Detection element, radiation detection device, and Compton camera

Abstract

A detection element comprises: an exposed electrode exposed on the first surface side of an insulating substrate and including a first exposed electrode, a second exposed electrode arranged in a first direction of the first exposed electrode, a third exposed electrode arranged in a second direction intersecting the first direction of the first exposed electrode, and a fourth exposed electrode arranged in the second direction of the second exposed electrode and in the first direction of the third exposed electrode; a first electrode pattern arranged on the opposite side of the first surface and including a pattern connected to the first exposed electrode and the second exposed electrode and a pattern connected to the third exposed electrode and the fourth exposed electrode; a second electrode pattern having a first exposed portion including a pattern arranged along the second direction, the first exposed portion being exposed on the first surface side and being arranged separately from the exposed electrode; and a third electrode pattern having a second exposed portion including a pattern arranged along the third direction and sandwiched by the first electrode pattern and the second electrode pattern, the second exposed portion being exposed on the first surface side and being arranged separately from the exposed electrode and the second electrode pattern.

Description

Technical Field

[0001] The present disclosure relates to a detection element, a radiation detection device, and a Compton camera. Background Art

[0002] Research on radiation detection devices based on gas electron amplification of pixel-type electrodes is progressing. Such radiation detection devices detect radiation by using pixel-type electrodes. At this time, the trajectory of charged particles can be detected (for example, Patent Document 1). Radiation detection devices using this technique are used as imaging devices for nuclear medicine that use drugs (radioactive isotopes) that emit extremely small amounts of radiation as markers to diagnose and treat diseases, such as positron emission tomography (PET) examinations and single photon emission computed tomography (SPECT) examinations. In addition, as other fields, applications as devices for monitoring radiation doses in the environment are expected.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2002-6047 Summary of the invention

[0006] Problems to be solved by the invention

[0007] According to the radiation detection device disclosed in Patent Document 1, radiation (charged particles) generates electrons by interacting with gas, and the electrons are captured at the pixel-type electrodes, thereby indirectly detecting radiation. However, if a large number of electrons are generated, there is a situation where the electrons are captured at multiple pixel-type electrodes at the same time. In such a case, the pixel-type electrode that captures the electron cannot be determined, resulting in a decrease in detection efficiency and detection accuracy.

[0008] An object of the present disclosure is to improve the detection efficiency and detection accuracy of radiation in a radiation detection device.

[0009] Means for solving problems

[0010] According to an embodiment of the present disclosure, a detection element is provided, which is characterized in that it includes: exposed electrodes, which are multiple exposed electrodes arranged to be exposed on the first surface side of an insulating substrate, including at least a first exposed electrode, a second exposed electrode arranged in a first direction of the first exposed electrode, a third exposed electrode arranged in a second direction intersecting with the first direction of the first exposed electrode, and a fourth exposed electrode arranged in the second direction of the second exposed electrode and arranged in the first direction of the third exposed electrode; a first electrode pattern, which is a first electrode pattern arranged on the second surface side opposite to the first surface of the insulating substrate, and includes at least a pattern connected to the first exposed electrode and the second exposed electrode through a first through electrode, and a pattern connected to the third exposed electrode and the fourth exposed electrode through a second through electrode. A pattern for connecting exposed electrodes; a second electrode pattern, as a second electrode pattern having a first exposed portion, at least including a pattern corresponding to the first exposed electrode and the third exposed electrode and arranged along the second direction, and a pattern corresponding to the second exposed electrode and the fourth exposed electrode and arranged along the second direction, the first exposed portion being exposed on the first surface side and arranged separately from the exposed electrode; and a third electrode pattern, as a third electrode pattern having a second exposed portion, at least including a pattern arranged along the third direction connecting the first exposed electrode and the fourth exposed electrode, and arranged to sandwich the third electrode pattern by the first electrode pattern and the second electrode pattern, the second exposed portion being exposed on the first surface side and arranged separately from the exposed electrode and the second electrode pattern.

[0011] In the above detection element, the second electrode pattern may include a first opening surrounding one of the exposed electrodes, the third electrode pattern may include a second opening surrounding one of the exposed electrodes, and the width of the first opening may be greater than that of the second opening.

[0012] In the above-mentioned detection element, the second exposed portion of the third electrode pattern may be arranged in the same layer as the second electrode pattern.

[0013] In the above-mentioned detection element, the exposed electrode may be arranged in the same layer as the second electrode pattern.

[0014] In the above detection element, at least any one of the first electrode pattern, the second electrode pattern, and the third electrode pattern may be electrically connected in a region surrounding the first exposed electrode, the second exposed electrode, and the fourth exposed electrode.

[0015] The above-mentioned detection element may include an insulating layer on the first electrode pattern on the second surface side.

[0016] In the above detection element, the first exposed electrode and the second exposed electrode may be arranged adjacent to each other, the first exposed electrode and the third exposed electrode may be arranged adjacent to each other, and the first exposed electrode and the fourth exposed electrode may be arranged adjacent to each other.

[0017] In the above detection element, a distance between the first exposed electrode and the second exposed electrode, a distance between the first exposed electrode and the third exposed electrode, and a distance between the first exposed electrode and the fourth exposed electrode may be equal.

[0018] In the above-mentioned detection element, it may also be that when the first imaginary straight line connecting the first exposed electrode and the third exposed electrode is set in the second electrode pattern, the distance between the center of the first exposed electrode and the first intersection point where the second imaginary straight line intersects with the edge of the second electrode pattern is greater than the distance between the midpoint between the first exposed electrode and the third exposed electrode and the second intersection point where the third imaginary straight line intersects with the edge of the second electrode pattern, the second imaginary straight line passes through the center of the first exposed electrode and is orthogonal to the first imaginary straight line, and the third imaginary straight line passes through the midpoint and is orthogonal to the first imaginary straight line.

[0019] In the above detection element, the second electrode pattern may have an edge portion in a wave line shape.

[0020] In the above-mentioned detection element, it may also be that the exposed electrode also includes a fifth exposed electrode, the fifth exposed electrode passes through the second exposed electrode and is arranged in the fourth direction passing through the first exposed electrode and the fourth exposed electrode, and also includes a fourth electrode pattern, which is a fourth electrode pattern having a third exposed portion, and at least includes a pattern corresponding to the first exposed electrode and the fifth exposed electrode and arranged along the fourth direction, and is arranged to sandwich the fourth electrode pattern by the second electrode pattern and the third electrode pattern, and the third exposed portion is exposed on the first surface side and is arranged separately from the exposed electrode, the second electrode pattern and the third electrode pattern.

[0021] In the above-mentioned detection element, it may also be that the third electrode pattern has a first ring pattern surrounding the first exposed electrode, a second ring pattern surrounding the fourth exposed electrode, and a connecting pattern connecting the first ring pattern and the second ring pattern, and the width of the connecting pattern is narrower than the outer peripheral width of the first ring pattern and the outer peripheral width of the second ring pattern.

[0022] In the above-mentioned detection element, it may also be that the third electrode pattern is arranged on an insulating surface, the insulating surface has a recess, the exposed electrode is arranged in the recess, and the distance from the surface of the recess to the exposed electrode is greater than the distance from the insulating surface to the third electrode pattern.

[0023] According to an embodiment of the present disclosure, there is provided a radiation detection device characterized by including: the above-mentioned detection element; and a power supply device connected to the exposed electrode of the detection element, the first electrode pattern, the second electrode pattern, and the third electrode pattern.

[0024] In the above-mentioned radiation detection device, the potential difference between the potential of the exposed electrode applied by the power supply device and the potential of the second electrode pattern may be greater than the potential difference between the potential of the exposed electrode applied by the power supply device and the potential of the third electrode pattern.

[0025] According to an embodiment of the present disclosure, there is provided a Compton camera characterized by including: a radiation detection device; and a detection module disposed to surround the radiation detection device and to detect light.

[0026] Effects of the Invention

[0027] According to one embodiment of the present disclosure, it is possible to improve the detection efficiency and detection accuracy of radiation in a radiation detection apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a block diagram showing the configuration of a radiation detection system according to a first embodiment of the present disclosure.

[0029] Figure 2 It is a diagram for explaining the detection element according to the first embodiment of the present disclosure.

[0030] Figure 3 It is a schematic plan view for explaining the electrode pattern of the detection element according to the first embodiment of the present disclosure.

[0031] Figure 4 1 is a diagram showing a cross-sectional structure of a detection element according to a first embodiment of the present disclosure ( Figure 3 Schematic diagram of the cross-sectional structure of the section line AA' in the figure.

[0032] Figure 5 1 is a diagram showing a cross-sectional structure of a detection element according to a first embodiment of the present disclosure ( Figure 3 Schematic diagram of the cross-sectional structure of the section line BB' in the figure.

[0033] Figure 61 is a diagram showing a cross-sectional structure of a detection element according to a first embodiment of the present disclosure ( Figure 3 Schematic diagram of the cross-sectional structure of the section line C-C' in the figure.

