangement of components will be described based on the above directions unless otherwise specified. In the following description, the upper side may be used, but this upper side is based on the state shown in FIG. 1 and is different from the upper side in actual use.

[0009] <First embodiment> Fig. 1 is a perspective view of a terahertz device A1 according to a first embodiment. Fig. 2 is a plan view of the terahertz device A1 shown in Fig. 1. Fig. 3 is a cross-sectional view of the terahertz device A1 shown in Fig. 1. Fig. 4 is a schematic circuit diagram of the terahertz device A1 according to the first embodiment.

[0010] As shown in FIGS. 1 to 4 , the terahertz device A1 includes a terahertz chip B1, a support 1, a resin portion 13, wires 141 and 142, wires 151 and 152, a current limiting portion 2, a first rectifying element 31, and a second rectifying element 32. The terahertz device A1 is configured in a single package. The terahertz device A1 has an anode terminal Tp and a cathode terminal Tm connected to a power supply (not shown). A reference voltage such as a ground voltage is applied to the cathode terminal Tm, and a voltage higher than the voltage applied to the cathode terminal Tm is applied to the anode terminal Tp. For example, the anode terminal Tp corresponds to a positive electrode, and the cathode terminal Tm corresponds to a negative electrode.

[0011] <Support Body 1> As shown in Figures 2 and 3, the support body 1 includes a wiring substrate 11 and a conductor layer 12. The wiring substrate 11 is, for example, a glass epoxy substrate. As shown in Figure 2, the wiring substrate 11 has a square shape when viewed in the Z direction. However, this is not limited thereto, and the wiring substrate 11 may have a rectangular shape, a polygonal shape, or a circular shape. The support body 1 does not necessarily have to include a glass epoxy substrate. The support body 1 may also have one or more leads derived from a lead frame.

[0012] A terahertz chip B1 is disposed on the wiring substrate 11. The conductive layer 12 is formed on the upper surface of the wiring substrate 11 in the Z direction. The conductive layer 12 includes a first conductive element 121 and a second conductive element 122. In the terahertz device A1, the first conductive element 121 is connected to an anode terminal Tp (see FIG. 4, etc.), and the second conductive element 122 is connected to a cathode terminal Tm (see FIG. 4, etc.). The first conductive element 121 and the second conductive element 122 are spaced apart from each other in the X direction.

[0013] As shown in FIG. 2 , the first conductive element 121 is elongated in the Y direction and includes a first portion 121A, a second portion 121B, and a third portion 121C. When viewed in the Z direction, the first portion 121A has a rectangular shape with the Y direction as its longitudinal direction. The second portion 121B is disposed on the X1 side of the first portion 121A. In the configuration shown in FIG. 2 , the X1-side edge of the first portion 121A has a notched shape with one end in the Y direction cut out, and the X2-side edge of the second portion 121B has a protruding shape that follows the notched shape of the first portion 121A. In other words, the gap between the first portion 121A and the second portion 121B is a broken line, or more specifically, a crank shape with two corners. However, the shapes of the first portion 121A and the second portion 121B are not limited to this, and the gap between the first portion 121A and the second portion 121B may be linear. The first portion 121A and the second portion 121B are disposed apart from each other and are electrically connected via the current limiting unit 2, which will be described later.

[0014] The third portion 121C protrudes in the X direction from the X1-side edge of the second portion 121B. The third portion 121C is connected to the middle portion of the X1-side edge of the second portion 121B. The second portion 121B and the third portion 121C are integrally formed.

[0015] As shown in FIG. 2 , the second conductive element 122 includes a first portion 122A and two second portions 122B. When viewed in the Z direction, the first portion 122A has a rectangular shape with its longitudinal direction in the Y direction. The second portion 122B has a rectangular shape with its longitudinal direction in the Y direction. The second portion 122B protrudes in the X direction from the X2-side edge of the first portion 122A. The two second portions 122B are spaced apart in the Y direction. In other words, the first portion 122A and the two second portions 122B form a recess 122R. The third portion 121C of the first conductive element 121 is disposed in the recess 122R.

[0016] 2 , the third portion 121C of the first conductive element 121 is disposed on the X2 side of the first portion 122A of the second conductive element 122 and spaced apart from the first portion 122A. The second portion 122B of the second conductive element 122 is disposed on the X2 side of the second portion 121B of the first conductive element 121 and spaced apart from the second portion 121B. Furthermore, the third portion 121C of the first conductive element 121 and the second portion 122B of the second conductive element 122 are disposed spaced apart in the Y direction. With this configuration, the area difference between the first conductive element 121 and the second conductive element 122 when viewed in the Z direction is kept small.

[0017] 2, the terahertz chip B1 is disposed above the first conductive element 121 in the Z direction so as to straddle the second portion 121B and the third portion 121C. With this configuration, the terahertz chip B1 can be disposed in the central portion of the wiring substrate 11 as viewed in the Z direction. Note that, as long as the configuration allows the terahertz chip B1 to be disposed in the central portion of the wiring substrate 11 as viewed in the Z direction, the terahertz chip B1 may be disposed so as to fit within the third portion 121C.

[0018] <Resin portion 13> As shown in FIGS. 1 and 3, in the terahertz device A1, the resin portion 13 is disposed above the wiring substrate 11 in the Z direction. The resin portion 13 may be formed of, for example, epoxy resin. A space 131 is formed in the resin portion 13 to accommodate the terahertz chip B1. The space 131 has a first side surface 131A and a second side surface 131B. The first side surface 131A is inclined with respect to the Z direction. The second side surface 131B is located between the first side surface 131A and the wiring substrate 11 in the Z direction. The second side surface 131B extends along the Z direction. A cross section of the space 131 cut along a plane perpendicular to the Z direction is circular, and the inner diameter is larger than that of the terahertz chip B1. Note that the cross-sectional shape is not limited to a circle.

[0019] As shown in FIG. 3 , in the terahertz device A1, a metal layer 132 is disposed on the inner surface of the space 131 of the resin part 13. By disposing the metal layer 132, terahertz waves emitted from the terahertz element 7 (described later) are reflected. This prevents the terahertz waves from being absorbed by the resin part 13, enabling the terahertz waves to be emitted effectively. The metal layer 132 may be disposed on the first side surface 131A. The metal layer 132 may also be disposed on the second side surface 131B. For example, a metal plating layer is used as the metal layer 132. The metal layer 132 is not limited to a metal plating layer as long as it is configured to efficiently reflect terahertz waves. In the resin part 13, the inner surface of the space 131 is formed of metal plating, but this is not limited thereto. The first side surface 131A and the second side surface 131B may also be formed of metal.

[0020] 2 and 3 , the wire 141 and the wire 142 are bonded to the terahertz chip B1 and the conductive layer 12 of the wiring substrate 11. More specifically, the wire 141 is bonded to a first electrode 54 (described later) of the terahertz chip B1 and a second portion 121B of the first conductive element 121 of the conductive layer 12. The wire 142 is bonded to a second electrode 64 (described later) of the terahertz chip B1 and a first portion 122A of the second conductive element 122 of the conductive layer 12. As shown in FIG. 4 , the wire 141 connects the terahertz chip B1 and the first conductive element 121, which is the cathode terminal, and the wire 142 connects the terahertz chip B1 and the second conductive element 122, which is the anode terminal.

[0021] <Current Limiting Unit 2> In the terahertz device A1 according to the present disclosure, the current limiting unit 2 is a resistor. The current limiting unit 2 is disposed on the upper surface of the conductor layer 12 in the Z direction. A first end of the conductor layer 12 is joined to the first portion 121A of the first conductive element 121, and a second end is joined to the second portion 121B. By disposing the current limiting unit 2 in this manner, the current limiting unit 2 is connected in series with the terahertz element 7 provided on the terahertz chip B1 (see FIG. 4 ). The second portion 121B of the first conductive element 121 of the conductor layer 12 serves as wiring connecting the current limiting unit 2 and the terahertz element 7.

[0022] In the terahertz device A1, the terahertz element 7 of the terahertz chip B1 is driven by applying a voltage to the first portion 121A of the first conductive element 121, which is the anode terminal, and the first portion 122A of the second conductive element 122, which is the cathode terminal. When the terahertz device A1 is driven, a current used for driving flows from the first conductive element 121, which is the anode terminal, to the terahertz element 7 of the terahertz chip B1. By providing a current limiting unit 2 in the wiring between the first conductive element 121 and the terahertz chip B1, it is possible to limit the current supplied to the terahertz element 7 via the first conductive element 121.

[0023] In the terahertz device A1 of the present disclosure, a resistor is used as the current limiting unit 2, but the current limiting unit is not limited to a resistor. The current limiting unit may be configured to limit the current supplied to the terahertz element 7, and may be a fuse, a polyswitch, a varistor, a current limiting circuit, or the like. An example of a current limiting circuit will now be described with reference to the drawings.

[0024] 5 is a circuit diagram showing an example of a current limiting circuit. As shown in FIG. 5, the current limiting circuit is a current clamp circuit and includes a first resistor R1, a second resistor R2, a first diode D1, a second diode D2, and a PNP bipolar transistor Q1.

[0025] A first end of the first resistor R1 is connected to the input DIN. A second end of the first resistor R1 is connected to the emitter of the PNP bipolar transistor Q1. A first end of the second resistor R2 is connected to the base of the PNP bipolar transistor Q1. A second end of the second resistor R2 is connected to ground. A cathode of the first diode D1 is connected to the anode of the second diode D2, and the anode of the first diode D1 is connected to the connection point connecting the input DIN and the first end of the first resistor R1. A cathode of the second diode D2 is connected to the connection point between the base of the PNP bipolar transistor Q1 and the first end of the second resistor R2. A collector of the PNP bipolar transistor Q1 is connected to the output DOUT. In other words, the current output from the PNP bipolar transistor Q1 is the output current.

[0026] In a current limiting circuit configured as described above, the current output from the collector of the PNP bipolar transistor Q1 is a constant current determined by the forward voltage drop of the first diode D1 and the resistance value of the first resistor R1. If the forward voltage drop of the first diode D1 is fixed regardless of the input voltage, the output current is also limited to a constant value. However, the current limiting circuit is not limited to this circuit, and a wide variety of circuits capable of limiting the output current can be used.

[0027] <First rectifying element 31, second rectifying element 32> An example of a specific structure of the first rectifying element 31 and the second rectifying element 32 will be described. Fig. 6 is a cross-sectional view of a rectifying element used as the first rectifying element 31 and the second rectifying element 32. The first rectifying element 31 and the second rectifying element 32 have the same configuration. Therefore, in the rectifying element shown in Fig. 6, the reference numerals related to the first rectifying element 31 and the second rectifying element 32 are both indicated.

