Radiation detector, detection unit, radiation imaging system, and manufacturing method for detection unit

Abstract

To provide a technique advantageous for the alignment of a radiation detector and a shielding member.SOLUTION: A radiation detector includes a first area, having a pixel unit including a plurality of pixels, as viewed in plan view, for detecting radiation at the pixel unit, a second area including a plurality of peripheral circuits, and a third area between the first area and the second area. A mark unit is arranged on the first area or the third area. The mark unit includes at least one of a first portion constituting a surface layer of the radiation detector and a second portion of a lower layer adjacent to the first portion.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a radiation detector, a detection unit, a radiation imaging system, and a method for manufacturing a detection unit.

Background Art

[0002] A radiation detector having a semiconductor substrate on which pixels and peripheral circuits are formed is known. When radiation is incident on the peripheral circuit region, there is a risk of malfunction or failure of the peripheral circuit. For this reason, a shielding member that shields radiation so that the radiation does not enter the peripheral circuit is provided in the radiation detector. An opening is formed in the shielding member at a position corresponding to the pixel region of the radiation detector. Therefore, alignment between the radiation detector and the shielding member is required so that radiation is incident on the pixels through the opening of the shielding member.

[0003] On the other hand, Patent Document 1 and Patent Document 2 disclose image sensors for light detection, although not for radiation detection. Patent Document 1 discloses that, when manufacturing an image sensor, alignment marks are provided during the photolithography process in order to accurately join divided regions during divided exposure. Further, Patent Document 2 discloses forming alignment marks for aligning a lens with respect to a photodiode.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, it is difficult to align the radiation detector and the shielding member using the alignment marks described in Patent Document 1 and Patent Document 2. If the positions of the radiation detector and the shielding member are misaligned, the shielding member may not overlap the peripheral circuit region, and there is a risk that radiation may enter the peripheral circuit region.

[0006] The present disclosure provides a technique advantageous for aligning a radiation detector and a shielding member.

Means for Solving the Problems

[0007] One aspect of the present disclosure is a radiation detector including, in plan view, a pixel portion including a plurality of pixels, a first region for detecting radiation in the pixel portion, a second region including a plurality of peripheral circuits, and a third region between the first region and the second region, wherein a mark portion is disposed in the first region or the third region, and the mark portion includes at least one of a first portion constituting a surface layer of the radiation detector and a second portion in a lower layer adjacent to the first portion.

Advantages of the Invention

[0008] According to the present disclosure, a technique advantageous for aligning a radiation detector and a shielding member is provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

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Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments according to 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 appropriately changed without departing from the gist thereof. Also, in the drawings described below, those having the same function are denoted by the same reference numerals, and the description thereof 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" generally refers to a system that uses radiation to acquire an image of an imaging target (subject, patient in the case of a medical imaging system, etc.) as electronic data. The "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) that is a component of a radiation imaging system and acquires an image as electronic data by converting the radiation image of the imaging target into an electrical signal.

[0012] [First Embodiment] FIG. 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 section, and a peripheral circuit section 3.

[0013] The pixel array 2 has a plurality of pixels 20 arranged in a matrix. The plurality of pixels 20 have effective pixels including detection diodes. Each pixel 20 accumulates charges generated by the irradiated radiation and outputs a pixel signal (analog signal) corresponding to the amount of the accumulated charges. Note that the plurality of pixels 20 may include dummy pixels and / or invalid pixels. Here, an effective pixel is a pixel used for image generation and is located in an effective pixel region (imaging region). An invalid pixel is located in a region other than the effective pixel region (invalid pixel region) and is a pixel not used for image generation. A dummy pixel is a pixel that does not have a detection diode.

[0014] The peripheral circuit section 3 has a plurality of peripheral circuits. For example, the peripheral circuit section 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 operations of the respective circuits 31 and 32 by a control signal. The vertical scanning circuit 31 sequentially selects the pixels 20 of the pixel array 2 row by row. The readout circuit 32 has an A / D conversion circuit and converts the pixel signal, which is an analog signal read from the pixel 20, into a digital signal. The signal output circuit 33 outputs the pixel signal converted into a digital signal to an external device. Note that the peripheral circuit section 3 may further include other peripheral circuits such as a column amplifier, a correlated double sampling (CDS) circuit, and an addition circuit.

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

[0016] 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 including the pixel array 2. The peripheral circuit region 103 is a region including the peripheral circuit section 3 and is a region 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 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 rectangular frame-shaped region and is adjacent to the pixel region 101 so as to surround the pixel region 101. The peripheral circuit region 103 is a rectangular frame-shaped region and is adjacent to the buffer region 102 so as to surround the buffer region 102. The pad region 104 is a rectangular frame-shaped region and is adjacent to the peripheral circuit region 103 so as to surround the peripheral circuit region 103. In the pad region 104, a plurality of pad electrodes 110 for electrically connecting to a driving substrate including a power supply (power supply circuit) by wire bonding are arranged. 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 arranged in the buffer region 102. It is preferable that the at least one mark portion is two or more mark portions. In the first embodiment, for example, four mark portions 105 are arranged as at least one mark portion in the buffer region 102. Each mark portion 105 is arranged near the corresponding corner among the four corners of the buffer region 102 viewed in the Z direction. Note that the arrangement position of the mark portion 105 is not limited to the vicinity of the corner of the buffer region 102. For example, a plurality of mark portions may be distributed and arranged throughout the buffer region 102.

[0019] The pixel region 101 has a separation region and an active region. And in the pixel region 101, a plurality of pixels 20 shown in FIG. 1 are two-dimensionally arranged.

[0020] Here, if radiation is incident on the peripheral circuit region 103, there is a possibility that charges are charged up in the peripheral circuits of the peripheral circuit section 3. In addition, there is a possibility that defects occur at the boundary between the insulating layer and the semiconductor substrate to become a source of dark current, or electrons generated by radiation enter the peripheral circuit and cause latch-up. Due to these factors, there is a risk of malfunction or failure of the peripheral circuit. For this reason, in the first embodiment, a shielding member for shielding radiation so that radiation is not incident on the peripheral circuit is provided in the radiation detector 1.

[0021] FIG. 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 composed of a metal member capable of shielding radiation. The shielding member 200 is disposed on the side where the radiation of the radiation detector 1 is incident. The shielding member 200 is disposed at a position that overlaps the entire peripheral circuit region 103, that is, the entire peripheral circuit section 3 in FIG. 1, when viewed in the Z direction so that the peripheral circuit region 103 is not irradiated with radiation.

[0022] An opening 201, which is a through hole, is formed in the shielding member 200. The opening 201 is formed at a position corresponding to the pixel array 2 so that radiation is 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 disposed in the pixel region 101 does not overlap the shielding member 200. The pixel array 2 disposed 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 the pixel array 2.

[0023] Here, in the alignment between the radiation detector 1 and the shielding member 200, it is necessary to consider alignment deviation, variation in the shape of the opening 201 of the shielding member 200, and the spread of radiation that enters the peripheral circuit region 103 from the opening 201 of the shielding member 200. Therefore, a buffer region 102 serving as an alignment margin is provided in the radiation detector 1 between the pixel region 101 and the peripheral circuit region 103.