[0034] Figure 7 yes Figure 6 An enlarged schematic diagram of a portion of the cross-sectional structure of a detection element.

[0035] Figure 8 It is a diagram for explaining the principle of radiation detection using the detection element according to the first embodiment of the present disclosure.

[0036] Fig. 9 This is a diagram for explaining the electric charges generated in each electrode when the anode electrode captures electrons in the detection element according to the first embodiment of the present disclosure.

[0037] Fig.10 This is a diagram for explaining a first example of a pattern of a detection signal output from the detection element according to the first embodiment of the present disclosure.

[0038] Fig.11 This is a diagram for explaining a second example of the pattern of the detection signal output from the detection element according to the first embodiment of the present disclosure.

[0039] Fig.12 It is explained based on Fig.10 The pattern of the detection signal shown is a three-dimensional diagram of the electron capture position calculated.

[0040] Fig.13 It is explained based on Fig.10 The pattern of the detection signal is shown as a schematic diagram of the electron capture position calculated.

[0041] Fig.14 It is a schematic cross-sectional view showing a method for manufacturing a detection element according to the first embodiment of the present disclosure.

[0042] Fig.15 It is a schematic cross-sectional view showing a method for manufacturing a detection element according to the first embodiment of the present disclosure.

[0043] Fig.16 It is a schematic cross-sectional view showing a method for manufacturing a detection element according to the first embodiment of the present disclosure.

[0044] Fig.17 It is a schematic cross-sectional view showing a method for manufacturing a detection element according to the first embodiment of the present disclosure.

[0045] Fig.18 It is a schematic cross-sectional view showing a method for manufacturing a detection element according to the first embodiment of the present disclosure.

[0046] Fig.19It is a schematic cross-sectional view showing a method for manufacturing a detection element according to the first embodiment of the present disclosure.

[0047] Fig. 20 It is a schematic cross-sectional view showing a method for manufacturing a detection element according to the first embodiment of the present disclosure.

[0048] Fig.21 It is a schematic cross-sectional view showing a method for manufacturing a detection element according to the first embodiment of the present disclosure.

[0049] Fig. 22 It is a schematic cross-sectional view showing a method for manufacturing a detection element according to the first embodiment of the present disclosure.

[0050] Fig.23 It is a schematic cross-sectional view showing a method for manufacturing a detection element according to the first embodiment of the present disclosure.

[0051] Fig.24 This is a modified example of the cross-sectional structure of the detection element according to the first embodiment of the present disclosure.

[0052] Fig.25 This is a modified example of the cross-sectional structure of the detection element according to the first embodiment of the present disclosure.

[0053] Fig.26 This is a modified example of the cross-sectional structure of the detection element according to the first embodiment of the present disclosure.

[0054] Fig. 27 This is a modified example of the cross-sectional structure of the detection element according to the first embodiment of the present disclosure.

[0055] Fig.28 It is a schematic diagram of the cross-sectional structure of the detection element according to the second embodiment of the present disclosure.

[0056] Fig.29 It is a schematic diagram of the cross-sectional structure of the detection element according to the third embodiment of the present disclosure.

[0057] Fig.30 It is a schematic diagram of the cross-sectional structure of the detection element according to the third embodiment of the present disclosure.

[0058] Fig.31 It is a schematic diagram of the cross-sectional structure of the detection element according to the third embodiment of the present disclosure.

[0059] Fig.32 It is a schematic diagram of the cross-sectional structure of the detection element according to the fourth embodiment of the present disclosure.

[0060] Fig.33 It is a schematic plan view illustrating an electrode pattern of a detection element according to a fifth embodiment of the present disclosure.

[0061] Fig.34 Yes Fig.33 Schematic diagram of an enlarged portion of .

[0062] Fig.35 It is a schematic plan view illustrating an electrode pattern of a detection element according to a fifth embodiment of the present disclosure.

[0063] Fig.36 It is a schematic plan view illustrating an electrode pattern of a detection element according to a sixth embodiment of the present disclosure.

[0064] Fig.37 It is a schematic diagram for explaining the electron capture position calculated based on the pattern of the detection signal according to the sixth embodiment of the present disclosure.

[0065] Fig.38 It is a schematic plan view illustrating an electrode pattern of a detection element according to a sixth embodiment of the present disclosure.

[0066] Fig.39 It is a schematic plan view illustrating an electrode pattern of a detection element according to a sixth embodiment of the present disclosure.

[0067] Fig.40 It is a schematic plan view illustrating an electrode pattern of a detection element according to a seventh embodiment of the present disclosure.

[0068] Fig.41 It is a schematic plan view illustrating an electrode pattern of a detection element according to an eighth embodiment of the present disclosure.

[0069] Fig.42 It is a schematic cross-sectional view illustrating the structure of a detection element according to an eighth embodiment of the present disclosure.

[0070] Fig.43 This is a radiation detection device equipped with the detection element according to the first to eighth embodiments of the present disclosure.

[0071] Fig.44 This is a Compton camera equipped with the radiation detection device according to the first to eighth embodiments of the present disclosure. DETAILED DESCRIPTION

[0072] Below, while referring to the attached Figure 1 A radiation detection device according to an embodiment of the present disclosure is described in detail. In addition, the embodiment shown below is an example of an embodiment of the present disclosure, and the present disclosure is not limited to these embodiments. In addition, in the drawings referred to in the present embodiment, the same parts or parts having the same functions are marked with the same symbols or similar symbols (only symbols such as A, B are marked after the numbers), and their repeated descriptions are sometimes omitted. In addition, for the sake of convenience of explanation, the dimensional ratios of the drawings (the ratios between the various components, the ratios in the vertical and horizontal directions, etc.) are sometimes different from the actual ratios, and part of the components are omitted from the drawings.

[0073] <First Embodiment>

[0074] [Radiation Detection System]

[0075] Figure 1 1 is a block diagram showing the structure of the radiation detection system of the first embodiment of the present disclosure. The radiation detection system 1 includes a radiation detection device 10 having a power supply device 60 and a detection element 100, an encoder 55, and a computing device 90. The detection element 100 outputs detection signals Sx, Sy, and Sw. In this example, the detection signals Sx, Sy, and Sw are amplified by an amplifier after the DC component is removed by a capacitor relative to the electrical signal output from each terminal of the detection element 100. The power supply device 60 applies a voltage to each structure (detection element 100, etc.) included in the radiation detection device 10. The encoder 55 samples the detection signals Sx, Sy, and Sw synchronously with the clock signal Ck, encodes them, and outputs them. The resolution of the detection signal is determined by the clock signal Ck. Sometimes this output signal is referred to as Sd. The computing device 90 calculates the trajectory of the radiation (charged particles) based on the output signal Sd.

[0076] [Radiation detection equipment]

[0077] The radiation detection device 10 has a cavity 50. A detection element 100, a drift cage 70, and a drift electrode 80 are arranged inside the cavity 50. The drift electrode 80 is arranged opposite to the detection element 100, and a negative voltage is applied to the drift electrode 80 relative to the ground voltage (GND). The drift cage 70 is arranged to surround the space between the detection element 100 and the drift electrode 80. The drift cage 70 is formed with a conductor (conductor) for gradually making the voltage close to the ground voltage (GND) from the drift electrode 80 toward the detection element 100, so as to make the electric field distribution between the detection element 100 and the drift electrode 80 uniform.

[0078] When detecting radiation, a mixed gas of a rare gas and a quenching gas is sealed inside the cavity 50. The rare gas may be, for example, argon or xenon. The quenching gas may be, for example, ethane, methane, or other gas having a light extinction effect, including alkanes or carbon dioxide, which maintain a gas state at room temperature. In addition, the gas sealed in the cavity 50 may be any single gas or a mixed gas of two or more gases.

[0079] [Detection element]

[0080] The structure of the detection element 100 is described. In the following description, regarding the detection element 100, an example is shown in which pixels (anode electrodes) that are units for capturing electrons are arranged in a hexagonal manner. In addition, this arrangement is an example for explaining the arrangement of anode electrodes. In fact, a large number of pixels on the scale of hundreds to millions can also be arranged. First, use Figure 2 The structure of the surface of the drift electrode 80 side of the detection element 100 is briefly described. Figure 3 to Figure 7 Each structure of the detection element 100 is described in detail. In addition, for the sake of explanation, when a drawing showing one anode electrode pattern is shown, adjacent anode electrode patterns may not be shown. The same is true for the first cathode electrode pattern and the second cathode electrode pattern.