[0028] 4, the first rectifying element 31 is electrically connected in parallel with the terahertz chip B1. The first rectifying element 31 is, for example, a diode. Specific examples of such diodes include a Zener diode, a Schottky diode, and a light-emitting diode.

[0029] 6 , the first rectifying element 31 includes a first semiconductor layer 311 and a second semiconductor layer 312. The first semiconductor layer 311 and the second semiconductor layer 312 are stacked on top of each other. The first semiconductor layer 311 has a first conductivity type, and the second semiconductor layer 312 has a second conductivity type opposite to the first conductivity type. When the first conductivity type is p-type, the second conductivity type is n-type. When the second conductivity type is n-type, the first conductivity type is p-type. In the first rectifying element 31 of the terahertz device A1 of the present disclosure, the first semiconductor layer 311 is p-type, and the second semiconductor layer 312 is n-type.

[0030] 6 , the first rectifying element 31 includes a first terminal 31A and a second terminal 31B. In the first rectifying element 31, the first terminal 31A is stacked in contact with the first semiconductor layer 311, and the second terminal 31B is stacked in contact with the second semiconductor layer 312. Therefore, in normal use, in the first rectifying element 31, a current easily flows from the first terminal 31A to the second terminal 31B, and a current does not easily flow from the second terminal 31B to the first terminal 31A.

[0031] 4, the second rectifying element 32 is electrically connected in parallel with the terahertz chip B1. The second rectifying element 32 is, for example, a diode. Specific examples of such diodes include a Zener diode, a Schottky diode, and a light-emitting diode.

[0032] 6 , the second rectifying element 32 includes a first semiconductor layer 321 and a second semiconductor layer 322. The first semiconductor layer 321 and the second semiconductor layer 322 are stacked on top of each other. The first semiconductor layer 321 has a first conductivity type, and the second semiconductor layer 322 has a second conductivity type opposite to the first conductivity type. When the first conductivity type is p-type, the second conductivity type is n-type. When the second conductivity type is n-type, the first conductivity type is p-type. In the second rectifying element 32 of the terahertz device A1 of the present disclosure, the first semiconductor layer 321 is p-type, and the second semiconductor layer 322 is n-type.

[0033] 6 , the second rectifying element 32 includes a first terminal 32A and a second terminal 32B. In the second rectifying element 32, the first terminal 32A is stacked in contact with the first semiconductor layer 321, and the second terminal 32B is stacked in contact with the second semiconductor layer 322. Therefore, in normal use, in the second rectifying element 32, a current easily flows from the first terminal 32A to the second terminal 32B, and a current does not easily flow from the second terminal 32B to the first terminal 32A.

[0034] 4, the first rectifying element 31 and the second rectifying element 32 are both connected in parallel to the terahertz chip B1. The first rectifying element 31 is connected so that the direction of current flow from the first conductive element 121 to the second conductive element 122 is the forward direction. The second rectifying element 32 is connected so that the direction of current flow from the second conductive element 122 to the first conductive element 121 is the forward direction.

[0035] FIG. 7 is a diagram showing the current-voltage characteristics of the first rectifying element 31. Note that the forward direction of the first rectifying element 31 is the direction in which current flows from the first terminal 31A to the second terminal 31B. As shown in FIG. 7 , the absolute value of the first rise voltage V311 at which current begins to flow through the first rectifying element 31 is smaller than the absolute value of the first breakdown voltage V312 of the first rectifying element 31. The first rise voltage V311 may be greater than the lower limit of the absolute value of the voltage range Vr in which the terahertz element 7 oscillates terahertz waves. The first rise voltage V311 may also be greater than the upper limit of the absolute value of the voltage range Vr in which the terahertz element 7 oscillates terahertz waves. The absolute value of the first rise voltage V311 is, for example, 0.4 to 0.9 V. The absolute value of the first breakdown voltage V312 is, for example, 2 to 8 V.

[0036] The current-voltage characteristics of the second rectifying element 32 are similar to those of the first rectifying element 31 shown in FIG. 7 . The second rising voltage V321 at which current begins to flow through the second rectifying element 32 is similar to the first rising voltage V311. As shown in FIG. 4 , the first rectifying element 31 and the second rectifying element 32 are connected in parallel so that their forward directions are reversed. Therefore, if the direction from the first conductive element 121, which is the anode terminal, to the second conductive element 122, which is the cathode terminal, is defined as the forward direction, the current-voltage characteristics of the composite element consisting of the first rectifying element 31 and the second rectifying element 32 are as shown in FIG. 8 . Note that FIG. 8 also shows the current value of the terahertz element 7. As shown in Figure 8, the current-voltage characteristics of the combined element of the first rectifying element 31 and the second rectifying element 32 are such that the current-voltage curve rises sharply at the first rise voltage value V311 and drops sharply at the negative absolute value of the second rise voltage value V321.

[0037] As shown in FIG. 2 , the first rectifying element 31 is disposed above the second portion 121B of the first conductive element 121 of the conductive layer 12 in the Z direction. The first rectifying element 31 is disposed such that the first terminal 31A is in contact with the second portion 121B of the first conductive element 121. One end of a wire 151 is joined to the second terminal 31B. The other end of the wire 151 is joined to the second portion 122B of the second conductive element 122 of the conductive layer 12. By joining in this manner, the first rectifying element 31 is connected to the wiring between the current limiting unit 2 and the terahertz element 7. The direction from the first conductive element 121 to the second conductive element 122 is the forward direction of the first rectifying element 31. Note that the wire 151 only needs to be electrically connected to the second conductive element 122, and may be joined to the first portion 122A.

[0038] 2 , the second rectifying element 32 is disposed above the second portion 122B of the second conductive element 122 of the conductive layer 12 in the Z direction. The second rectifying element 32 is disposed such that the first terminal 32A is in contact with the second portion 122B of the second conductive element 122. One end of a wire 152 is joined to the second terminal 32B. The other end of the wire 152 is joined to the second portion 121B of the first conductive element 121 of the conductive layer 12. By joining in this manner, the second rectifying element 32 is connected to the wiring between the current limiting unit 2 and the terahertz element 7. The direction from the second conductive element 122 to the first conductive element 121 is the forward direction of the second rectifying element 32. As a result, the first rectifying element 31 and the second rectifying element 32 constitute the circuit shown in FIG. 4 . The second rectifying element 32 only needs to be electrically connected to the second conductive element 122, and may be disposed in the first portion 122A.

[0039] <Terahertz Chip B1> Details of the terahertz chip B1 will be described with reference to the drawings. Fig. 9 is a plan view of the terahertz chip B1. Fig. 10 is a partial enlarged view of region X of the terahertz chip B1 shown in Fig. 9. Fig. 11 is a cross-sectional view taken along line XI-XI shown in Fig. 10. Fig. 12 is a partial enlarged cross-sectional view of Fig. 11.

[0040] The terahertz chip B1 emits high-frequency electromagnetic waves in the terahertz band. The terahertz chip B1 may not emit high-frequency electromagnetic waves in the terahertz band, but may receive them. The terahertz chip B1 may emit and receive high-frequency electromagnetic waves in the terahertz band. The terahertz chip B1 includes a semiconductor substrate 4, a first conductor layer 5, a second conductor layer 6, an insulating layer 40 (see FIG. 14 , etc.), a terahertz element 7, a capacitor 71, and a parallel resistor 72 (see FIG. 4 , etc.).

[0041] The semiconductor substrate 4 is made of a semiconductor. The semiconductor that constitutes the semiconductor substrate 4 is, for example, InP, but may be a semiconductor other than InP. The semiconductor substrate 4 has a surface 41. The surface 41 refers to the upper surface of the semiconductor substrate 4 in the Z direction.

[0042] 9, the semiconductor substrate 4 has a square shape when viewed in the Z direction. However, the semiconductor substrate 4 does not have to have a square shape when viewed in the Z direction, and may have, for example, a rectangular shape. The peripheral portions of both ends of the semiconductor substrate 4 in the X direction extend in the Y direction. The peripheral portions of both ends of the semiconductor substrate 4 in the Y direction also extend in the X direction. In other words, the semiconductor substrate 4 is arranged to have a similar shape to the wiring substrate 11.

[0043] 11 and 12 , the terahertz element 7 is formed on the semiconductor substrate 4. The terahertz element 7 is electrically connected to the first conductor layer 5 and the second conductor layer 6. The electromagnetic waves emitted from the terahertz element 7 are reflected by the back reflector metal layer 16, and the terahertz element 7 has a surface emission radiation pattern on the upper side in the Z direction with respect to the semiconductor substrate 4.

[0044] The terahertz element 7 is typically an RTD (Resonant Tunneling Diode), but may also be configured by a diode other than an RTD or a transistor. The terahertz element 7 may be configured by, for example, a TUNNETT (Tunnel Transit Time) diode, an IMPATT (Impact Ionization Avalanche Transit Time) diode, a GaAs-based field effect transistor (FET), a GaN-based FET, a high electron mobility transistor (HEMT), or a heterojunction bipolar transistor (HBT).

[0045] An example for realizing the terahertz device 7 will be described with reference to FIG. 12 . As shown in FIG. 12 , a GaInAs layer 92a is disposed on a semiconductor layer 91a (e.g., made of GaInAs) and doped with n-type impurities. A GaInAs layer 93a is disposed on the GaInAs layer 92a and is not doped with impurities. An AlAs layer 94a is disposed on the GaInAs layer 93a, an InGaAs layer 95 is disposed on the AlAs layer 94a, and an AlAs layer 94b is located on the InGaAs layer 95. The AlAs layer 94a, the InGaAs layer 95, and the AlAs layer 94b constitute an RTD section. The GaInAs layer 93b is disposed on the AlAs layer 94b and is not doped with impurities. The GaInAs layer 92b is disposed on the GaInAs layer 93b and is doped with n-type impurities. A GaInAs layer 91b is disposed on a GaInAs layer 92b and is heavily doped with n-type impurities, and a first conductor layer 5 is disposed on the GaInAs layer 91b.

[0046] 12, a GaInAs layer doped with a high concentration of n-type impurities may be interposed between the GaInAs layer 91b and the first conductor layer 5. This improves the contact between the first conductor layer 5 and the GaInAs layer 91b.

