Antenna device and detection system

Abstract

To provide an antenna device that suppresses pixel defects while also suppressing crosstalk between antennas, thereby improving image quality and yield.SOLUTION: An antenna device includes: an antenna array including a plurality of antennas arranged on a support substrate; a signal processing substrate stacked on the support substrate; a plurality of rectifying elements arranged in accordance with the plurality of antennas, respectively; and peripheral electrodes arranged between the plurality of antennas on the support substrate. The antenna is composed of a first part electrically connected to one terminal of the rectifying element, a second part electrically connected to the other terminal of the rectifying element, a first draw wire connected to the first part, a second draw wire connected to the second part, and a first through electrode connected to the first draw wire and the signal processing substrate. The second draw wire of the antenna is connected to the peripheral electrode.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an antenna device for receiving electromagnetic waves and a detection system.

Background Art

[0002] Terahertz waves can be defined as electromagnetic waves having frequencies from 30 GHz to 30 THz. There is known a detection system that irradiates an object with terahertz waves and acquires an image by a detection device that receives the reflected terahertz waves to perform inspection.

[0003] As the detection device, a thermal sensing type sensor such as a bolometer may be used, but it is easily affected by low-frequency noise such as 1 / f noise, and furthermore, it is difficult to increase the frame rate in video imaging, so it is difficult to reduce noise. Therefore, a detection device has been proposed that realizes high speed and low noise by an antenna device including an antenna array in which antennas for receiving terahertz waves are two-dimensionally arranged as pixels and a signal processing circuit for processing signals from the antennas.

[0004] As the antenna array, Patent Document 1 discloses a configuration in which each antenna is arranged surrounded by a common electrode. The common electrode is connected to the lower conductive layer by vias to reduce impedance, thereby reducing the potential fluctuation of the common electrode and suppressing crosstalk between antennas.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In an imaging device that stacks an antenna substrate on which an antenna array is mounted and a signal processing circuit that processes signals from the antennas, each antenna at each pixel needs to be connected to the signal processing circuit via a through-electrode. In such an imaging device, increasing the resolution of the acquired image and narrowing the antenna placement pitch increases the alignment accuracy required for positioning the antenna substrate and the circuit board. In this case, in an antenna array with a large number of through-electrodes as disclosed in Patent Document 1, poor bonding of the through-electrodes is likely to occur, and there is a high possibility of pixel defects. Therefore, it is necessary to reduce the number of through-electrodes to suppress pixel defects and reduce potential fluctuations.

[0007] This disclosure is made in view of the above, and aims to provide an antenna device that suppresses crosstalk between antennas while suppressing pixel defects, thereby improving image quality and yield. [Means for solving the problem]

[0008] To achieve the above objectives, the antenna device relating to this disclosure is A first substrate having a first surface and a second surface opposite to the first surface, A signal processing substrate is laminated on the first substrate and positioned on the second surface side of the first substrate, Multiple An antenna array consisting of several antennas 、 before Multiple rectifier elements are arranged corresponding to each of the multiple antennas, Zhou Edge electrodes and, Equipped with, The aforementioned antenna is Located on the opposite side from the first side, A first portion electrically connected to one terminal of the rectifier element, Arranged on the first surface side, A second portion electrically connected to the other terminal of the rectifier element, Arranged on the first surface side, A first lead wire connected to the first part, Arranged on the first surface side, A second lead wire connected to the second part, The first lead wire and a first through electrode connected to the signal processing board, comprising The peripheral electrodes are arranged between the plurality of antennas on the first surface side. the second lead wire to is connected An antenna device characterized by the above is included. Furthermore, the antenna device related to this disclosure is Arranged on the first substrate, it includes multiple antennas, including a first antenna and a second antenna, Multiple rectifier elements arranged on the first substrate, Peripheral electrodes arranged on the first substrate, A signal processing circuit arranged on a signal processing board, Equipped with, The aforementioned first antenna and the aforementioned second antenna are, A first portion electrically connected to one of the terminals of the plurality of rectifier elements, <00><00000 A second portion electrically connected to another terminal of the plurality of terminals of the plurality of rectifier elements, A first lead wire connected to the first part, A second lead wire connected to the second part, A first through electrode connected to the first lead wire and the signal processing circuit, Equipped with, The peripheral electrodes are connected to the second lead wire of the first antenna and the second lead wire of the second antenna. Includes an antenna device characterized by the following features.

[0009] Also, in order to achieve the above object, the detection system according to the present disclosure the above antenna device, a transmission device for transmitting electromagnetic waves, a processing unit for processing a signal from the antenna device, A detection system characterized by comprising the above is included.

Advantages of the Invention

[0010] According to the present disclosure, it is possible to provide an antenna device that suppresses crosstalk between antennas while suppressing pixel defects, improving image quality and yield.

Brief Description of the Drawings

[0011] [[ID=6*]] [Figure 1] An example of a plan view of pixels of an antenna device according to the first embodiment [Figure 2] An example of a cross-sectional view of a pixel of an antenna device according to the first embodiment. [Figure 3] An example of a cross-sectional view of a pixel of an antenna device according to the first embodiment. [Figure 4] An example of a cross-sectional view of a pixel of an antenna device according to the first embodiment. [Figure 5] An example of a graph showing the output characteristics of the antenna device according to the first embodiment. [Figure 6] An example of the circuit configuration of an antenna device according to the first embodiment. [Figure 7] An example of a plan view of the antenna array of an antenna device according to the first embodiment. [Figure 8] An example of a plan view of the antenna array of an antenna device according to the first embodiment. [Figure 9] An example of a plan view of pixels of an antenna device according to the second embodiment. [Figure 10] An example of a plan view of pixels of an antenna device according to the second embodiment. [Figure 11] An example of a plan view of pixels in an antenna device according to the third embodiment. [Figure 12] Schematic diagram illustrating the camera system according to the fourth embodiment. [Modes for carrying out the invention]

[0012] Embodiments of this disclosure will be described below with reference to the drawings. However, this disclosure is not limited to the embodiments described below, and may be modified as appropriate without departing from its essence. Furthermore, in the drawings described below, components having the same function will be denoted by the same reference numerals, and their descriptions may be omitted or simplified.