[0081] Figure 2 1 is a diagram for explaining a detection element according to a first embodiment of the present disclosure. The detection element 100 is described in detail later, but includes a substrate (also referred to as an insulating substrate) disposed on a substrate having an insulating surface. Figures 4 to 7 The pattern of the conductive metal on the substrate 110 shown in the figure is formed by exposing and disposing the anode electrode 101 (exposed electrode) on the insulating substrate. First, the anode electrode 101 (exposed electrode) is exposed on the insulating substrate. In this example, the anode electrode 101 is arranged in a matrix along the X direction (the second direction) and the Y direction (the first direction). In this example, the X direction and the Y direction intersect at 120 degrees. In addition, in this example, the distance between the adjacent anode electrodes 101 in the X direction, the distance between the adjacent anode electrodes 101 in the Y direction, and the distance between the adjacent anode electrodes 101 in the W direction (the third direction) are equal. In addition, the so-called W direction is a direction other than the X direction and the Y direction. In this example, with respect to any one of the straight line extending in the X direction and the straight line extending in the Y direction, it corresponds to the direction along the line intersecting at 60 degrees. In addition, the X direction and the Y direction are not limited to the case where they intersect at 120 degrees. For example, they can also be arranged orthogonally (90 degrees). In addition, the distance between adjacent anode electrodes 101 in the X direction and the Y direction can also be different.

[0082] The anode electrode 101 corresponds to a pixel that is a unit for capturing electrons. As described above, in this example, the anode electrode 101 is configured with 4 to 7 pixels in the X direction and 4 to 7 pixels in the Y direction, for a total of 37 pixels. In the following description, the area where 37 pixels are configured is sometimes referred to as the detection area. In this case, Figure 2 The outer shape of the detection area shown (a shape obtained by connecting the centers of pixels corresponding to the outer peripheral portion among 37 pixels) is a hexagon.

[0083] On the insulating substrate, a first cathode electrode pattern 205 (second electrode pattern) is arranged along the X direction. An opening 202 is provided in the first cathode electrode pattern 205 corresponding to the pixel. Each opening 202 is formed to surround the anode electrode 101 for each pixel. At the end of the first cathode electrode pattern 205, outside the detection area, a first cathode terminal portion 208 is arranged. The first cathode electrode pattern 205 is formed in a strip shape, and is therefore also called a first cathode strip electrode. An anode terminal portion 108 and a second cathode terminal portion 308 are also arranged outside the detection area. The anode terminal portion 108, the first cathode terminal portion 208, and the second cathode terminal portion 308 are terminals for outputting the above-mentioned detection signals Sx, Sy, and Sw to the outside of the detection element 100.

[0084] The anode terminal portion 108 is connected to the anode electrode 101 via the anode electrode pattern 105 (first electrode pattern) arranged along the Y direction. The second cathode terminal portion 308 is connected to the second cathode electrode pattern 305 (third electrode pattern) arranged along the W direction.

[0085] Figure 3 It is a diagram for explaining the electrode pattern of the detection element according to the first embodiment of the present disclosure. Figure 4 1 is a diagram showing a cross-sectional structure of a detection element according to a first embodiment of the present disclosure ( Figure 3 Schematic diagram of the cross-sectional structure of the section line AA' in the figure. Figure 5 1 is a diagram showing a cross-sectional structure of a detection element according to a first embodiment of the present disclosure ( Figure 3 Schematic diagram of the cross-sectional structure of the section line BB' in the figure. Figure 6 1 is a diagram showing a cross-sectional structure of a detection element according to a first embodiment of the present disclosure ( Figure 3 Schematic diagram of the cross-sectional structure of the section line C-C' in the figure. Figure 7 yes Figure 6 The enlarged schematic diagram of a part of the cross-sectional structure of the detection element. Figure 3 As shown in FIG. 1 , the Z direction is defined as a direction perpendicular to the X direction, the Y direction, and the W direction (a direction perpendicular to the surface on which the anode electrode 101 is arranged).

[0086] In the following description, Figure 3 As shown, the plurality of anode electrodes 101 are referred to as anode electrodes 101-xy according to the locations where they are arranged. Here, x represents the anode electrode 101-11 (in Figure 3On the other hand, y represents the coordinate (1 to 7) in the Y direction based on the anode electrode 101-11. In this example, anode electrode 101-41 corresponds to the anode electrode 101 at the lower center, anode electrode 101-14 corresponds to the anode electrode 101 at the upper left, anode electrode 101-44 corresponds to the anode electrode 101 at the center, anode electrode 101-74 corresponds to the anode electrode 101 at the lower right, anode electrode 101-47 corresponds to the anode electrode 101 at the upper center, and anode electrode 101-77 corresponds to the anode electrode 101 at the upper right. In addition, a pixel representing the position of a pixel is sometimes also referred to as pixel (xy). For example, pixel (11) corresponds to anode electrode 101-11.

[0087] The plurality of anode electrodes 101 arranged in the X direction are electrically connected via an anode electrode pattern 105 arranged along the Y direction on the second surface 110b of the substrate 110. The anode electrode pattern 105 is formed in a strip shape, and is therefore also referred to as an anode strip pattern. The anode electrode patterns 105 (105-1 to 105-7) are arranged in parallel in a direction orthogonal to the Y direction. The anode electrode pattern 105 is connected to the anode terminal portion 108 at its end. For example, the anode electrodes 101-11, 101-12, 101-13, and 101-14 are electrically connected to the anode terminal portion 108-1 via the anode electrode pattern 105-1.

[0088] The anode electrode 101 and the anode electrode pattern 105 are formed by Figure 4 The anode electrode 101 and the through electrode 112 may be connected to each other as shown. In addition, the anode electrode 101 and the through electrode 112 may be integrated. For example, the portion of the through electrode 112 exposed from the substrate 110 may be defined as the anode electrode 101. In this case, the anode electrode 101 may or may not protrude from the substrate 110.

[0089] In addition, if Figure 7 As shown, a via electrode 102 may be provided between the anode electrode 101 and the through electrode 112 together with the insulating layer 120. The width of the via electrode 102 is preferably narrower than the width of the anode electrode 101. Thus, the positional deviation between the through electrode 112 and the anode electrode 101 can be alleviated, and a uniform electric field is formed on the surface of the detection element 100. In addition, the via electrode 102 may not be required. In addition, an insulating layer 140 and a via electrode 142 may be provided between the through electrode 112 and the anode electrode pattern 105 on the second surface 110b side.

[0090] The first cathode electrode pattern 205 exposed along the X direction on the first surface 110a of the substrate 110 surrounds the anode electrodes 101 arranged in the X direction through the opening 202 (first opening) and is arranged separately from the anode electrodes 101. In addition, in this example, the entire upper surface and side surface of the first cathode electrode pattern 205 are exposed, but only a part may be exposed. Therefore, the first cathode electrode pattern 205 can have an exposed portion. The first cathode electrode pattern 205 is connected to the first cathode terminal portion 208 at its end. The first cathode electrode pattern 205 (205-1 to 205-7) is arranged in parallel in a direction orthogonal to the X direction. For example, the first cathode electrode pattern 205-1 surrounds the anode electrodes 101-11, 101-21, 101-31, and 101-41 through the opening 202, and is connected to the first cathode terminal portion 208-1. Hereinafter, such a relationship between the first cathode electrode pattern 205 and the anode electrode 101 is defined as a relationship in which the first cathode electrode pattern 205 and the anode electrode 101 are arranged correspondingly. For example, the first cathode electrode pattern 205-1 is arranged correspondingly to the anode electrodes 101-11, 101-21, 101-31, and 101-41.

[0091] The anode electrode pattern 105 and the first cathode electrode pattern 205 are arranged separately, so that on the first surface 110a of the substrate 110, the second cathode electrode pattern 305 (305-1 to 305-7) arranged along the W direction is sandwiched between the anode electrode pattern 105 and the first cathode electrode pattern 205 between the anode electrode 101 arranged along the W direction. In the case of the second cathode electrode pattern 305-1 as an example, the second cathode electrode pattern 305-1 is sandwiched by the first cathode electrode patterns 205-1 to 205-4 and the anode electrode patterns 105-4 to 105-7 in the Z direction.

[0092] The second cathode electrode pattern 305 has an exposed portion 305a on the first surface 110a side of the substrate 110. The exposed portion 305a surrounds the anode electrodes 101 arranged in the W direction through the openings 302 (second openings) and is arranged separately from the anode electrodes 101. The width of the opening 302 is smaller than the width of the opening 202. Therefore, the exposed portion 305a is arranged between the anode electrode 101 and the first cathode electrode pattern 205. The second cathode electrode pattern 305 is connected to the second cathode terminal portion 308 at its end. The second cathode electrode pattern 305 (305-1 to 305-7) is arranged in parallel in a direction orthogonal to the W direction. For example, the second cathode electrode pattern 305-1 surrounds the anode electrodes 101-41, 101-52, 101-63, and 101-74 through the openings 302, and is connected to the second cathode terminal portion 308-1. Hereinafter, the relationship between the second cathode electrode pattern 305 and the anode electrode 101 is defined as the relationship between the first cathode electrode pattern 205 and the anode electrode 101. For example, the second cathode electrode pattern 305-1 is arranged corresponding to the anode electrodes 101-41 to 101-74.