[0024] When the visibility of the mark portion 105 and focus adjustment are easy in the measurement of the mark portion 105 when aligning the shielding member 200, it is 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 viewed in the Z direction, the larger the alignment margin becomes, and it becomes easier to align the radiation detector 1 and the shielding member 200. However, this leads to an increase in the size of the semiconductor substrate 100. Also, the wider the width W of the buffer region 102, the longer the wiring of 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 increasing the alignment accuracy between the radiation detector 1 and the shielding member 200, the width W of the buffer region 102 can be narrowed, leading to a reduction in the manufacturing cost of the radiation detector 1 and an increase in the signal speed.

[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. Also, 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 along line A-B in FIG. 2(a). The radiation detector 1 includes a wiring structure 150 including a semiconductor substrate 100, an interlayer insulating layer 115 disposed on the semiconductor substrate 100 and composed of an insulator, and a plurality of wiring layers (conductor layers) 112 disposed in the interlayer insulating layer 115.

[0028] The semiconductor substrate 100 has the pixel array 2 and the peripheral circuit unit 3 shown in FIG. 1. At least a part of the pixel array 2 and the peripheral circuit unit 3 is formed on the semiconductor substrate 100.

[0029] Also, on the main surface 125 of the interlayer insulating layer 115, a wiring pattern (conductor pattern) 109, a passivation layer 106, and a pad electrode 110 are disposed. The passivation layer 106 is adjacent to the wiring pattern 109 and the interlayer insulating layer 115, and is a layer that protects members 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 where the wiring pattern 109 is not in contact.

[0030] Here, 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 the interlayer insulating layer. However, in the radiation detector 1, since it is for radiation detection, the color filter layer and the microlens layer do not need to be disposed.

[0031] Examples of the material of the passivation layer 106 include any of organic insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, polyimide, or a combination of two or more of these materials. Examples of the material of each conductor pattern of the outermost layer wiring layer and the wiring layer 112 include any of copper, aluminum, tungsten, tantalum, titanium, polysilicon, or an alloy containing at least one of these metals. Examples of the material of the interlayer insulating layer 115 include any of silicon oxide, BPSG (borophosphosilicate glass), PSG (phosphosilicate glass), BSG (borosilicate glass), silicon nitride, 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, the pad electrode 110, the wiring layer 112, the via 111, and the via 172. A part of the wiring connecting the pixel array 2 and the peripheral circuit section 3 is disposed in the buffer region 102. Also, a mark section 105 is disposed in the buffer region 102. The opening 201 of the shielding member 200 is aligned with the mark section 105. Since a 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] The main surface 120 of the semiconductor substrate 100 is in contact with the interlayer insulating layer 115. A detection diode for detecting radiation and a transistor 114 configured to output a detection signal of the detection diode are disposed on the semiconductor substrate 100. Also, the gate of the transistor 114 is disposed on the main surface 120 of the semiconductor substrate 100. The detection diode and the transistor 114 are included in the active pixels and the inactive pixels among the plurality of pixels 20 (FIG. 1) and are located in the pixel region 101 when viewed in the Z direction.

[0034] Note that the structure of the pixel 20 may be a direct connection type composed of three transistors, or a transfer type including four transistors that are connected to the gate electrode of the amplification transistor via a transistor that transfers the charge accumulated in the diode. It is possible to select a structure that provides advantageous characteristics according to the application of the radiation detector 1.

[0035] Also, since the pixel region 101 is irradiated with radiation, it is preferable that the transistors in the pixel region 101 are designed in consideration of radiation resistance. Also, radiation has the property of passing through wiring and transistors. For example, when the radiation is an electron beam, even if wiring and transistors are disposed on the detection diode, the electron beam reaches the detection diode, so the detection diode can detect the electron beam.

[0036] Also, a transistor 113 that constitutes a peripheral circuit, such as a signal processing circuit, included in the peripheral circuit section 3 is disposed on the semiconductor substrate 100, and the gate of the transistor 113 is disposed on the main surface 120 thereof. The transistor 113 is located in the peripheral circuit region 103 when viewed in the Z direction. The peripheral circuit region 103 is provided with a peripheral circuit section 3 including a plurality of peripheral circuits as described above, and the peripheral circuit section 3 is shielded from radiation by the 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 surface wiring layer. In other words, in the present embodiment, the pad electrodes 110 and the wiring pattern 109 are arranged in the same height layer. The pad electrodes 110 are provided on the main surface 125 of the interlayer insulating layer 115 corresponding to the opening of the passivation layer 106, and are electrically connected to a drive substrate or the like arranged outside the radiation detector 1 by a wire. 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 a through wiring.

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

[0039] In the first embodiment, the mark portion 105 is a + (plus) shaped mark in a plan view, that is, as viewed in the Z direction. The mark portion 105 is composed of an opening 108 in the passivation layer 106 and a wiring pattern 109. In the first embodiment, the opening 108 is a through hole penetrating the passivation layer 106. The opening 108 has a + shape as 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 as viewed in the Z direction. In the wiring pattern 109, the position corresponding to the opening 108 constitutes the mark portion 105. In other words, in the wiring pattern 109, the region 142 visible through the opening 108 constitutes the mark portion 105.

[0041] Thus, the mark portion 105 is located in the outermost layer wiring layer which is the lower layer adjacent to the passivation layer 106 and is adjacent to the opening 108 of the passivation layer 106, and is a recess including a wiring pattern 109 visible through the opening 108. The passivation layer 106 and its opening 108 are an example of the first portion, and the wiring pattern 109 is an example of the second portion. Here, the outermost layer 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. First, the radiation detector 1 and the shielding member 200 are prepared.

[0043] Next, the mark portion 105 is measured from the side of the incident surface of the radiation detector 1 using a measuring device such as a microscope. In the first embodiment, since the mark portion 105 serving as an alignment reference is arranged, it becomes easy to optically measure the mark portion 105, and it also becomes easy to adjust the focus of the measuring device.

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

[0045] During this alignment, since the visibility of the mark portion 105 is high, the shielding member 200 can be aligned with the radiation detector 1 with high precision. For example, as shown in FIG. 2(b), by aligning the corner of the opening 201 of the shielding member 200 with the corner of the cross-shaped mark portion 105, each mark portion 105 overlaps the shielding member 200, and the shielding member 200 can be aligned with the radiation detector 1 with high precision.

[0046] As described above, according to the first embodiment, a technique advantageous for aligning the radiation detector 1 and the shielding member 200 is provided. Since the visibility of the mark portion 105 is high, it is possible to align the shielding member 200 with the radiation detector 1 with high precision.

[0047] In addition, since the radiation is shielded by the shielding member 200, the incidence of radiation on the peripheral circuit portion 3 in the peripheral circuit region 103 is reduced, the charging of the circuit in the peripheral circuit portion 3 with electric charge is reduced, and the failure of the circuit in the peripheral circuit portion 3 is reduced. Also, in the peripheral circuit region 103, the occurrence of defects at the interface between the interlayer insulating layer 115 and the semiconductor substrate 100 is reduced, and the generation of dark current is reduced. As a result, the operation of the circuit in the peripheral circuit portion 3 becomes stable. Further, the electrons generated by the irradiation of radiation are less likely to enter the circuit in the peripheral circuit portion 3, and the occurrence of malfunction such as latch-up is reduced. As a result, the operation of the circuit in the peripheral circuit portion 3 becomes stable. In addition, since the pixel array 2 disposed in the pixel region 101 does not overlap with the shielding member 200 when viewed in the Z direction, the occurrence of image defects is reduced.