[0047] Fig. 13 is a cross-sectional view taken along line XIII-XIII in Fig. 9. Fig. 14 is a cross-sectional view taken along line XIV-XIV in Fig. 9. Fig. 15 is a cross-sectional view taken along line XV-XV in Fig. 9. Fig. 16 is a cross-sectional view taken along line XVI-XVI in Fig. 9. Fig. 17 is a cross-sectional view taken along line XVII-XVII in Fig. 9. Fig. 18 is a cross-sectional view taken along line XVIII-XVIII in Fig. 9. Fig. 19 is a cross-sectional view taken along line XIX-XIX in Fig. 9. Fig. 20 is a cross-sectional view taken along line XX-XX in Fig. 9. Fig. 21 is a cross-sectional view taken along line XXI-XXI in Fig. 9.

[0048] 14, 16, etc., the insulating layer 40 is formed on the semiconductor substrate 4. The insulating layer 40 is made of, for example, SiO ２ Alternatively, the material constituting the insulating layer 40 may be Si ３ N ４ , SiON, HfO ２ , or Al ２ O ３ The insulating layer 40 may have a thickness of, for example, 10 nm to 1000 nm. The insulating layer 40 may be formed by, for example, CVD or sputtering.

[0049] As shown in FIG. 9 and other figures, the first conductive layer 5 and the second conductive layer 6 are each formed on a semiconductor substrate 4. The first conductive layer 5 and the second conductive layer 6 are insulated from each other. As shown in FIG. 11, when viewed in the Z direction of the semiconductor substrate 4, the terahertz element 7 is spaced from the end of the second conductive layer 6 on the X2 side. The first conductive layer 5 and the second conductive layer 6 each have a metal laminate structure. The laminate structure of the first conductive layer 5 and the second conductive layer 6 is, for example, a laminate structure of Au, Pd, and Ti. Alternatively, the laminate structure of the first conductive layer 5 and the second conductive layer 6 is, for example, a laminate structure of Au and Ti. The thickness of the first conductive layer 5 and the second conductive layer 6 is, for example, 10 to 2000 nm. The first conductive layer 5 and the second conductive layer 6 may each be formed by vacuum deposition, sputtering, or the like.

[0050] 9 , the first conductor layer 5 includes a first portion 51, a first inductance portion 52, a first capacitor portion 53, and a first electrode 54. The second conductor layer 6 includes a second portion 61, a second inductance portion 62, a second capacitor portion 63, and a second electrode 64.

[0051] 9 to 12, the first portion 51 extends along the X direction. The first portion 51 includes a first conductive portion 511 and a second conductive portion 512.

[0052] 9 and other figures, the first conductive portion 511 is a rectangular portion. The first conductive portion 511 extends along the X direction and can function as an antenna. The second conductive portion 512 extends from the first conductive portion 511 toward the second conductor layer 6 when viewed in the Z direction. The second conductive portion 512 overlaps the terahertz element 7 when viewed in the Z direction.

[0053] The first inductance portion 52 shown in Figures 9, 10, etc. is connected to the first portion 51 and the first capacitor portion 53 and extends from the first portion 51 to the first capacitor portion 53. The first inductance portion 52 functions as an inductance. The length of the first inductance portion 52 in the Y direction (see Figure 10) is, for example, 5 μm to 100 μm. The width of the first inductance portion 52 is, for example, 1 μm to 10 μm.

[0054] The second portion 61 is disposed closer to the X1 side than the first portion 51 and extends along the X direction. The second portion 61 can function as an antenna. The second inductance portion 62 is connected to the second portion 61 and the second capacitor portion 63 and extends along the X direction from the second portion 61 to the second capacitor portion 63. The second inductance portion 62 functions as an inductance. The length of the second inductance portion 62 in the Y direction (see FIG. 10) is, for example, 5 μm to 100 μm. The width of the second inductance portion 62 is, for example, 1 μm to 10 μm.

[0055] 9 and other figures, the first capacitor section 53 is disposed apart from the terahertz element 7 in the Y direction. In this embodiment, the first capacitor section 53 has a rectangular shape when viewed in the Z direction.

[0056] The second capacitor portion 63 is disposed at a distance from the terahertz element 7 in the Y direction. As shown in FIGS. 18 and 19 , the second capacitor portion 63 is interposed between the first capacitor portion 53 and the semiconductor substrate 4. Unlike the present embodiment, the first capacitor portion 53 may be interposed between the second capacitor portion 63 and the semiconductor substrate 4. The first capacitor portion 53 is stacked on the second capacitor portion 63 and is insulated from the second capacitor portion 63 via the insulating layer 40. The first capacitor portion 53 and the second capacitor portion 63 form a capacitor 71. The capacitor 71 is rectangular when viewed in the Z direction.

[0057] In this embodiment, the first electrode 54 is a pad portion to which a wire 141 (see FIGS. 9, 17, etc.) is bonded. As shown in FIG. 17, the first electrode 54 has a portion that directly contacts the semiconductor substrate 4. When viewed in the Z direction, this contact portion overlaps with the wire bonding portion where the wire 141 and the first electrode 54 contact each other.

[0058] 9 , in the present embodiment, the outer edge of the first electrode 54 may be arranged inside the peripheral edge of the semiconductor substrate 4 when viewed in the Z direction. In this case, in the manufacturing process of the terahertz chip B1, it is possible to suppress the generation of burrs that are caused by cutting the first electrode 54 when dicing the semiconductor substrate 4.

[0059] The second electrode 64 is connected to the second capacitor portion 63. In this embodiment, the second electrode 64 is a pad portion to which the wire 142 (see FIGS. 9 and 20) is bonded. As shown in FIG. 20 , the second electrode 64 has a portion that directly contacts the semiconductor substrate 4. When viewed in the Z direction, this contact portion overlaps with the wire bonding portion where the wire 142 and the second electrode 64 contact each other.

[0060] 9 , when viewed in the Z direction, the second electrode 64 may be configured such that the outer edge of the second electrode 64 is disposed inside the peripheral edge of the semiconductor substrate 4. In this case, in the manufacturing process of the terahertz chip B1, it is possible to suppress the generation of burrs that are caused by cutting the second electrode 64 when dicing the semiconductor substrate 4.

[0061] 4, 9, etc., the terahertz chip B1 includes a capacitor 71 and a parallel resistor 72 connected in parallel to the terahertz element 7. By including the capacitor 71 and the parallel resistor 72, abnormal oscillation of the terahertz chip B1 is suppressed.

[0062] 4, the resistance value of the current limiting unit 2 was changed, and the current flowing through the terahertz element 7 relative to the input voltage and the voltage applied to the terahertz element 7 were investigated. The results of the investigation are shown below.

[0063] Fig. 22 is a diagram showing the relationship between the input voltage of the terahertz device A1 and the current flowing through the terahertz element 7. Fig. 23 is a diagram showing the relationship between the input voltage of the terahertz device A1 and the voltage applied to the terahertz element 7.

[0064] The diagram shown in Fig. 22 shows the relationship between the input voltage value and the current value flowing through the terahertz element 7 when the resistance value of the current limiting unit 2 is changed to 0Ω, 20Ω, and 47Ω in the circuit shown in Fig. 4. The diagram shown in Fig. 23 shows the relationship between the input voltage value and the voltage value applied to the terahertz element 7 when the resistance value of the current limiting unit 2 is changed in the same way. Note that in Figs. 22 and 23, the results when the resistance value of the current limiting unit 2 is 0Ω are shown by a dashed line, the results when it is 20Ω are shown by a dashed line, and the results when it is 47Ω are shown by a solid line. In Figs. 22 and 23, applying a voltage to the terahertz device A1 means applying a voltage between the anode terminal Tp and the cathode terminal Tm in the circuit diagram shown in Fig. 4.

[0065] 22 , when the resistance value of the current limiting unit 2 is 0Ω, i.e., when the current limiting unit 2 is not provided, the current flowing through the terahertz element 7 increases sharply when the input voltage is around 1 V. On the other hand, when the resistance value of the current limiting unit 2 is 20Ω or 47Ω, the current value flowing through the terahertz element 7 increases gradually even when the input voltage exceeds 1 V. Note that when the resistance value is 47Ω, the current flowing through the terahertz element 7 increases more slowly with increasing input voltage than when the resistance value is 20Ω. From this, it is possible to limit the increase in the current flowing through the terahertz element 7 by electrically connecting the current limiting unit 2 in series with the terahertz element 7.

[0066] 23 , when the resistance value of the current limiting unit 2 is 0Ω, the voltage applied to the terahertz element 7 increases linearly with the input voltage. On the other hand, when the resistance value of the current limiting unit 2 is 20Ω, the voltage applied to the terahertz element 7 increases until the input voltage reaches approximately 1.3 V. Thereafter, even if the input voltage increases, the voltage applied to the terahertz element 7 stabilizes at a voltage lower than 1 V. Furthermore, when the resistance value of the current limiting unit 2 is 47Ω, the voltage applied to the terahertz element 7 increases until the input voltage reaches approximately 2 V. Thereafter, even if the input voltage increases, the voltage applied to the terahertz element 7 stabilizes at a voltage lower than 1 V. In other words, by providing the current limiting unit 2, the voltage applied to the terahertz element 7 is limited to a constant voltage even if the input voltage increases. The voltage applied to the terahertz element 7 is considered to be due to the influence of the forward voltages of the first rectifying element 31 and the second rectifying element 32. When a resistor is used as the current limiting section 2, it is preferable that the resistance value is 100Ω or less.

[0067] As described above, in the terahertz device A1, by providing the current limiting unit 2, it is possible to limit an increase in the current value flowing through the terahertz element 7 due to an increase in the input voltage. It was also found that an increase in the voltage applied to the terahertz element 7 can be suppressed even if the input voltage increases.

[0068] Next, the effects of this embodiment will be described.

[0069] 4 , the terahertz device A1 includes a current limiting unit 2 electrically connected in series with the terahertz element 7. With this configuration, even if a large voltage is applied between the anode terminal Tp and the cathode terminal Tm of the terahertz device A1 due to, for example, static electricity, the large voltage can be prevented from being applied to the terahertz element 7.

[0070] Furthermore, even if the large voltage described above is applied between both ends of the anode terminal Tp and the cathode terminal Tm of the terahertz device A1, it is possible to prevent a large current from being applied to the terahertz element 7.

[0071] The terahertz device A1 utilizes the voltage drop effect of the current limiting unit 2 by providing the current limiting unit 2 so as to be electrically connected in series with the terahertz element 7. Therefore, the terahertz device A1 can prevent a large current from flowing through the terahertz element 7 regardless of whether the voltage applied to the anode terminal Tp is positive or negative.