[0013] (First Embodiment) An antenna device in the first embodiment of this disclosure will be described with reference to Figures 1 to 8.

[0014] <Pixel configuration> Figure 1 is a plan view showing the pixels of the antenna device in this embodiment. Figure 2 is a cross-sectional view taken along the line A-A' in Figure 1. Figure 3 is a cross-sectional view taken along the line B-B' in Figure 1.

[0015] The pixels of the antenna device in this embodiment are equipped with a ring-shaped loop antenna 101, which is an example of an antenna in this embodiment, and are placed on an antenna substrate 104, which is a support substrate. The antenna substrate 104 is made of a semiconductor substrate such as Si, GaAs, or InP. Here, the loop antenna 101 is made of a thin film of a conductive metal or alloy. Therefore, the loop antenna 101 is in contact with the antenna substrate 104 via an insulating layer 105 so as not to be electrically connected. As the material for the loop antenna 101, metals and alloys such as Ag, Au, Cu, W, Ni, Cr, Ti, Al, AlCu, AlSi, AuIn, and TiN are used. The loop antenna 101 receives electromagnetic waves in the terahertz frequency band. It receives electromagnetic waves (hereinafter simply referred to as "terahertz waves") that include at least a part of the frequency band from the millimeter wave band to the terahertz band (30 GHz to 30 THz).

[0016] The layers constituting the insulating layer 105 are, for example, silicon oxide, BPSG, PSG, BSG, silicon nitride, and silicon carbide. Furthermore, the loop antenna 101 is covered with an insulating layer 106 for protection, and the insulating layer 106 can be made of the same material as the insulating layer 105.

[0017] A rectifier element 107 is provided on the antenna substrate 104 and is connected to the loop antenna 101. The loop antenna 101 has a notch 110 to drive the rectifier element 107, and is divided into a first section 102 and a second section 103 with the rectifier element 107 in between. A capacitance is formed between the first section 102 and the second section 103 in the notch 110, resulting in capacitive coupling.

[0018] The first section 102 is electrically connected to the first lead wire 108, and the second section 103 is electrically connected to the second lead wire 109. The first lead wire 108 and the second lead wire 109 extend perpendicularly to the tangent to the loop portion of the loop antenna 101. A driving voltage or current can be applied across the rectifier element 107 via the first lead wire 108 and the second lead wire 109. The voltage application condition in this case is that the voltage is applied so that a current flows in the forward direction through the rectifier element 107.

[0019] In this embodiment, the first lead wire 108 and the second lead wire 109 are connected to the nodes of the electromagnetic field distributed in the loop antenna 101, and the antenna characteristics can be maintained even if other circuits or wiring are connected to the first lead wire 108 and the second lead wire 109. Here, an electromagnetic field node refers to a location where the impedance of the electromagnetic field distributed in the loop antenna 101 can be considered zero for the wavelength λ (resonant wavelength λ) of a radio wave of the frequency selected as the resonant frequency in the loop antenna 101. The resonant wavelength λ will be explained later in the section on <loop antenna>.

[0020] The first lead wire 108 is connected to the first through electrode 111. The first through electrode 111 is formed to penetrate the antenna substrate 104 and is connected to the signal processing circuit board 112, which serves as a signal processing substrate on which the antenna substrate 104 is laminated. An insulating layer 113 is formed between the first through electrode 111 and the antenna substrate 104 to prevent electrical connection. An adhesive layer 116 is placed between the antenna substrate 104 and the signal processing circuit board 112 for bonding. A thermosetting resin is preferred as the adhesive layer 116, and for example, benzocyclobutene (BCB) can be used.

[0021] The first through electrode 111 is manufactured by the following procedure. First, the antenna substrate 104 and the signal processing circuit board 112 are joined with an adhesive layer 116. Then, contact holes are drilled in the antenna substrate 104 at the location where the first through electrode 111 will be installed, until the wiring of the signal processing circuit board 112 is reached, using a method such as dry etching. At this time, the adhesive layer 116 and the insulating layer of the wiring layer 115 on the signal processing circuit board 112 are also removed. Furthermore, an insulating layer 113 is formed on the side wall of the hole so that the first through electrode 111 and the antenna substrate 104 do not conduct electricity. The same material as insulating layers 105 and 106 can be used for the insulating layer 113. For example, silicon oxide can be formed to a thickness of 1 μm. After that, the first through electrode 111 is manufactured by creating a metal film in the hole using sputter deposition or plating. It is desirable that the first through electrode 111 be formed from a metal with high conductivity. In this embodiment, the rectifier element is formed by plating and growing copper. In this way, a driving voltage or current output from the signal processing circuit board 112 can be applied to the rectifier element 107 via the first through electrode 111 and the first lead wire 108. Regarding the connection, a metal-to-metal connection with a metal film formed on the connection surface or a wiring connection using bumps (connecting electrodes) may also be used.

[0022] The signal processing circuit board 112 is arranged on a semiconductor substrate such as silicon, with transistor layers 114 that constitute pixel circuits and drive circuits that drive those pixel circuits, and on top of the transistor layers 114, a wiring layer 115 containing multiple insulating films and wiring. The first through electrode 111 is connected to the wiring included in the wiring layer 115.

[0023] On the antenna substrate 104, peripheral electrodes 117 are arranged around the loop antenna 101, and the second lead wire 109 is connected to the peripheral electrodes 117. The peripheral electrodes 117 are spaced apart so as not to be electrically connected to the first lead wire 108 or the first through electrode 111.

[0024] In this embodiment, the first lead wire 108, the second lead wire 109, and the peripheral electrode 117 are formed from the same conductive layer as the loop antenna 101 to facilitate manufacturing, but they may be formed from different layers or different materials via through holes. Suitable materials include metals and alloys such as Ag, Au, Cu, W, Ni, Cr, Ti, Al, AlCu, AlSi, AuIn, and TiN. Also, similar to the loop antenna 101, they are in contact with the antenna substrate 104 via an insulating layer 105 to avoid electrical connection, and are covered with an insulating layer 106 for protection.

