Radiation detector, detection unit, and radiation imaging system

Abstract

To provide a technique that is advantageous for stable operation of a radiation detector.SOLUTION: A radiation detector includes a semiconductor substrate having a pixel unit and a peripheral circuit unit and a mark unit having a conducting property. The mark unit is arranged in a first area or a third area among the first area including the pixel unit, as viewed in plan view, a second area outside the first area and including the peripheral circuit unit, and the third area between the first and the second area. The mark unit is connected to a predetermined potential.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a radiation detector, a detection unit, and a radiation imaging system. [Background technology]

[0002] Radiation detectors are known that have a semiconductor substrate on which pixels and peripheral circuits are formed. If radiation is incident on the peripheral circuit region, there is a risk that the peripheral circuit may malfunction or fail. For this reason, the radiation detector is provided with a shielding member that blocks radiation so that the radiation does not enter the peripheral circuit. The shielding member has openings formed in positions corresponding to the pixel regions of the radiation detector. For this reason, it is necessary to align the radiation detector with the shielding member so that radiation is incident on the pixels through the openings in the shielding member.

[0003] On the other hand, Patent Document 1 discloses an image sensor for detecting light, but not for detecting radiation. Patent Document 1 discloses forming marks on the image sensor that are used in the exposure process during the manufacture of the image sensor or in the inspection process of the image sensor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-48356 Summary of the Invention [Problem to be solved by the invention]

[0005] Although this is not a problem with an image sensor for detecting light such as that disclosed in Patent Document 1, in the case of a radiation detector that detects ionizing radiation such as X-rays or electron beams, there is a risk that an electric charge will be built up on the mark portion when the mark portion is irradiated with radiation. If the electric charge built up on the mark portion is discharged to the circuit around the mark portion, there is a risk that the circuit will malfunction or break down.

[0006] The present disclosure provides techniques that are advantageous for stable operation of radiation detectors. [Means for solving the problem]

[0007] One aspect of the present disclosure is a radiation detector comprising a semiconductor substrate having a pixel portion and a peripheral circuit portion, and a conductive mark portion, wherein the mark portion is arranged in a first region or a third region among a first region including the pixel portion, a second region outside the first region including the peripheral circuit portion, and a third region between the first region and the second region, in a planar view, and the mark portion is connected to a predetermined potential. [Effects of the Invention]

[0008] According to the present disclosure, a technique advantageous for stable operation of a radiation detector is provided. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing the configuration of a radiation detector according to a first embodiment. [Figure 2] 1A is a plan view of the radiation detector according to the first embodiment, and FIG. 1B is an exploded perspective view of the detection unit according to the first embodiment. [Figure 3] 1A is a cross-sectional view of the radiation detector according to the first embodiment, and FIGS. 1B and 1C are explanatory views of a mark portion according to the first embodiment. [Figure 4] FIG. 10 is a cross-sectional view of a radiation detector according to a modified example of the first embodiment. [Figure 5] 10(a) is a plan view of a mark portion according to the second embodiment, and FIG. 10(b) is a cross-sectional view of the radiation detector according to the second embodiment. [Figure 6] FIG. 10 is a cross-sectional view of a radiation detector according to a third embodiment. [Figure 7] 10(a) is a plan view of a mark portion according to a fourth embodiment, and FIG. 10(b) is a cross-sectional view of a radiation detector according to the fourth embodiment. [Figure 8] 10(a) is a plan view of a radiation detector according to a fifth embodiment, and (b) and (c) are cross-sectional views of the radiation detector according to the fifth embodiment. [Figure 9] FIG. 10 is a cross-sectional view of a radiation detector according to a sixth embodiment. [Figure 10] 10(a) is a plan view of a radiation detector according to a seventh embodiment, and (b) is a cross-sectional view of the radiation detector according to the seventh embodiment. [Figure 11] 13(a) is a plan view of a radiation detector according to an eighth embodiment, and (b) is a plan view of a detection unit according to the eighth embodiment. [Figure 12] 13(a) is a cross-sectional view of a radiation detector according to a ninth embodiment, and (b) is a plan view for explaining a connection state between a region of a mark portion and a pad electrode according to the ninth embodiment. [Figure 13] FIG. 22 is a cross-sectional view of a radiation detector according to a tenth embodiment. [Figure 14] FIG. 22 is a cross-sectional view of a radiation detector according to an eleventh embodiment. [Figure 15] 12(a) is a cross-sectional view of a radiation detector according to a twelfth embodiment, and FIG. 12(b) is a plan view for explaining a connection state between a mark portion and a pad electrode according to the twelfth embodiment. [Figure 16] FIG. 22 is a diagram illustrating a system according to a thirteenth embodiment. [Figure 17] 14(a) and 14(b) are diagrams showing a system according to a fourteenth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the present invention is not limited to the following embodiments and can be modified as appropriate without departing from the spirit of the present invention. In the drawings described below, elements having the same functions are designated by the same reference numerals, and their description will be omitted.

[0011] In the following description, "radiation" is a concept that includes ionizing radiation (X-rays, gamma rays) and particle radiation (electron beams, proton beams, neutron beams, alpha rays, etc.). "Radiation imaging system" refers to a system in general that uses radiation to obtain an image of an imaging target (a subject, a patient in the case of a medical imaging system, etc.) as electronic data. "Image" may be a still image or a moving image. "Radiation detector" refers to an image sensor unit (also called a camera or imaging unit), which is a component of a radiation imaging system, that obtains an image as electronic data by converting a radiation image of the imaging target into an electrical signal.

[0012] [First embodiment] 1 is a schematic diagram showing the configuration of a radiation detector 1 according to the first embodiment. The radiation detector 1 is an image sensor, for example, a CMOS image sensor. The radiation detector 1 includes a pixel array 2, which is an example of a pixel unit, and a peripheral circuit unit 3.

[0013] The pixel array 2 has a plurality of pixels 20 arranged in a matrix. The plurality of pixels 20 includes effective pixels including a detection diode. Each pixel 20 accumulates charge generated by irradiated radiation and outputs a pixel signal (analog signal) corresponding to the amount of accumulated charge. The plurality of pixels 20 may include invalid pixels and / or dummy pixels. Here, effective pixels are pixels used for image generation and are located in an effective pixel area (imaging area). Invalid pixels are pixels located in an area other than the effective pixel area (invalid pixel area) and are not used for image generation. Dummy pixels are pixels that do not have a detection diode.

[0014] The peripheral circuit unit 3 has multiple peripheral circuits. For example, the peripheral circuit unit 3 has peripheral circuits such as a vertical scanning circuit 31, a readout circuit 32, a signal output circuit 33, and a timing generator 34. The timing generator 34 controls the operation of each circuit 31, 32 using a control signal. The vertical scanning circuit 31 sequentially selects the pixels 20 in the pixel array 2 row by row. The readout circuit 32 has an A / D conversion circuit and converts analog pixel signals read from the pixels 20 into digital signals. The signal output circuit 33 outputs the digital pixel signals to an external device. The peripheral circuit unit 3 may also include peripheral circuits such as a column amplifier, a correlated double sampling (CDS) circuit, an adder circuit, etc.

[0015] Fig. 2(a) is a plan view of the radiation detector 1 according to the first embodiment. Fig. 2(a) shows a plan view of the radiation incident side (incident surface) of the radiation detector 1, i.e., a view seen in the Z direction. The Z direction is a direction perpendicular to the incident surface of the radiation detector 1 and points towards the incident surface.

[0016] When viewed in the Z direction, the radiation detector 1 is divided into a plurality of regions. The plurality of regions include a pixel region 101, a buffer region 102, a peripheral circuit region 103, and a pad region 104. The pixel region 101 is a region that includes the pixel array 2. The peripheral circuit region 103 is a region that includes the peripheral circuit section 3 and is located outside the pixel region 101. The buffer region 102 is a region between the pixel region 101 and the peripheral circuit region 103. The pad region 104 is a region that is located outside the peripheral circuit region 103. Neither the pixel array 2 nor the peripheral circuit section 3 exists in the buffer region 102.

[0017] The pixel region 101 is a rectangular region. The buffer region 102 is a square-frame-shaped region that is adjacent to the pixel region 101 and surrounds the pixel region 101. The peripheral circuit region 103 is a square-frame-shaped region that is adjacent to the buffer region 102 and surrounds the buffer region 102. The pad region 104 is a square-frame-shaped region that is adjacent to the peripheral circuit region 103 and surrounds the peripheral circuit region 103. A plurality of pad electrodes 110 are arranged in the pad region 104 for electrical connection by wire bonding to a drive substrate including a power supply (power supply circuit), etc. The pixel region 101 is an example of a first region. The peripheral circuit region 103 is an example of a second region. The buffer region 102 is an example of a third region.

[0018] When viewed in the Z direction, at least one mark portion is disposed in the buffer region 102. Preferably, the at least one mark portion is two or more mark portions. In the first embodiment, for example, four mark portions 105 are disposed as the at least one mark portion in the buffer region 102. Each mark portion 105 is disposed near a corresponding one of the four corners of the buffer region 102 when viewed in the Z direction. Note that the position of the mark portion 105 is not limited to near the corner of the buffer region 102. For example, multiple mark portions may be disposed distributed throughout the entire buffer region 102.

[0019] The pixel region 101 has an isolation region and an active region, and in the pixel region 101, a plurality of pixels 20 shown in FIG.