[0072] Therefore, it is possible to provide a good terahertz device A1 that can operate stably even in an environment where a large voltage is applied due to static electricity, etc. Furthermore, even if a large voltage is applied due to static electricity, etc., it is possible to limit the voltage applied to the terahertz element 7 and the current supplied thereto, so it is possible to provide a terahertz device A1 that can be operated stably for a long period of time.

[0073] <First Modification> A first modification of the terahertz device of the first embodiment will be described with reference to the drawings. Fig. 24 is a plan view of a terahertz device A11 of the first modification. As shown in Fig. 24, the terahertz device A11 differs from the terahertz device A1 in that it has first conductive elements 123 and second conductive elements 124 instead of first conductive elements 121 and second conductive elements 122. Other than this, the terahertz device A11 has the same configuration as the terahertz device A1, and parts of the terahertz device A11 that are substantially the same as those of the terahertz device A1 are designated by the same reference numerals and detailed description thereof will be omitted.

[0074] 24 , the first conductive element 123 of the terahertz device A11 of the first modified example has a first portion 123A, a second portion 123B, and a third portion 123C. The first portion 123A of the first conductive element 123 of the terahertz device A11 and the first portion 121A of the first conductive element 121 of the terahertz device A1 have the same configuration. The second portion 123B has an elongated shape extending in the Y direction and is disposed on the X1 side of the first portion 123A. The gap between the first portion 123A and the second portion 123B adjacent to each other in the X direction is polygonal, or more specifically, crank-shaped.

[0075] The third portion 123C protrudes in the X direction from the X1-side edge of the second portion 123B. The third portion 123C has a rectangular shape with its longitudinal direction in the Y direction extending from a first end in the Y direction of the X1-side edge of the second portion 123B to the middle portion.

[0076] 24 , the second conductive element 124 includes a first portion 124A and one second portion 124B. When viewed in the Z direction, the first portion 124A has a rectangular shape with its longitudinal direction extending in the Y direction. The second portion 124B has a rectangular shape with its longitudinal direction extending in the Y direction. The second portion 124B protrudes in the X direction from the edge portion on the X2 side of the first portion 124A.

[0077] 24 , the third portion 123C of the first conductive element 123 is disposed on the X2 side of the first portion 124A of the second conductive element 124 and spaced apart from the first portion 124A. The second portion 124B of the second conductive element 124 is disposed on the X1 side of the first portion 123A of the first conductive element 123 and spaced apart from the first portion 123A. Furthermore, the third portion 121C of the first conductive element 121 and the second portion 124B of the second conductive element 124 are disposed spaced apart in the Y direction. When viewed in the Z direction, the third portion 121C of the first conductive element 121 and the second portion 124B of the second conductive element 124 of the conductive layer 12 are disposed spaced apart in the Y direction. In other words, the gap between the first conductive element 123 and the second conductive element 124 has two bent line-shaped bends, i.e., a crank shape.

[0078] In the terahertz device A11, the first rectifying element 31 is disposed above the third portion 123C of the first conductive element 123 in the Z direction. The first terminal 31A of the first rectifying element 31 is disposed in contact with the third portion 123C of the first conductive element 123. The second terminal 31B of the first rectifying element 31 and the first portion 124A of the second conductive element 124 are electrically connected by a wire 151. The first terminal 32A of the second rectifying element 32 is disposed in contact with the second portion 124B of the second conductive element 124. The second terminal 32B of the second rectifying element 32 and the second portion 123B of the first conductive element 123 are electrically connected by a wire 152. By making the connections as described above, the terahertz device A11 of the first modified example can also operate in the same manner as the terahertz device A1.

[0079] <Second Modification> A second modification of the terahertz device of the first embodiment will be described with reference to the drawings. Fig. 25 is a plan view of a terahertz device A12 of the second modification. As shown in Fig. 25, the terahertz device A12 differs from the terahertz device A1 in that it has first conductive elements 125 and second conductive elements 126 instead of the first conductive elements 121 and second conductive elements 122. The terahertz device A12 also differs from the terahertz device A1 in the positions of the first rectifying element 31 and the second rectifying element 32 and the joints of the wires 151 and 152. Other than this, the terahertz device A12 has the same configuration as the terahertz device A1. Parts of the terahertz device A11 that are substantially the same as those of the terahertz device A1 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0080] 25 , the first conductive element 125 has a first portion 125A and a second portion 125B. The first portion 125A of the first conductive element 125 of the conductor layer 12 has a shape in which the first portion 121A and the second portion 121B of the first conductive element 121 are integrally formed. The second portion 125B of the first conductive element 125 has the same configuration as the third portion 121C of the first conductive element 121 and is integrally formed with the first portion 125A. In other words, the first conductive element 125 has a configuration in which the first portion 121A and the second portion 121B of the first conductive element 121 are connected and integrally formed.

[0081] The second conductive element 126 has the same configuration as the second conductive element 122. That is, the second conductive element 126 has a first portion 126A and two second portions 126B. The two second portions 126B are arranged spaced apart in the Y direction.

[0082] The current limiting unit 2 is disposed on the upper surface of the conductive layer 12 in the Z direction. The current limiting unit 2 is bonded to the first portion 125A of the first conductive element 125 of the conductive layer 12 and to the wire 141. As shown in FIG. 4 , the current limiting unit 2 is connected in series with the terahertz element 7 provided on the terahertz chip B1 (see FIG. 4 ). The wire 141 is bonded to the first electrode 54 of the terahertz chip B1 and the current limiting unit 2 bonded to the first portion 125A of the first conductive element 125 of the conductive layer 12. The current limiting unit 2 can be provided on the wiring between the first conductive element 125 and the terahertz chip B1.

[0083] 25 , the first rectifying element 31 is disposed above the second portion 126B of the second conductive element 126 of the conductive layer 12 in the Z direction. The first rectifying element 31 is disposed such that the second terminal 31B is in contact with the second portion 126B of the second conductive element 126. One end of a wire 151 is joined to the first terminal 31A. The other end of the wire 151 is joined to the first electrode 54 of the terahertz chip B1. By joining in this manner, the direction from the first conductive element 125 to the second conductive element 126 is the forward direction of the first rectifying element 31. The first rectifying element 31 is also connected between the terahertz element 7 and the current limiting unit 2.

[0084] 25 , the second rectifying element 32 is disposed above the second portion 126B of the second conductive element 126 of the conductive layer 12 in the Z direction. The second rectifying element 32 is disposed such that the first terminal 32A is in contact with the second conductive element 126. One end of a wire 152 is joined to the second terminal 32B. The other end of the wire 152 is joined to the first electrode 54 of the terahertz chip B1. By joining in this manner, the direction from the second conductive element 126 to the first conductive element 125 becomes the forward direction of the second rectifying element 32. The second rectifying element 32 is also connected between the terahertz element 7 and the current limiting unit 2. Similar to the terahertz device A1, the terahertz device A12 shown in FIG. 2 also has a configuration in which the current limiting unit 2 can limit the current supplied to the terahertz element 7.

[0085] The terahertz device A11 of the first modified example and the terahertz device A12 of the second modified example described above also have the same effects as the terahertz device A1.

[0086] Second Embodiment Fig. 26 is a cross-sectional view of a terahertz device A2 according to a second embodiment. The terahertz device A2 shown in Fig. 26 differs from the terahertz device A1 in that it includes a cover member 17 arranged to cover the opening of the space 131 in the resin portion 13. Other than this, the terahertz device A2 has the same configuration as the terahertz device A1, and the same reference numerals are used to designate parts of the terahertz device A2 that are substantially the same as those of the terahertz device A1, and detailed descriptions of the same parts will be omitted.

[0087] 26 , the terahertz device A2 includes a cover member 17 arranged to cover an upper opening in the Z direction of the space 131 of the resin part 13. In this embodiment, the space 131 is filled with a gas. Specific examples of the gas include an inert gas (e.g., nitrogen) and air.

[0088] As shown in FIG. 26 , in this embodiment, the cover member 17 includes a first portion 171 and a second portion 172 .

[0089] The first portion 171 may be made of, for example, an insulating material. The first portion 171 may also be, for example, a substrate (including sheet-shaped or film-shaped materials). The material constituting the first portion 171 preferably has, for example, low absorption loss for terahertz waves and high transmittance for terahertz waves. For example, a thin film sheet with a low dielectric constant, a high-resistance Si substrate, or the like can be used as the substrate constituting the first portion 171. When a Si substrate is used, it is easy to form a stacked structure.

[0090] Other examples of materials constituting the first portion 171 include, for example, polymers and MgO. When using a polymer, the first portion 171 can be formed, for example, by transferring a pattern onto a sheet-like material. When MgO is used, the absorption loss of terahertz waves can be reduced. Alternatively, a compound semiconductor (SiC, GaN, GaAs, InP, sapphire, etc.) may be used as the material constituting the first portion 171. The resistivity may be increased by adjusting a dopant in the compound semiconductor.

[0091] The second portion 172 is made of a conductive material. Examples of conductive materials include metals such as Cu, Al, and Au. The second portion 172 can exhibit a desired function for terahertz waves. Specifically, the second portion 172 can exhibit at least one of a polarizing function for terahertz waves, a frequency filter function, and a planar lens function. The second portion 172 may include multiple layers. In a planar view, the second portion 172 may include at least one of at least one strip portion, at least one ring portion, and at least one dot.

[0092] Third Embodiment Fig. 27 is a plan view of a terahertz chip B3 of a terahertz device A3 of the third embodiment. Fig. 28 is a plan view of the terahertz device A3 of the third embodiment. Fig. 29 is a circuit diagram of the terahertz device A3 of the third embodiment. The terahertz chip B3 differs from the terahertz chip B1 in that it does not include a parallel resistor 72. The terahertz device A3 also differs from the terahertz device A1 in that it includes a parallel resistor 21 joined to the first conductive element 121 and the second conductive element 122. Other than this, the terahertz device A3 has the same configuration as the terahertz device A1. Therefore, parts of the terahertz device A3 that are substantially the same as those of the terahertz device A1 are assigned the same reference numerals, and detailed descriptions of the same parts will be omitted.

[0093] As shown in Fig. 27 , the terahertz chip B3 is configured such that the parallel resistor 72 is omitted from the terahertz chip B1. As shown in Fig. 28 , the terahertz device A3 includes a parallel resistor 21 arranged to join the first conductive element 121 and the second conductive element 122. As shown in Fig. 29 , even if the parallel resistor 21 is arranged outside the terahertz chip B3, it is connected in parallel to the terahertz element 7.