[0025] <Recess structure> The loop antenna 101 has recess structures 118 and 119 between it and the peripheral electrode 117, and a recess structure 120 inside the loop antenna 101. The recess structures 118, 119 and 120 are indentations where a portion of the antenna substrate 104 has been removed. The recess structures 118 and 119 have a ring shape in plan view. The antenna substrate 104 is not removed below or near the first lead wire 108 and the second lead wire 109, so no step is created, and thus it is possible to prevent the wiring from being interrupted at a step in the first lead wire 108 and the second lead wire 109.

[0026] When an antenna is fabricated on an antenna substrate 104, it is known that terahertz waves propagate within the antenna substrate 104, resulting in loss. Therefore, by forming recess structures 118, 119, and 120, the antenna substrate 104 is partially removed, and by causing loss in modes other than the substrate propagation mode of the terahertz waves to be detected, it is possible to reduce the received power loss.

[0027] The recess structures 118, 119, and 120 can be formed by processing the antenna substrate 104 using a photolithography process and an etching process using the Bosch method. Alternatively, they can be manufactured by wet etching using potassium hydroxide (KOH) or tetramethylammonium hydroxide (TMAH), or by gas etching using xenon difluoride (XeF2). They can also be manufactured using sandblasting or laser ablation.

[0028] <Rectifier element> The rectifier element 107 is electrically connected to the loop antenna 101 via a contact hole opened in the insulating layer 105 that insulates the loop antenna 101 from the antenna substrate 104. Furthermore, in order to detect the frequency of terahertz waves, it is desirable to use a rectifier element 107 with high switching characteristics, such as a Schottky barrier diode. However, it is also possible to use rectifier diodes such as pn junction diodes, not just Schottky barrier diodes, as rectifier element 107.

[0029] Figure 4 is a cross-sectional view illustrating a configuration using a Schottky barrier diode as the rectifier element 107, and is a cross-sectional view taken along the line C-C' in Figure 1. In Figure 4, the signal processing circuit board 112 is omitted for simplification.

[0030] The rectifier element 107 has a configuration in which a first semiconductor layer 121, a second semiconductor layer 122 having the same conductivity as the first semiconductor layer 121 but with a lower impurity concentration than the first semiconductor layer 121, and a metal layer 123 are formed in that order on the antenna substrate 104. The surface area of ​​the first semiconductor layer 121 is larger than the surface area of ​​the second semiconductor layer 122. The first semiconductor layer 121 and the metal layer 123 serve as terminals of the rectifier element 107, and the first semiconductor layer 121 and the metal layer 123 are connected to the loop antenna 101 via contact holes opened in the insulating layer 105. In this embodiment, the first portion 102 of the loop antenna is connected to the metal layer 123, and the second portion 103 of the loop antenna is connected to the first semiconductor layer 121. A conductive plug 124 is embedded in the contact hole opened in the insulating layer 105, and the rectifier element 107 and the loop antenna 101 are connected. Tungsten can be used as the plug 124. Alternatively, a loop antenna 101 may be formed to cover the inside of the contact hole and the rectifier element 107 and the loop antenna 101 may be connected directly.

[0031] In fabricating the Schottky barrier diode, which is the rectifier element 107, the impurity concentration of the second semiconductor layer 122 is set to approximately 1 × 10⁻¹⁶ to create Schottky contacts on the silicon antenna substrate 104. 18 [pcs / cm 3 It is preferable to do the following. Furthermore, it is preferable that the thickness of the second semiconductor layer 122 be 50 nm to 500 nm. For controlling the impurity concentration, there are methods such as directly growing a silicon crystal thin film with the desired impurity concentration by epitaxy growth, or directly implanting impurity atoms into silicon by techniques such as ion implantation. For example, an impurity concentration of 2 × 10 16 [pcs / cm 3n-type silicon having [ ] is epitaxy-grown to a thickness of approximately 200 nm and used. Note that the characteristics of a Schottky barrier diode are determined by the work function of silicon (second semiconductor layer 122) and metal (metal layer 123), so the characteristics change greatly depending on the type of material used for the metal layer 123 as an electrode. For example, a 50 nm thick Co can be used for the metal layer 123. In addition, Al, W, Cr, Mo, Ni, V, Pd, Mg, Ti, etc. can generally be used. A barrier layer such as TiN may be provided on the metal layer 123.

[0032] <Loop antenna> The circumference of the loop antenna 101, which is the resonator length, can be determined by the resonant frequency of the loop antenna 101 (design resonant frequency; the frequency of the received terahertz wave). Specifically, for the wavelength λ (resonant wavelength λ) of the radio wave at the selected resonant frequency in the loop antenna 101, the circumference of the loop antenna 101 is set to a length of approximately (n+0.5)×λ (where n is 0 or a natural number), such as 0.5λ, 1.5λ, or 2.5λ. In other words, by the length of the loop antenna 101 being 0.5 times, 1.5 times, or 2.5 times the resonant wavelength λ of the antenna, the loop antenna 101 can receive terahertz waves at the frequency corresponding to the resonant wavelength λ.

[0033] The resonant wavelength of an object refers to the wavelength at which the terahertz wave received by the receiver (loop antenna 101) propagates through that object. Specifically, the resonant wavelength of the loop antenna 101 refers to the wavelength of the terahertz wave that resonates with the loop antenna 101 as it propagates through it. Therefore, the resonant wavelength in the air, the resonant wavelength of the loop antenna 101, and the resonant wavelength of the antenna substrate 104 are all different values. The resonant wavelength of the loop antenna 101 is different from the resonant wavelength of the air surrounding the loop antenna 101 and the resonant wavelength of the antenna substrate 104. 104 can be expressed as a combined value of the relative permittivity of the insulating layer 105 that joins the loop antenna 101 and the antenna substrate 104. In this embodiment, for example, if the loop antenna 101 receives a terahertz wave with a frequency of 1 THz and a wavelength of 300 μm in air, the resonant wavelength λ of the loop antenna 101 will be 150 μm, which is about half of the wavelength of 300 μm in air.