[0020] If radiation were to be incident on the peripheral circuit region 103, there is a possibility that electrical charges would be accumulated in the peripheral circuits of the peripheral circuit section 3. In addition, there is a possibility that defects would occur at the boundary between the insulating layer and the semiconductor substrate, becoming a source of dark current, or that electrons generated by the radiation would find their way into the peripheral circuits and cause latch-up. These factors could cause malfunction or failure of the peripheral circuits. For this reason, in the first embodiment, the radiation detector 1 is provided with a shielding member that blocks radiation to prevent it from being incident on the peripheral circuits.

[0021] 2(b) is an exploded perspective view of the detection unit 300 according to the first embodiment. The detection unit 300 includes a radiation detector 1 and a shielding member 200. The shielding member 200 is made of a metal member capable of blocking radiation. The shielding member 200 is disposed on the side of the radiation detector 1 on which radiation is incident. The shielding member 200 is disposed in a position overlapping the entire peripheral circuit region 103, i.e., the entire peripheral circuit section 3 in FIG. 1, when viewed in the Z direction, so as to prevent radiation from being irradiated onto the peripheral circuit region 103.

[0022] The shielding member 200 has an opening 201, which is a through-hole. The opening 201 is formed at a position corresponding to the pixel array 2 so that radiation can be incident on the pixel array 2. The opening 201 has a rectangular shape with an area larger than the area of ​​the pixel region 101 when viewed in the Z direction. That is, when viewed in the Z direction, the pixel array 2 arranged in the pixel region 101 does not overlap with the shielding member 200. The pixel array 2 arranged in the pixel region 101 is irradiated with radiation that has passed through the opening 201 of the shielding member 200. The mark portion 105 is used to align the shielding member 200 with respect to the radiation detector 1 so that the shielding member 200 does not overlap with the pixel array 2.

[0023] Here, when aligning the radiation detector 1 with the shielding member 200, it is necessary to take into consideration misalignment, variations in the shape of the opening 201 in the shielding member 200, and the spread of radiation that circulates from the opening 201 in the shielding member 200 into the peripheral circuit region 103. For this reason, the radiation detector 1 is provided with a buffer region 102 between the pixel region 101 and the peripheral circuit region 103, which serves as an alignment margin.

[0024] If the visibility and focus of the mark portion 105 can be easily adjusted when measuring the mark portion 105 when aligning the shielding member 200, it becomes possible to reduce the cost and increase the accuracy of the system for aligning the radiation detector 1 and the shielding member 200.

[0025] The wider the width W of the buffer region 102 as viewed in the Z direction, the greater the alignment margin and the easier it is to align the radiation detector 1 with the shielding member 200, but this leads to an increase in the size of the semiconductor substrate 100. Furthermore, the wider the width W of the buffer region 102, the longer the wiring for pixel signals and control signals between the pixel region 101 and the peripheral circuit region 103 becomes, leading to a decrease in the signal transmission speed. Therefore, by improving the accuracy of alignment between the radiation detector 1 and the shielding member 200, the width W of the buffer region 102 can be narrowed, leading to reduced manufacturing costs for the radiation detector 1 and faster signal transmission.

[0026] Considering the scattering of radiation incident on the radiation detector 1, the width W of the buffer region 102 is preferably 200 μm or more. Furthermore, considering the transmission speed of pixel signals and control signals in the buffer region 102, the width W of the buffer region 102 is preferably 2000 μm or less.

[0027] Fig. 3(a) is a cross-sectional view of the radiation detector 1 taken along line AB in Fig. 2(a). The radiation detector 1 includes a semiconductor substrate 100, an interlayer insulating layer 115 made of an insulator and disposed on the semiconductor substrate 100, and a wiring structure 150 including a plurality of wiring layers (conductor layers) 112 disposed within the interlayer insulating layer 115.

[0028] 1, the pixel array 2 and the peripheral circuit section 3 are at least partially formed on the semiconductor substrate 100.

[0029] Furthermore, a wiring pattern (conductor pattern) 109, a passivation layer 106, and a pad electrode 110 are arranged on a main surface 125 of the interlayer insulating layer 115. The passivation layer 106 is adjacent to the wiring pattern 109 and the interlayer insulating layer 115, and is a layer that protects components of the radiation detector 1, such as the wiring pattern 109 and the interlayer insulating layer 115. That is, the wiring pattern 109 is in contact with the main surface 125 of the interlayer insulating layer 115, and the passivation layer 106 is in contact with a portion of the main surface 125 of the interlayer insulating layer 115 that is not in contact with the wiring pattern 109.

[0030] In a CMOS image sensor for light detection, a color filter layer for color recognition and a microlens layer for focusing light onto each pixel may be disposed on an interlayer insulating layer. However, since the radiation detector 1 is for radiation detection, a color filter layer and a microlens layer do not need to be disposed.

[0031] Examples of materials for the passivation layer 106 include organic insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, and polyimide, or a combination of two or more of these materials. Examples of materials for the wiring patterns of the outermost wiring layer and the wiring layer 112 include copper, aluminum, tungsten, tantalum, titanium, and polysilicon, or alloys containing at least one of these metals. Examples of materials for the interlayer insulating layer 115 include silicon oxide, BPSG (borophosphosilicate glass), PSG (phosphosilicate glass), BSG (borosilicate glass), silicon nitride, and silicon carbide, or a combination of two or more of these insulating materials.

[0032] Control signal lines such as vertical signal lines, reset signal lines, and selection signal lines can be transmitted through the wiring pattern 109, pad electrodes 110, wiring layer 112, vias 111, and vias 172. Part of the wiring connecting the pixel array 2 and the peripheral circuit section 3 is arranged in the buffer region 102. Also, a mark section 105 is arranged in the buffer region 102. An opening 201 in the shielding member 200 is aligned with the mark section 105. Because part of the buffer region 102 may be irradiated with radiation, it is preferable that the members in the buffer region 102 have resistance to radiation irradiation.

[0033] A main surface 120 of the semiconductor substrate 100 is in contact with an interlayer insulating layer 115. A detector diode for detecting radiation and a transistor 114 configured to output a detection signal from the detector diode are arranged on the semiconductor substrate 100. A gate of the transistor 114 is also arranged on the main surface 120 of the semiconductor substrate 100. The detector diode and the transistor 114 are included in effective pixels and ineffective pixels of the plurality of pixels 20 (FIG. 1), and are located in a pixel region 101 when viewed in the Z direction.

[0034] The structure of the pixel 20 may be a direct-coupled type consisting of three transistors, or a transfer type having four transistors connected to the gate electrode of the amplifying transistor via a transistor that transfers the charge accumulated in the diode. It is possible to select a structure that provides advantageous characteristics depending on the application of the radiation detector 1.

[0035] Furthermore, since the pixel region 101 is irradiated with radiation, it is preferable that the transistors in the pixel region 101 are designed with radiation resistance in mind. Radiation has the property of passing through wiring and transistors. For example, if the radiation is an electron beam, even if wiring and transistors are arranged on the detection diode, the electron beam will reach the detection diode, and the detection diode will be able to detect the electron beam.

[0036] Furthermore, a peripheral circuit included in the peripheral circuit unit 3, for example, a transistor 113 constituting a signal processing circuit, is arranged on the semiconductor substrate 100, and the gate of the transistor 113 is arranged on the main surface 120. The transistor 113 is located in the peripheral circuit region 103 when viewed in the Z direction. As described above, the peripheral circuit unit 3 including a plurality of peripheral circuits is arranged in the peripheral circuit region 103, and the peripheral circuit unit 3 is shielded from radiation by a shielding member 200 shown in FIG. 2(b).

[0037] As described above, a plurality of pad electrodes 110 are arranged in the pad region 104. The pad electrodes 110 are arranged in the outermost wiring layer. In other words, in this embodiment, the pad electrodes 110 and the wiring pattern 109 are arranged in layers at the same height. The pad electrodes 110 are provided on the main surface 125 of the interlayer insulating layer 115 in correspondence with the openings in the passivation layer 106, and are electrically connected by wires to a drive substrate or the like arranged outside the radiation detector 1. Note that the pad electrodes 110 may be electrically connected to the drive substrate from the surface opposite to the surface on which the passivation layer 106 is arranged, using through wiring.

[0038] The mark portion 105 arranged in the buffer region 102 will now be described. Figures 3(b) and 3(c) are explanatory diagrams of the mark portion 105. Figure 3(b) is a plan view of the passivation layer 106, from which a region including the mark portion 105 has been cut out as viewed in the Z direction. Figure 3(c) is a plan view of the wiring pattern 109 and the interlayer insulating layer 115, from which a region including the mark portion 105 has been cut out as viewed in the Z direction.

[0039] In the first embodiment, the mark portion 105 is a mark having a + (plus) shape when viewed from above, i.e., in the Z direction. The mark portion 105 is conductive. In the first embodiment, the mark portion 105 is composed of an opening 108 provided in the passivation layer 106 and a wiring pattern 109 that forms part of the outermost wiring layer. In the first embodiment, the opening 108 is a through-hole that penetrates the passivation layer 106. The opening 108 is + shaped when viewed in the Z direction.

[0040] The wiring pattern 109 is a solid pattern having an area larger than the area of ​​the opening 108 when viewed in the Z direction. In the wiring pattern 109, a position corresponding to the opening 108 constitutes the mark portion 105. In other words, in the wiring pattern 109, an area 142 visible through the opening 108 constitutes the mark portion 105.