[0093] By arranging the electrode patterns as described above, the plurality of anode electrodes 101 corresponding to one second cathode electrode pattern 305 are connected to different anode electrode patterns 105. In addition, the plurality of anode electrodes 101 corresponding to one second cathode electrode pattern 305 are corresponding to different first cathode electrode patterns 205.

[0094] In this embodiment, the thickness of the anode electrode 101, the first cathode electrode pattern 205, and the second cathode electrode pattern 305 is 2 μm or more, preferably 30 μm or less, and desirably 5 μm. Thus, the wiring resistance can be suppressed. In addition, the thickness of the insulating layer 130 is 3 μm or more, preferably 100 μm or less, and desirably 20 μm. Thus, the crosstalk of the detection signal can be suppressed.

[0095] Here, the dimensions of each structure of the detection element 100 are exemplified as follows.

[0096] The distance d1 between the centers of adjacent anode electrodes 101 (length of one pixel): 554.26 μm

[0097] · Diameter d2 of anode electrode 101: 60 μm

[0098] Line width d3 of the first cathode electrode pattern 205: 440 μm

[0099] Diameter d4 of the opening 202: 340 μm

[0100] Line width d5 ​​of anode electrode pattern 105: 300 μm

[0101] Line width d6 of the second cathode electrode pattern 305: 440 μm

[0102] Diameter d7 of the opening 302: 260 μm

[0103] Diameter d9 of through electrode 112: 50 μm

[0104] Diameter d10 of via electrode 102: 30 μm

[0105] Distance d11 between anode electrode patterns 105: 180 μm

[0106] Distance d12 between first cathode electrode patterns 205: 40 μm

[0107] · Distance d between the second cathode electrode patterns 305 1340 μm

[0108] [Radiation detection principle]

[0109] Next, the principle of radiation detection in the radiation detection device 10 is described using Figure 8 as well as Fig. 9 In addition, the drift electrode 80 applies a negative voltage to the ground voltage (GND). The first cathode electrode pattern 205 and the second cathode electrode pattern 305 are applied with a ground voltage (GND). The anode electrode 101 (anode electrode pattern 105) applies a positive voltage to the ground voltage (GND).

[0110] Figure 8 1 is a diagram for explaining the principle of detecting radiation using the detection element of the first embodiment of the present disclosure. If radiation (charged particles EP) enters the cavity 50, an electron cloud EC is formed by interaction with the gas present in the cavity 50. Each electron of the electron cloud is attracted toward the detection element 100 side along the Z direction by the electric field E generated between the drift electrode 80 and the first cathode electrode pattern 205. The electrons attracted to the detection element 100 side are accelerated by the electric field formed by the first cathode electrode pattern 205 and the anode electrode 101, and are thereby attracted toward the anode electrode 101. At this time, the electrons collide with the gas, thereby ionizing the gas. The electrons generated by the ionization increase in an avalanche-like manner and are captured by the anode electrode 101.

[0111] Fig. 9This is a diagram illustrating the charges generated at each electrode when the anode electrode captures electrons in the detection element of the first embodiment of the present disclosure. If the electrons that increase in an avalanche are captured by the anode electrode 101, negative charges are temporarily generated in the anode electrode 101. On the other hand, a group of cations as ionized gas is attached to the first cathode electrode pattern 205 and the second cathode electrode pattern 305, and positive charges are temporarily generated. Due to the influence of the multiplied electrons, the pulse signal (voltage change) generated from these charges becomes larger to the extent that it can be read as an electrical signal (detection signal Sx, Sy, Sw) from the anode terminal portion 108, the first cathode terminal portion 208, and the second cathode terminal portion 308. In the following description, the detection signal Sx output from the anode terminal portions 108-1 to 108-7 is sometimes referred to as the detection signal Sx-1 to Sx-7. The detection signals Sy output from the first cathode terminal portions 208-1 to 208-7 may be referred to as detection signals Sy-1 to Sy-7. The detection signals Sw output from the second cathode terminal portions 308-1 to 308-7 may be referred to as detection signals Sw-1 to Sw-7.

[0112] By using the timing of voltage changes in the detection signals Sx, Sy, and Sw and the position of the terminal that outputs the electrical signal generated by the voltage changes, the trajectory of the charged particle EP can be calculated. In addition, the position in the Z direction of the trajectory can be calculated as a relative position.

[0113] Fig.10 This is a diagram for explaining a first example of a pattern of a detection signal output from the detection element according to the first embodiment of the present disclosure. Fig.10 The pattern of the detection signal shown is as Figure 8 As shown, it is assumed that a charged particle EP is incident. In this example, the electron is captured by the anode electrode 101-34 (pixel (34)), and then the electron is captured by the anode electrode 101-46 (pixel (46)).

[0114] According to such a situation, first, corresponding to the capture of electrons by the anode electrode 101-34, voltage changes occur in the detection signals Sx-3, Sy-4, and Sw-5. In other words, if the operation device 90 determines that the time when the voltage changes occur in the detection signals Sx-3, Sy-4, and Sw-5 is the same, the anode electrode 101-34 at the intersection of the anode electrode pattern 105-3, the first cathode electrode pattern 205-4, and the second cathode electrode pattern 305-5 corresponding to the detection signals Sx-3, Sy-4, and Sw-5 is determined as the anode electrode 101 that captures the electrons.

[0115] Then, corresponding to the capture of electrons by the anode electrode 101-46, voltage changes occur in the detection signals Sx-4, Sy-6, and Sw-6. In other words, if the operation device 90 determines that the time when the voltage changes occur in the detection signals Sx-4, Sy-6, and Sw-6 is the same, the anode electrode 101-46 at the intersection of the anode electrode pattern 105-4, the first cathode electrode pattern 205-6, and the second cathode electrode pattern 305-6 corresponding to the detection signals Sx-4, Sy-6, and Sw-6 is determined as the anode electrode 101 that captures the electrons.

[0116] In such a case, even if none of the detection signals Sx, Sy, and Sw exists, that is, based on the two detection signals, the anode electrode that has captured the electron can be determined. On the other hand, as described below, if the electron is captured by the anode electrodes 101-34 and 101-46 at the same time, the computing device 90 cannot correctly determine the anode electrode 101 that has captured the electron based on only the two detection signals.

[0117] Fig.11 This is a diagram for explaining a second example of the pattern of the detection signal output from the detection element of the first embodiment of the present disclosure. In the second example, the situation where electrons are captured by the anode electrode 101-34 (pixel (34)) and the anode electrode 101-46 (pixel (46)) at the same time is shown.

[0118] Based on this situation, the computing device 90 determines that the time when the voltage changes in the detection signals Sx-3, Sx-4, Sy-4, Sy-6, Sw-5, and Sw-6 are the same. At this time, if the detection signals Sx, Sy, and Sw are used, the anode electrode 101 that captures the electrons can be correctly determined, but it cannot be correctly determined using only two detection signals (such as Sx and Sy) as in the prior art. In this case, using Fig.12 To explain.

[0119] Fig.12 It is explained based on Fig.11 The pattern of the detection signal shown is a three-dimensional diagram of the electron capture position calculated. Fig.13 It is explained based on Fig.11 Schematic diagram of the top view of the electron capture position calculated based on the pattern of the detection signal shown. First, when the detection signals Sx and Sy are used, the intersection of the anode electrode patterns 105-3 and 105-4 and the first cathode electrode patterns 205-4 and 205-6 becomes the anode electrodes 101-34, 101-44, 101-36, and 101-46 (pixels (34), (44), (36), and (46)). Therefore, in fact, the anode electrodes 101-44 and 101-36 (pixels (44) and (36)) that have not captured the electrons are misdetected.

[0120] On the other hand, when the detection signals Sx, Sy, and Sw are used, the intersection of the anode electrode patterns 105-3 and 105-4, the first cathode electrode patterns 205-4 and 205-6, and the second cathode electrode patterns 305-5 and 305-6 becomes the anode electrodes 101-34 and 101-46 (pixels (34) and (46)). Therefore, the false detection that occurs when only the detection signals Sx and Sy are used does not occur when the detection signals Sx, Sy, and Sw are used.

[0121] As described above, the radiation detection device 10 of the present embodiment can identify the two anode electrodes 101 even when electrons are captured simultaneously in two anode electrodes 101 because three detection signals Sx, Sy, and Sw are used. In addition, even when the three detection signals Sx, Sy, and Sw are used, if electrons are captured simultaneously in three anode electrodes 101, false detection may be performed. However, the probability of electrons being captured simultaneously in three anode electrodes 101 is lower than the probability of electrons being captured simultaneously in two anode electrodes 101. Therefore, false detection can be reduced, and as a result, the detection efficiency and detection accuracy of radiation are improved.

[0122] In this example, the detection element 100 has 37 pixels (anode electrodes 101) arranged in a hexagonal pattern, but the structure can be generalized by having at least two anode electrodes 101 arranged in the X direction and two anode electrodes 101 arranged in the Y direction based on one anode electrode 101. The two anode electrodes 101 arranged in the X direction or the Y direction can be defined as adjacent anode electrodes 101 or non-adjacent anode electrodes 101. In the case of generalization by two non-adjacent anode electrodes 101, another anode electrode 101 exists between them.