[0034] In this embodiment, the circumference of the loop antenna 101 is adjusted to be 1.5λ with respect to the wavelength λ (resonant wavelength λ) of the resonant frequency (design resonant frequency) of the loop antenna 101. In other words, the relationship 2πr = 1.5λ holds between the radius r of the loop antenna 101 and the resonant wavelength λ. When miniaturizing the loop antenna 101, the circumference of the loop antenna 101 may be adjusted to 0.5λ so that the relationship 2πr = 0.5λ holds. On the other hand, if the receiving area of ​​the loop antenna 101 is to be increased, the circumference of the loop antenna 101 may be adjusted to (n + 0.5) × λ, thereby increasing the value of the natural number n. However, since the impedance of the loop antenna 101 also changes when the circumference of the loop antenna 101 is adjusted, it is necessary to adjust the impedance matching with the rectifier element 107.

[0035] Considering the reduction of antenna resistance loss and the suppression of manufacturing variations, the width of the loop antenna 101 is preferably 0.1 μm to 10 μm, and the film thickness of the loop antenna 101 is preferably 0.1 μm to 1 μm.

[0036] The thickness of the insulating layer 105 that joins the loop antenna 101 and the antenna substrate 104 is preferably 1.6 μm to 2.6 μm. Within this range, it is possible to achieve both impedance matching between the loop antenna 101 and the rectifier element 107 and suppression of connection failures at the contact holes between the loop antenna 101 and the rectifier element 107.

[0037] <Pillar width> The pillar width of the loop portion of the loop antenna 101 is defined on the antenna substrate 104 below the loop antenna 101, which is sandwiched between recess structure 118 and recess structure 120, or recess structure 119 and recess structure 120. Specifically, in a plan view of the loop antenna 101, the pillar width is the dimension perpendicular to the tangent to the loop portion of the loop antenna 101 (dimension L1 indicated by the arrow in Figures 1 and 2).

[0038] As described above, the resonant wavelength λ of the loop antenna 101 depends on the relative permittivity of the air surrounding the loop antenna 101, the antenna substrate 104, and the insulating layer 105 that joins the loop antenna 101 and the antenna substrate 104. Therefore, the resonant wavelength λ depends on the pillar width L1, which is a dimension of a part of the antenna substrate 104.

[0039] Figure 5 is a graph showing the relationship between the pillar width L1 and the normalized antenna received output (a standard value where the peak value of the antenna received output is set to 1). According to Figure 5, the antenna received output peaks at a pillar width of λ / 24. If the effective range is defined as the range until the antenna received output is halved, the pillar width is preferably λ / 30 to λ / 18. When receiving terahertz waves with a frequency of 0.5 THz and a wavelength of 600 μm in air, the resonant wavelength λ of the loop antenna 101 is 300 μm, and the pillar width L1 is preferably 10 μm to 17 μm.

[0040] <Reflection layer> One means of adjusting the antenna's radiation pattern is to provide a reflective layer 125 on the back surface of the antenna substrate 104, on the front surface of the signal processing circuit board 112, or between the antenna substrate 104 and the signal processing circuit board 112. That is, it is preferable to provide a reflective layer 125 between the loop antenna 101 and the signal processing circuit board 112. The material of the reflective layer 125 and Similar to the loop antenna 101, metal or alloy is used for the reflective layer 125. In order to obtain effects such as improved directivity from the reflective layer 125, the distance between the loop antenna 101 and the reflective layer 125 is set to about 0.5 times the resonant wavelength of the antenna substrate 104, thereby allowing the radiation pattern to be adjusted without degrading the reception sensitivity of terahertz waves.

[0041] Furthermore, in order for the reflective layer 125 to play a role in adjusting the directivity of the loop antenna 101, it is preferable that the reflective layer 125 covers an area larger than the loop antenna 101. More preferably, it is preferable that it covers an area within 0.25 times the resonant wavelength at a distance from the loop antenna 101. As a result, most of the terahertz waves propagating in the antenna substrate 104 are reflected by the reflective layer 125 without being affected by scattering and are re-radiated into the atmosphere, so that the radiation pattern can be concentrated perpendicular to the loop antenna 101.

[0042] Furthermore, if the reflective layer 125 is electrically connected between pixels, terahertz waves may propagate through the reflective layer 125, which is made of a conductive metal, causing the received terahertz waves to leak to adjacent pixels. Therefore, in order to prevent crosstalk between pixels and to prevent noise interference, it is preferable that the reflective layer 125 is electrically insulated from other components and the reflective layers 125 of other pixels, that is, in an electrically floating state. For this reason, it is preferable to form an insulating layer 126 between the antenna substrate 104 and the reflective layer 125.

[0043] <Signal Processing Circuit Board> Figure 6 shows an example of a circuit mounted on the signal processing circuit board 112, which is the signal processing board of the antenna device in this embodiment.

[0044] The signal processing circuit board 112 includes a pixel circuit area 127, a vertical scanning circuit 128, a readout circuit 129, an A / D conversion circuit 130, a signal output circuit 131, and a timing generator (T / G) 132. The pixel circuit area 127 contains a large number of pixel circuits arranged in a two-dimensional manner. Each pixel circuit is connected to each loop antenna 101 in the antenna array of the antenna board 104, and performs signal accumulation and amplification from the antennas. The vertical scanning circuit 128 outputs control signals to sequentially select the pixel circuits in the pixel circuit area 127 row by row. The readout circuit 129 includes, for example, a column amplifier, a correlated double sampling (CDS) circuit, and an adder circuit, and performs amplification, addition, etc., on the pixel signals read out from the pixel circuits of the row selected by the vertical scanning circuit 128 via vertical signal lines (not shown). The A / D conversion circuit 130 converts the analog signals based on the pixel signals output from the readout circuit 129 into digital signals. The signal output circuit 131 transmits the digital signal output from the A / D conversion circuit 130 as an image signal to an external device in a predetermined manner. The timing generator (T / G) 132 transmits timing signals to the vertical scanning circuit 128, the readout circuit 129, the A / D conversion circuit 130, and the signal output circuit 131 to control the operation of each circuit. It also receives control signals from external devices to switch operating modes or change the pulse width and output timing of the timing signals.

[0045] <Antenna array configuration> Figure 7 is an example of a plan view showing the arrangement of the antenna array of the antenna device in this embodiment. Figure 7 shows an example of a 4x5 antenna array in which multiple pixels, as described using Figures 1 to 4, are arranged on the antenna substrate 104.