[0041] In this way, the mark portion 105 is a recess that includes the opening 108 in the passivation layer 106 and the wiring pattern 109 that is located in the outermost wiring layer, which is a lower layer adjacent to the passivation layer 106, and is visible through the opening 108. Here, the outermost wiring layer constitutes a part of the outermost layer of the radiation detector 1.

[0042] A method for manufacturing the detection unit 300 shown in Fig. 2(b) will be described below. First, the radiation detector 1 and the shielding member 200 are prepared.

[0043] Next, the mark portion 105 is measured using a measurement device such as a microscope from the incident surface side of the radiation detector 1. In the first embodiment, the mark portion 105 that serves as the reference for alignment is disposed, so that it is easy to optically measure the mark portion 105 and also to adjust the focus of the measurement device.

[0044] Next, the shielding member 200 is aligned with respect to the radiation detector 1 so that the peripheral circuit region 103 of the radiation detector 1 is covered with the shielding member 200 when viewed in the Z direction. Specifically, the radiation detector 1 and the shielding member 200 are aligned and fixed so that the shielding member 200 overlaps part or all of each mark portion 105 and does not overlap the pixel array 2 (pixel region 101) when viewed in the Z direction. In the first embodiment, the shielding member 200 is aligned with respect to the radiation detector 1 so that it overlaps all of each mark portion 105.

[0045] During this alignment, the highly visible mark portions 105 allow for highly accurate alignment of the shielding member 200 with respect to the radiation detector 1. For example, as shown in FIG. 2(b), by aligning the corners of the openings 201 of the shielding member 200 with the corners of the cross-shaped mark portions 105, each mark portion 105 overlaps with the shielding member 200, allowing for highly accurate alignment of the shielding member 200 with respect to the radiation detector 1.

[0046] As described above, the first embodiment provides a technique that is advantageous for aligning the radiation detector 1 with the shielding member 200. Furthermore, since the mark portion 105 has high visibility, it is possible to align the shielding member 200 with respect to the radiation detector 1 with high accuracy.

[0047] Furthermore, since the shielding member 200 blocks radiation, the incidence of radiation on the peripheral circuit section 3 in the peripheral circuit region 103 is reduced, which reduces charge buildup in the circuits of the peripheral circuit section 3 and reduces circuit failures in the peripheral circuit section 3. Furthermore, the occurrence of defects at the interface between the interlayer insulating layer 115 and the semiconductor substrate 100 in the peripheral circuit region 103 is reduced, which reduces the occurrence of dark current. This stabilizes the operation of the circuits in the peripheral circuit section 3. Furthermore, the intrusion of electrons generated by irradiation of radiation into the circuits of the peripheral circuit section 3 is reduced, which reduces the occurrence of malfunctions such as latch-up. This stabilizes the operation of the circuits in the peripheral circuit section 3. Furthermore, the pixel array 2 arranged in the pixel region 101 does not overlap with the shielding member 200 when viewed in the Z direction, which reduces the occurrence of image defects.

[0048] Even if the buffer region 102 is provided widely, the mark portion 105 is disposed near the edge of the opening 201 of the shielding member 200, and therefore radiation that has passed through the opening 201 may be incident on the mark portion 105. The radiation that is incident on the mark portion 105 may include components of the radiation that spread at the opening 201 and components due to backscatter that are scattered inside the radiation detector 1 and return upward. If the wiring pattern 109 of the mark portion 105 is at a floating potential, radiation irradiated onto a region 142 of the wiring pattern 109 will cause electric charge to build up in the wiring pattern 109.

[0049] In the first embodiment, the wiring pattern 109 of the mark portion 105 is connected to a predetermined potential. The predetermined potential is a fixed potential set in a power supply or the like, and is a potential excluding floating potentials. In the example of the first embodiment, the predetermined potential is a ground potential GND set by the power supply.

[0050] The wiring pattern 109 of the mark portion 105 is connected to the ground potential GND via a wiring pattern 171. The multiple wiring layers 112 arranged inside the interlayer insulating layer 115 at intervals in the Z direction include a wiring layer 1121 adjacent to the wiring pattern 109 via the insulator of the interlayer insulating layer 115. Here, the wiring pattern 109 is an example of a first wiring pattern, and the wiring layer 1121 is an example of a wiring layer on which a second wiring pattern is arranged. The wiring layer 1121 is adjacent to the wiring pattern 109 via the insulator of the interlayer insulating layer 115, and is a wiring layer located between the wiring pattern 109 and the semiconductor substrate 100.

[0051] In the first embodiment, the wiring layer 1121 has a wiring pattern 171 that overlaps with the wiring pattern 109 and the pad electrode 110 when viewed in the Z direction. The wiring pattern 171 extends at least from the buffer region 102 to the pad region 104. The wiring pattern 109 and the pad electrode 110 are electrically connected via wiring that includes the wiring pattern 171, a via 172 that connects the wiring pattern 109 and the wiring pattern 171, and a via 111 that connects the pad electrode 110 and the wiring pattern 171. The pad electrode 110 is connected to a power supply via a wire.

[0052] By connecting the mark portion 105 to the ground potential GND, even if the wiring pattern 109 becomes charged due to irradiation with radiation, the charged charge is discharged to the outside (power supply) through the via 172, the wiring pattern 171, the via 111, and the pad electrode 110. This reduces charge-up in the mark portion 105. This makes it possible to prevent malfunctions and failures of circuits included in the radiation detector 1, such as the peripheral circuit portion 3.

[0053] As described above, according to the first embodiment, charge buildup in the mark portion 105 is reduced, and malfunctions and breakdowns of the radiation detector 1 are prevented. In this way, according to the first embodiment, a technique advantageous for stable operation of the radiation detector 1 is provided.

[0054] [Modification of the first embodiment] A modified example of the predetermined potential to which the mark portion 105 is connected will be described. Fig. 4 is a cross-sectional view of the radiation detector 1 according to the modified example. Fig. 4 schematically shows a cross-sectional view of the radiation detector 1 taken along line AB in Fig. 2(a).

[0055] In the first embodiment, the mark unit 105 is connected to the ground potential GND, but the present invention is not limited to this. For example, the mark unit 105 may be connected to a power supply potential VDD of a driving power supply used to drive the radiation detector 1. The power supply potential VDD may be a potential output directly from the power supply, or may be a potential generated by boosting or lowering the potential output from the power supply. The boosting or lowering may be performed by a circuit external to the radiation detector 1. The boosting or lowering may also be performed by a circuit included in the radiation detector 1. In other words, the mark unit 105 may be an internal potential generated inside the radiation detector 1.

[0056] The driving power supply is a DC constant voltage source, and the value of the power supply potential VDD is constant over time. Note that the power supply is not limited to a constant voltage source, but may be a variable voltage source that can adjust the power supply potential VDD. The variable voltage source may include a switching power supply that switches the potential over time.

[0057] Furthermore, the predetermined potential to which the mark section 105 is connected may be the potential of a power supply other than the driving power supply used to drive the radiation detector 1. For example, to enhance the effect of discharging the charge stored in the mark section 105, the potential to which the mark section 105 is connected may be a potential higher than the driving power supply potential VDD. If the charge stored in the mark section 105 is an electron, the potential to which the mark section 105 is connected is preferably a positive potential. If the charge stored in the mark section 105 is a hole, the hole has a lower mobility than the electron. Therefore, in this case, a negative potential may be applied to remove the hole. In the case of a variable voltage source, the predetermined potential may be switched between a positive potential and a negative potential depending on the polarity of the charge.

[0058] [Second embodiment] A radiation detector according to the second embodiment will be described with reference to the drawings. In the second embodiment, the description of matters common to the first embodiment will be simplified or omitted, and the description will focus on the differences from the first embodiment. The schematic configuration of the radiation detector 1 of the second embodiment is as described in the first embodiment using FIGS. 1 and 2(a). Furthermore, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 of the second embodiment is as described in the first embodiment using FIG. 2(b).

[0059] Fig. 5(a) is a plan view of a mark portion 105A according to the second embodiment, and Fig. 5(b) is a cross-sectional view of the radiation detector 1 taken along line AA' in Fig. 5(a). In the second embodiment, the mark portion 105A is formed by one of a plurality of wiring layers 112 arranged inside the interlayer insulating layer 115.

[0060] For example, the multiple wiring layers 112 include wiring layers 1121, 1122, and 1123 that are spaced apart from one another in the Z direction. The wiring layer 1122 is closer to the semiconductor substrate 100 than the wiring layer 1121. The wiring layer 1123 is closer to the semiconductor substrate 100 than the wiring layer 1122. That is, the distance in the Z direction between the wiring layer 1122 and the semiconductor substrate 100 is shorter than the distance in the Z direction between the wiring layer 1121 and the semiconductor substrate 100. Furthermore, the distance in the Z direction between the wiring layer 1123 and the semiconductor substrate 100 is shorter than the distance in the Z direction between the wiring layer 1122 and the semiconductor substrate 100. The mark portion 105A is a wiring pattern 301 that is arranged on the wiring layer 1121, which is the farthest from the semiconductor substrate 100, among the wiring layers 1121 to 1123.