[0094] In this way, even if the parallel resistor 21 is arranged outside the terahertz chip B3, it is possible to suppress abnormal oscillation of the terahertz element 7. Furthermore, since the parallel resistor 21 is arranged outside the terahertz chip B3, it is also possible to check and adjust the resistance value of the parallel resistor 21 while checking the operation of the terahertz device A3.

[0095] <Third Modification> A third modification of the terahertz device of the third embodiment will be described with reference to the drawings. Fig. 30 is a plan view of a terahertz device A31 of the third modification. The terahertz device A31 shown in Fig. 30 differs from the terahertz device A3 shown in Fig. 27 in that a first conductive element 123 and a second conductive element 124 are employed as the conductive layer 12. In other respects, the terahertz device A31 has the same configuration as the terahertz device A3, and portions of the terahertz device A31 that are substantially the same as those of the terahertz device A3 are designated by the same reference numerals and will not be described in detail.

[0096] The terahertz device A31 of the third modified example shown above has the same circuit configuration as the terahertz device A3 shown in FIG. 29, and can operate in the same manner as the terahertz device A3.

[0097] <Fourth Modification> A fourth modification of the terahertz device of the third embodiment will be described with reference to the drawings. Fig. 31 is a plan view of a terahertz device A32 of the second modification. The terahertz device A32 shown in Fig. 31 differs from the terahertz device A3 shown in Fig. 27 in that a first conductive element 125 and a second conductive element 126 are employed as the conductive layer 12. The terahertz device A32 also differs from the terahertz device A3 in that a first rectifying element 31 and a second rectifying element 32 are attached to the second conductive element 126. In other respects, the terahertz device A32 has the same configuration as the terahertz device A3, and portions of the terahertz device A32 that are substantially the same as those of the terahertz device A3 are designated by the same reference numerals and will not be described in detail.

[0098] The configurations of the first rectifying element 31 and the wire 151 and the second rectifying element 32 and the wire 152 of the terahertz device A32 shown in Fig. 31 are the same as those of the terahertz device A12 shown in Fig. 25. Therefore, the terahertz device A32 of the fourth modified example configured in this manner also has the same circuit configuration as the terahertz device A3 shown in Fig. 29 and can operate in the same way as the terahertz device A3.

[0099] 32 is a circuit diagram of a terahertz device A33 according to a fifth modification. In the terahertz device A33, abnormal oscillation of the terahertz element 7 may be suppressed by adjusting the current limiting unit 2. In such a case, the parallel resistor 21 may be omitted, as in the terahertz device A33 shown in FIG.

[0100] Fourth Embodiment FIG. 33 is a plan view of a terahertz device A4 of the fourth embodiment. FIG. 34 is a plan view of a terahertz chip B4 provided in the terahertz device A4 of the fourth embodiment. FIG. 35 is a circuit diagram of the terahertz device A4 of the fourth embodiment. The terahertz device A4 differs from the terahertz device A1 and the terahertz chip B1 in that the current limiting unit 24 is included in the terahertz chip B4. The terahertz device A4 also differs from the terahertz device A1 in that it includes a wire 143 connecting the second terminal portion 552 of the terahertz chip B4 to the second portion 121B of the first conductive element 121 of the conductor layer 12. The terahertz device A4 has the same configuration as the terahertz device A1 in all other respects. Therefore, parts of the terahertz device A4 that are substantially the same as those of the terahertz device A1 are denoted by the same reference numerals, and detailed descriptions of the same parts will be omitted.

[0101] 34 , the first conductor layer 5 of the terahertz chip B4 includes a first electrode 55. The first electrode 55 includes a first terminal 551 and a second terminal 552 that are insulated from each other. The first inductance portion 52 and the first capacitor portion 53 of the first conductor layer 5 are integrally formed with the second terminal 552. The current limiting portion 24 is joined to the first terminal 551 and the second terminal 552. That is, the first terminal 551 and the second terminal 552 are electrically connected via the current limiting portion 24. The second terminal 552 and the second electrode 64 are electrically connected via the parallel resistor 72. That is, the current limiting portion 24, the capacitor 71, and the parallel resistor 72 are disposed inside the terahertz chip B4.

[0102] The first portion 121A of the first conductive element 121 of the conductive layer 12 of the terahertz device A4 is connected to the first terminal portion 551 of the first electrode 55 of the terahertz chip B4 via a wire 141. The second portion 121B of the first conductive element 121 of the conductive layer 12 of the terahertz device A4 is connected to the second terminal portion 552 of the first electrode 55 via a wire 143. By connecting the wire 143 in this manner, the second portion 121B of the first conductive element 121 has the same potential as the wiring between the current limiting unit 24 and the terahertz chip B4. By connecting the second portion 121B of the first conductive element 121 to the second conductive element 122 via the wire 143, the terahertz device A4 having the circuit shown in FIG.

[0103] With this configuration, no current limiting section is disposed on the wiring board 11 of the terahertz device A4, which makes it easy to attach the wires 141, 142, 143, 151, and 152. This reduces the time and effort required to manufacture the terahertz device A4.

[0104] <Sixth Modification> A sixth modification of the terahertz device of the fourth embodiment will be described with reference to the drawings. Fig. 36 is a plan view of a terahertz device A41 of the sixth modification. The terahertz device A41 shown in Fig. 36 differs from the terahertz device A4 shown in Fig. 33 in that a first conductive element 123 and a second conductive element 124 are used as the conductive layer 12. In other respects, the terahertz device A41 has the same configuration as the terahertz device A4, and parts of the terahertz device A41 that are substantially the same as those of the terahertz device A4 are designated by the same reference numerals and will not be described in detail.

[0105] The terahertz device A41 of the sixth modified example shown above has the same circuit configuration as the terahertz device A4 shown in FIG. 35, and can operate in the same manner as the terahertz device A4.

[0106] <Seventh Modification> A seventh modification of the terahertz device of the fourth embodiment will be described with reference to the drawings. Fig. 37 is a plan view of a terahertz device A42 of the seventh modification. The terahertz device A42 shown in Fig. 37 differs from the terahertz device A4 shown in Fig. 33 in that a first conductive element 125 and a second conductive element 126 are used as the conductive layer 12. The terahertz device A42 also differs from the terahertz device A4 in that the first rectifying element 31 and the second rectifying element 32 are attached to the second conductive element 126. In other respects, the terahertz device A42 has the same configuration as the terahertz device A4, and parts of the terahertz device A42 that are substantially the same as those of the terahertz device A4 are designated by the same reference numerals and will not be described in detail.

[0107] The configurations of the first rectifying element 31 and the second rectifying element 32 of the terahertz device A42 shown in Fig. 37 are the same as those of the terahertz device A12 shown in Fig. 25. The first terminal 31A of the first rectifying element 31 and the first electrode 54 of the terahertz chip B3 are electrically connected by a wire 151. The second terminal 32B of the second rectifying element 32 and the first electrode 54 of the terahertz chip B3 are electrically connected by a wire 152.

[0108] The terahertz device A42 of the seventh modified example configured in this manner also has the same circuit configuration as the terahertz device A4 shown in FIG. 33, and can operate in the same manner as the terahertz device A4.

[0109] Fifth Embodiment Fig. 38 is a circuit diagram of a terahertz device A5 of the fifth embodiment. Fig. 39 is a plan view of a terahertz chip B5 used in the terahertz device A5 of the fifth embodiment. The terahertz device A5 differs from the terahertz device A4 and the terahertz chip B4 in that the parallel resistor 72 is omitted from the terahertz chip B5. Other than this, the terahertz device A5 has the same configuration as the terahertz device A4. Therefore, parts of the terahertz device A5 that are substantially the same as those of the terahertz device A4 are assigned the same reference numerals, and detailed descriptions of the same parts will be omitted.

[0110] The terahertz chip B5 has a current limiting unit 24 disposed therein. By disposing the current limiting unit 24, abnormal oscillation of the terahertz element 7 can be suppressed in some cases, and in this case, the parallel resistor can be omitted, as in the terahertz chip B5 shown in Fig. 39. By using such a terahertz chip B5, it is possible to manufacture a terahertz device A5 having the circuit configuration shown in Fig. 38.

[0111] Sixth Embodiment Fig. 40 is a plan view of a terahertz device A6 according to a sixth embodiment. Fig. 41 is a circuit diagram of the terahertz device A6 according to the sixth embodiment. In the terahertz device A6, the conductive layer 12 has a first conductive element 127 and a second conductive element 128. In the terahertz device A6, the current limiting unit 25, the first rectifying element 31, the second rectifying element 32, and the wires 141, 142, 151, and 152 are connected in a different manner than in the terahertz device A1. Components of the terahertz device A6 that are substantially the same as those of the terahertz device A1 are denoted by the same reference numerals, and detailed descriptions of the same components will be omitted.

[0112] 40, the first conductive element 127 of the conductive layer 12 has the same configuration as the first conductive element 127 of the conductive layer 12 of the terahertz device A12 shown in Fig. 25. In other words, the first portion 127A and the second portion 127B of the first conductive element 127 correspond to the first portion 125A and the second portion 125B of the first conductive element 125.

[0113] The second conductive element 128 of the conductive layer 12 has a first portion 128A, a second portion 128B, and a third portion 128C. When viewed in the Z direction, the first portion 128A is elongated and extends in the Y direction. The second portion 128B is disposed on the X2 side of the first portion 128A. In the configuration shown in FIG. 40 , the X2-side edge of the first portion 128A has a notched shape with one end in the Y direction cut out, and the X1-side edge of the second portion 128B has a protruding shape that follows the notched shape of the first portion 128A. In other words, the gap between the first portion 128A and the second portion 128B is a broken line, or more specifically, a crank shape with two corners. However, the first portion 128A and the second portion 128B are not limited to this shape, and the gap between the first portion 128A and the second portion 128B may be linear. The first portion 128A and the second portion 128B are disposed apart from each other and are electrically connected via the current limiting unit 25.

[0114] The two third portions 128C of the second conductive element 128 protrude in the X direction from the X2 side of the second portion 128B. The two third portions 128C are spaced apart in the Y direction. The second portion 128B and the third portion 128C are integrally formed. In other words, the second conductive element 128 has a recess 128R formed by the second portion 128B and the two third portions 128C. The second portion 127B of the first conductive element 127 is disposed in the recess 128R.

[0115] The first rectifying element 31 is disposed above the first conductive element 127 in the Z direction. The first rectifying element 31 is disposed such that the first terminal 31A contacts the first portion 127A of the first conductive element 127. The second terminal 31B is electrically connected to the third portion 128C of the second conductive element 128 by the wire 151. As a result, the forward direction of the first rectifying element 31 is the direction from the first conductive element 127 to the second conductive element 128. The second rectifying element 32 is disposed on the upper surface of the second conductive element 128 in the Z direction. The second rectifying element 32 is disposed such that the first terminal 32A contacts the third portion 128C of the second conductive element 128. The second terminal 32B is electrically connected to the first portion 127A of the first conductive element 127 by the wire 152. As a result, the direction from the second conductive element 128 to the first conductive element 127 becomes the forward direction of the second rectifying element 32 .