[0048] [Modification Example of the First Embodiment] A modification example of the mark portion 105 of the first embodiment will be described. In the first embodiment, the case where the mark portion 105 is a cross-shaped mark has been described, but the shape is not limited thereto. The shape of the mark portion 105 may be, for example, an L-shape, an H-shape, a square shape, a square frame shape, or the like. Also, the mark portion 105 may be a combination of a plurality of marks. FIGS. 4(a) to 4(f) are explanatory diagrams of the mark portion 105 of the modification example.

[0049] The mark portion 105 shown in FIG. 4(a) includes a cross-shaped mark 160 1 and a square frame-shaped mark 160 surrounding the cross-shaped mark 2 The passivation layer 106 has a cross-shaped opening 108 (through hole) and a square frame-shaped opening (through hole) 131. The wiring layer 121 has a wiring pattern 109. The cross-shaped mark 160 1is composed of an opening 108 and a wiring pattern 109, and is a rectangular frame-shaped mark 160 2 is composed of an opening 131 and a wiring pattern 109.

[0050] When aligning the shielding member 200 with respect to the radiation detector 1, the frame-shaped mark 160 is measured at a low magnification, and the shielding member 200 is aligned with the radiation detector 1 with low accuracy. Thereafter, the cross-shaped mark 160 is measured at a high magnification, and the shielding member 200 is aligned with the radiation detector 1 with high accuracy. Then, by fixing the shielding member 200 and the radiation detector 1, the detection unit 300 is manufactured. 2 is measured, and the shielding member 200 is aligned with the radiation detector 1 with low accuracy. Then, the cross-shaped mark 160 1 is measured, and the shielding member 200 is aligned with the radiation detector 1 with high accuracy. Then, by fixing the shielding member 200 and the radiation detector 1, the detection unit 300 is manufactured.

[0051] The mark portion 105 shown in FIG. 4(b) is obtained by inverting the opening and non-opening of the passivation layer 106 in the mark portion 105 shown in FIG. 4(a). The mark portion 105 shown in FIG. 4(b) is selected according to visibility and member layout.

[0052] The mark portion 105 shown in FIG. 4(c) has a plurality of rectangular marks 160. Each of the plurality of marks 160 shown in FIG. 4(c) is rectangular with a long side parallel to the vertical direction of FIG. 4(c). The plurality of marks 160 shown in FIG. 4(c) are arranged at intervals in the horizontal direction.

[0053] The mark portion 105 shown in FIG. 4(d) has a plurality of rectangular marks 160. Each of the plurality of marks 160 shown in FIG. 4(d) is rectangular with a long side parallel to the horizontal direction of FIG. 4(d). The plurality of marks 160 shown in FIG. 4(d) are arranged at intervals in the vertical direction.

[0054] In the example of FIG. 2(a), in the vertically wide area in the buffer area 102, the mark portion 105 shown in FIG. 4(c) may be arranged, and in the horizontally wide area in the buffer area 102, the mark portion 105 shown in FIG. 4(d) may be arranged. Thereby, the alignment adjustment of the shielding member 200 in the rotation direction about the irradiation direction of the radiation can be performed using the long side of the mark 160 in FIG. 4(c) or FIG. 4(d), and the shielding member 200 can be accurately aligned in the rotation direction.

[0055] Each of the mark portion 105 shown in FIG. 4(e) and the mark portion 105 shown in FIG. 4(f) has a plurality of marks 160 and can be diverted to another process such as a photolithography process in addition to the alignment of the shielding member 200. For example, the mark portion 105 shown in FIG. 4(e) can be used as a mark for defining a dicing line in the dicing process of a semiconductor chip. Further, for example, the mark portion 105 shown in FIG. 4(f) can be used as a mark for measuring the overlay accuracy in the photolithography process. By forming these mark portions 105, it is possible to simplify the manufacturing mask for forming the mark portions 105.

[0056] [Second Embodiment] With reference to the drawings, a radiation detector according to the second embodiment will be described. In the second embodiment, descriptions 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 in the second embodiment is as described with reference to FIGS. 1 and 2(a) in the first embodiment. Further, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 in the second embodiment is as described with reference to FIG. 2(b) in the first embodiment.

[0057] FIG. 5(a) is a cross-sectional view of the radiation detector 1 taken along line A-B of FIG. 2(a).

[0058] The wiring structure 150 of the second embodiment includes an interlayer insulating layer 115 made of an insulator and a plurality of wiring layers (conductor layers) 112 disposed within the interlayer insulating layer 115. Further, a wiring pattern 109 of the outermost layer wiring layer is disposed on the interlayer insulating layer 115, and a passivation layer 106 is disposed on the interlayer insulating layer 115 and the wiring pattern 109. The passivation layer 106 is adjacent to 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 where the wiring pattern 109 is not in contact. The passivation layer 106 is the outermost layer, and the wiring pattern 109 is a lower layer with respect to the passivation layer 106. The mark portion 105A is disposed in the buffer region 102 when viewed in the Z direction.

[0059] FIGS. 5(b) and 5(c) are explanatory views of the mark portion 105A. FIG. 5(b) is a plan view of the passivation layer 106 in which a region including the mark portion 105A is cut out when viewed in the Z direction. FIG. 5(c) is a plan view of the wiring pattern 109 and the interlayer insulating layer 115 in which a region including the mark portion 105A is cut out when viewed in the Z direction.

[0060] The mark portion 105A includes the wiring pattern 109 adjacent to the passivation layer 106 (outermost layer). In the second embodiment, the mark portion 105A is composed of the wiring pattern 109. That is, in the second embodiment, the mark portion 105A does not include the insulator portion of the passivation layer 106 that is an upper layer with respect to the wiring pattern 109. The wiring pattern 109 is covered by the passivation layer 106.

[0061] In the second embodiment, the mark portion 105A is a + (plus) shaped mark when viewed in plan, that is, when viewed in the Z direction. That is, the wiring pattern 109 is + shaped when viewed in the Z direction.

[0062] Note that the manufacturing method of the detection unit 300 according to the second embodiment is the same as that described in the first embodiment, and the description thereof is omitted.

[0063] In the second embodiment, the wiring pattern 109 is covered with the passivation layer 106. The passivation layer 106 has permeability at the wavelength of visible light. That is, the passivation layer 106 is transparent or translucent at the wavelength of visible light. Therefore, even if the mark portion 105A is covered with the passivation layer 106 as shown in FIG. 5(b), light can pass through the passivation layer 106, so that it can be visually recognized in optical measurement.

[0064] The wiring pattern 109 may be a part of the wiring. The wiring pattern 109 may be used as a ground electrode and has little influence on signal lines and control lines. Also, there is a large degree of freedom in designing the shape and size of the mark portion 105A. Further, since the wiring pattern 109 is covered with the passivation layer 106, it is more advantageous than the first embodiment from the viewpoints of humidity countermeasures and surface protection.