[0061] In the second embodiment, the wiring layer 1121 is an example of a first wiring layer, and the wiring layer 1122 is an example of a second wiring layer. That is, the wiring layer 1122 is adjacent to the wiring layer 1121 via the insulator of the interlayer insulating layer 115, and is located between the wiring layer 1121 and the semiconductor substrate 100. The wiring pattern 301 is an example of a first wiring pattern.

[0062] The wiring pattern 301 is isolated from other wiring patterns in the wiring layer 1121, and functions as a mark. Furthermore, when viewed in the Z direction, the wiring pattern 301 does not overlap with the wiring pattern 109 that constitutes part of the outermost wiring layer of the first embodiment. Furthermore, the passivation layer 106 and the interlayer insulating layer 115 are transparent to visible light wavelengths. That is, the passivation layer 106 and the interlayer insulating layer 115 are transparent or translucent to visible light wavelengths. Therefore, even if the mark portion 105A overlaps with the passivation layer 106 and the interlayer insulating layer 115 in the Z direction, as shown in FIG. 5(b), light passes through the passivation layer 106, and thus the mark portion 105A can be visually recognized in optical measurement.

[0063] The wiring pattern 301, which is the mark portion 105A, is connected to the ground potential GND. As shown in FIG. 5(b), the wiring pattern 301 is connected to the ground potential GND via a wiring including a wiring pattern 303 arranged on the wiring layer 1122 and a wiring pattern 305 arranged on the wiring layer 1123. The wiring further includes a via 302 connecting the wiring pattern 301 (mark portion 105A) and the wiring pattern 303, and a via 304 connecting the wiring pattern 303 and the wiring pattern 305. The wiring pattern 305 is then connected to the pad electrode 110 shown in FIG. 3(a) through the via. As a result, the mark portion 105A is electrically connected to the pad electrode 110. The pad electrode 110 is connected to the ground potential GND of the power supply. As a result, the mark portion 105A is connected to the ground potential GND.

[0064] In the second embodiment, it is not necessary to form the opening 108 shown in Fig. 2(a) in the passivation layer 106 at the position corresponding to the wiring pattern 301. This makes it possible to increase the coverage of the passivation layer 106 and improve the reliability of the radiation detector 1.

[0065] Furthermore, depending on the materials of the passivation layer 106, the interlayer insulating layer 115, etc., forming the edge of the mark portion 105A by patterning the conductor of the wiring layer 1121 can improve the contrast between the mark portion 105A and the surrounding components. Therefore, depending on the materials of the passivation layer 106, the interlayer insulating layer 115, etc., it can improve the visibility of the mark portion 105A compared to forming the edge of the mark portion 105A by the opening 108 in the passivation layer 106 as in the first embodiment.

[0066] In the second embodiment, the wiring pattern 303 is formed at a position that overlaps with the mark portion 105A when viewed in the Z direction. The wiring pattern 303 is formed to a size and shape that allows it to be hidden by the mark portion 105A when viewed in the Z direction. This makes it difficult to see the wiring pattern 303 behind the mark portion 105A, improving the visibility of the mark portion 105A.

[0067] In the second embodiment, the wiring pattern 303 is formed to have the same size and shape as the mark portion 105A when viewed in the Z direction, which reduces the electrical resistance of the wiring pattern 303 and further enhances the charge discharging effect when the mark portion 105A is charged.

[0068] The vias 302 and 304 are formed at positions that overlap the mark portion 105A when viewed in the Z direction. The vias 302 and 304 are sized and shaped so that they are hidden by the mark portion 105A when viewed in the Z direction, for example, they have a columnar shape with a substantially circular cross section in a direction perpendicular to the Z direction. This makes it difficult to see the vias 302 and 304 behind the mark portion 105A, improving the visibility of the mark portion 105A.

[0069] Note that the mark portion 105A of the second embodiment can also be modified in various ways, similar to the first embodiment and its modifications.

[0070] [Third embodiment] A radiation detector according to the third embodiment will be described with reference to the drawings. In the third embodiment, the description of matters common to the first or second embodiment will be simplified or omitted, and the description will focus on the differences from the first or second embodiment. The schematic configuration of the radiation detector 1 of the third embodiment is as described in the first embodiment using FIGS. 1 and 2(a). Furthermore, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 of the third embodiment is as described in the first embodiment using FIG. 2(b).

[0071] Fig. 6 is a cross-sectional view of the radiation detector 1 taken along line AA' in Fig. 5(a). The radiation detector 1 has a mark portion 105A having the same configuration as that of the second embodiment. The configuration of vias 302 and 304 for connecting the mark portion 105A to the ground potential GND differs from that of the second embodiment.

[0072] The vias 302 and 304 are formed at positions that overlap the mark portion 105A when viewed in the Z direction. The vias 302 and 304 are formed to a size and shape that allows them to be hidden by the mark portion 105A when viewed in the Z direction. This makes it difficult to see the vias 302 and 304 behind the mark portion 105A, improving the visibility of the mark portion 105A.

[0073] In the third embodiment, the vias 302 and 304 are formed to have the same size and shape as the mark portion 105A when viewed in the Z direction, which reduces the electrical resistance of the vias 302 and 304 and further enhances the charge discharging effect when the mark portion 105A is charged.

[0074] Note that the mark portion 105A of the third embodiment can also be modified in various ways, similar to the first and second embodiments and their modifications.

[0075] [Fourth embodiment] A radiation detector according to the fourth embodiment will be described with reference to the drawings. In the fourth embodiment, the description of matters common to the first to third embodiments will be simplified or omitted, and the description will focus on the differences from the first to third embodiments. The schematic configuration of the radiation detector 1 of the fourth embodiment is as described in the first embodiment using FIGS. 1 and 2(a). Furthermore, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 of the fourth embodiment is as described in the first embodiment using FIG. 2(b).

[0076] FIG. 7(a) is a plan view of a mark unit 105B according to the fourth embodiment, and FIG. 7(b) is a cross-sectional view of the radiation detector 1 taken along line AA' in FIG. 7(a). In the fourth embodiment, the mark unit 105B is formed by wiring patterns 5011 and 5012 arranged on a wiring layer 1121 located inside the interlayer insulating layer 115. The mark unit 105B includes a mark 1601 that is cross-shaped when viewed in the Z direction, and a mark 1602 that is rectangular and surrounds the cross-shaped mark 1601 when viewed in the Z direction. When viewed in the Z direction, the mark 1601 is arranged inside the mark 1602. The mark 1601 of the mark unit 105B is the wiring pattern 5011 arranged on the wiring layer 1121. The mark 1602 of the mark unit 105B is the wiring pattern 5012 arranged on the wiring layer 1121.

[0077] In the fourth embodiment, the wiring layer 1121 is an example of a first wiring layer, and the wiring layer 1122 is an example of a second wiring layer. That is, the wiring layer 1122 is adjacent to the wiring layer 1121 via the insulator of the interlayer insulating layer 115, and is located between the wiring layer 1121 and the semiconductor substrate 100. The wiring pattern 5011 is an example of a first wiring pattern.

[0078] When aligning the shielding member 200 with respect to the radiation detector 1, the frame-shaped wiring pattern 5012 is measured at low magnification, and the shielding member 200 is aligned with low precision with respect to the radiation detector 1. Thereafter, the cross-shaped wiring pattern 5011 is measured at high magnification, and the shielding member 200 is aligned with high precision with respect to the radiation detector 1. Then, the shielding member 200 is fixed to a module including the radiation detector 1, and the detection unit 300 is manufactured.

[0079] The wiring pattern 5011 is a wiring pattern that is isolated from other wiring patterns in the wiring layer 1121, and functions as the mark 1601. The wiring pattern 5012 is a wiring pattern that is isolated from other wiring patterns in the wiring layer 1121, and the wiring pattern 5012 functions as the mark 1602.

[0080] The wiring pattern 5011, which is the mark 1601, and the wiring pattern 5012, which is the mark 1602, are connected to the ground potential GND.

[0081] 7(b), the wiring pattern 5011 and the wiring pattern 5012 are electrically connected to a wiring pattern 505 arranged on the wiring layer 1123. The wiring pattern 5011 is connected to the ground potential GND via a wiring including a wiring pattern 5031 arranged on the wiring layer 1122 and a wiring pattern 505 arranged on the wiring layer 1123. The wiring pattern 5012 is connected to the ground potential GND via a wiring including a wiring pattern 5032 arranged on the wiring layer 1122 and a wiring pattern 505 arranged on the wiring layer 1123. The wiring further includes a via 5021 connecting the wiring pattern 5011 and the wiring pattern 5031 and a via 5041 connecting the wiring pattern 5031 and the wiring pattern 505. The wiring also includes a wiring pattern 5032 arranged on the wiring layer 1122 , a via 5022 connecting the wiring pattern 5012 and the wiring pattern 5032 , and a via 5042 connecting the wiring pattern 5032 and the wiring pattern 505 .

[0082] In this way, the wiring patterns 5011 and 5012 are electrically connected to the wiring pattern 505. The wiring pattern 505 is then connected to the pad electrode 110 shown in FIG. 3(a) by a via. As a result, the marks 1601 and 1602 of the mark portion 105B are electrically connected to the pad electrode 110. The pad electrode 110 is connected to the ground potential GND of the power supply. As a result, the mark portion 105B is connected to the ground potential GND.

[0083] In the fourth embodiment, it is not necessary to form openings 108 as shown in Fig. 2(a) in the passivation layer 106 at positions corresponding to the wiring patterns 5011 and 5012. This makes it possible to increase the coverage of the passivation layer 106 and improve the reliability of the radiation detector 1.