[0116] The first conductive element 127 of the conductive layer 12 and the first electrode 54 of the first conductive layer 5 of the terahertz chip B1 are electrically connected via a wire 141. The second part 128B of the second conductive element 128 and the second electrode 64 of the second conductive layer 6 of the terahertz chip B1 are electrically connected via a wire 142.

[0117] In the second conductive element 128 of the conductor layer 12, the first portion 128A and the second portion 128B are connected via the current limiting unit 25. The second electrode 64 of the terahertz chip B1 and the second portion 128B of the second conductive element 128 are connected via a wire 142. That is, the second portion 128B of the second conductive element 128 has the same potential as the wiring connecting the current limiting unit 25 and the terahertz element 7. In this way, the terahertz device A6 forms the circuit shown in FIG.

[0118] The same effect can be obtained even when the current limiting unit 25 is disposed on the side of the second conductive element 122, which is the cathode terminal of the terahertz element 7. That is, in the terahertz device A6, the effect of the current limiting unit 25 suppresses an increase in the flowing current even when the voltage applied to the terahertz device A6 increases, and limits the voltage applied to the terahertz element 7.

[0119] <Fifth Modification> A fifth modification of the terahertz device of the sixth embodiment will be described with reference to the drawings. Fig. 42 is a plan view of a terahertz device A61 of the fifth modification. The terahertz device A61 shown in Fig. 42 differs from the terahertz device A6 shown in Fig. 40 in that a first conductive element 129 and a second conductive element 120 are employed as the conductive layer 12. In other respects, the terahertz device A61 has the same configuration as the terahertz device A6, and portions of the terahertz device A61 that are substantially the same as those of the terahertz device A6 are designated by the same reference numerals and will not be described in detail.

[0120] 42 , the first conductive element 129 has a first portion 129A and a second portion 129B. The first portion 129A of the first conductive element 129 is rectangular with its longitudinal direction in the Y direction. The second portion 129B of the first conductive element 129 is rectangular with its longitudinal direction in the Y direction and protrudes in the X direction from the edge portion on the X1 side of the first portion 129A.

[0121] The second conductive element 120 includes a first portion 120A, a second portion 120B, and a third portion 120C. When viewed in the Z direction, the first portion 120A is elongated and extends in the Y direction. The second portion 120B is disposed on the X2 side of the first portion 120A. In the configuration shown in FIG. 42 , the X2-side edge of the first portion 120A has a notched shape with one end in the Y direction cut out, and the X1-side edge of the second portion 120B has a protruding shape that follows the notched shape of the first portion 120A. In other words, the gap between the first portion 120A and the second portion 120B is a broken line, or more specifically, a crank shape with two corners. However, the shapes of the first portion 120A and the second portion 120B are not limited to this, and the gap between the first portion 120A and the second portion 120B may be linear. The first portion 120A and the second portion 120B are disposed apart from each other and are electrically connected via the current limiting portion 25 .

[0122] The third portion 120C of the second conductive element 120 protrudes in the X direction from the X2 side of the second portion 120B. The third portion 129C of the first conductive element 129 and the third portion 120C of the second conductive element 120 are arranged to be spaced apart in the Y direction. With this configuration, the second portion 120B of the second conductive element 120 serves as wiring between the current limiting unit 25 and the terahertz element 7.

[0123] The terahertz device A61 of the fifth modified example shown above has the same circuit configuration as the terahertz device A6 shown in FIG. 41, and can operate in the same manner as the terahertz device A6.

[0124] <Sixth Modification> A fifth modification of the terahertz device of the sixth embodiment will be described with reference to the drawings. Fig. 43 is a plan view of a terahertz device A62 of the sixth modification. The terahertz device A62 shown in Fig. 43 differs from the terahertz device A6 shown in Fig. 40 in that it employs a first conductive element 125 and a second conductive element 126 as the conductive layer 12. It also differs from the terahertz device A6 in that the first rectifying element 31 and the second rectifying element 32 are attached to the first conductive element 125. The terahertz device A62 otherwise has the same configuration as the terahertz device A6, and parts of the terahertz device A62 that are substantially the same as those of the terahertz device A6 are designated by the same reference numerals and will not be described in detail.

[0125] The first rectifying element 31 is disposed above the first conductive element 125 in the Z direction. The first rectifying element 31 is disposed so that a first terminal 31A is in contact with the first conductive element 125. The second terminal 31B of the first rectifying element 31 is electrically connected to the second electrode 64 of the terahertz chip B1 via a wire 151. The second rectifying element 32 is disposed above the first conductive element 125 in the Z direction. The second rectifying element 32 is disposed so that a second terminal 32B is in contact with the first conductive element 125.

[0126] The terahertz device A62 of the sixth modified example shown above has the same circuit configuration as the terahertz device A6 shown in FIG. 41, and can operate in the same manner as the terahertz device A6.

[0127] Seventh Embodiment Fig. 44 is a plan view of a terahertz device A7 of the seventh embodiment. Fig. 45 is a circuit diagram of the terahertz device A7 of the seventh embodiment. The terahertz device A7 differs from the terahertz device A6 in that it uses a terahertz chip B3. The terahertz device A7 also differs from the terahertz device A6 in that it includes a parallel resistor 21 joined to the first conductive element 121 and the second conductive element 122. Other than this, the terahertz device A7 has the same configuration as the terahertz device A6. Therefore, parts of the terahertz device A7 that are substantially the same as those of the terahertz device A6 are assigned the same reference numerals, and detailed descriptions of the same parts will be omitted.

[0128] 44, the terahertz device A7 includes a parallel resistor 21 arranged to be joined to the first conductive element 121 and the second conductive element 122. As shown in Fig. 45, the parallel resistor 21 is connected in parallel to the terahertz element 7 even if it is arranged outside the terahertz chip B3.

[0129] In this way, even if the parallel resistor 21 is arranged outside the terahertz chip B3, it is possible to suppress abnormal oscillation of the terahertz element 7. Furthermore, since the parallel resistor 21 is arranged outside the terahertz chip B3, it is also possible to check and adjust the resistance value of the parallel resistor 21 while checking the operation of the terahertz device A3.

[0130] <Tenth Modification> A tenth modification of the terahertz device of the seventh embodiment will be described with reference to the drawings. Fig. 46 is a plan view of a terahertz device A71 of the tenth modification. The terahertz device A71 shown in Fig. 46 differs from the terahertz device A7 shown in Fig. 44 in that a first conductive element 129 and a second conductive element 120 are used as the conductive layer 12. In other respects, the terahertz device A71 has the same configuration as the terahertz device A7, and portions of the terahertz device A71 that are substantially the same as those of the terahertz device A7 are designated by the same reference numerals and detailed description thereof will be omitted.

[0131] The terahertz device A71 of the tenth modified example described above has the same circuit configuration as the terahertz device A7 shown in FIG. 45, and can operate in the same manner as the terahertz device A7.

[0132] <Eleventh Modification> An eleventh modification of the terahertz device of the seventh embodiment will be described with reference to the drawings. Fig. 47 is a plan view of a terahertz device A72 of the eleventh modification. The terahertz device A62 shown in Fig. 47 differs from the terahertz device A7 shown in Fig. 44 in that it employs a first conductive element 125 and a second conductive element 126 as the conductive layer 12. Furthermore, the connection between the first rectifying element 31 and the second rectifying element 32 is the same as that of the terahertz device A6 shown in Fig. 42.

[0133] The terahertz device A72 of the eleventh modified example described above has the same circuit configuration as the terahertz device A7 shown in FIG. 45, and can operate in the same manner as the terahertz device A7.

[0134] 48 is a circuit diagram of a terahertz device A73 according to a twelfth modification of the seventh embodiment. In the terahertz device A73, abnormal oscillation of the terahertz element 7 may be suppressed by adjusting the current limiting unit 2. In such a case, the parallel resistor 21 may be omitted, as in the terahertz device A73 shown in FIG.

[0135] Eighth Embodiment Fig. 49 is a plan view of a terahertz device A8 of the eighth embodiment. Fig. 50 is a plan view of a terahertz chip B8 provided in the terahertz device A8 of the eighth embodiment. Fig. 51 is a circuit diagram of the terahertz device A8 of the eighth embodiment. The terahertz device A8 differs from the terahertz device A6 and the terahertz chip B1 in that the current limiting unit 26 is included in the terahertz chip B8. Other than this, the terahertz device A8 has the same configuration as the terahertz device A6. Therefore, parts of the terahertz device A8 that are substantially the same as those of the terahertz device A6 are assigned the same reference numerals, and detailed descriptions of the same parts will be omitted.

[0136] 50 , the second conductor layer 6 of the terahertz chip B8 includes a second electrode 65. The second electrode 65 includes a first terminal 651 and a second terminal 652 that are insulated from each other. The second inductance portion 62 and the second capacitor portion 63 of the second conductor layer 6 are integrally formed with the second terminal 652. The current limiting portion 26 is joined to the first terminal 651 and the second terminal 652. That is, the first terminal 651 and the second terminal 652 are electrically connected via the current limiting portion 26. The second terminal 652 and the first electrode 54 are electrically connected via the parallel resistor 72. That is, the current limiting portion 25, the capacitor 71, and the parallel resistor 72 are disposed inside the terahertz chip B4.

[0137] The first conductive element 127 of the conductor layer 12 of the terahertz device A8 is connected to the first electrode 54 of the first conductor layer 5 via a wire 141. The first portion 128A of the second conductive element 128 of the conductor layer 12 is connected to the first terminal portion 651 of the second electrode 65 via a wire 142. The second portion 128B of the second conductive element 128 of the conductor layer 12 is connected to the second terminal portion 652 of the second electrode 65 via a wire 144. By connecting them in this manner, the second portion 128B of the second conductive element 128 has the same potential as the wiring connecting the current limiting unit 26 and the terahertz element 7. By connecting the wires 141, 142, 144, 151, and 152 in this manner, the terahertz device A8 having the circuit shown in FIG.

[0138] With this configuration, no current limiting section is disposed on the wiring board 11 of the terahertz device A8, which makes it easy to attach the wires 141, 142, 144, 151, and 152. This reduces the time and effort required to manufacture the terahertz device A8.