[0046] As shown in Figure 7, peripheral electrodes 117 are positioned between the loop antennas at each pixel, and the second lead wires 109 of each pixel are commonly connected by the peripheral electrodes 117. It is preferable to apply a fixed voltage to the peripheral electrodes 117. The fixed voltage may be 0V (ground potential), or any constant voltage other than 0V.

[0047] Pixel circuits are arranged on the signal processing circuit board 112 on which the antenna substrate 104 is stacked, corresponding to the pixels, and the first lead line 108 of each pixel is connected to the pixel circuit via a first through electrode 111. Therefore, the signals from the antenna of each pixel are read out independently via their respective first lead line 108 and first through electrode 111.

[0048] The peripheral electrodes 117 are arranged in the antenna array region 134 (the region indicated by the dashed line). The row dimension of the antenna array region 134 is defined as the number of rows of the pixel pitch, and the column dimension is defined as the number of columns of the pixel pitch. The pixel pitch is preferably less than or equal to the wavelength of the received terahertz wave in the atmosphere, and more preferably less than or equal to half the wavelength of the received terahertz wave in the atmosphere. The antenna array region 134 illustrated in Figure 7 shows an example where the row dimension is 4 times the pixel pitch and the column dimension is 5 times the pixel pitch.

[0049] It is preferable to cover more than 50% of the antenna array region 134 with peripheral electrodes 117, excluding the regions of recess structures 118, 119, and 120. This is because, since the antenna substrate 104 is covered with a conductive layer, the received power loss due to the propagation of terahertz waves within the antenna substrate 104 can be reduced, and disturbances in the radiation direction of terahertz waves can be suppressed. In addition, the area of ​​the peripheral electrodes 117 is increased, the impedance is reduced, the potential fluctuations of the peripheral electrodes 117 are suppressed, and inter-pixel crosstalk can be reduced.

[0050] However, it is necessary to secure space for the loop antenna 101, the first lead wire 108, the second lead wire 109, and the recess structures 118, 119, and 120 for the stable fabrication of these. For this reason, it is more preferable to cover 75% or less of the area of ​​the antenna array region 134, excluding the areas of the recess structures 118, 119, and 120, with the peripheral electrodes 117.

[0051] In the outer periphery of the antenna array region 134, it is easier to secure space for placing through electrodes on the peripheral electrodes 117, so multiple second through electrodes 133 can be placed. The second through electrodes 133 may be placed on all four sides of the peripheral electrodes 117, on two opposing sides, or on only one side. By connecting the second through electrodes 133 to the wiring of the signal processing circuit board 112, the impedance of the peripheral electrodes 117 can be reduced, further reducing potential fluctuations. The second through electrodes 133 can be manufactured using the same process as the first through electrodes 110.

[0052] Figure 8 is another example of a plan view showing the arrangement of the antenna array in the antenna device of this embodiment. The difference from the configuration in Figure 7 is that it has a pad terminal 135 connected to a peripheral electrode 117 which is connected to all pixels in common. The pad terminal 135 is formed of the same conductive layer as the peripheral electrode 117, with the surface of the conductive layer open. Therefore, external power circuits, control circuits, etc. can be connected using wire bonding or an anisotropic conductive film. Note that the pad terminal 135 and the peripheral electrode 117 may be connected via through holes and different conductive layers.

[0053] As described above, according to the configuration of this embodiment, through electrodes are placed only on the first leader line 108, and the second leader line 109 is connected in common to all pixels. Furthermore, since no through electrodes are placed on the second leader line 109, the number of through electrodes can be reduced accordingly, thereby reducing the possibility of bonding defects.

[0054] Furthermore, since the pixel circuit is arranged on the signal processing circuit board 112 in accordance with the loop antenna 101 of each pixel, it is necessary to secure a wiring area for connecting the through electrodes. Therefore, reducing the number of through electrodes required per pixel improves the design flexibility of the pixel circuit and improves the resolution of the pixel. It contributes to improvement.

[0055] Furthermore, by reducing the number of through electrodes, the impedance of the peripheral electrodes can be lowered, thereby reducing the potential fluctuations of the peripheral electrode 117. As a result, the operation of the antenna device becomes more stable, inter-pixel crosstalk is suppressed, and image quality can be improved.

[0056] (Second embodiment) An antenna device according to a second embodiment of this disclosure will be described with reference to Figures 9 and 10. The antenna device according to the second embodiment differs from the antenna device according to the first embodiment in that it has distributed constant filters on the first leader line 108 and the second leader line 109. A stub is used as the distributed constant filter. In this embodiment, the same configuration as in the first embodiment will not be described.

[0057] The antenna device in this embodiment includes a first stub 201 connected to a first lead wire 108 and a second stub 202 connected to a second lead wire 109. The first stub 201 and the second stub 202 are metal wirings formed from the same conductive layer as the loop antenna 101, the first lead wire 108, the second lead wire 109, and the peripheral electrodes 117. They are also in contact with the antenna substrate 104 via an insulating layer 105 so as not to be electrically connected, and are covered with an insulating layer 106 for protection.

[0058] By adjusting the position and shape of the stub, it is possible to add a distributed-parameter filter to the first leader line 108 and the second leader line 109. For example, with respect to the resonant wavelength λ, a notch filter with respect to the wavelength λ can be formed by providing a stub with a length of approximately λ / 4 at a position approximately λ / 4 from the node of the electromagnetic field (the connection point of the first leader line 108 and the second leader line 109). In Figure 9, the first stub 201 and the second stub 202 are shown as an example of an L-shaped stub, but various shapes of stubs, such as rectangular or fan-shaped, can be applied. By providing such a distributed-parameter filter, the pixels composed of the rectifier element 107, the loop antenna 101, and the recess structures 118, 119, and 120 can be easily isolated from the signal processing circuit board 112 to which the first leader line 108 is connected. Alternatively, pixels composed of the rectifier element 107, loop antenna 101, and recess structures 118, 119, and 120 can be easily isolated from the surrounding electrode 117, to which the second lead line 109 is connected. As a result, it becomes easier to maintain impedance matching in the antenna device.