[0065] As described above, according to the second embodiment, a technique advantageous for alignment between the radiation detector 1 and the shielding member 200 is provided. And since the visibility of the mark portion 105A is high, it is possible to align the shielding member 200 with the radiation detector 1 with high precision. Also, since the radiation is shielded by the shielding member 200, the circuit operation of the peripheral circuit portion 3 is stabilized, the failure of the peripheral circuit portion 3 is reduced, and the occurrence of image defects is also reduced.

[0066] Note that various modifications are possible for the mark portion 105A of the second embodiment as well, similar to the first embodiment. For example, the mark portion 105A can be modified as in the modification examples shown in FIGS. 4(a) to 4(f).

[0067] [Third Embodiment] Referring to the drawings, the radiation detector according to the third embodiment will be described. In the third embodiment, for matters common to the first embodiment, the description 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 third embodiment is as described with reference to FIGS. 1 and 2(a) in the first embodiment. Also, 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 with reference to FIG. 2(b) in the first embodiment.

[0068] FIG. 6(a) is a cross-sectional view of the radiation detector 1 taken along line A-B in FIG. 2(a).

[0069] The wiring structure 150 of the third embodiment includes an interlayer insulating layer 115 made of an insulator and a plurality of wiring layers (conductor layers) 112 disposed in the interlayer insulating layer 115. Also, a wiring pattern 109 which is a part of the outermost layer wiring layer is disposed on the interlayer insulating layer 115, and a passivation layer 106 disposed on the interlayer insulating layer 115 and the wiring pattern 109. The passivation layer 106 is adjacent to 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 where the wiring pattern 109 is not in contact. The passivation layer 106 is the outermost layer, and the interlayer insulating layer 115 is the lower layer with respect to the passivation layer 106.

[0070] FIGS. 6(b) and 6(c) are explanatory views of the mark portion 105B. FIG. 6(b) is a plan view of the passivation layer 106 in which a region including the mark portion 105B is cut out as viewed in the Z direction. FIG. 6(c) is a plan view of the wiring pattern 109 and the interlayer insulating layer 115 in which a region including the mark portion 105B is cut out as viewed in the Z direction.

[0071] The mark portion 105B is a recess including an opening 108 in the passivation layer 106 (surface layer) and an interlayer insulating layer 115 (lower layer) adjacent to the passivation layer 106. The passivation layer 106 and its opening 108 are an example of a first portion, and the interlayer insulating layer 115 is an example of a second portion.

[0072] In the third embodiment, the mark portion 105B is a +-shaped mark when viewed in a plan view (viewed in the Z direction).

[0073] The interlayer insulating layer 115 is a solid pattern having an area larger than the area of the opening 108 when viewed in the Z direction. In the interlayer insulating layer 115, a +-shaped region 143 viewed in the Z direction and visible through the opening 108 constitutes a part of the mark portion 105B.

[0074] Note that the manufacturing method of the detection unit 300 according to the third embodiment is the same as that described in the first embodiment, and the description thereof is omitted.

[0075] In the third embodiment, it is possible to visually recognize the mark portion 105B by optical measurement from the step between the opening 108 of the passivation layer 106 and the interlayer insulating layer 115. Further, compared with the first and second embodiments, the mark portion 105B can be laid out regardless of the arrangement of the wiring pattern 109, so that the degree of freedom in the layout of the mark portion 105B is high.

[0076] As described above, according to the third embodiment, a technique advantageous for aligning the radiation detector 1 and the shielding member 200 is provided. And since the visibility of the mark portion 105B is high, it is possible to align the shielding member 200 with the radiation detector 1 with high precision. Further, since the radiation is shielded by the shielding member 200, the circuit operation of the peripheral circuit portion 3 is stabilized, the failure of the peripheral circuit portion 3 is reduced, and the occurrence of image defects is also reduced.

[0077] Note that various modifications are possible for the mark portion 105B in the third embodiment as well, similar to the first embodiment. For example, the mark portion 105B can be modified as in the modification examples shown in FIGS. 4(a) to 4(f).

[0078] [Fourth Embodiment] With reference to the drawings, a radiation detector according to the fourth embodiment will be described. In the fourth embodiment, matters common to the first embodiment will be simplified or omitted in the description, and the description will focus on the differences from the first embodiment. The schematic configuration of the radiation detector 1 in the fourth embodiment is as described with reference to FIGS. 1 and 2(a) in the first embodiment. Also, the schematic configuration of the detection unit 300 including the radiation detector 1 and the shielding member 200 in the fourth embodiment is as described with reference to FIG. 2(b) in the first embodiment.

[0079] FIG. 7(a) is a cross-sectional view of the radiation detector 1 along line A-B of FIG. 2(a).

[0080] The wiring structure 150 in the fourth embodiment includes an interlayer insulation layer 115 made of an insulator and a plurality of wiring layers (conductor layers) 112 disposed in the interlayer insulation layer 115. A passivation layer 107 is disposed on the interlayer insulation layer 115, and a passivation layer 106 is disposed on the passivation layer 107. Note that a wiring layer may be disposed on the interlayer insulation layer 115, that is, between the interlayer insulation layer 115 and the passivation layer 107. The passivation layer 107 is adjacent to the interlayer insulation layer 115. That is, the passivation layer 107 is in contact with the main surface 125 of the interlayer insulation layer 115. The passivation layer 106 is adjacent to the passivation layer 107. That is, the passivation layer 106 is in contact with the main surface 127 of the passivation layer 107. Note that a pad electrode 110 is disposed at a position corresponding to the opening of the passivation layer 106 on the passivation layer 107. The passivation layer 106 is the surface layer, and the passivation layer 107 is the lower layer with respect to the passivation layer 106. The passivation layer 106 is an example of a first passivation layer, and the passivation layer 107 is an example of a second passivation layer.

[0081] Figures 7(b) and 7(c) are explanatory diagrams of the mark portion 105C. Figure 7(b) is a plan view of the passivation layer 106 in which the region including the mark portion 105C is cut out as viewed in the Z direction. Figure 7(c) is a plan view of the passivation layer 107 in which the region including the mark portion 105C is cut out as viewed in the Z direction.

[0082] The mark portion 105C is a recess including the opening 108 of the passivation layer 106 (surface layer) and the passivation layer 107 (lower layer) adjacent to the passivation layer 106. The passivation layer 106 and its opening 108 are an example of the first part, and the passivation layer 107 is an example of the second part.

[0083] In the fourth embodiment, the mark portion 105C is a +-shaped mark when viewed in plan (viewed in the Z direction). In the fourth embodiment, the opening 108 is a through-hole penetrating the passivation layer 106, and the opening 108 is +-shaped when viewed in the Z direction.

[0084] The passivation layer 107 is a solid pattern having an area larger than the area of the opening 108 when viewed in the Z direction. It is a +-shaped portion when viewed in the Z direction. In the passivation layer 107, the region 144 visible through the opening 108 and the opening 108 constitute the mark portion 105.

[0085] Examples of the materials of the passivation layers 106 and 107 include any one of organic insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, and polyimide, or a combination of two or more of these materials.

[0086] Also, the material of the passivation layer 107 is preferably different from that of the passivation layer 106. For example, the passivation layer 107 may be an etch stop layer when forming the opening 108 in the passivation layer 106 by etching in a photolithography process. In this case, the process of forming the opening 108 in the passivation layer 106 becomes easier. Note that when the passivation layer 107 is an etch stop layer, there may be another insulating layer between the passivation layer 107 and the interlayer insulating layer 115.