[0139] <Thirteenth Modification> A thirteenth modification of the terahertz device of the eighth embodiment will be described with reference to the drawings. Fig. 52 is a plan view of a terahertz device A81 of the thirteenth modification. The terahertz device A81 shown in Fig. 52 differs from the terahertz device A8 shown in Fig. 49 in that a first conductive element 129 and a second conductive element 120 are employed as the conductive layer 12. In other respects, the terahertz device A81 has the same configuration as the terahertz device A7, and portions of the terahertz device A81 that are substantially the same as those of the terahertz device A8 are designated by the same reference numerals and will not be described in detail.

[0140] The terahertz device A81 of the thirteenth modified example described above has the same circuit configuration as the terahertz device A8 shown in FIG. 51, and can operate in the same manner as the terahertz device A8.

[0141] <Fourteenth Modification> A fourteenth modification of the terahertz device of the eighth embodiment will be described with reference to the drawings. Fig. 53 is a plan view of a terahertz device A82 of the tenth modification. The terahertz device A82 shown in Fig. 53 differs from the terahertz device A8 shown in Fig. 49 in that a first conductive element 125 and a second conductive element 126 are employed as the conductive layer 12. Furthermore, the connection between the first rectifying element 31 and the second rectifying element 32 is the same as that of the terahertz device A8 shown in Fig. 49.

[0142] The terahertz device A82 of the fourteenth modified example shown above has the same circuit configuration as the terahertz device A8 shown in FIG. 50, and can operate in the same manner as the terahertz device A8.

[0143] <Ninth Embodiment> Fig. 54 is a circuit diagram of a terahertz device A9 of the ninth embodiment. Fig. 55 is a plan view of a terahertz chip B9 used in the terahertz device A9 of the ninth embodiment. The terahertz device A9 differs from the terahertz device A8 and the terahertz chip B8 in that the parallel resistor 72 is omitted from the terahertz chip B9. Other than this, the terahertz device A9 has the same configuration as the terahertz device A8. Therefore, parts of the terahertz device A9 that are substantially the same as those of the terahertz device A8 are assigned the same reference numerals, and detailed descriptions of the same parts will be omitted.

[0144] The terahertz chip B9 has a current limiting unit 25 disposed therein. By disposing the current limiting unit 25, abnormal oscillation of the terahertz element 7 can be suppressed in some cases, and in this case, the parallel resistor can be omitted, as in the terahertz chip B9 shown in Fig. 55. By using such a terahertz chip B9, it is possible to manufacture a terahertz device A9 having the circuit configuration shown in Fig. 54.

[0145] <Use> A device using the terahertz device A1 shown in the first embodiment will be described. Fig. 56 is a schematic configuration diagram of a sensing device SS using the terahertz device A1. As shown in Fig. 56, the sensing device SS includes a transmitter S1, a receiver S2, and a controller S3. In the sensing device SS, the transmitter S1 includes the terahertz device A1 as a transmitter device that emits electromagnetic waves in the terahertz frequency range (terahertz waves Tz). Furthermore, the receiver S2 includes the terahertz device A1 as a receiver device that receives the terahertz waves Tz.

[0146] The controller S3 is connected to the transmitter S1 and the receiver S2. The controller S3 is a control unit as well as a processing unit that processes information and transmits it to an external device. The controller S3 transmits a control signal to the transmitter S1 to cause it to transmit the terahertz wave Tz. The controller S3 is also connected to the receiver S2 and acquires information about the terahertz wave Tz received by the receiver S2. The controller S3 then processes the received information.

[0147] The sensing device SS may be configured, for example, such that a transmitter S1 transmits terahertz waves Tz, and a receiver S2 receives the terahertz waves Tz reflected by an object Dp to detect the object. The sensing device SS may be configured such that a controller S3 detects the distance to the object Dp and the position of the object Dp, for example, from the time when the transmitter S1 transmits the terahertz waves Tz and the time when the receiver S2 detects the reflected waves.

[0148] In this way, by configuring the sensing device SS using terahertz waves Tz, highly accurate sensing is possible. Note that the above-mentioned sensing device SS may be configured such that the transmitter S1 and the receiver S2 are arranged opposite each other and an object passing in front of the transmitter S1 or the receiver S2 is detected.

[0149] The terahertz device A1 can also be used as an imaging device ST as shown in Fig. 57. Fig. 57 is a schematic configuration diagram of an imaging device ST using the terahertz device A1. As shown in Fig. 57, the imaging device ST includes a transmitter T1, a receiver T2, a controller T3, and a scanner T4. In the imaging device ST, the transmitter T1 includes the terahertz device A1 as a transmitter device that emits electromagnetic waves in the terahertz frequency range (terahertz waves Tz). Furthermore, the receiver T2 includes the terahertz device A1 as a receiver device that receives the terahertz waves Tz.

[0150] The controller T3 transmits a control signal to the transmitter T1 to cause the transmitter T1 to transmit the terahertz waves Tz. The controller T3 is also connected to the receiver S2 and acquires information about the terahertz waves Tz received by the receiver S2. The controller T3 then processes the received information. The controller T3 also controls the scanner T4. The transmitter T1 is attached to the scanner T4. The scanner T4 operates in response to a control signal from the controller T3, and moves the terahertz waves Tz transmitted from the transmitter T1 back and forth in a first direction while sequentially shifting them in a second direction perpendicular to the first direction, thereby irradiating a predetermined imaging area Ar.

[0151] The terahertz wave Tz reflected by the object placed in the imaging area Ar is detected by the receiving unit T2. The receiving unit T2 sends the received information to the controller T3, and the controller T3 acquires the shape of the object placed in the imaging area Ar based on the received information.

[0152] As described above, by using the imaging device ST using the terahertz waves Tz, it is possible to acquire the shape of an object with high precision.

[0153] <Others> The above-described embodiments should be considered to be illustrative in all respects and not restrictive, and the technical scope of the present disclosure is indicated by the claims rather than the description of the above-described embodiments, and should be understood to include all modifications that fall within the meaning and scope equivalent to the claims.

[0154] <Supplementary Note> Supplementary notes are provided for the present disclosure, the specific configuration examples of which have been shown in the above-described embodiments.

[0155] A terahertz device (A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5, A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9) according to the present disclosure includes a terahertz element (7), a current limiting unit (2, 24, 25, 26) configured to be electrically connected in series with the terahertz element (7), a first rectifying element (31) configured to be electrically connected in parallel with the terahertz element (7) and connected between the terahertz element (7) and the current limiting unit (2, 24, 25, 26), and The configuration (first configuration) includes a second rectifying element (32) that is electrically parallel to the terahertz element (7) and the first rectifying element (31) and is connected between the terahertz element (7) and the current limiting section (2, 24, 25, 26) so that its forward direction is opposite to the forward direction of the first rectifying element (31).

[0156] In the terahertz device (A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5, A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9) of the first configuration described above, the first rectifying element (31) and the second rectifying element (32) may be configured (second configuration) such that the threshold voltage (V3111, V321) of a combined element of the first rectifying element (31) and the second rectifying element (32) is greater than the upper limit of the absolute value of the value in the voltage region in which the terahertz element (7) oscillates terahertz waves.

[0157] The terahertz device (A1, A11, A12, A2, A3, A31, A32, A33, A6, A61, A62, A7, A71, A72, A73) of the first or second configuration may be provided with a terahertz chip having a configuration including a terahertz element (7) therein, and the first rectifying element (3), the second rectifying element (32), and the current limiting unit (2, 25) may be configured to be arranged outside the terahertz chip (B1, B3), and may also be configured to be arranged inside one package together with the terahertz chip (B1, B3) (third configuration).

[0158] The terahertz device (A1, A11, A12, A2, A3, A31, A32, A33, A6, A61, A62, A7, A71, A72, A73) of the third configuration may be configured (fourth configuration) to include a parallel resistor (72) that is disposed inside the terahertz chip (B1, B3) and electrically connected in parallel with the terahertz element (7).

[0159] The terahertz device (A3, A31, A32, A33, A7, A71, A72, A73) of the third configuration may be configured (fifth configuration) to include a parallel resistor (21) that is arranged outside the terahertz chip (B3) and is electrically connected in parallel with the terahertz element (7).

[0160] The terahertz device (A4, A41, A42, A5, A8, A9) of the first configuration may be provided with a terahertz chip (B4, B5, B8, B9) configured to include a terahertz element (7) and a current limiting unit (24, 26) therein, and the first rectifying element (31) and the second rectifying element (32) may be configured to be arranged outside the terahertz chip (B4, B5, B8, B9) and may be configured to be arranged inside one package together with the terahertz chip (B4, B5, B8, B9) (sixth configuration).

[0161] The terahertz device (A4, A41, A42, A8, A81, A82) of the third configuration may be configured (seventh configuration) to include a parallel resistor (21) that is disposed inside the terahertz chip (B4, B8) and is electrically connected in parallel with the terahertz element (7).

[0162] The terahertz device (A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5) of any of the first to seventh configurations may be provided with an anode terminal (Tp) and a cathode terminal (Tm), and a first end of the terahertz element (7) may be connected to the anode terminal (Tp) via a current limiting unit (2, 24), and a second end may be connected to the cathode terminal (Tm) (eighth configuration).

[0163] The terahertz device (A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9) of any of the first to seventh configurations may be provided with an anode terminal (Tp) and a cathode terminal (Tm), and a first end of the terahertz element (7) may be connected to the anode terminal (Tp), and a second end may be connected to the cathode terminal (Tm) via a current limiting unit (24, 26) (ninth configuration).

[0164] The terahertz device (A1, A11, A12, A2, A3, A31, A32, A33) of the eighth configuration includes a support (1) having a configuration in which a terahertz chip (B1, B3), a first rectifying element (31), a second rectifying element (32), and a current limiting unit (2, 24) are arranged on an upper surface, the support (1) having a first conductive element (121) configured to be connected to an anode terminal (Tp) and a second conductive element (122) configured to be connected to a cathode terminal (Tm), the terahertz chip (B1, B3) having a configuration in which a first electrode (54) configured to be connected to a first end of the terahertz element (7) and a second electrode (64) configured to be electrically connected to a second end of the terahertz element (7), a first conductive element (121, 123) of the support (1) has a first portion (121A, 123A) and a second portion (121B, 123B), the first portion (121A, 123A) and the second portion (121B, 123B) are electrically connected via a current limiting portion (2), and the second portion (2) and a first electrode (54) of the terahertz chip (B1, B3) are electrically connected via a wire (141); a second conductive element (122) of the support (1) and a second electrode (64) of the terahertz chip (B1, B3) are electrically connected via a wire (142); The support (1) may have a configuration (tenth configuration) in which the second portion (121B, 123B) of the first conductive element (121, 123) and the second conductive element (122) are electrically connected via the first rectifying element (31) and the wire (151), and the second portion (121B, 123B) of the first conductive element (121, 123) and the second conductive element (122) are electrically connected via the second rectifying element (32) and the wire (152).