[0123] When adjacent to each other, the 4 (2×2) anode electrodes 101 correspond to, for example, anode electrodes 101-22, 101-23, 101-32, 101-33 (pixels (22), (23), (32), (33)). When not adjacent to each other, the 4 (2×2) anode electrodes 101 correspond to, for example, anode electrodes 101-11, 101-14, 101-41, 101-44 (pixels (11), (14), (41), (44)).

[0124] [Method for manufacturing detection element]

[0125] Next, use Figures 14 to 23 , a method for manufacturing the detection element 100 of this embodiment is described.

[0126] First, if Fig.14 As shown, a through hole 111 is formed on the substrate 110, which passes from the first surface 110a to the second surface 110b. For the substrate 110, an insulating material with high insulation can be used. In this example, a glass substrate such as a soda glass substrate, an alkali-free glass substrate, a quartz glass substrate, etc. can be used for the substrate 110. The thickness of the substrate 110 can be appropriately set within a range of 100 μm or more and 1000 μm or less. In this example, the thickness of the substrate 110 is 380 μm.

[0127] The through hole 111 is formed, for example, by using a laser irradiation method (which can be called a laser ablation method) on the substrate 110. For the laser, an excimer laser, a neodymium: yttrium aluminum laser (Nd: YAG) laser, a femtosecond laser, etc. can be used. When using an excimer laser, light in the ultraviolet region is irradiated. For example, when xenon chloride is used in the excimer laser, light with a wavelength of 308 nm is irradiated. In addition, the irradiation diameter based on the laser can also be set to be greater than 10 μm and less than 250 μm. The aperture of the through hole 111 can be appropriately set within the range of greater than 10 μm and less than 250 μm. In this example, the aperture of the through hole 111 is fixed to 50 μm in the vertical direction relative to the substrate 110. In addition, in the case of forming the through hole 111 of the substrate 110, in addition to the laser irradiation method, a dry etching method or a wet etching method can also be used.

[0128] Next, if Fig.15 As shown, a through electrode 112 is formed with respect to the through hole 111. For the through electrode 112, copper (Cu), nickel (Ni), gold (Au), silver (Ag), tin (Sn), etc. can be used. The through electrode 112 is formed by a plating method. For example, the through electrode 112 uses copper (Cu) formed by a plating method. The through electrode 112 formed by the plating method is planarized by a chemical mechanical polishing (CMP: Chemical Mechanical Polishing) method.

[0129] Next, if Fig.16 As shown, an insulating layer 120 is formed on the first surface 110a of the substrate 110. The insulating layer 120 uses an inorganic insulating material or an organic insulating material, or a material obtained by mixing an inorganic insulating material and an organic insulating material. The insulating layer 120 is formed by a coating method and a lamination method. Specific examples of the coating method include spin coating, spray coating, slit coating, dip coating, etc. In this example, the insulating layer 120 uses a polyimide film formed by spin coating, etc. The thickness of the insulating layer 120 is not particularly limited, but is in the range of more than 1 μm and less than 20 μm. In this example, the thickness of the insulating layer 120 is 4 μm.

[0130] Next, if Fig.17 As shown in FIG. 1 , an opening 121 is provided in the insulating layer 120. The opening 121 can be formed by using, for example, photolithography and etching. Fig.17 In the case where the insulating layer 120 includes a photosensitive material, the opening 121 may be formed only by photolithography. Thus, the number of manufacturing steps can be reduced.

[0131] Next, if Fig.18 As shown, an anode electrode 101, a via electrode 102, and a second cathode electrode pattern 305 are formed on the through electrode 112 and the insulating layer 120. The anode electrode 101, the via electrode 102, and the second cathode electrode pattern 305 are formed by plating, CVD, sputtering, or printing. Copper (Cu) is used for the anode electrode 101, the via electrode 102, and the second cathode electrode pattern 305. In addition to copper (Cu), metal materials such as aluminum (Al), gold (Au), silver (Ag), nickel (Ni), tungsten (W), molybdenum (Mo), or titanium (Ti) can also be used for the anode electrode 101, the via electrode 102, and the second cathode electrode pattern 305.

[0132] In the above case, an example is shown in which the anode electrode 101 and the via electrode 102 are formed at once, but the via electrode 102 may be formed before forming the anode electrode 101 and the second cathode electrode pattern 305 .

[0133] Next, if Fig.19 As shown in FIG. 1 , an insulating layer 130 is formed on the insulating layer 120, the anode electrode 101, and the second cathode electrode pattern 305. The insulating layer 130 can also be formed using the same material and method as the insulating layer 120.

[0134] Next, if Fig. 20 As shown in FIG. 1 , the end of the anode electrode 101 side of the anode electrode 101 and the second cathode electrode pattern 305, which is the exposed portion 305a, and the insulating layer 120 are exposed, thereby forming the opening 202 and the opening 302. The opening 202 and the opening 302 can also be formed by the same method as the opening 121. At this time, the insulating layer 130 can also be removed to expose the portion 305b that does not overlap the first cathode electrode pattern 205 and the second cathode electrode pattern 305 to be formed later. Thereby, the insulating layer 130 can be prevented from being charged during radiation detection, thereby suppressing abnormal discharge.

[0135] Next, if Fig.21 As shown, a first cathode electrode pattern 205 is formed on the insulating layer 130. The first cathode electrode pattern 205 can be formed using the same material and method as the anode electrode 101, the via electrode 102, and the second cathode electrode pattern 305.

[0136] Next, if Fig. 22 As shown, an insulating layer 140 is formed on the second surface 110b of the substrate 110. The insulating layer 140 can be formed using the same material and method as the insulating layer 120. In this example, a polyimide film formed by spin coating can be used for the insulating layer 140.

[0137] Next, if Fig.23 As shown, a portion of the insulating layer 140 is removed, and a via electrode 142 and an anode electrode pattern 105 are formed on the through electrode 112 and the insulating layer 140. The via electrode 142 and the anode electrode pattern 105 can be formed using the same material and method as the via electrode 102, the anode electrode 101, and the second cathode electrode pattern 305. By the above method, the detection element 100 can be manufactured.

[0138] (Variation Example)

[0139] In addition, in this embodiment, the through hole 111 is described as a through hole having a cylindrical shape, but it is not limited to this. The diameter of the through hole may also change relative to the vertical direction of the substrate (in other words, the side surface of the through hole may not be parallel to the direction vertical to the substrate 110, but may have an inclination). For example, Fig.24 As shown, the through hole 111 may have a shape in which the diameter of the through hole 111 decreases from the second surface 110b side toward the first surface 110a (ie, a conical trapezoidal shape).

[0140] In this embodiment, the insulating layer 140 and the anode electrode pattern 105 are formed after forming the elements on the first surface side, but the present invention is not limited thereto. The insulating layer 140 and the anode electrode pattern 105 may be formed first, and then the elements on the first surface side may be formed.

[0141] Furthermore, in the present embodiment, the portion 305 b of the second cathode electrode pattern may not necessarily be exposed (ie, only the exposed portion 305 a of the second cathode electrode pattern 305 is exposed).

[0142] In addition, in this embodiment, an example is shown in which the diameter d4 of the opening 202 of the first cathode electrode pattern 205 is larger than the diameter d7 of the opening 302 of the second cathode electrode pattern 305, but the present invention is not limited thereto. In addition, the side surface of the first cathode electrode pattern 205 may not be flush with the side surface of the insulating layer 130. For example, the diameter d4 of the opening 202 of the first cathode electrode pattern 205 may be the same as the diameter d7 of the opening 302 of the second cathode electrode pattern 305. In addition, as Fig.25As shown in FIG. 1 , the diameter d4 of the opening 202 of the first cathode electrode pattern 205 may be narrower than the diameter d7 of the opening 302 of the second cathode electrode pattern 305, and the first cathode electrode pattern 205 may cover a portion of the side surface 130a of the insulating layer 130. In this case, only the side surface of the second cathode electrode pattern 305 may be exposed. Fig.26 As shown, the side surface of the first cathode electrode pattern 205 may be arranged to be further away from the anode electrode 101 than the side surface 130 a of the insulating layer 130 .

[0143] In addition, if Fig. 27 As shown in FIG. 1 , in addition to the insulating layer 130, another insulating layer 131 may be further provided, and a plurality of insulating layers may be provided between the first cathode electrode pattern 205 and the second cathode electrode pattern 305. The insulating layer 131 may be formed of the same material as the insulating layer 130 or a different material from the insulating layer 130. In addition, in this case, the side surface of the insulating layer 130 and the side surface of the insulating layer 131 may be continuously arranged as in the case of a single layer, or may be arranged as in FIG. Fig. 27 The configuration shown is stepped.