[0087] Note that the manufacturing method of the detection unit 300 according to the fourth embodiment is the same as that described in the first embodiment, and the description thereof is omitted.

[0088] In the fourth embodiment, it is possible to visually recognize the mark portion 105C by optical measurement from the step between the opening 108 of the passivation layer 106 and the passivation layer 107. Also, compared with the radiation detector 1 of the first to third embodiments, the radiation detector 1 of the fourth embodiment is more strongly protected on the surface side by the passivation layers 106 and 107.

[0089] As described above, according to the fourth embodiment, a technique advantageous for alignment between the radiation detector 1 and the shielding member 200 is provided. And since the visibility of the mark portion 105C is high, it is possible to align the shielding member 200 with the radiation detector 1 with high precision. Also, since the radiation is shielded by the shielding member 200, the circuit operation of the peripheral circuit portion 3 is stabilized, the failure of the peripheral circuit portion 3 is reduced, and the occurrence of image defects is also reduced.

[0090] Note that various modifications are possible for the mark portion 105C of the fourth embodiment as well, similar to the first embodiment. For example, the mark portion 105C can be modified as in the modified examples shown in FIGS. 4(a) to 4(f).

[0091] [Fifth Embodiment] Referring to the drawings, the radiation detector according to the fifth embodiment will be described. In the fifth embodiment, for matters common to the first embodiment, the description 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 fifth embodiment is as described with reference to FIGS. 1 and 2(a) in the first embodiment. Also, 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 with reference to FIG. 2(b) in the first embodiment.

[0092] FIG. 8(a) is a cross-sectional view of the radiation detector 1 taken along line A - B of FIG. 2(a). The radiation detector 1 of the fifth embodiment does not have a passivation layer. That is, the radiation detector 1 of the fifth embodiment is used for applications that do not require a passivation layer.

[0093] The wiring structure 150 of the fifth embodiment includes an interlayer insulation layer 115 made of an insulator and a plurality of wiring layers (conductor layers) 112 disposed within the interlayer insulation layer 115. A wiring pattern 109, which is a part of the outermost surface wiring layer, is disposed on the interlayer insulation layer 115. The wiring pattern 109 is adjacent to the interlayer insulation layer 115. That is, the wiring pattern 109 is in contact with the main surface 125 of the interlayer insulation layer 115. The wiring pattern 109 is the surface layer, and the interlayer insulation layer 115 is the lower layer with respect to the wiring pattern 109.

[0094] FIG. 8(b) is an explanatory diagram of the mark portion 105D. FIG. 8(b) is a plan view of the wiring pattern 109 and the interlayer insulation layer 115 in which the region including the mark portion 105D is cut out as viewed in the Z direction.

[0095] The mark portion 105D includes the wiring pattern 109 (surface layer). The wiring pattern 109 is an example of the first portion. In the fifth embodiment, the mark portion 105D is the wiring pattern 109. That is, in the fifth embodiment, the mark portion 105D does not include the interlayer insulation layer 115, which is the lower layer with respect to the wiring pattern 109.

[0096] In the fifth embodiment, the mark portion 105D, that is, the wiring pattern 109, is a +-shaped mark when viewed in a plan view (viewed in the Z direction). The interlayer insulating layer 115 is a solid pattern having an area larger than the area of the wiring pattern 109 when viewed in the Z direction. Therefore, the contrast between the wiring pattern 109 and the interlayer insulating layer 115 becomes clear, and it can be easily visually recognized. Note that the wiring pattern 109 may or may not be connected to the wiring layer 112 via a via.

[0097] The manufacturing method of the detection unit 300 according to the fifth embodiment is as described in the first embodiment, and the description thereof is omitted.

[0098] In the fifth embodiment, by omitting the passivation layer, or the passivation layer and the via, the energy loss of the radiation when the radiation passes through the radiation detector 1 can be reduced, and the scattering of the radiation can be reduced. For example, when the radiation is an electron beam, this effect is particularly remarkable.

[0099] As described above, according to the fifth embodiment, a technique advantageous for aligning the radiation detector 1 and the shielding member 200 is provided. And since the visibility of the mark portion 105D is high, it is possible to align the shielding member 200 with the radiation detector 1 with high precision. Further, since the radiation is shielded by the shielding member 200, the circuit operation of the peripheral circuit portion 3 is stabilized, the failure of the peripheral circuit portion 3 is reduced, and the occurrence of image defects is also reduced.

[0100] Note that various modifications are possible for the mark portion 105D of the fifth embodiment as well, similar to the first embodiment. For example, the mark portion 105D can be modified as in the modification examples shown in FIGS. 4(a) to 4(f).

[0101] [Sixth Embodiment] With reference to the drawings, a radiation detector and a detection unit according to the sixth embodiment will be described. In the sixth embodiment, descriptions of matters common to the first embodiment will be simplified or omitted, and the description will focus on the differences from the first embodiment.

[0102] FIG. 9(a) is a plan view of the radiation detector 1 according to the sixth embodiment. FIG. 9(a) shows a plan view of the radiation incident side surface (incident surface) of the radiation detector 1, that is, a view seen in the Z direction. Note that the circuit configuration of the radiation detector 1 of the sixth embodiment is as described with reference to FIG. 1 in the first embodiment, and thus the same reference numerals are used and the description thereof is omitted.

[0103] 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, similar to the first embodiment. The pixel region 101 is an example of the first region. The peripheral circuit region 103 is an example of the second region. The buffer region 102 is an example of the third region. 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 the corresponding corner among the four corners of the pixel region 101 viewed in the Z direction.

[0104] FIG. 9(b) is a plan view of the detection unit 300 according to the sixth embodiment. The detection unit 300 includes the radiation detector 1 and a shielding member 200. The shielding member 200 is composed of a metal member capable of shielding radiation. The shielding member 200 is arranged on the side where radiation of the radiation detector 1 is incident. The shielding member 200 is arranged at a position that overlaps the entire peripheral circuit region 103, that is, the entire peripheral circuit portion 3 in FIG. 1, when viewed in the Z direction so that the peripheral circuit region 103 is not irradiated with radiation.

[0105] The shielding member 200 is formed with 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 is incident on the pixel array 2. When viewed in the Z direction, the opening 201 has a rectangular shape with an area substantially the same as that of the pixel region 101. That is, when viewed in the Z direction, the pixel array 2 disposed in the pixel region 101 does not overlap with the shielding member 200. The pixel array 2 (FIG. 1) disposed 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.

[0106] FIG. 10(a) is a cross-sectional view of the radiation detector 1 along the line A-B in FIG. 9(a). FIGS. 10(b) and 10(c) are explanatory views of the mark portion 105 disposed in the pixel region 101. FIG. 10(b) is a plan view of the passivation layer 106 in which the region including the mark portion 105 is cut out when viewed in the Z direction. FIG. 10(c) is a plan view of the wiring pattern 109 and the interlayer insulating layer 115 in which the region including the mark portion 105 is cut out when viewed in the Z direction.

[0107] In the sixth embodiment, the mark portion 105 is a +-shaped mark when viewed in plan (when viewed in the Z direction). The mark portion 105 is composed of an opening 108 in the passivation layer 106 and a wiring pattern 109 which is a part of the outermost layer wiring layer. In the sixth embodiment, the opening 108 is a through-hole that penetrates the passivation layer 106. The opening 108 has a +-shape when viewed in the Z direction.