[0059] As shown in Figure 9, the L-shaped first stub 201 and the first lead wire 108, or the L-shaped second stub 202 and the second lead wire 109, face each other. With this configuration, the direction of the current distributed in the first stub 201 and the first lead wire 108, or the second stub 202 and the second lead wire 109, is opposite to each other. As a result, electromagnetic fields leaking to the outside from the first lead wire 108, the second lead wire 109, the first stub 201, and the second stub 202 are suppressed, and side lobes and spread of directivity in the antenna's directivity can be suppressed.

[0060] Next, the positional relationship between the connection point of the second stub 202 in the second lead wire 109 and the surrounding electrode 117 will be explained.

[0061] At the connection point of the second stub 202, the electric field is minimal at the resonant wavelength λ, and the impedance is almost zero. Therefore, by connecting the second lead wire 109 and the peripheral electrode 117 as close as possible to the connection point of the second stub 202, the current distribution can be suppressed and the potential of the peripheral electrode 117 can be stabilized.

[0062] Figure 10 is an enlarged view of the connection point of the second stub 202 in the second leader line 109. L2 is defined as the distance between the center of the line width of the second stub 202 at the connection point and the end of the peripheral electrode 117.

[0063] In this embodiment, it is preferable that the distance L2 be 1 / 10 or less of the resonant wavelength λ. More preferably, the distance L2 is 1 / 20 or less of the resonant wavelength λ. This is because, in electromagnetic field theory, if the size is 1 / 20 to 1 / 10 or less of the resonant wavelength λ, the effects of reflection, refraction, and scattering are extremely small with respect to that wavelength λ, and it can be considered as being in contact with the wavelength. Furthermore, in computer simulations such as the finite element method, the above size is used as an indicator of the mesh size.

[0064] When receiving terahertz waves with a frequency of 0.5 THz and a wavelength of 600 μm in air, the resonant wavelength λ of the loop antenna 101 is 300 μm, and the distance L2 is preferably 30 μm or less, and more preferably 15 μm or less.

[0065] As described above, according to the configuration of this embodiment, a second stub 202 is provided connected to the second lead wire 109, and the second lead wire 109 and the peripheral electrode 117 are connected as close as possible to the connection point. At the connection point of the second stub 202, the electric field is minimized at the resonant wavelength λ, and by connecting the second lead wire 109 and the peripheral electrode 117 as close as possible to the connection point, the current distribution can be suppressed, and the potential fluctuation of the peripheral electrode 117 can be reduced. As a result, the operation of the antenna device is stabilized, crosstalk between pixels is suppressed, and image quality can be improved.

[0066] (Third embodiment) An antenna device according to a third embodiment of this disclosure will be described with reference to Figure 11. The antenna device according to the third embodiment differs from the antenna device according to the second embodiment in the shape of the portion where the second lead wire 109 connects to the peripheral electrode 117. In this embodiment, the same configuration as in the first and second embodiments will not be described.

[0067] In the third embodiment, the peripheral electrode 117 has a notch 301 at the point where the second lead wire 109 connects to the peripheral electrode 117. The second lead wire 109 is connected to the peripheral electrode 117 inside the notch 301.

[0068] As mentioned above, since the second stub 202 is positioned at approximately λ / 4 of the electromagnetic field node (the connection point between the loop antenna 101 and the second lead wire 109) relative to the resonant wavelength λ, the second lead wire 109 needs to be of that length. Therefore, by connecting the second lead wire 109 within the notch 301, the required length of the second lead wire 109 can be secured while ensuring a wide area for the peripheral electrode 117.

[0069] Although this embodiment describes a configuration that includes a second stub 202, the above-described configuration of the notch 301 can also be applied to configurations that do not include a second stub 202, such as the first embodiment.

[0070] As described above, with the configuration of this embodiment, since the second lead wire 109 is connected to the peripheral electrode 117 inside the notch 301 formed in the peripheral electrode 117, the area of ​​the peripheral electrode 117 can be widened while ensuring the required length of the second lead wire 109. Therefore, the impedance of the peripheral electrode 117 can be lowered, and the potential fluctuation of the peripheral electrode 117 can be reduced. As a result, the operation of the antenna device becomes stable, crosstalk between pixels is suppressed, and image quality can be improved.

[0071] (Fourth embodiment) The detection system according to this embodiment will be described with reference to Figure 12. The detection system may be a system capable of capturing images, for example, a camera system. In this embodiment, a camera system will be used as an example. Figure 12 is a schematic diagram illustrating the configuration of a camera system 1200 using terahertz waves.

[0072] The camera system 1200 includes a transmitter 1201, a detection device 1202, and a processing unit 1203. The transmitter 1201 is capable of transmitting electromagnetic waves such as terahertz waves, and may be an antenna device using a semiconductor element such as a resonant tunneling diode (RTD). The detection device 1202 can be an antenna device as described in each embodiment. The detection device 1202 is capable of detecting electromagnetic waves transmitted from the transmitter 1201. The terahertz waves transmitted from the transmitter 1201 are reflected by the subject 1205 and detected by the detection device 1202. The processing unit 1203 processes the signal detected by the detection device 1202. Image data generated by the processing unit 1203 is output from the output unit 1204. With this configuration, a terahertz image can be acquired.

[0073] The transmitter 1201 and the detection device 1202 may be provided with an optical section. The optical section may consist of multiple layers and may include at least one material that is transparent to terahertz waves, such as polyethylene, Teflon®, high-resistance silicon, or polyolefin resin.

[0074] The camera system described in this embodiment is merely an example, and other configurations are possible. In particular, the information acquired by the system is not limited to image information; it may also be a detection system that detects signals.

[0075] Each embodiment merely illustrates an example of how the present invention can be implemented, and the technical scope of the invention should not be interpreted as being limited by these embodiments. In other words, the present invention can be implemented in various forms without departing from its technical concept or its main features.

[0076] For example, in the above embodiment, at least one of the recess structures 118 and 119 between the loop antenna 101 and the peripheral electrode 117, and the recess structure 120 inside the loop antenna 101, may be provided. Even in this case, the antenna substrate 104 is partially removed, and by causing loss to modes other than the substrate propagation mode of the terahertz wave to be detected, a reduction in received power loss can be achieved.