[0144] In addition, in the present embodiment, the ground potential (GND) is applied to the first cathode electrode pattern 205 and the second cathode electrode pattern 305, but the present invention is not limited thereto. For example, the potential applied to the first cathode electrode pattern 205 and the potential applied to the second cathode electrode pattern 305 may be different. The applied potential may also be changed according to the distance from the anode electrode 101. For example, since the first cathode electrode pattern 205 is farther from the anode electrode 101 than the second cathode electrode pattern 305, -100 V may be applied to the first cathode electrode pattern 205 and 0 V may be applied to the second cathode electrode pattern 305. At this time, if 500 V is applied to the anode electrode 101, the potential difference between the anode electrode 101 and the first cathode electrode pattern 205 is greater than the potential difference between the anode electrode 101 and the second cathode electrode pattern 305. Thus, the electric field strength between the anode electrode 101 and the first cathode electrode pattern 205 is greater than the electric field strength between the anode electrode 101 and the second cathode electrode pattern 305 , and a signal can be sufficiently detected in the first cathode electrode pattern 205 even if away from the anode electrode 101 .

[0145] <Second Embodiment>

[0146] In the second embodiment, a detection element in which an insulating layer is formed on the anode electrode pattern 105 will be described.

[0147] exist Fig.28 A cross-sectional schematic diagram of the detection element 100A is shown in FIG. Fig.28As shown, the detection element 100A is different from the detection element 100 shown in the first embodiment, and further has an insulating layer 150 on the substrate 110 and the anode electrode pattern 105. In the insulating layer 150, an inorganic insulating material or an organic insulating material is provided. The thickness of the insulating layer 150 is greater than 1 μm and less than 100 μm, preferably greater than 10 μm and less than 30 μm. In this example, the thickness of the insulating layer 150 is 20 μm. By providing the insulating layer 150, the warping of the substrate 110 generated when the detection element 100 is manufactured can be suppressed. In addition, it is desirable that, when forming the insulating layer 150, the insulating layer 150 is formed after the insulating layer 140 and the anode electrode pattern 105 are formed, and the various elements on the first surface 110a side are formed thereafter.

[0148] <Third Embodiment>

[0149] In the first embodiment, an example in which a glass substrate is used as an insulating substrate is described. However, in the present embodiment, an example in which a material different from the glass substrate is used is described.

[0150] For the substrate 110, in addition to the glass substrate, a semiconductor substrate such as a silicone substrate, a sapphire substrate, an aluminum carbide (Al2O3) substrate, an aluminum nitride (AlN) substrate, an inorganic insulating material such as a zirconium oxide (ZrO2) substrate, a resin substrate such as acrylic acid or polycarbonate, or a substrate obtained by stacking these substrates can also be used.

[0151] Fig.29 FIG. 1 is a schematic cross-sectional view of a detection element 100B using a silicone substrate as the substrate 110B. Fig.29 As shown in FIG. 1 , when the substrate 110B is a silicone substrate, an insulating layer 115 is provided on the surface of the substrate 110B. The insulating layer 115 may be a thermal oxide film, or may be a silicone nitride film (SiNx) or a silicone oxide film (SiO2) formed by coating, CVD or sputtering. x ) and other insulating materials. Therefore, by combining the silicone substrate and the insulating layer 115, leakage current does not occur through the substrate, and it can be used as a substrate with an insulating surface.

[0152] Fig.30 FIG. 1 is a schematic cross-sectional view of a detection element 100C in which an organic resin is used for a substrate 110C. Fig.30In the present invention, for the substrate 110C, a polyimide resin or epoxy resin containing glass fiber for improving strength is used. On the other hand, when an organic resin such as a polyimide resin or an epoxy resin is used, it will bend, so a sufficient thickness is required. However, in the relationship of forming a through electrode 112 on the substrate 110C, there is a limit on the thickness of the substrate. Therefore, it is desirable to additionally set a substrate 160 and a substrate 170 on the anode electrode pattern 105. Thereby, the strength of the detection element 100C can be maintained. The substrate 160 and the substrate 170 use a polyimide resin containing glass fiber.

[0153] In addition, when the strength of the detection element 100 is maintained by the substrates 160 and 170, the strength can also be maintained by the substrate 110C. In this case, a polyimide resin that does not contain glass fibers can also be used for the substrate 110C. By not containing glass fibers, the substrate 110C can be easily processed. Fig.31 is a cross-sectional schematic diagram of the detection element 100D. Fig.31 As shown, the surface of the substrate 110D may be cut to provide a recess 110Dc. In this case, the distance d101 from the surface of the recess 110Dc to the upper surface 101a of the anode electrode 101 is greater than the distance d305 from the first surface 110Da of the substrate 110D to the upper surface of the second cathode electrode pattern 305. By having the recess 110Dc, a portion of the through electrode 112 is exposed, and the exposed area of ​​the entire anode electrode can be expanded to match the anode electrode 101. As a result, the electric field can be expanded, and the detection sensitivity of radiation can be improved.

[0154] <Fourth Implementation Method>

[0155] In this embodiment, an example of a detection element in which the first cathode electrode pattern, the exposed portion of the second cathode electrode pattern, and the anode electrode are arranged in the same layer is described.

[0156] Fig.32 is a cross-sectional schematic diagram of the detection element 100E. Fig.32As shown, in the detection element 100E, the exposed portion 305Ea of the second cathode electrode pattern 305E is arranged on the via electrode portion 305Ec, and is provided in an exposed manner on the same layer as the first cathode electrode pattern 205 (on the insulating layer 130 in this example). Similarly, the anode electrode 101E is also provided in an exposed manner on the same layer as the first cathode electrode pattern 205 via the electrode 103 and the via electrode 104. By having the above structure, the distance from the drift electrode 80 to the first cathode electrode pattern 205 is the same as the distance from the drift electrode 80 to the second cathode electrode pattern 305. Thus, the speed at which the ionized electrons reach the two cathode electrode patterns can be made uniform. Therefore, the detection sensitivity of radiation can be improved. In addition, in Fig.32 In the case of the above, the anode electrode 101E, the first cathode electrode pattern 205, and the exposed portion 305Ea of the second cathode electrode pattern 305E are formed on the flat insulating surface based on the insulating layer 130. Therefore, the conductive film formed on the insulating layer 130 can be processed to stably form the anode electrode 101E, the first cathode electrode pattern 205, and the exposed portion 305Ea of the second cathode electrode pattern 305E.

[0157] <Fifth Implementation Method>

[0158] In this embodiment, an example of a detection element having a different shape of the first cathode electrode pattern is shown.

[0159] Fig.33 100F is a schematic top view of the detection element 100F. Fig.34 Yes Fig.33 A schematic diagram of a part of the enlarged Fig.33 as well as Fig.34 As shown in FIG. 1 , the edge of the first cathode electrode pattern 205 of this embodiment has a wave-like shape, which is different from the straight edge of the first cathode electrode pattern 205 shown in the first embodiment. In this example, the edge of the first cathode electrode pattern 205F (205F-1 to 205F-7) has a streamline shape. Fig.34As shown in FIG. 1 , when an imaginary straight line 205Fa is provided to connect the anode electrode 101-22 and the anode electrode 101-32 adjacent in the X direction, a point where an imaginary straight line 205Fb orthogonal to the straight line 205Fa from the center of the anode electrode 101-22 intersects with the edge of the first cathode electrode pattern 205F-2 is set as a point 205Fc. In addition, when a point between the anode electrode 101-22 and the anode electrode 32 is set as an intermediate point 205Fd, a point where an imaginary straight line 205Fe orthogonal to the straight line 205Fa from the intermediate point 205Fd intersects with the edge of the first cathode electrode pattern 205F-2 is set as a point 205Ff. If the distance from the center of the anode electrode 101-22 to the point 205Fc is set as a distance d14, and the distance from the intermediate point 205Fd to the point 205Ff is set as a distance d15, the distance d14 becomes larger than the distance d15. With the above-described shape, since the lines of electric force are directed toward the first cathode electrode pattern closest to the anode electrode 101 , the accuracy of detecting radiation can be further improved.

[0160] In addition, the shape of the edge of the first cathode electrode pattern 205 is not limited to a streamline shape. Fig.35 As shown, the edge of the first cathode electrode pattern 205 may have a sawtooth shape.

[0161] <Sixth Implementation Method>

[0162] The sixth embodiment is different from the first embodiment in the structure of the second cathode electrode pattern, that is, it is an example in which two adjacent second cathode electrode patterns are connected to form a detection element having a second cathode electrode pattern with a large line width.