[0108] The wiring pattern 109 is a solid pattern that has an area larger than the area of the opening 108 when viewed in the Z direction. In the wiring pattern 109, a +-shaped region 142 that is visible through the opening 108 and viewed in the Z direction constitutes a part of the mark portion 105.

[0109] Thus, the mark portion 105 is a recess including the opening 108 of the passivation layer 106 and the wiring pattern 109 which is the lower layer adjacent to the passivation layer 106. The passivation layer 106 and its opening 108 are an example of the first portion, and the wiring pattern 109 is an example of the second portion.

[0110] The radiation passes through both the opening 108 and the wiring pattern 109 included in the mark portion 105. Therefore, the mark portion 105 may be disposed above the detection diode included in the pixel 20 which is an effective pixel disposed in the pixel region 101. Since the radiation passes through the mark portion 105 and reaches the detection diode included in the pixel 20 which is an effective pixel, the radiation detector 1 can perform imaging even if the mark portion 105 exists in the pixel region 101.

[0111] With the above configuration, the radiation detector 1 can narrow the width W of the buffer region 102, for example, the width W can be set to be 200 μm or more and 2000 μm or less, and the radiation detector 1 can be miniaturized. Furthermore, it is possible to more strongly shield the peripheral circuit portion 3 (FIG. 1) disposed in the peripheral circuit region 103 from radiation by the shielding member 200.

[0112] A method for manufacturing the detection unit 300 shown in FIG. 9(b) will be described. First, the radiation detector 1 and the shielding member 200 are prepared.

[0113] Next, the mark portion 105 is measured from the side of the incident surface of the radiation detector 1 using a measuring device such as a microscope. In the sixth embodiment, it becomes easy to optically measure the mark portion 105, and it also becomes easy to adjust the focus of the measuring device.

[0114] Next, when viewed in the Z direction, the shielding member 200 is aligned with the radiation detector 1 such that the peripheral circuit region 103 of the radiation detector 1 is covered by the shielding member 200. Specifically, when viewed in the Z direction, the shielding member 200 is aligned with the radiation detector 1 so that the shielding member 200 does not overlap with each mark portion 105 and the shielding member 200 does not overlap with the pixel array 2 (pixel region 101), and the shielding member 200 and the radiation detector 1 are fixed.

[0115] At the time of this alignment, since the visibility of the mark portion 105 is high, the shielding member 200 can be aligned with the radiation detector 1 with high precision. For example, as shown in FIG. 9(b), by aligning two sides of the opening 201 of the shielding member 200 with two sides of the cross-shaped mark portion 105, the shielding member 200 can be aligned with the radiation detector 1 with high precision. Note that, depending on the variation in the alignment between the opening 201 of the shielding member 200 and the pixel region 101 when viewed in the Z direction, electrical correction may be performed to electrically select the imaging region of the pixel array 2 (FIG. 1) disposed in the pixel region 101.

[0116] As described above, according to the sixth embodiment, a technique advantageous for aligning the radiation detector 1 and the shielding member 200 is provided. Since the visibility of the mark portion 105A is high, the shielding member 200 can be aligned with the radiation detector 1 with high precision. Further, since the radiation is shielded by the shielding member 200, the circuit operation of the peripheral circuit portion 3 is stabilized, the failure of the peripheral circuit portion 3 is reduced, and the occurrence of image defects is also reduced.

[0117] [Modification Example of the Sixth Embodiment] A modification example of the detection unit 300 of the sixth embodiment will be described. FIGS. 11(a) and 11(b) are plan views of the detection unit 300 of the modification example.

[0118] A modification example shown in Fig. 11(a) will be described. As shown in Fig. 11(a), the mark portion 105 is arranged in the pixel region 101 when viewed in the Z direction. In the modification example shown in Fig. 11(a), when viewed in the Z direction, the area of the opening 201 is larger than the area of the pixel region 101 and smaller than the area of the portion surrounded by the outer shape of the buffer region 102. That is, the size of the opening 201 of the shielding member 200 is set so that when the shielding member 200 is aligned in the Z direction so that all of the plurality of mark portions 105 can be seen from the opening 201, the shielding member 200 overlaps with all of the peripheral circuit portion 3 and does not overlap with the pixel array 2. And when the shielding member 200 is aligned so as not to overlap with all of the mark portions 105 in the Z direction, it does not overlap with the pixel array 2 (Fig. 1) arranged in the pixel region 101. Thus, the size of the opening 201 does not have to be the same as the size of the pixel region 101.

[0119] A modification example shown in Fig. 11(b) will be described. As shown in Fig. 11(b), the mark portion 105 is arranged in the pixel region 101 when viewed in the Z direction. In the modification example shown in Fig. 11(a), when viewed in the Z direction, the area of the opening 201 is smaller than the area of the pixel region 101. That is, the size of the opening 201 of the shielding member 200 is set to be the same as or larger than the area of the region of the pixels that are effective pixels among the plurality of pixels 20 of the pixel array 2 when viewed in the Z direction.

[0120] When the shielding member 200 is aligned so as to overlap a part or all of each mark portion 105, all in Fig. 11(b) in the Z direction, it does not overlap with the effective pixels included in the pixel array 2. At that time, the shielding member 200 overlaps with the ineffective pixels in the Z direction. Thus, the boundary of the shielding member 200 may be set within the pixel region 101. At this time, electrical correction for electrically selecting the imaging region in the pixel region 101 may be performed according to the variation in the alignment of the shielding member 200.

[0121] Note that various modifications are possible for the mark portion 105 of the sixth embodiment as well, in the same manner as in the first embodiment. For example, the mark portion 105 can be modified as in the modification examples shown in Figs. 4(a) to 4(f).

[0122] Further, in the radiation detector 1 of the sixth embodiment, the mark portion 105 may be replaced with any one of the mark portions 105A to 105D of the first to fifth embodiments.

[0123] [Seventh Embodiment] In the above first to sixth embodiments, a configuration example of the detection unit 300 including the radiation detector 1 and the shielding member 200 has been described. In the seventh embodiment, a radiation imaging system including the detection unit 300 will be described.

[0124] The radiation imaging system 1100 shown in FIG. 12 is a detection system including an imaging unit 1101 which is a detection unit 300 including a radiation detector 1 and a shielding member 200, an exposure control unit 1102, a radiation source 1103 as an irradiation unit of energy rays, and a computer 1104. The imaging unit 1101 has an imaging panel 100P provided with a pixel array 2. As the configuration of the imaging unit 1101, the detection unit 300 having the radiation detector 1 described in the first to sixth embodiments can be used.

[0125] The radiation source 1103 starts radiation irradiation according to an exposure command from the exposure control unit 1102. The radiation emitted from the radiation source 1103 passes through the imaging object (subject) and enters the imaging panel 100P of the imaging unit 1101. The radiation source 1103 stops radiation emission according to a stop command from the exposure control unit 1102.

[0126] The imaging unit 1101 is, for example, a flat panel detector used for radiation imaging in medical image diagnosis, non-destructive inspection, etc. The imaging panel 100P of the imaging unit 1101 can be in the shape of a plate having a size adapted to the size of the imaging object. For example, on a substrate of 550 mm × 445 mm, 3300 × 2800 pixels are arranged for the imaging panel 100P.