[0084] Moreover, in the fourth embodiment, the wiring pattern 5031 is formed at a position overlapping the wiring pattern 5011 when viewed in the Z direction. The wiring pattern 5031 is formed to a size and shape that allows it to be hidden by the wiring pattern 5011 when viewed in the Z direction. This makes it difficult to see the wiring pattern 5031 behind the wiring pattern 5011, thereby improving the visibility of the wiring pattern 5011 that constitutes the mark portion 150B.

[0085] Furthermore, in the fourth embodiment, the wiring pattern 5032 is formed at a position overlapping the wiring pattern 5012 when viewed in the Z direction. The wiring pattern 5032 is formed to a size and shape that allows it to be hidden by the wiring pattern 5012 when viewed in the Z direction. This makes it difficult to see the wiring pattern 5032 behind the wiring pattern 5012, thereby improving the visibility of the wiring pattern 5012 that constitutes the mark portion 150B.

[0086] The vias 5021 and 5041 are formed at positions overlapping the wiring pattern 5011 when viewed in the Z direction. The vias 5021 and 5041 have a size and shape that allows them to be hidden by the wiring pattern 5011 when viewed in the Z direction, for example, a cylindrical shape whose cross section in a direction perpendicular to the Z direction is substantially circular. This makes it difficult to see the vias 5021 and 5041 behind the wiring pattern 5012, improving the visibility of the mark 1601.

[0087] The vias 5022 and 5042 are formed at positions overlapping the wiring pattern 5012 when viewed in the Z direction. The vias 5022 and 5042 have a size and shape that allows them to be hidden by the wiring pattern 5012 when viewed in the Z direction, for example, a cylindrical shape whose cross section in a direction perpendicular to the Z direction is substantially circular. This makes it difficult to see the vias 5022 and 5042 behind the wiring pattern 5012, improving the visibility of the mark 1602.

[0088] 7(b), the mark portion 105B can be configured by a plurality of wiring patterns 5011 and 5012 spaced apart from each other, and the mark portion 105B can be electrically connected to the wiring pattern 505. Therefore, the charges accumulated in the mark portion 105B can be collectively discharged to the ground potential GND.

[0089] Note that the mark portion 105B of the fourth embodiment can also be modified in various ways, similar to the first to third embodiments and their modifications.

[0090] [Fifth embodiment] A radiation detector according to the fifth embodiment will be described with reference to the drawings. In the fifth embodiment, the description of matters common to the first to fourth embodiments will be simplified or omitted, and the description will focus on the differences from the first to fourth embodiments. The schematic configuration of the radiation detector 1 of the fifth embodiment is as described in the first embodiment using FIGS. 1 and 2(a). Furthermore, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 of the fifth embodiment is as described in the first embodiment using FIG. 2(b). In the fifth embodiment, of the multiple mark portions, one or more mark portions and one or more mark portions are connected to different potentials.

[0091] FIG. 8(a) is a plan view of a radiation detector 1 according to a fifth embodiment. FIG. 8(b) is a cross-sectional view of the radiation detector 1 taken along line AA' in FIG. 8(a). FIG. 8(c) is a cross-sectional view of the radiation detector 1 taken along line BB' in FIG. 8(a). Of the four mark portions 105 shown in FIG. 8(a), two or more mark portions are connected to two or more predetermined potentials that are different from each other. For example, of the two mark portions 1051 and 1052, the mark portion 1051 is connected to the ground potential GND, and the mark portion 1052 is connected to the power supply potential VDD. Note that each of the mark portions 1051 and 1052 has the same configuration as the mark portion 105 described in the first embodiment.

[0092] The mark portion 1051 has a wiring pattern 109 arranged on the top wiring layer. The wiring pattern 109 of the mark portion 1051 is connected to the ground potential GND. The mark portion 1052 has a wiring pattern 109 arranged on the top wiring layer. The wiring pattern 109 of the mark portion 1052 is connected to the power supply potential VDD.

[0093] The pad electrode 1101 is connected to the ground potential GND of the power supply via a wire, and the pad electrode 1102 is connected to the power supply potential VDD of the power supply via a wire.

[0094] The degree of freedom in wiring layout is improved by connecting the mark portion 1051 to the pad electrode 1101 that is relatively close, and connecting the mark portion 1052 to the pad electrode 1102 that is relatively close. Furthermore, since the length of each wire can be shortened, the impedance of the wire can be lowered and the charge of the mark portions 1051 and 1052 can be efficiently discharged.

[0095] In addition, in the fifth embodiment, a ground potential GND is applied to the pad electrode 1101, and a power supply potential VDD is applied to the pad electrode 1102, thereby making it possible to discharge charges for both electrons and holes.

[0096] The power supply potential VDD is not limited to being a fixed potential, and may be changed depending on the application, or the positive and negative polarities may be reversed.

[0097] Note that the mark portions 1051 and 1052 of the fifth embodiment can also be modified in various ways, similar to the first to fourth embodiments and their modifications.

[0098] [Sixth embodiment] A radiation detector according to the sixth embodiment will be described with reference to the drawings. In the sixth embodiment, the description of matters common to the first to fifth embodiments will be simplified or omitted, and the description will focus on the differences from the first to fifth embodiments. The schematic configuration of the radiation detector 1 of the sixth embodiment is as described in the first embodiment using FIGS. 1 and 2(a). Furthermore, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 of the sixth embodiment is as described in the first embodiment using FIG. 2(b).

[0099] 9 is a cross-sectional view of the radiation detector 1 taken along line AB in FIG. 2(a). In the sixth embodiment, the mark portion 105 is connected to the ground potential GND via at least a well 701 included in the semiconductor substrate 100. Specifically, the mark portion 105 is connected to the ground potential GND via wiring and the well 701. The well 701 is, for example, a well disposed across the buffer region 102, the peripheral circuit region 103, and the pad region 104.

[0100] The wiring has a plurality of wiring patterns arranged on the wiring layer 112, a plurality of vias connecting the plurality of wiring patterns and the wiring pattern 109 constituting the mark unit 105, and a via 111 connecting any of the wiring patterns on the wiring layer 112 to the pad electrode 110. The wiring is also connected to the well 701 via a contact plug that connects the semiconductor substrate to the wiring pattern. In this way, the mark unit 105 is connected to the ground potential GND via the well 701 and the wiring.

[0101] If the potential applied to the pad electrode 110 is the ground potential GND, the well 701 may be an N-well. If the potential applied to the pad electrode 110 is the power supply potential VDD, the well 701 may be a P-well.

[0102] According to the sixth embodiment, the charge stored in the mark portion 105 is received by the substrate capacitance, thereby improving the resistance of the radiation detector 1 to the occurrence of a momentary large amount of charge. Furthermore, since the mark portion 105 is connected to the ground potential GND via the well 701, it becomes possible to freely lay out wiring for other purposes in the region 702 in the interlayer insulating layer 115 located above the well 701.

[0103] Although the mark portion 105 is connected to the ground potential GND via the well 701 arranged in the peripheral circuit region 103, it may be connected to the ground potential GND via a well in the pixel region 101.

[0104] Moreover, the mark portion 105 of the sixth embodiment can also be modified in various ways, similar to the first to fifth embodiments and their modifications.

[0105] [Seventh embodiment] A radiation detector according to the seventh embodiment will be described with reference to the drawings. In the seventh embodiment, the description of matters common to the first to sixth embodiments will be simplified or omitted, and the description will focus on the differences from the first to sixth embodiments. The schematic configuration of the radiation detector 1 of the seventh embodiment is as described in the first embodiment using FIG. 1. Furthermore, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 of the seventh embodiment is as described in the first embodiment using FIG. 2(b).

[0106] FIG. 10(a) is a plan view of a radiation detector 1 according to a seventh embodiment. FIG. 10(b) is a cross-sectional view of the radiation detector 1 taken along line AB in FIG. 10(a). The radiation detector 1 of the seventh embodiment has a mark portion 105C arranged on a wiring structure 150. The mark portion 105C is arranged so as to surround the pixel region 101 (the pixel array 2 in FIG. 1) in a plan view, i.e., when viewed in the Z direction. The mark portion 105C is conductive. In the seventh embodiment, the mark portion 105C is composed of an opening 108C in the passivation layer 106 and a wiring pattern 109 in the outermost wiring layer. In the seventh embodiment, the opening 108C is a through-hole that penetrates the passivation layer 106. The opening 108C has a rectangular frame shape when viewed in the Z direction. The wiring pattern 109 can be viewed through the opening 108C.

[0107] The wiring pattern 109 of the mark portion 105C is connected to the ground potential GND. The interlayer insulating layer 115 contains a plurality of wiring layers 801 arranged at intervals in the Z direction. The plurality of wiring layers 801 includes a wiring layer 8011 adjacent to the wiring pattern 109 via the insulator of the interlayer insulating layer 115. Here, the outermost wiring layer is an example of a first wiring layer, and the wiring layer 8011 is an example of a second wiring layer. The wiring layer 8011 is adjacent to the wiring pattern 109 via the insulator of the interlayer insulating layer 115 and is located between the outermost wiring layer and the semiconductor substrate 100. The wiring pattern 109 is an example of a first wiring pattern.