[0163] Fig.36 3 is a diagram for explaining the second cathode electrode pattern of the detection element. In the detection element 100 of the first embodiment, the plurality of anode electrodes 101 corresponding to one second cathode electrode pattern 305 are connected to mutually different anode electrode patterns 105. In addition, the plurality of anode electrodes 101 corresponding to one second cathode electrode pattern 305 are in a corresponding relationship with mutually different first cathode electrode patterns 205. On the other hand, in the detection element 100G of the present embodiment, Fig.36As shown, among the plurality of anode electrodes 101 corresponding to one second cathode electrode pattern 305G in the detection element 100B, there are two anode electrodes 101 connected to the same anode electrode pattern 105 and two anode electrodes 101 corresponding to the same first cathode electrode pattern 205. In this example, the second cathode electrode pattern 305G-4 has a region (exposed portions 305Ga-12, 305Ga-22, 305Ga-23) including the anode electrode 101-22 arranged in parallel in the X direction relative to the anode electrode 101-12, and the anode electrode 101-23 arranged in parallel in the W direction relative to the anode electrode 101-12. In the second cathode electrode pattern 305G-4, the exposed portions 305Ga-12, 305Ga-22, 305Ga-23 are electrically connected.

[0164] For example, the second cathode electrode patterns 305-2 and 305-3 of the first embodiment are electrically connected as the second cathode electrode pattern 305G-2 of this embodiment. Fig.37 The following example shows a situation where electrons are captured by the anode electrode 101-22 (pixel (22)) and the anode electrode 101-31 (pixel (31)) at the same time. First, when using the detection signals Sx and Sy, the intersection of the anode electrode patterns 105-2 and 105-3 and the first cathode electrode patterns 205-1 and 205-2 becomes the anode electrodes 101-21, 101-22, 101-31, and 101-32 (pixels (21), (22), (31), and (32)). Therefore, in reality, the anode electrodes 101-21 and 101-32 (pixels (21) and (32)) that do not capture electrons will be misdetected.

[0165] On the other hand, when using detection signals Sx, Sy, and Sw, the location detected as anode electrodes 101-22, 101-31 (pixels (22), (31)) can be determined based on the intersection of the anode electrode patterns 105-2, 105-3, the first cathode electrode patterns 205-1, 205-2, and the second cathode electrode patterns 305G-2 and 305G-4.

[0166] In addition, when the electron is captured by the anode electrode 101-21 (pixel 21) and the anode electrode 101-32 (pixel (32)) at the same time, only the second cathode electrode pattern 305G-2 can be detected as the intersecting portion. Even in the case where two adjacent second cathode electrode patterns are connected to form a detection element of a second cathode electrode pattern with a large line width, it is possible to identify whether the second cathode electrode pattern is associated with one or two, thereby preventing false detection.

[0167] Furthermore, by reducing the number of second cathode electrode patterns, it is possible to reduce the number of radiation detection signals Sw. Therefore, by using this embodiment, it is possible to reduce power consumption and detection costs without reducing detection resolution.

[0168] In addition, even when three detection signals Sx, Sy, and Sw are used, it may be erroneously detected that electrons are captured simultaneously in the three anode electrodes 101. However, the probability of electrons being captured simultaneously in the three anode electrodes 101 is lower than the probability of electrons being captured simultaneously in two anode electrodes 101. Therefore, erroneous detection can be reduced, and as a result, the detection accuracy of radiation is improved.

[0169] In addition, in this embodiment, an example is shown in which two adjacent second cathode electrode patterns are connected to form a second cathode electrode pattern with a large line width, but three second cathode electrode patterns may be connected.

[0170] In addition, the method is not limited to connecting adjacent second cathode electrode patterns, and adjacent first cathode electrode patterns may be connected in the same manner. Fig.38 In the embodiment, for example, the first cathode electrode pattern 205-2 and the first cathode electrode pattern 205-3 of the first embodiment are connected to form a first cathode electrode pattern 205G-2. Fig.38 In the embodiment, since the area of ​​the first cathode electrode pattern becomes larger, an electric field can be formed in a wide area, making it easier to absorb ions when detecting radiation. In addition, the insulating layer 120 and the insulating layer 130 can be suppressed from being charged. Therefore, by using the detection element of this embodiment, radiation can be stably detected.

[0171] In addition, if Fig.39 As shown, adjacent anode electrode patterns may be connected. In this example, the anode electrode pattern 105-2 and the anode electrode pattern 105-3 of the first embodiment are connected to form an anode electrode pattern 105G-2.

[0172] <Seventh Implementation Method>

[0173] In this embodiment, an example of a detection element in which the arrangement of anode electrodes and the shape of the second cathode electrode pattern are different is described.

[0174] Fig.40 is a top view schematic diagram of the detection element 100H. Fig.40 As shown, in this embodiment, unlike the configuration of the anode electrode 101 in the first embodiment, the X direction and the Y direction are configured to be orthogonal (90 degrees). At this time, the W direction represents the direction along the line intersecting at 45 degrees with respect to either the straight line extending in the X direction or the straight line extending in the Y direction.

[0175] exist Fig.40 In the embodiment, the second cathode electrode pattern 305H (305H-1 to 305H-7) includes a straight-line connection pattern 305He connecting the annular pattern 305Hd and the adjacent annular pattern. The annular pattern 305Hd is substantially the same as the exposed portion 305a of the first embodiment. In the second cathode electrode pattern 305H, the width d16 (equivalent to the diameter of the opening 202) of the outer periphery of the annular pattern 305Hd is preferably larger than the width d17 of the connection pattern 305He. Thus, even if the annular pattern is configured to be larger, contact with the adjacent second cathode electrode pattern 305 can be prevented.

[0176] In addition, in this embodiment, the connection pattern has a straight line shape, but the present invention is not limited thereto. As shown in the fifth embodiment, the connection pattern may also have a wavy line shape. In this way, crosstalk noise with the first cathode electrode pattern 205 can be suppressed.

[0177] <Eighth Implementation Method>

[0178] In this embodiment, an example of a detection element having a third cathode electrode pattern will be described.

[0179] Fig.41 100I is a schematic top view of the detection element 100I. Fig.41 FIG. 1 is a schematic cross-sectional view of a portion of the detection element 100I. Fig.41 As shown, the detection element 100I has a third cathode electrode pattern 405I in addition to the anode electrode 101, the anode electrode pattern 105, the first cathode electrode pattern 205, and the second cathode electrode pattern 305I. In the detection element 100I, the anode electrode 101 and the first cathode electrode pattern 205 are arranged orthogonally. The second cathode electrode pattern 305I is arranged along the W direction. For example, the second cathode electrode pattern 305I-4 corresponds to the anode electrode 101-22 and the anode electrode 101-33 and is arranged along the W direction. The third cathode electrode pattern 405I (405I-1 to 405I-7) is arranged along the V direction, which is a direction orthogonal to the W direction. The third cathode electrode pattern 405I-3 corresponds to the anode electrode 100-23 and the anode electrode 101-32 and is arranged along the V direction. The third cathode electrode pattern 405I is electrically connected to the third cathode terminal 408I.

[0180] In addition, if Fig.42As shown, the third cathode electrode pattern 405I has a portion sandwiched by the first cathode electrode pattern 205 and the second cathode electrode pattern 305I. In this example, the third cathode electrode pattern 405I is sandwiched by the insulating layer 130 on the second cathode electrode pattern 305I and the insulating layer 131 under the first cathode electrode pattern 205. Furthermore, the third cathode electrode pattern 405I has an exposed portion 405Ia. The exposed portion 405Ia is exposed on the first surface 110a side of the substrate 110 in the same manner as the exposed portion 305Ia. The exposed portion 405Ia is configured separately from the anode electrode 101, the first cathode electrode pattern 205, and the second cathode electrode pattern 305I. By using this embodiment, the possibility of simultaneous detection is high, and in a high-dose environment, the detection efficiency of radiation can be improved.

[0181] In addition, in this embodiment, an example is shown in which the third cathode electrode pattern 405I (405I-1 to 405I-7) is arranged along the V direction which is a direction orthogonal to the W direction, but the present invention is not limited thereto. The third cathode electrode pattern 405I may also be arranged in a direction passing through the anode electrode 101-23 and passing between the anode electrode 101-22 and the anode electrode 101-33. For example, the direction may pass through the anode electrode 101-23 and the anode electrode 101-31, or may pass through the anode electrode 101-23 and the anode electrode 101-42.

[0182] In addition, in this embodiment, an example with three cathode electrode patterns is shown, but the present invention is not limited thereto, and four or more cathode electrode patterns may be provided. This further increases the possibility of simultaneous detection, and in a high-dose environment, the efficiency of radiation detection can be improved.

[0183] <Specific structural example>

[0184] The radiation detection device 10 of each embodiment described above can be used as follows: Fig.43 as well as Fig.44 The specific structural example shown is implemented.

[0185] Fig.43 1 is a diagram illustrating a specific structural example of a radiation detection device according to each embodiment of the present disclosure. As described above, the radiation detection device 10 includes a power supply device (not shown) and a cavity 50. A detection element 100 (in the case of the first embodiment), a drift cage 70, and a drift electrode 80 are arranged inside the cavity 50. The detection element 100 and the drift electrode 80 are arranged opposite to each other. When detecting radiation, a mixed gas of a rare gas and a quenching gas as described above is sealed inside the cavity 50.