[0127] The imaging unit 1101 may have a direct conversion configuration in which radiation is converted into signal charges by detection diodes provided in the pixel array 2 of the imaging panel 100P. Further, the imaging unit 1101 may have an indirect conversion configuration in which radiation is converted into fluorescence by a scintillator layer provided on the upper layer of the pixel array 2 of the imaging panel 100P, and the fluorescence is converted into signal charges by the detection diodes of the pixel array 2.

[0128] The imaging unit 1101 includes the above-described imaging panel 100P, 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 them as digital image data to the computer 1104. Further, the signal processing unit 1106 may, for example, 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.

[0129] The control unit 1105 may be configured by, for example, 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 incorporated with a program, or a combination of all or part of these.

[0130] In the seventh embodiment, although the signal processing unit 1106 is shown to be arranged within the control unit 1105 or to be part of the functions of the control unit 1105, it is not limited thereto. The control unit 1105 and the signal processing unit 1106 may have separate configurations. Further, the signal processing unit 1106 may be arranged separately from the imaging unit 1101. For example, the computer 1104 may have the functions 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 the signals output from the imaging unit 1101.

[0131] 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 processes for displaying it as a radiation image. Further, the computer 1104 can function as an input unit for a user to input the conditions for imaging a radiation image.

[0132] As an example, the exposure control unit 1102 has an exposure switch. When the exposure switch is turned on by the user, in addition to sending an exposure command to the radiation source 1103, it 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 thereto, the control unit 1105 causes the imaging panel 100P to generate a signal corresponding to the incident radiation.

[0133] [Eighth Embodiment] In the eighth embodiment, another example of the radiation imaging system will be described. FIG. 13(a) 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.

[0134] The radiation detector 1 has a pixel array 2 in which pixels 20 are arranged in a matrix, and a peripheral circuit unit 3 arranged around it. The peripheral circuit unit 3 includes a plurality of peripheral circuits. And the shielding member 200 is arranged on the radiation incident side of the radiation detector 1.

[0135] 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 forms an image of radiation on the radiation detector 1 and is, for example, a lens, a shutter, or a mirror. The optical system OPT may form an image of a particle beam such as an electron beam or a proton beam on the radiation detector 1 according to the type of radiation to be handled. The control device CTRL controls the radiation detector 1 and is, for example, an ASIC. The processing device PRCS processes the signal output from the radiation detector 1 and is a device such as a CPU or an ASIC for constituting an AFE (analog front end) or a DFE (digital front end). The display device DSPL is an EL display device or a liquid crystal display device that displays the 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 a semiconductor device that stores the information obtained by the radiation detector 1. The memory device MMRY is a volatile memory such as an SRAM or a DRAM, or a non-volatile memory such as a flash memory or a hard disk drive. The mechanical device MCHN has a movable part or a propulsion part such as a motor or an engine.

[0136] The equipment EQP displays the signal output from the radiation detector 1 on the display device DSPL or transmits it externally by a communication device (not shown) provided in the equipment EQP. For this purpose, it is preferable that the equipment EQP further includes a memory device MMRY and a processing device PRCS separately from the memory circuit and the arithmetic circuit of the radiation detector 1. The mechanical device MCHN may be controlled based on the signal output from the radiation detector 1.

[0137] The equipment EQP shown in Fig. 13(a) may be a medical device such as an endoscope or a radiation diagnostic device, a measuring device such as a distance measuring sensor, or an analytical device such as an electron microscope.

[0138] FIG. 13(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 includes 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 (column), an objective lens 1206, and a magnifying lens system 1207. The device EQP also includes a camera 1209 as an imaging unit. The camera 1209 includes a detection unit 300 having a direct radiation detector 1200 (Direct Electron Detector) as a direct detection type radiation detector 1. That is, the direct radiation detector 1200 corresponds to the radiation detector 1.

[0139] The electron beam 1203, which is an energy beam emitted from the electron beam source 1202, is focused by the irradiation lens 1204 and irradiated onto a sample S as an analysis target held by a sample holder. The space through which the electron beam 1203 passes is formed by the vacuum chamber 1201 (column), and this space is maintained in a vacuum. The radiation detector 1 is arranged 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 the objective lens 1206 and the magnifying lens system 1207 and projected onto the radiation detector 1. The electron optical system for irradiating the sample S with an electron beam is called an 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 an imaging optical system.

[0140] The electron beam source 1202 is controlled by an electron beam source control device 1211. The irradiation lens 1204 is controlled by an irradiation lens control device 1212. The objective lens 1206 is controlled by an objective lens control device 1213. The magnifying lens system 1207 is controlled by a magnifying lens system control device 1214. The control mechanism 1205 of the sample holder is controlled by a holder control device 1215 that controls the drive mechanism of the sample holder.

[0141] The electron beam 1203 transmitted through the sample S is detected by the direct radiation detector 1200 of the camera 1209. The output signal from the direct radiation detector 1200 is processed by the signal processing device 1216 and the image processing device 1218 as the processing device PRCS, and an image signal is generated. The generated image signal (transmission electron image) is displayed on the image display monitor 1220 and the analysis monitor 1221 corresponding to the display device DSPL.

[0142] The camera 1209 is provided below the equipment EQP. At least a part of the camera 1209 is provided in the vacuum chamber 1201 so as to be exposed to the vacuum space formed by the vacuum chamber 1201.

[0143] Each of the electron beam source control device 1211, the irradiation lens control device 1212, the objective lens control device 1213, the magnifying lens system control device 1214, and the holder control device 1215 is connected to the image processing device 1218. As a result, data can be exchanged with each other in order to set the imaging conditions of the electron microscope. For example, the irradiation rate of the electron beam can be set to be 0.5 electron / pix / frm or less. In this case, the electron beam source control device 1211 and the image processing device 1218 function as control means for controlling the irradiation rate of the radiation. The drive control of the sample holder and the setting of the observation conditions of each lens can be performed by the signal from the image processing device 1218.

[0144] The operator prepares the sample S to be imaged and sets the imaging conditions using the input device 1219 connected to the image processing device 1218. Predetermined data is input to the electron beam source control device 1211, the irradiation lens control device 1212, the objective lens control device 1213, and the magnifying lens system control device 1214 respectively, so as to obtain a desired acceleration voltage, magnification, and observation mode. In addition, the operator inputs conditions such as the number of continuous field images, the imaging start position, and the moving speed of the sample holder to the image processing device 1218 using the input device 1219 such as a mouse, keyboard, or touch panel. It is also possible to adopt a specification in which the image processing device 1218 automatically sets the conditions regardless of the operator's input.

[0145] The systems described in the above seventh and eighth embodiments are merely examples, and the radiation detectors described in the first to sixth embodiments may be applied to other systems.

[0146] The disclosure of the above embodiments includes the following items.

[0147] (Item 1) A radiation detector including, in plan view, a pixel portion including a plurality of pixels for detecting radiation in the pixel portion, a second region including a plurality of peripheral circuits, and a third region between the first region and the second region, a mark portion is disposed in the first region or the third region, the mark portion includes at least one of a first portion constituting the surface layer of the radiation detector and a second portion of a lower layer adjacent to the first portion, A radiation detector characterized by the above.