[0108] In the seventh embodiment, the wiring layer 8011 has a wiring pattern 171C that overlaps with the wiring pattern 109 and the pad electrode 110 when viewed in the Z direction. The wiring pattern 171C extends at least from the buffer region 102 to the pad region 104, and is connected to the pad electrode 110 by a via.

[0109] By connecting the mark portion 105C to the ground potential GND, even if the wiring pattern 109 of the mark portion 105C becomes charged due to irradiation with radiation, the charged charge is discharged to the outside (power supply) via the wiring. Therefore, charge-up of the mark portion 105C is reduced. This makes it possible to prevent malfunctions and failures of circuits included in the radiation detector 1, such as the peripheral circuit portion 3.

[0110] In the seventh embodiment, a conductive ring structure 803 is arranged below the mark portion 105C to surround the pixel region 101 as viewed in the Z direction. The ring structure 803 is formed in a rectangular frame shape as viewed in the Z direction so as to surround the outer periphery of the pixel region 101 as viewed in the Z direction.

[0111] The wiring pattern 109 of the mark portion 105C is also formed in a rectangular frame shape when viewed in the Z direction. The wiring also includes a plurality of wiring patterns 173C arranged in a plurality of wiring layers 801 below the outermost wiring layer, each of which is formed in a rectangular frame shape when viewed in the Z direction, and a plurality of vias 174C arranged along the rectangular frame when viewed in the Z direction. The plurality of wiring patterns 173C also includes a wiring pattern 171C connected to the ground potential GND. Furthermore, a well 802 included in the semiconductor substrate 100 is also formed in a rectangular frame shape so as to surround the outer periphery of the pixel region 101.

[0112] In the seventh embodiment, the vias 174C connecting the multiple wiring patterns 173C have a columnar structure, but are preferably arranged with a high occupancy rate. Alternatively, the vias 174C may be solid like the wiring patterns 173C of the wiring layer 801. The shape of the vias 174C may be determined in consideration of the planarization step of the semiconductor process. The rectangular frame-shaped wiring pattern 109, the rectangular frame-shaped wiring pattern 173C included in the wiring layer 801, the vias 174C arranged along the rectangular frame, and the well 802 form a ring structure 803. In other words, the wiring and the well 802 are connected.

[0113] The ring structure 803 spatially separates the outside (peripheral circuit region 103 side) and the inside (pixel region 101 side) of the ring structure 803 when viewed in the Z direction. As a result, even if electromagnetic noise occurs outside, the electric field caused by the noise is blocked by the ring structure 803, reducing the impact on the pixels 20 (FIG. 1) located in the internal pixel region 101. In other words, blocking external electromagnetic noise stabilizes the operation of the pixels 20.

[0114] Although the case where the ring structure 803 includes the well 802, i.e., the case where the wiring is connected to the well 802, has been described, the well 802 may be omitted from the ring structure 803. In other words, the wiring does not have to be connected to the well 802.

[0115] Moreover, the mark portion 105C of the seventh embodiment can also be modified in various ways, similar to the first to sixth embodiments and their modifications.

[0116] [Eighth embodiment] A radiation detector and a detection unit according to the eighth embodiment will be described with reference to the drawings. In the eighth embodiment, the description of matters common to the first embodiment will be simplified or omitted, and the description will focus on the differences from the first embodiment.

[0117] Fig. 11(a) is a plan view of a radiation detector 1 according to an eighth embodiment. Fig. 11(a) shows a plan view of the radiation incident side (incident surface) of the radiation detector 1, i.e., a view seen in the Z direction. The circuit configuration of the radiation detector 1 according to the eighth embodiment is as described in the first embodiment using Fig. 1.

[0118] When viewed in the Z direction, the radiation detector 1 is divided into a plurality of regions. Similar to the first embodiment, the plurality of regions include a pixel region 101, a buffer region 102, a peripheral circuit region 103, and a pad region 104. The pixel region 101 is an example of a first region. The peripheral circuit region 103 is an example of a second region. The buffer region 102 is an example of a third region. When viewed in the Z direction, a plurality of mark portions, for example, four mark portions 105, are arranged in the pixel region 101. Each mark portion 105 is arranged near a corresponding one of the four corners of the pixel region 101 when viewed in the Z direction.

[0119] 11(b) is a plan view of a detection unit 300 according to the eighth embodiment. The detection unit 300 includes a radiation detector 1 and a shielding member 200. The shielding member 200 is made of a metal member capable of blocking radiation. The shielding member 200 is disposed on the side of the radiation detector 1 on which radiation is incident. The shielding member 200 is disposed in a position overlapping the entire peripheral circuit region 103, i.e., the entire peripheral circuit section 3 in FIG. 1, when viewed in the Z direction, so as to prevent radiation from being irradiated onto the peripheral circuit region 103.

[0120] The shielding member 200 has an opening 201, which is a through-hole. The opening 201 is formed at a position corresponding to the pixel array 2 so that radiation can be incident on the pixel array 2. When viewed in the Z direction, the opening 201 has a rectangular shape with approximately the same area as the pixel region 101. That is, when viewed in the Z direction, the pixel array 2 arranged in the pixel region 101 does not overlap with the shielding member 200. The pixel array 2 ( FIG. 1 ) arranged in the pixel region 101 is irradiated with radiation that has passed through the opening 201 of the shielding member 200. The mark portion 105 is used to align the shielding member 200 with respect to the radiation detector 1 so that the shielding member 200 does not overlap with the pixel array 2.

[0121] In the above configuration, the mark portion 105 of the eighth embodiment is connected to a predetermined potential, for example, ground potential or power supply potential, as in the first to seventh embodiments described above. This reduces charge buildup in the mark portion 105, preventing malfunctions and breakdowns of the radiation detector 1. In this way, the eighth embodiment provides a technology that is advantageous for stable operation of the radiation detector 1.

[0122] [Ninth embodiment] A radiation detector according to the ninth embodiment will be described with reference to the drawings. In the ninth embodiment, the description of matters common to the first to eighth embodiments will be simplified or omitted, and the description will focus on the differences from the first to eighth embodiments. The schematic configuration of the radiation detector 1 of the ninth embodiment is as described in the first embodiment using FIG. 1. Furthermore, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 of the ninth embodiment is as described in the first embodiment using FIG. 2(b).

[0123] Fig. 12(a) is a cross-sectional view of the radiation detector 1 according to the ninth embodiment. Fig. 12(a) shows a cross section of the radiation detector 1 taken along line AB in Fig. 2(a). Fig. 12(b) is a plan view for explaining the connection state between the mark portion 105 and the pad electrode 110 according to the ninth embodiment.

[0124] The mark portion 105 is a conductor disposed on the outermost wiring layer. In the ninth embodiment, the mark portion 105 and the pad electrode 110 are connected by a solid wiring pattern 109. The mark portion 105 is visible through an opening 108 in the passivation layer 106.

[0125] With the above configuration, the charge stored in the mark portion 105 can be discharged to the ground potential GND via the shortest path. In addition, the solid wiring pattern 109 also functions to block light incident on the peripheral circuit region 103, thereby preventing malfunction of the transistors 113 in the peripheral circuit region 103.

[0126] The wiring layer 1121 has a wiring pattern 1711 connected to the mark portion 105 through a via 172, and a wiring pattern 1712 connected to the pad electrode 110 through a via 111. In the wiring layer 1121, the wiring pattern 1711 and the wiring pattern 1712 are not connected to each other.

[0127] [Tenth embodiment] A radiation detector according to the tenth embodiment will be described with reference to the drawings. In the tenth embodiment, the description of matters common to the first to ninth embodiments will be simplified or omitted, and the description will focus on the differences from the first to ninth embodiments. The schematic configuration of the radiation detector 1 of the tenth embodiment is as described in the first embodiment using FIG. 1. Furthermore, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 of the tenth embodiment is as described in the first embodiment using FIG. 2(b).

[0128] Fig. 13 is a cross-sectional view of the radiation detector 1 according to the tenth embodiment. Fig. 13 shows a cross section of the radiation detector 1 taken along line AB in Fig. 2(a). In the tenth embodiment, the via 111 connected to the pad electrode 110 and the via 172 connected to the mark portion 105 are connected by a wiring pattern 171 of the wiring layer 1121.

[0129] With the above configuration, the mark portion 105 and the pad electrode 110 are connected via the wiring pattern 109 and the wiring pattern 171, so the electrical resistance of the path through which the charge stored in the mark portion 105 is released to the ground potential GND is lower than in the ninth embodiment. As a result, more charge can be discharged to the ground potential GND.

[0130] [Eleventh embodiment] A radiation detector according to the eleventh embodiment will be described with reference to the drawings. In the eleventh embodiment, the description of matters common to the first to tenth embodiments will be simplified or omitted, and the description will focus on the differences from the first to tenth embodiments. The schematic configuration of the radiation detector 1 of the eleventh embodiment is as described in the first embodiment using FIG. 1. Furthermore, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 of the eleventh embodiment is as described in the first embodiment using FIG. 2(b).

[0131] Fig. 14 is a cross-sectional view of the radiation detector 1 according to the eleventh embodiment. Fig. 14 shows a cross section of the radiation detector 1 taken along line AB in Fig. 2(a). The radiation detector 1 of the eleventh embodiment is obtained by omitting the vias 111 and 172 from the radiation detector 1 of the tenth embodiment. This improves the degree of freedom in the layout of the wiring layer 112.