[0077] This embodiment includes the following configuration. (Configuration 1) An antenna array consisting of multiple antennas arranged on a support substrate, A signal processing board laminated on the support substrate, Multiple rectifier elements arranged in accordance with each of the aforementioned multiple antennas, Peripheral electrodes arranged between the plurality of antennas on the support substrate, Equipped with, The aforementioned antenna is A first portion electrically connected to one terminal of the rectifier element, A second portion electrically connected to the other terminal of the rectifier element, A first lead wire connected to the first part, A second lead wire connected to the second part, The first lead wire and the first through electrode connected to the signal processing board, It consists of, The second lead wire of the antenna is connected to the peripheral electrode. An antenna device characterized by the following features. (Configuration 2) The antenna device according to Configuration 1, characterized in that a recess structure is formed between the antenna and the peripheral electrode and on the inside of the antenna. (Configuration 3) The recess structure is formed between the antenna and the peripheral electrode and inside the antenna, In a plan view of the antenna, the dimension of the support substrate below the antenna, sandwiched within the recess structure, perpendicular to the tangent to the loop portion of the antenna, is between 1 / 30 and 1 / 18 of the antenna's resonant wavelength. The antenna device according to configuration 2, characterized in that it is a device that provides an antenna device. (Configuration 4) The recess structure is formed between the antenna and the peripheral electrode and inside the antenna, In a plan view of the antenna, the dimension of the support substrate below the antenna, sandwiched within the recess structure, perpendicular to the tangent to the loop portion of the antenna, is 10 μm to 17 μm. The antenna device according to configuration 2, characterized in that it is a device that provides an antenna device. (Configuration 5) An antenna device according to any one of Configurations 2 to 4, characterized in that, in a plan view of the support substrate, 50% or more of the area occupied by the antenna array, excluding the area occupied by the recess structure, is covered by the peripheral electrodes. (Configuration 6) An antenna device according to any one of Configurations 2 to 4, characterized in that, in a plan view of the support substrate, 75% or less of the area occupied by the antenna array, excluding the area occupied by the recess structure, is covered by the peripheral electrodes. (Configuration 7) An antenna device according to any one of Configurations 1 to 6, characterized in that it comprises a second through electrode that electrically connects the peripheral electrode and the signal processing board at the outer periphery of the antenna array. (Configuration 8) The antenna device according to any one of Configurations 1 to 7, characterized by comprising a pad terminal formed in the same conductive layer as the peripheral electrode. (Configuration 9) The antenna device according to any one of Configurations 1 to 8, characterized in that the first lead wire, the second lead wire, and the peripheral electrode are formed of the same conductive layer as the antenna. (Configuration 10) The antenna device according to any one of Configurations 1 to 9, characterized in that the second lead wire has a stub. (Configuration 11) The antenna device according to Configuration 10, characterized in that the length of the stub is 1 / 4 of the resonant wavelength of the antenna. (Configuration 12) The antenna device according to configuration 10 or 11, characterized in that the stub is formed of the same conductive layer as the antenna. (Configuration 13) An antenna device according to any one of Configurations 10 to 12, characterized in that the second lead wire and the peripheral electrode are connected at a position less than or equal to 1 / 10 of the resonant wavelength of the antenna from the connection position of the second lead wire and the stub. (Configuration 14) An antenna device according to any one of Configurations 10 to 13, characterized in that the second lead wire and the peripheral electrode are connected at a position less than or equal to 1 / 20 of the resonant wavelength of the antenna from the connection position of the second lead wire and the stub. (Configuration 15) An antenna device according to any one of Configurations 10 to 13, characterized in that the second lead wire and the peripheral electrode are connected at a position 30 μm or less from the connection position of the second lead wire and the stub. (Configuration 16) An antenna device according to any one of Configurations 10 to 13, characterized in that the second lead wire and the peripheral electrode are connected at a position 15 μm or less from the connection position of the second lead wire and the stub. (Configuration 17) The antenna device according to any one of Configurations 10 to 16, characterized in that the stub has a portion that extends to face the second lead wire. (Configuration 18) The peripheral electrode has a notch formed therein, The second lead wire is connected to the peripheral electrode inside the notch. An antenna device according to any one of configurations 1 to 17, characterized by the features described herein. (Configuration 19) The antenna device according to any one of Configurations 1 to 18, characterized in that the rectifier element is a Schottky barrier diode. (Configuration 20) The antenna device according to any one of Configurations 1 to 19, characterized in that the length of the antenna is 0.5 times, 1.5 times, or 2.5 times the resonant wavelength of the antenna. (Configuration 21) The antenna device according to any one of Configurations 1 to 20, characterized in that the width of the antenna is 0.1 μm to 10 μm. (Configuration 22) The antenna device according to any one of Configurations 1 to 21, characterized in that the thickness of the antenna is 0.1 μm to 1 μm. (Configuration 23) An antenna device according to any one of Configurations 1 to 22, characterized in that a reflective layer made of metal or an alloy is provided between the support substrate and the signal processing substrate. (Configuration 24) An antenna device according to any one of Configurations 1 to 23, characterized in that a fixed voltage is applied to the peripheral electrodes. (Configuration 25) The antenna device according to any one of Configurations 1 to 24, characterized in that the antenna device detects terahertz waves having a frequency of 0.03 THz or more and 30 THz or less. (Configuration 26) The antenna device according to any one of Configurations 1 to 25, characterized in that the antenna is a loop antenna. (Configuration 27) An antenna device described in any one of Configurations 1 to 26, A transmitting device for emitting electromagnetic waves, A processing unit that processes signals from the aforementioned antenna device, A detection system characterized by comprising the following features. [Explanation of Symbols]

[0078] 100 Antenna device, 101, 102, 103 Loop antenna, 104 Antenna board, 107 Rectifier element, 108, 109 Lead wires, 111 Through electrode, 112 Signal processing circuit board, 117 Peripheral electrode

Claims

1. A first substrate having a first surface and a second surface opposite to the first surface, A signal processing substrate is laminated on the first substrate and positioned on the second surface side of the first substrate, An antenna array consisting of multiple antennas, Multiple rectifier elements arranged in accordance with each of the aforementioned multiple antennas, Peripheral electrodes and Equipped with, The aforementioned antenna is A first portion, which is arranged on the opposite side from the first side and is electrically connected to one terminal of the rectifier element, A second portion, arranged on the first side, is electrically connected to the other terminal of the rectifier element, A first leader wire, positioned on the first surface side and connected to the first portion, A second lead wire, positioned on the first surface side and connected to the second portion, The first lead wire and the first through electrode connected to the signal processing board, It consists of, The peripheral electrodes are positioned between the plurality of antennas on the first side and connected to the second lead wires. An antenna device characterized by the following features.