[0186] Fig.44FIG. 2 is a schematic diagram of the structure of a Compton camera 20 using the radiation detection device 10. Fig.44 As shown, the detection modules 52 are arranged to surround the radiation detection device 10 from five directions. Fig.44 In FIG. 5 , the detection modules at five locations are respectively labeled with reference numerals 52a to 52e. In addition, although the example in which the detection modules 52 are arranged in five directions is shown, it is sufficient to arrange them in at least one direction (for example, the downward direction of the anode electrode 101).

[0187] The principle of the Compton camera 200 is as follows: First, when gamma rays are incident on the radiation detection device 10 from the outside, the incident gamma rays collide with the gas in the cavity 50 with a certain probability, and the gamma rays are scattered. Fig.44 The symbol A shown is the collision position. The scattered gamma rays whose traveling direction has changed due to the collision are transmitted through the radiation detection device 10 and incident on the detection module 52. If the scattered gamma rays are incident on the detection module 52, light emission is generated, and the light emission is converted into an electrical signal by a photomultiplier tube or the like. The electrical signal obtained in this way can be obtained as information indicating the position and time of the incident scattered gamma rays. At this time, the energy of the scattered gamma rays can also be obtained. If the energy of the scattered gamma rays is obtained, the detection is performed by limiting the energy range assumed when the gamma rays from a given line source are scattered only once in the cavity, thereby eliminating the influence (noise) of the gamma rays caused by multiple scatterings.

[0188] On the other hand, the gas in the cavity 50 that collides with the incident gamma ray emits rebound electrons e- (charged particles) from the position of symbol A in a given direction. As a result, an electron cloud is generated along the trajectory of the rebound electrons. The electrons constituting the electron cloud are attracted to the pixel electrode (anode electrode 101) by the electric field between the drift electrode 80 and the pixel electrode (anode electrode 101). At this time, the electrons attracted to the vicinity of the pixel electrode (anode electrode 101) collide with the gas, thereby ionizing the gas. Furthermore, the electrons generated by ionization increase in an avalanche-like manner and are detected by the pixel electrode (anode electrode 101). The electrical signal obtained in this way is equivalent to a detection signal, which is a signal that can determine the position of the pixel where the electron is detected and the moment when the electron is detected in the pixel.

[0189] In addition, the distance (position in the Z direction) from the pixel electrode (anode electrode 101) to the position where the electron cloud is generated can be calculated based on the time from the scattered gamma rays entering the detection module 52 to the time when the electrons are detected by the pixel electrode (anode electrode 101).

[0190] Explanation of symbols

[0191] 1: Radiation detection system; 10: Radiation detection device; 20: Compton camera; 50: Cavity; 52: Detection module; 55: Encoder; 60: Power supply device; 70: Drift cage; 80: Drift electrode; 90: Operation device; 100: Detection element; 101: Anode electrode; 102: Via electrode; 103: Electrode; 104: Via electrode; 105: Anode electrode pattern; 108: Anode terminal; 110: Substrate; 111: Via electrode Through hole; 112: through electrode; 115: insulating layer; 120: insulating layer; 121: opening; 130: insulating layer; 131: insulating layer; 140: insulating layer; 142: via electrode; 150: insulating layer; 160: substrate; 170: substrate; 202: opening; 205: first cathode electrode pattern; 208: first cathode terminal; 302: opening; 305: second cathode electrode pattern; 308: second cathode terminal.

Claims

1. A detection element, characterized in that: have: exposed electrodes, as a plurality of exposed electrodes disposed in an exposed manner on a first surface side of an insulating substrate, including a first exposed electrode, a second exposed electrode disposed in a first direction of the first exposed electrode, a third exposed electrode disposed in a second direction intersecting the first direction of the first exposed electrode, and a fourth exposed electrode disposed in the second direction of the second exposed electrode and disposed in the first direction of the third exposed electrode; a first electrode pattern, as a first electrode pattern disposed on a second surface side opposite to the first surface of the insulating substrate, including at least a pattern connected to the first exposed electrode and the second exposed electrode via a first through electrode, and a pattern connected to the third exposed electrode and the fourth exposed electrode via a second through electrode; a second electrode pattern, as a second electrode pattern having a first exposed portion, comprising at least a pattern corresponding to the first exposed electrode and the third exposed electrode and arranged along the second direction, and a pattern corresponding to the second exposed electrode and the fourth exposed electrode and arranged along the second direction, wherein the first exposed portion is exposed on the first surface side and is arranged separately from the exposed electrodes; and The third electrode pattern, as the third electrode pattern having a second exposed portion, at least includes a pattern arranged along a third direction connecting the first exposed electrode and the fourth exposed electrode, and is arranged as a pattern in which the third electrode pattern is clamped by the first electrode pattern and the second electrode pattern, the second exposed portion is exposed on the first surface side, and is arranged separately from the exposed electrode and the second electrode pattern.

2. The detection element according to claim 1, characterized in that: The second electrode pattern has a first opening surrounding one of the exposed electrodes, The third electrode pattern has a second opening surrounding one of the exposed electrodes, The width of the first opening is greater than the width of the second opening.

3. The detection element according to claim 1, characterized in that: The second exposed portion of the third electrode pattern is arranged on the same layer as the second electrode pattern.

4. The detection element according to claim 3, characterized in that: The exposed electrode and the second electrode pattern are arranged on the same layer.

5. The detection element according to claim 1, characterized in that: At least any one of the first electrode pattern, the second electrode pattern, and the third electrode pattern is electrically connected in a region surrounding the first exposed electrode, the second exposed electrode, and the fourth exposed electrode.

6. The detection element according to claim 1, characterized in that: The second surface side includes an insulating layer on the first electrode pattern.

7. The detection element according to claim 1, characterized in that: The first exposed electrode and the second exposed electrode are arranged adjacent to each other. The first exposed electrode and the third exposed electrode are arranged adjacent to each other. The first exposed electrode and the fourth exposed electrode are arranged adjacent to each other.

8. The detection element according to claim 7, characterized in that: A distance between the first exposed electrode and the second exposed electrode, a distance between the first exposed electrode and the third exposed electrode, and a distance between the first exposed electrode and the fourth exposed electrode are equal.

9. The detection element according to claim 8, characterized in that: When the second electrode pattern is provided with a first imaginary straight line connecting the first exposed electrode and the third exposed electrode, the distance between the center of the first exposed electrode and the first intersection point where the second imaginary straight line intersects with the edge of the second electrode pattern is greater than the distance between the midpoint between the first exposed electrode and the third exposed electrode and the second intersection point where the third imaginary straight line intersects with the edge of the second electrode pattern, the second imaginary straight line passes through the center of the first exposed electrode and is orthogonal to the first imaginary straight line, and the third imaginary straight line passes through the midpoint and is orthogonal to the first imaginary straight line.

10. The detection element according to claim 9, characterized in that: The second electrode pattern has a wave-line-shaped edge.

11. The detection element according to claim 1, characterized in that: The exposed electrode further includes a fifth exposed electrode disposed in a fourth direction, the fourth direction passing through the second exposed electrode and passing between the first exposed electrode and the fourth exposed electrode, It also includes a fourth electrode pattern, which is a fourth electrode pattern having a third exposed portion, and at least includes a pattern corresponding to the first exposed electrode and the fifth exposed electrode and arranged along the fourth direction, and is arranged as a pattern in which the fourth electrode pattern is clamped by the second electrode pattern and the third electrode pattern, and the third exposed portion is exposed on the first surface side and is arranged separately from the exposed electrode, the second electrode pattern and the third electrode pattern.

12. The detection element according to claim 7, characterized in that: The third electrode pattern includes a first annular pattern surrounding the first exposed electrode, a second annular pattern surrounding the fourth exposed electrode, and a connection pattern connecting the first annular pattern and the second annular pattern. The width of the connection pattern is narrower than the outer circumference width of the first annular pattern and the outer circumference width of the second annular pattern.

13. The detection element according to claim 1, characterized in that: The third electrode pattern is arranged on the insulating surface, The insulating surface has a recessed portion, The exposed electrode is disposed in the recessed portion, A distance from a surface of the recessed portion to an upper surface of the exposed electrode is greater than a distance from the insulating surface to an upper surface of the third electrode pattern.

14. A radiation detection device, characterized in that: include: The detection element according to any one of claims 1 to 13; and A power supply device is connected to the exposed electrode of the detection element, the first electrode pattern, the second electrode pattern, and the third electrode pattern.

15. The radiation detection device according to claim 14, characterized in that: A potential difference between the potential of the exposed electrode applied by the power supply device and the potential of the second electrode pattern is greater than a potential difference between the potential of the exposed electrode applied by the power supply device and the potential of the third electrode pattern.

16. A Compton camera, characterized in that: include: The radiation detection device according to claim 14; and The detection module is arranged to surround the radiation detection device and detect light.

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