[0148] (Item 2) The surface layer is a passivation layer provided with an opening, the mark portion includes the opening as the first portion, The radiation detector according to Item 1, characterized by the above.

[0149] (Item 3) the opening is a through hole, the lower layer is a wiring layer including a wiring pattern, the mark portion includes, as the second portion, a region corresponding to the through hole in the wiring pattern, The radiation detector according to Item 2, characterized by the above.

[0150] (Item 4) the opening is a through hole, the lower layer is an interlayer insulating layer, the mark portion includes, as the second portion, a region corresponding to the through hole in the interlayer insulating layer, The radiation detector according to Item 2, characterized by the above.

[0151] (Item 5) The passivation layer is a first passivation layer, The opening is a through hole, The lower layer is a second passivation layer, The mark portion includes, as the second portion, a region corresponding to the through hole in the second passivation layer. The radiation detector according to claim 2, characterized in that.

[0152] (Item 6) The material of the first passivation layer is different from the material of the second passivation layer. The radiation detector according to claim 5, characterized in that.

[0153] (Item 7) The second passivation layer is an etch stop layer. The radiation detector according to claim 6, characterized in that.

[0154] (Item 8) The surface layer is a wiring layer including a wiring pattern, The mark portion includes the wiring pattern as the first portion. The radiation detector according to claim 1, characterized in that.

[0155] (Item 9) The surface layer is a passivation layer, The lower layer is a wiring layer having a wiring pattern covered by the passivation layer, The mark portion includes the wiring pattern as the second portion. The radiation detector according to claim 1, characterized in that.

[0156] (Item 10) The width of the third region is 200 μm or more and 2000 μm or less. The radiation detector according to any one of claims 1 to 9, characterized in that.

[0157] (Item 11) The mark portion includes a mark in the shape of a plus sign in the plan view. The radiation detector according to any one of Items 1 to 10, characterized in that.

[0158] (Item 12) The mark portion includes a mark surrounding the plus-sign-shaped mark in the plan view. The radiation detector according to Item 11, characterized in that.

[0159] (Item 13) The mark portion includes a plurality of marks. The radiation detector according to any one of Items 1 to 10, characterized in that.

[0160] (Item 14) The radiation detector according to any one of Items 1 to 13, and a shielding member disposed on the side where radiation of the radiation detector is incident and having an opening formed at a position corresponding to the pixel portion. The shielding member overlaps with all of the second region in the plan view. The detection unit, characterized in that.

[0161] (Item 15) The mark portion is disposed in the third region in the plan view. The shielding member overlaps with a part or all of the mark portion and does not overlap with the pixel portion in the plan view. The detection unit according to Item 14, characterized in that.

[0162] (Item 16) The mark portion is disposed in the first region in the plan view. The shielding member does not overlap with the mark portion and the pixel portion in the plan view. The detection unit according to Item 14, characterized in that.

[0163] (Item 17) The mark portion of the radiation detector is arranged in the first region in the plan view. The shielding member overlaps a part or all of the mark portion in the plan view and does not overlap the effective pixels included in the pixel portion of the radiation detector. The detection unit according to claim 14, characterized in that.

[0164] (Claim 18) A radiation source for irradiating a radiation imaging target, The detection unit according to any one of claims 14 to 17, and a radiation imaging system characterized by comprising: The radiation imaging system according to claim 14, characterized in that.

[0165] (Claim 19) A method for manufacturing a detection unit, Prepare a radiation detector according to any one of claims 1 to 13, Measure the mark portion of the radiation detector, Align the shielding member with the radiation detector so that the second region of the radiation detector is covered with the shielding member in the plan view. A method for manufacturing a detection unit, characterized in that.

Explanation of reference numerals

[0166] 1... Radiation detector, 2... Pixel array (pixel portion), 20... Pixel, 31 to 34... Peripheral circuits, 100... Semiconductor substrate, 101... Pixel region (first region), 102... Buffer region (third region), 103... Peripheral circuit region (second region), 105... Mark portion

Claims

1. A radiation detector having a pixel portion including a plurality of pixels in a plan view, the radiation detector including a first region for detecting radiation in the pixel portion, a second region including a plurality of peripheral circuits, and a third region between the first region and the second region, A mark portion is disposed in the first region or the third region, the mark portion includes at least one of a first portion constituting a surface layer of the radiation detector and a second portion constituting a lower layer adjacent to the first portion, A radiation detector comprising:

2. the surface layer is a passivation layer having an opening; The mark portion includes the opening as the first portion.

2. The radiation detector according to claim 1 .

3. The opening is a through hole, the lower layer is a wiring layer including a wiring pattern, the mark portion includes, as the second portion, a region of the wiring pattern corresponding to the through hole; 3. The radiation detector according to claim 2.

4. The opening is a through hole, the lower layer is an interlayer insulating layer, the mark portion includes, as the second portion, a region of the interlayer insulating layer corresponding to the through hole; 3. The radiation detector according to claim 2.

5. the passivation layer is a first passivation layer; The opening is a through hole, the lower layer is a second passivation layer; the mark portion includes, as the second portion, a region of the second passivation layer corresponding to the through hole; 3. The radiation detector according to claim 2.

6. The material of the first passivation layer is different from the material of the second passivation layer.

6. The radiation detector according to claim 5.

7. the second passivation layer being an etch stop layer; 7. The radiation detector according to claim 6.

8. the surface layer is a wiring layer including a wiring pattern, the mark portion includes the wiring pattern as the first portion, 2. The radiation detector according to claim 1 .

9. the surface layer is a passivation layer, the lower layer is a wiring layer having a wiring pattern covered with the passivation layer, the mark portion includes the wiring pattern as the second portion, 2. The radiation detector according to claim 1 .

10. The width of the third region is 200 μm or more and 2000 μm or less.

2. The radiation detector according to claim 1 .

11. The mark portion includes a mark having a plus shape in the plan view.

2. The radiation detector according to claim 1 .

12. The mark portion includes a mark surrounding the plus-shaped mark in the plan view. The radiation detector according to claim 11 .

13. The mark portion includes a plurality of marks.

2. The radiation detector according to claim 1 .

14. A radiation detector according to any one of claims 1 to 13, 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:

15. the mark portion is disposed in the third region in the plan view, the shielding member overlaps a part or the whole of the mark portion and does not overlap the pixel portion in the plan view; 15. A detection unit according to claim 14.

16. the mark portion is disposed in the first region in the plan view, the shielding member does not overlap the mark portion and the pixel portion in the plan view; 15. A detection unit according to claim 14.

17. the mark portion of the radiation detector is disposed in the first region in the plan view, the shielding member overlaps a part or the whole of the mark portion in the plan view, and does not overlap with effective pixels included in the pixel portion of the radiation detector.

15. A detection unit according to claim 14.

18. a radiation source for irradiating an imaging target with radiation; A detection unit according to claim 14, A radiation imaging system comprising:

19. A method for manufacturing a detection unit, comprising the steps of: Providing a radiation detector according to any one of claims 1 to 13; measuring the mark portion of the radiation detector; aligning a shielding member with respect to the radiation detector such that, in the plan view, the second region of the radiation detector is covered by the shielding member; A method for manufacturing a detection unit comprising the steps of:

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