[0132] [Twelfth embodiment] A radiation detector according to the twelfth embodiment will be described with reference to the drawings. In the twelfth embodiment, the description of matters common to the first to eleventh embodiments will be simplified or omitted, and the description will focus on the differences from the first to eleventh embodiments. The schematic configuration of the radiation detector 1 of the twelfth embodiment is as described in the first embodiment using FIG. 1. Furthermore, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 of the twelfth embodiment is as described in the first embodiment using FIG. 2(b).

[0133] Fig. 15(a) is a cross-sectional view of the radiation detector 1 according to the twelfth embodiment. Fig. 15(a) shows a cross section of the radiation detector 1 taken along line AB in Fig. 2(a). Fig. 15(b) is a plan view for explaining the connection state between the mark portion 105D and the pad electrode 110 according to the twelfth embodiment.

[0134] The radiation detector 1 of the twelfth embodiment has a mark portion 105D instead of the mark portion 105 shown in Fig. 12(a). The mark portion 105D has a + (plus) shaped mark 1051 and a square frame shaped mark 1052 surrounding the + shaped mark 1051 in a plan view, i.e., when viewed in the Z direction. The mark 1051 is disposed inside the mark 1052 when viewed in the Z direction.

[0135] Specifically, the passivation layer 106 has an opening 1081 that is cross-shaped when viewed in the Z direction and an opening 1082 that is rectangular and surrounds the opening 1081 when viewed in the Z direction. The openings 1081 and 1082 are through-holes that penetrate the passivation layer 106. The mark 1051 is made of a conductor that is disposed at a position corresponding to the opening 1081, and the mark 1052 is made of a conductor that is disposed at a position corresponding to the opening 1082. The marks 1051 and 1052 are disposed on the outermost wiring layer and connected to the wiring pattern 109. The marks 1051 and 1052 are visible through the openings 1081 and 1082, respectively. The wiring pattern 109 is connected to a pad electrode 110, as in the ninth embodiment.

[0136] The above configuration improves the visibility of the mark portion 105D. For example, when aligning the shielding member 200 (FIG. 2(b)) with respect to the radiation detector 1, the frame-shaped mark 1052 is measured at low magnification, and the shielding member 200 is aligned with the radiation detector 1 with low precision. Thereafter, the cross-shaped mark 1051 is measured at high magnification, and the shielding member 200 is aligned with the radiation detector 1 with high precision. Then, the shielding member 200 is fixed to a module including the radiation detector 1, thereby manufacturing the detection unit 300 (FIG. 2(b)).

[0137] [Thirteenth embodiment] In the above first to twelfth embodiments, examples of the configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 have been described. In the thirteenth embodiment, a radiation imaging system including the detection unit 300 will be described.

[0138] 16 is a detection system including an imaging section 1101 which is a detection unit 300 including a radiation detector 1 and a shielding member 200, an exposure control section 1102, a radiation source 1103 which is an energy ray irradiator, and a computer 1104. The imaging section 1101 has an imaging panel 100P which has a pixel array 2. The imaging section 1101 can be configured using the detection unit 300 which has the radiation detector 1 described in the first to twelfth embodiments.

[0139] The radiation source 1103 starts irradiating radiation in accordance with an exposure command from the exposure control unit 1102. The radiation emitted from the radiation source 1103 passes through the imaging target (subject) and enters the imaging panel 100P of the imaging unit 1101. The radiation source 1103 stops emitting radiation in accordance with a stop command from the exposure control unit 1102.

[0140] The imaging unit 1101 is, for example, a flat panel detector used for radiography in medical image diagnosis, non-destructive testing, etc. The imaging panel 100P of the imaging unit 1101 can be a plate-shaped panel sized to match the size of the object to be imaged. For example, the imaging panel 100P has 3300 x 2800 pixels arranged on a 550 mm x 445 mm substrate.

[0141] The imaging unit 1101 may be of a direct conversion type, in which radiation is converted into signal charges by detector diodes provided in the pixel array 2 of the imaging panel 100P. Alternatively, the imaging unit 1101 may be of an indirect conversion type, in which radiation is converted into fluorescence by a scintillator layer provided above the pixel array 2 of the imaging panel 100P, and the fluorescence is converted into signal charges by detector diodes in the pixel array 2.

[0142] The imaging unit 1101 includes the imaging panel 100P described above, a control unit 1105 for controlling the imaging panel 100P, and a signal processing unit 1106 for processing signals output from the imaging panel 100P. The signal processing unit 1106 may, for example, perform A / D conversion on the signals output from the imaging panel 100P and output the signals as digital image data to the computer 1104. The signal processing unit 1106 may also generate a stop signal for stopping the irradiation of radiation from the radiation source 1103 based on the signals output from the imaging panel 100P. The stop signal is supplied to the exposure control unit 1102 via the computer 1104, and the exposure control unit 1102 sends a stop command to the radiation source 1103 in response to the stop signal.

[0143] The control unit 1105 can be configured, for example, by a PLD (abbreviation for Programmable Logic Device) such as an FPGA (abbreviation for Field Programmable Gate Array), or an ASIC (abbreviation for Application Specific Integrated Circuit), or a general-purpose computer with a built-in program, or a combination of all or part of these.

[0144] In the thirteenth embodiment, the signal processing unit 1106 is shown as being arranged in the control unit 1105 or as a part of the function of the control unit 1105, but this is not limiting. The control unit 1105 and the signal processing unit 1106 may be configured separately. Furthermore, the signal processing unit 1106 may be arranged separately from the imaging unit 1101. For example, the computer 1104 may have the function of the signal processing unit 1106. Therefore, the signal processing unit 1106 may be included in the radiation imaging system 1100 as a signal processing device that processes signals output from the imaging unit 1101.

[0145] The computer 1104 can control the imaging unit 1101 and the exposure control unit 1102, receive radiation image data from the imaging unit 1101, and perform processing to display the data as a radiation image. The computer 1104 can also function as an input unit for the user to input conditions for capturing a radiation image.

[0146] As an example, the exposure control unit 1102 has an exposure switch, and when the user turns on the exposure switch, it sends an exposure command to the radiation source 1103 and also sends a start notification indicating the start of radiation emission to the computer 1104. In response to the start notification, the computer 1104 notifies the control unit 1105 of the imaging unit 1101 of the start of radiation irradiation. In response to this, the control unit 1105 causes the imaging panel 100P to generate a signal corresponding to the incident radiation.

[0147] [Fourteenth embodiment] 17A shows an apparatus EQP as a radiation imaging system. The apparatus EQP includes a detection unit 300 having a radiation detector 1 and a shielding member 200.

[0148] The radiation detector 1 has a pixel array 2 in which pixels 20 are arranged in a matrix, and a peripheral circuit section 3 arranged around the pixel array 2. The peripheral circuit section 3 includes a plurality of peripheral circuits. A shielding member 200 is arranged on the radiation incident side of the radiation detector 1.

[0149] The equipment EQP may further include at least one of an optical system OPT, a control device CTRL, a processing device PRCS, a display device DSPL, a memory device MMRY, and a mechanical device MCHN. The optical system OPT focuses radiation on the radiation detector 1 and is, for example, a lens, a shutter, or a mirror. Depending on the type of radiation being handled, the optical system OPT may focus particle beams, such as electron beams or proton beams, on the radiation detector 1. The control device CTRL controls the radiation detector 1 and is, for example, an ASIC. The processing device PRCS processes signals output from the radiation detector 1 and is a device such as a CPU or ASIC that constitutes an AFE (analog front end) or DFE (digital front end). The display device DSPL is an EL display device or liquid crystal display device that displays information obtained by the radiation detector 1 in the form of a visible image or the like. The memory device MMRY is a magnetic device or semiconductor device that stores information obtained by the radiation detector 1. The memory device MMRY is a volatile memory such as an SRAM or DRAM, or a non-volatile memory such as a flash memory or a hard disk drive. The mechanical device MCHN has moving parts or propulsion parts, such as a motor or engine.

[0150] The equipment EQP displays the signal output from the radiation detector 1 on the display device DSPL and transmits the signal to the outside via a communication device (not shown) provided in the equipment EQP. For this purpose, the equipment EQP preferably further includes a memory device MMRY and a processing device PRCS in addition to the memory circuit and arithmetic circuit provided in the radiation detector 1. The mechanical device MCHN may be controlled based on the signal output from the radiation detector 1.

[0151] The device EQP shown in FIG. 17(a) may be a medical device such as an endoscope or a radiological diagnostic device, a measuring device such as a distance sensor, or an analytical device such as an electron microscope.

[0152] 17(b) is a schematic diagram showing the configuration of a transmission electron microscope (TEM) as an example of the device EQP. The device EQP as an electron microscope has an electron beam source 1202 (electron gun) as an irradiation unit of an energy beam (electron beam), an irradiation lens 1204, a vacuum chamber 1201 (lens barrel), an objective lens 1206, and a magnifying lens system 1207. The device EQP also has a camera 1209 as an imaging unit. The camera 1209 is equipped with a detection unit 300 having a direct electron detector 1200 as a direct detection type radiation detector 1. In other words, the direct electron detector 1200 corresponds to the radiation detector 1.