2. The antenna device according to claim 1, characterized in that a recess structure is formed between the antenna and the peripheral electrode and on the inside of the antenna.

3. The recess structure is connected between the antenna and the peripheral electrode and inside the antenna. In a plan view of the antenna, the dimension of the first substrate below the antenna, sandwiched within the recess structure, perpendicular to the tangent to the loop portion of the antenna, is between 1 / 30 and 1 / 18 of the resonant wavelength of the antenna. The antenna device according to feature 2.

4. The recess structure is connected between the antenna and the peripheral electrode and inside the antenna. In a plan view of the antenna, the dimension of the first substrate below the antenna, sandwiched between the recess structures, perpendicular to the tangent to the loop portion of the antenna, is 10 μm to 17 μm. The antenna device according to feature 2.

5. The antenna device according to claim 2, characterized in that, in a plan view of the first substrate, 50% or more of the area occupied by the antenna array, excluding the area occupied by the recess structure, is covered by the peripheral electrodes.

6. The antenna device according to claim 2, characterized in that, in a plan view of the first substrate, 75% or less of the area occupied by the antenna array, excluding the area occupied by the recess structure, is covered by the peripheral electrodes.

7. The antenna device according to any one of claims 1 to 6, further characterized by comprising a second through-electrode that electrically connects the peripheral electrode and the signal processing substrate at the outer periphery of the antenna array.

8. The antenna device according to any one of claims 1 to 6, characterized in that it comprises a pad terminal formed in the same conductive layer as the peripheral electrode.

9. The antenna device according to any one of claims 1 to 6, characterized in that the first lead wire, the second lead wire, and the peripheral electrode are formed of the same conductive layer as the antenna.

10. The antenna device according to any one of claims 1 to 6, characterized in that the second lead wire has a stub.

11. The antenna device according to claim 10, characterized in that the length of the stub is 1 / 4 of the resonant wavelength of the antenna.

12. The antenna device according to claim 10, characterized in that the stub is formed of the same conductive layer as the antenna.

13. The antenna device according to claim 10, characterized in that the second lead wire and the peripheral electrode are connected at a position less than or equal to 1 / 10 of the resonant wavelength of the antenna from the connection position of the second lead wire and the stub.

14. The antenna device according to claim 10, characterized in that the second lead wire and the peripheral electrode are connected at a position less than or equal to 1 / 20 of the resonant wavelength of the antenna from the connection position of the second lead wire and the stub.

15. The antenna device according to claim 10, characterized in that the second lead wire and the peripheral electrode are connected at a position 30 μm or less from the connection position of the second lead wire and the stub.

16. At a position 15 μm or less from the connection position between the second lead wire and the stub, the second The antenna device according to claim 10, characterized in that the lead wire and the peripheral electrode are connected.

17. The antenna device according to claim 10, characterized in that the stub has a portion that extends to face the second lead wire.

18. A notch is formed in the peripheral electrode, The second lead wire is connected to the peripheral electrode inside the notch. The antenna device according to any one of claims 1 to 6.

19. The antenna device according to any one of claims 1 to 6, characterized in that the width of the antenna is 0.1 μm to 10 μm.

20. The antenna device according to any one of claims 1 to 6, characterized in that the thickness of the antenna is 0.1 μm to 1 μm.

21. The antenna device according to any one of claims 1 to 6, characterized in that the rectifier element is a Schottky barrier diode.

22. The antenna device according to any one of claims 1 to 6, characterized in that the length of the antenna is 0.5 times, 1.5 times, or 2.5 times the resonant wavelength of the antenna.

23. The antenna device according to any one of claims 1 to 6, characterized in that a reflective layer made of metal or an alloy is provided between the first substrate and the signal processing substrate.

24. The antenna device according to any one of claims 1 to 6, characterized in that a fixed voltage is applied to the peripheral electrodes.

25. The antenna device according to any one of claims 1 to 6, characterized in that it detects terahertz waves having a frequency of 0.03 THz or more and 30 THz or less.

26. The antenna device according to any one of claims 1 to 6, characterized in that the antenna is a loop antenna.

27. An antenna device according to any one of claims 1 to 6, A transmitting device for emitting electromagnetic waves, A processing unit that processes signals from the aforementioned antenna device, A detection system characterized by comprising the following features.

28. The antenna device according to any one of claims 1 to 6, further comprising a second through electrode that is electrically connected to the peripheral electrode and positioned on the outer periphery of the antenna array region.

29. The antenna device according to claim 28, characterized in that the number of the plurality of antennas in the antenna array region is equal to the number of the first through-electrodes.

30. The antenna device according to any one of claims 1 to 6, further comprising a pad terminal electrically connected to the peripheral electrode.

31. The antenna device according to any one of claims 1 to 6, further comprising a pad terminal formed in a conductive layer common to the peripheral electrode.

32. A first substrate is arranged, and a plurality of antennas including a first antenna and a second antenna, Multiple rectifier elements arranged on the first substrate, Peripheral electrodes arranged on the first substrate, A signal processing circuit arranged on a signal processing board, Equipped with, The first antenna and the second antenna are, A first portion electrically connected to one of the terminals of the plurality of rectifier elements, A second portion electrically connected to another terminal of the plurality of terminals of the plurality of rectifier elements, A first lead wire connected to the first part, A second lead wire connected to the second part, A first through electrode connected to the first lead wire and the signal processing circuit, Equipped with, The peripheral electrodes are connected to the second lead wire of the first antenna and the second lead wire of the second antenna. An antenna device characterized by the following features.

33. The antenna device according to claim 32, further comprising a second through electrode electrically connected to the peripheral electrode and positioned on the outer periphery of the region where the first antenna and the second antenna are located.

34. The antenna device according to claim 32 or 33, A transmitting device for emitting electromagnetic waves, A processing unit that processes signals from the aforementioned antenna device, A detection system characterized by comprising the following features.

Images