[0165] The terahertz device (A6, A61, A62, A7, A71, A72, A73) of the ninth configuration includes a terahertz chip (B1, B3) configured to include at least a terahertz element (7) therein, and a B3 support (1) configured to have the terahertz chip (B1, B3), a first rectifying element (31), a second rectifying element (32), and a current limiting section (25) arranged on an upper surface thereof, wherein the support (1) includes a first conductive element (121) configured to be connected to an anode terminal (Tp) and a second conductive element (122) configured to be connected to a cathode terminal (Tm), and the terahertz chip (B1, B3) includes a first electrode (54) configured to be connected to a first end of the terahertz element (7) and a second electrode (64) configured to be electrically connected to a second end of the terahertz element (7), the second conductive element (122, 124) of the support (1) has a first portion (122A, 124A) and a second portion (122B, 124B), the first portion (122A, 124A) and the second portion (122B, 124B) are electrically connected via a current limiting portion (25), and the second portion (122B, 124B) and the second electrode (64) of the terahertz chip (B1, B3) are electrically connected via a wire (142); the first conductive element (121, 123) of the support (1) and the first electrode (54) of the terahertz chip (B1, B3) are electrically connected via a wire (141); The support (2) may have a configuration (11th configuration) in which the second portion (122B, 124B) of the second conductive element (122, 124) and the first conductive element (121, 123) are electrically connected via the first rectifying element (31) and the wire (151), and the second portion (122B, 124B) of the second conductive element (122, 124) and the first conductive element (121, 123) are electrically connected via the second rectifying element (32) and the wire (152).

[0166] The terahertz device (A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5, A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9) of the tenth or eleventh configuration may further include a resin part (13) in which a space (131) surrounding the terahertz chip (B1, B3, B4, B5, B8, B9) is formed, and a cover member (17) disposed in the resin part (13) and having a portion covering the space (131), wherein the space (131) is filled with gas (twelfth configuration).

[0167] In the terahertz device of the twelfth configuration (A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5, A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9), the cover member (17) is configured to include a first portion (171) arranged in the resin portion (131) and a second portion (172) arranged in the first portion (171), and the second portion (172) may be configured to be made of a conductive material (thirteenth configuration).

[0168] In the terahertz device of any of the first to thirteenth configurations (A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5, A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9), the current limiting section (2, 24, 25, 26) may be configured to be composed of a resistor (fourteenth configuration).

[0169] In the terahertz device of the above-mentioned 14th configuration (A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5, A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9), the resistance value of the resistor may be configured to be 100 Ω or less (15th configuration).

[0170] In the terahertz device of any of the first to thirteenth configurations (A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5, A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9), the current limiting unit (2, 24, 25, 26) may be configured to be composed of a fuse (sixteenth configuration).

[0171] In the terahertz device of any of the first to thirteenth configurations (A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5, A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9) described above, the current limiting unit (2, 24, 25, 26) may be configured to be composed of a current limiting circuit (seventeenth configuration).

[0172] The sensing device (SS) of the present disclosure may include a terahertz device (A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5, A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9) having any of the first to seventeenth configurations described above, and may have a configuration (eighteenth configuration) configured to be capable of performing imaging processing.

[0173] The imaging device (AT) of the present disclosure may be equipped with a terahertz device (A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5, A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9) having any of the first to seventeenth configurations described above, and may be configured to be capable of executing sensing processing (19th configuration).

[0174] A1, A11, A12, A2, A3, A31, A32, A33, A4, A41, A42, A5, A6, A61, A62, A7, A71, A72, A73, A8, A81, A82, A9 Terahertz device B1, B3, B4, B5, B8, B9 Terahertz chip 1 Support 11 Wiring board 12 Conductor layer 121, 123, 125, 127, 129 First conductive element 121A, 123A, 125A, 127A, 129A First part 121B, 123B, 125B, 127B, 129B Second part 121C, 123C, 129C Third part 122, 124, 126, 128, 120 Second conductive element 122A First portion 122B Second portion 128C, 120C Third portion 122R Recess 13 Resin portion 131 Space 131A First side surface 131B Second side surface 132 Metal layer 141, 142, 143, 144, 151, 152 Wire 16 Rear surface reflector metal layer 17 Cover member 171 First portion 172 Second portion 2, 24, 25, 26 Current limiting portion 21 Parallel resistor 31 First rectifying element 31A First terminal 31B Second terminal 311 First semiconductor layer 312 Second semiconductor layer 32 Second rectifying element 32A First terminal 32B Second terminal 321 First semiconductor layer 322 Second semiconductor layer 4 Semiconductor substrate 40 Insulating layer 41 Surface 5 First conductive layer 51 First portion 511 First conductive portion 512 Second conductive portion 52 First inductance portion 53 First capacitor portion 54, 55 First electrode 551 First terminal portion 552 Second terminal portion 6 Second conductive layer 61 Second portion 62 Second inductance portion 63 Second capacitor portion 64, 65 Second electrode 651 First terminal portion 652 Second terminal portion 7 Terahertz element 71 Capacitor 72 Parallel resistance SS Sensing device S1 Transmitter S2 ReceiverS3 Controller ST Imaging device T1 Transmitter T2 Receiver T3 Controller T4 Scanner V311 Voltage value V312 First breakdown voltage value V321 Voltage value

Claims

1. A terahertz device comprising: a terahertz element; a current limiting unit configured to be electrically connected in series with the terahertz element; a first rectifying element configured to be electrically parallel to the terahertz element and connected between the terahertz element and the current limiting unit; and a second rectifying element configured to be electrically parallel to the terahertz element and the first rectifying element and connected between the terahertz element and the current limiting unit so that its forward direction is opposite to the forward direction of the first rectifying element.

2. The terahertz device according to claim 1, wherein the first rectifying element and the second rectifying element are configured so that the threshold voltage of the combined element of the first rectifying element and the second rectifying element is greater than the upper limit of the absolute value of the value in the voltage region in which the terahertz element oscillates terahertz waves.

3. A terahertz device according to claim 1 or claim 2, comprising a terahertz chip configured to include the terahertz element therein, wherein the first rectifying element, the second rectifying element, and the current limiting unit are configured to be arranged outside the terahertz chip and are configured to be arranged inside a single package together with the terahertz chip.

4. A terahertz device according to claim 1 or claim 2, comprising a terahertz chip configured to include the terahertz element and the current limiting section therein, wherein the first rectifying element and the second rectifying element are configured to be arranged outside the terahertz chip and are configured to be arranged together with the terahertz chip inside a single package.

5. The terahertz device according to claim 3 or 4, which is configured to include a parallel resistor disposed inside the terahertz chip and electrically connected in parallel with the terahertz element.

6. A terahertz device according to any one of claims 3 to 5, which is configured to include a parallel resistor disposed outside the terahertz chip and electrically connected in parallel with the terahertz element.

7. A terahertz device according to any one of claims 1 to 6, comprising an anode terminal and a cathode terminal, wherein a first end of the terahertz element is connected to the anode terminal via the current limiting section, and a second end is connected to the cathode terminal.

8. A terahertz device according to any one of claims 1 to 6, comprising an anode terminal and a cathode terminal, wherein a first end of the terahertz element is connected to the anode terminal, and a second end is connected to the cathode terminal via the current limiting section.

9. A terahertz chip including at least the terahertz element therein; and a support having the terahertz chip, the first rectifying element, the second rectifying element, and the current limiting unit disposed on an upper surface thereof, wherein the support has a first conductive element connected to the anode terminal and a second conductive element connected to the cathode terminal, the terahertz chip having a first electrode configured to be connected to a first end of the terahertz element and a second electrode configured to be electrically connected to a second end of the terahertz element, the first conductive element of the support having a first portion and a second portion, the first portion and the second portion being electrically connected via the current limiting unit, and the second portion and the first electrode of the terahertz chip being electrically connected via a wire, and the second conductive element of the support and the second electrode of the terahertz chip being electrically connected via a wire, 8. The terahertz device according to claim 7, wherein the second portion of the first conductive element of the support and the second conductive element are electrically connected via the first rectifying element and a wire, and the second portion of the first conductive element and the second conductive element are electrically connected via the second rectifying element and a wire.

10. A terahertz chip comprising: a terahertz chip configured to include at least the terahertz element therein; and a support configured to have the terahertz chip, the first rectifying element, the second rectifying element, and the current limiting unit disposed on an upper surface thereof; the support comprising a first conductive element configured to be connected to the anode terminal and a second conductive element configured to be connected to the cathode terminal; the terahertz chip comprising a first electrode configured to be connected to a first end of the terahertz element and a second electrode configured to be electrically connected to a second end of the terahertz element; the second conductive element of the support having a first portion and a second portion, the first portion and the second portion being electrically connected via the current limiting unit, and the second portion and the second electrode of the terahertz chip being electrically connected via a wire; and the first conductive element of the support and the first electrode of the terahertz chip being electrically connected via a wire.

9. The terahertz device according to claim 8, wherein the second portion of the second conductive element of the support and the first conductive element are electrically connected via the first rectifying element and a wire, and the second portion of the second conductive element and the first conductive element are electrically connected via the second rectifying element and a wire.

11. A terahertz device as described in claim 9 or claim 10, further comprising: a resin part in which a space surrounding the terahertz chip is formed; and a cover member disposed on the resin part and having a portion covering the space, wherein the space is configured to be filled with gas.

12. The terahertz device according to claim 11, wherein the cover member is configured to have a first portion disposed on the resin portion and a second portion disposed on the first portion, and the second portion is configured to be made of a conductive material.

13. A terahertz device according to any one of claims 1 to 12, wherein the current limiting section is constituted by a resistor.

14. The terahertz device according to claim 13, wherein the resistance of the resistor is 100 Ω or less.

15. A terahertz device according to any one of claims 1 to 12, wherein the current limiting section is constituted by a fuse.

16. A terahertz device according to any one of claims 1 to 12, wherein the current limiting section is configured as a current limiting circuit.

17. An imaging device comprising the terahertz device according to any one of claims 1 to 16, and configured to be able to perform imaging processing.

18. A sensing device comprising the terahertz device according to any one of claims 1 to 16, and configured to be able to perform sensing processing.

Images