[0153] An electron beam 1203, which is an energy beam emitted from an electron beam source 1202, is focused by an irradiation lens 1204 and irradiated onto a sample S to be analyzed, which is held in a sample holder. The space through which the electron beam 1203 passes is formed by a vacuum chamber 1201 (optical column), and this space is maintained at a vacuum. The radiation detector 1 is disposed so as to face the vacuum space through which the electron beam 1203 passes. The electron beam 1203 that has passed through the sample S is magnified by an objective lens 1206 and a magnifying lens system 1207 and projected onto the radiation detector 1. The electron optical system for irradiating the sample S with the electron beam is called the irradiation optical system, and the electron optical system for forming an image of the electron beam that has passed through the sample S on the radiation detector 1 is called the imaging optical system.

[0154] The electron beam source 1202 is controlled by an electron beam source controller 1211. The illumination lens 1204 is controlled by an illumination lens controller 1212. The objective lens 1206 is controlled by an objective lens controller 1213. The magnifying lens system 1207 is controlled by a magnifying lens system controller 1214. The sample holder control mechanism 1205 is controlled by a holder controller 1215, which controls the drive mechanism of the sample holder.

[0155] The electron beam 1203 transmitted through the sample S is detected by a direct radiation detector 1200 of a camera 1209. An output signal from the direct radiation detector 1200 is processed by a signal processing device 1216 and an image processing device 1218 serving as a processing device PRCS, and an image signal is generated. The generated image signal (transmitted electron image) is displayed on an image display monitor 1220 and an analysis monitor 1221, which correspond to a display device DSPL.

[0156] The camera 1209 is provided below the device EQP. The camera 1209 is provided inside the vacuum chamber 1201 so that at least a portion of the camera 1209 is exposed to the vacuum space formed by the vacuum chamber 1201.

[0157] The electron beam source controller 1211, the irradiation lens controller 1212, the objective lens controller 1213, the magnifying lens system controller 1214, and the holder controller 1215 are each connected to an image processor 1218. This allows mutual data exchange to set the imaging conditions of the electron microscope. For example, the electron beam irradiation rate can be set to 0.5 electron / pix / frm or less. In this case, the electron beam source controller 1211 and the image processor 1218 function as control means for controlling the radiation irradiation rate. Drive control of the sample holder and setting of the observation conditions for each lens can be performed using signals from the image processor 1218.

[0158] The operator prepares a sample S to be photographed and sets the photographing conditions using an input device 1219 connected to the image processing device 1218. Predetermined data is input to the electron beam source control device 1211, the illumination lens control device 1212, the objective lens control device 1213, and the magnifying lens system control device 1214, respectively, to obtain the desired acceleration voltage, magnification, and observation mode. The operator also inputs conditions such as the number of consecutive field-of-view images, the photographing start position, and the specimen holder movement speed into the image processing device 1218 using the input device 1219 such as a mouse, keyboard, or touch panel. The image processing device 1218 may be designed to automatically set the conditions without relying on operator input.

[0159] The systems described above in the thirteenth and fourteenth embodiments are merely examples, and the radiation detectors described in the first to twelfth embodiments may be applied to other systems.

[0160] The disclosure of the above embodiments includes the following sections.

[0161] (Section 1) a semiconductor substrate having a pixel portion and a peripheral circuit portion; a mark portion having conductivity, the mark portion is arranged in a first region or a third region among a first region including the pixel portion, a second region including the peripheral circuit portion and located outside the first region, and a third region between the first region and the second region, in a plan view; The mark portion is connected to a predetermined potential. A radiation detector characterized by:

[0162] (Section 2) the mark portion is connected to the predetermined potential at least via a wiring; Item 1. The radiation detector according to item 1.

[0163] (Section 3) the wiring includes a second wiring pattern adjacent to the first wiring pattern in which the mark portion is arranged via an insulator and positioned between the first wiring pattern and the semiconductor substrate, and a via connecting the mark portion and the second wiring pattern; Item 3. The radiation detector according to item 2, characterized in that:

[0164] (Section 4) the second wiring pattern overlaps with the mark portion in the plan view; Item 4. The radiation detector according to item 3,

[0165] (Section 5) the second wiring pattern is formed to a size that is hidden by the mark portion in the plan view; Item 5. The radiation detector according to item 4,

[0166] (Section 6) the via overlaps with the mark portion in the plan view; Item 6. The radiation detector according to any one of items 3 to 5, characterized in that:

[0167] (Section 7) the via is formed to a size that is hidden by the mark portion in the plan view; Item 7. The radiation detector according to item 6, characterized in that:

[0168] (Section 8) the mark portion is connected to the predetermined potential via at least a well included in the semiconductor substrate; 8. The radiation detector according to any one of items 1 to 7, characterized in that:

[0169] (Section 9) The predetermined potential is a potential set by a power supply. Item 9. The radiation detector according to any one of items 1 to 8, characterized in that:

[0170] (Section 10) the predetermined potential is a power supply potential or a ground potential of the power supply; Item 10. The radiation detector according to item 9, characterized in that:

[0171] (Section 11) The power supply is a constant voltage source. Item 11. The radiation detector according to item 9 or 10,

[0172] (Section 12) the power supply is a variable voltage source that can adjust the predetermined potential; Item 10. The radiation detector according to item 9, characterized in that:

[0173] (Section 13) The radiation detector has two or more of the mark portions. 13. The radiation detector according to any one of items 1 to 12, characterized in that:

[0174] (Section 14) the two or more mark portions are connected to two or more predetermined potentials different from each other, respectively; Item 14. The radiation detector according to item 13,

[0175] (Section 15) the mark portion includes a frame-shaped mark arranged so as to surround the pixel portion in the plan view, Item 15. The radiation detector according to any one of items 1 to 14,

[0176] (Section 16) the frame-shaped mark is connected to the predetermined potential at least via a wiring; the wiring includes a plurality of wiring patterns connected by vias, which are arranged so as to surround the pixel unit in the plan view; Item 16. The radiation detector according to item 15,

[0177] (Section 17) the mark portion further includes a cross-shaped mark disposed inside the frame-shaped mark in the plan view. Item 17. The radiation detector according to item 15 or 16,

[0178] (Section 18) The radiation detector according to any one of items 1 to 17, a shielding member disposed on a radiation incident side of the radiation detector, the shielding member having an opening formed at a position corresponding to the pixel portion; the shielding member overlaps the entire second region in the plan view; A detection unit characterized by:

[0179] (Section 19) a radiation source that irradiates the imaging target with radiation; Item 18. The detection unit according to item 18, A radiation imaging system comprising: [Explanation of symbols]

[0180] 1...radiation detector, 2...pixel array (pixel section), 3...peripheral circuit section, 100...semiconductor substrate, 101...pixel region (first region), 102...buffer region (third region), 103...peripheral circuit region (second region), 105...mark section

Claims

1. a semiconductor substrate having a pixel portion and a peripheral circuit portion; A mark portion having electrical conductivity, the mark portion is arranged in a first region including the pixel portion, a second region including the peripheral circuit portion and located outside the first region, and a third region between the first region and the second region, in a plan view; The mark portion is connected to a predetermined potential. A radiation detector comprising:

2. the mark portion is connected to the predetermined potential at least via a wiring; 2. The radiation detector according to claim 1 .

3. the wiring includes a second wiring pattern adjacent to the first wiring pattern in which the mark portion is arranged via an insulator and located between the first wiring pattern and the semiconductor substrate, and a via connecting the mark portion and the second wiring pattern.

3. The radiation detector according to claim 2.

4. the second wiring pattern overlaps with the mark portion in the plan view; 4. The radiation detector according to claim 3.

5. the second wiring pattern is formed to a size such that it is hidden by the mark portion in the plan view; 5. The radiation detector according to claim 4.

6. The via overlaps with the mark portion in the plan view.

4. The radiation detector according to claim 3.

7. the via is formed to a size such that it is hidden by the mark portion in the plan view; 7. The radiation detector according to claim 6.

8. the mark portion is connected to the predetermined potential via at least a well included in the semiconductor substrate; 2. The radiation detector according to claim 1 .

9. The predetermined potential is a potential set by a power source.

2. The radiation detector according to claim 1 .

10. The predetermined potential is a power supply potential or a ground potential of the power supply.

10. The radiation detector according to claim 9.

11. The power source is a constant voltage source.

10. The radiation detector according to claim 9.

12. The power supply is a variable voltage source capable of adjusting the predetermined potential.

10. The radiation detector according to claim 9.

13. The radiation detector includes two or more of the mark portions.

2. The radiation detector according to claim 1 .

14. the two or more mark portions are connected to two or more predetermined potentials different from each other, 14. The radiation detector according to claim 13.

15. the mark portion includes a frame-shaped mark arranged so as to surround the pixel portion in the plan view, 2. The radiation detector according to claim 1 .

16. the frame-shaped mark is connected to the predetermined potential at least via a wiring; the wiring includes a plurality of wiring patterns connected by vias, the wiring patterns being arranged so as to surround the pixel unit in the plan view, 16. The radiation detector according to claim 15.

17. the mark portion further includes a +-shaped mark disposed inside the frame-shaped mark in the plan view, 16. The radiation detector according to claim 15.

18. A radiation detector according to any one of claims 1 to 17; a shielding member disposed on a radiation incident side of the radiation detector and having an opening formed at a position corresponding to the pixel portion; The shielding member overlaps the entire second region in the plan view. A detection unit comprising:

19. a radiation source for irradiating an imaging target with radiation; A detection unit according to claim 18, A radiation imaging system comprising:

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