JP2014211383A - Radiation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation detector capable of fining a pixel.SOLUTION: A flat panel type X-ray detector includes silicon penetration electrodes TSV used for a three-dimensional mounting package in which a plurality of IC chips are stacked vertically. In other words, through holes VIA in a substrate 1 into which the silicon penetration electrodes TSV are to be inserted can be fined, and the pitch of silicon penetration electrodes TSV inserted into the through holes VIA can be made narrower than the conventional pitch. A pixel electrode 41 is formed by inserting the silicon penetration electrodes TSV into the through holes VIA in the substrate 1 made of silicon, so that the pixel can be fined.

Description

  The present invention relates to a direct conversion type radiation detector that detects radiation by directly converting radiation into electric charge, and more particularly to a technique for medical and industrial use.

  An explanation will be given by taking X-rays as an example of radiation. As an X-ray detection method using an X-ray detector, an indirect conversion type and a direct conversion type can be cited. In an indirect conversion type X-ray detector, the X-ray is charged by converting the X-ray into another light by a scintillator and converting the light into a charge by a photo sensor such as a photodiode or a CCD (solid-state imaging device). Indirectly detected and detected. In a direct conversion type X-ray detector, an X-ray sensitive semiconductor (direct conversion layer) converts X-rays directly into electron-hole pairs and collects pixel electrodes (collection) attached to the semiconductor. X-rays are detected by reading out electrons or holes (holes) with an electrode.

  In the indirect conversion type X-ray detector, there is a difference between the X-ray reaction position (light emission position by X-ray) and the position where the photosensor captures light. On the other hand, in the direct conversion type X-ray detector, the charge made up of electrons and holes drifts from the X-ray reaction position toward the pixel electrode, so that the indirect conversion type X-ray detector is used. Better position resolution can be obtained. Hereinafter, a direct conversion type X-ray detector will be described.

  Silicon-On-Insulator (SOI) is an example of an X-ray detector equipped with fine pixels. In this technique, a thin insulating oxide film is formed on a silicon wafer, and an electric circuit (readout circuit) such as a thin film transistor (TFT) is formed thereon. As a result, the detection portion (sensor) and the readout circuit can be integrated, and readout pixels (pixels) are being miniaturized (for example, see Patent Document 1).

JP 2012-194046 A

  In the above-described X-ray detector, the distance (pitch) between adjacent pixels is about 100 μm to 200 μm. Therefore, in order to realize even higher resolution, a structure in which pixels (pixels) are further miniaturized (for example, at a pitch of 10 μm or less) is required.

  This invention is made in view of such a situation, Comprising: It aims at providing the radiation detector which can implement | achieve refinement | miniaturization of a pixel (picture element).

  As a result of earnest research to solve the above problems, the inventors have obtained the following knowledge.

  That is, the pixel electrode associated with the pixel is usually patterned by a technique such as photolithography. However, in this technique, as described above, the pitch is about 100 μm to 200 μm. Therefore, attention was paid to a technology that replaces the photolithography technology.

  In a three-dimensional mounting package in which a plurality of IC chips are stacked vertically, a through silicon via (TSV) is used. Therefore, attention was focused on through silicon vias. Usually, for example, as shown in the cross-sectional view of FIG. 10, when two IC chips 101 and 102 are vertically mounted, a substrate S made of silicon is sandwiched therebetween. The substrate S has a through hole VIA, and the silicon through electrode TSV is inserted into the through hole VIA. When the two IC chips 101 and 102 are electrically connected to each other, they are connected via the through silicon via TSV.

  This through hole VIA can be designed to have a pitch of 10 μm or less. Therefore, focusing on the silicon through electrode used in the three-dimensional mounting package, we have found that if the conductor of the silicon through electrode is mounted as a pixel electrode, the pixel (pixel) can be miniaturized.

The present invention based on such knowledge has the following configuration.
That is, the radiation detector according to the present invention (the former invention) is a direct conversion type radiation detector that detects the radiation by directly converting the radiation into an electric charge, and has an insulator having a through hole. Alternatively, a substrate made of the insulator or the semiconductor formed by inserting a conductor into the through hole in a semiconductor, and a direct conversion layer that directly converts the radiation into the charge and is formed on the substrate And the conductor inserted into the through hole collects the electric charge and is mounted as a pixel electrode associated with the pixel.

  [Operation / Effect] According to the radiation detector according to the present invention (the former invention), the through-holes of the substrate can be miniaturized, and the pitch of the conductors inserted into the through-holes can be made narrower than before. it can. Since a pixel electrode is formed by inserting a conductor into a through hole of a substrate made of an insulator or a semiconductor, pixel miniaturization can be realized. In the former invention, the direct conversion layer that directly converts radiation into electric charge is formed on the substrate.

  In the former invention, it is preferable that a readout circuit for reading out electric charges as a detection signal is provided, and the readout circuit is mounted on the side opposite to the direct conversion layer side of the substrate. Since the readout circuit is mounted on the side opposite to the direct conversion layer side of the substrate, it is possible to prevent the readout circuit from being damaged due to heat during film formation (for example, vapor deposition) of the direct conversion layer on the substrate.

  In the former invention, an example of the substrate described above is silicon. That is, it is a substrate made of silicon having a through silicon via (TSV). Since silicon has heat resistance, even if the conversion layer is directly formed on the silicon by vapor deposition, there is no adverse effect due to heat.

  Further, a radiation detector according to the present invention (the latter invention) different from the former invention is a direct conversion type radiation detector that detects the radiation by directly converting the radiation into an electric charge, An insulator or a semiconductor having a through hole, and a substrate made of the insulator or the semiconductor formed by inserting a conductor into the through hole, and a direct conversion layer for directly converting the radiation into the charge. The conductor inserted into the through hole collects the electric charge and is mounted as a pixel electrode associated with the pixel, and is configured by bonding the substrate and the direct conversion layer together. It is a feature.

  According to the radiation detector according to the present invention (the latter invention), the through-holes in the substrate can be miniaturized as in the former invention, and the pitch of the conductors inserted into the through-holes can be made narrower than before. Can do. Since a pixel electrode is formed by inserting a conductor into a through hole of a substrate made of an insulator or a semiconductor, pixel miniaturization can be realized. Unlike the former invention, in the latter invention, a direct conversion layer that directly converts radiation into electric charge and a substrate are bonded together. Therefore, the conversion layer is not directly formed on the substrate (for example, vapor deposition), and there is no adverse effect due to heat on the substrate. Therefore, the substrate does not necessarily have heat resistance, and a direct conversion type radiation detector can be realized by bonding the direct conversion layer and the substrate.

  Similar to the former invention, the latter invention may be provided with a readout circuit for reading out charges as a detection signal, and the readout circuit may be mounted on the side opposite to the direct conversion layer side of the substrate.

  Similar to the former invention, in the latter invention, an example of the substrate described above is silicon. That is, it is a substrate made of silicon having a through silicon via (TSV).

According to the radiation detector according to the present invention, the through-holes of the substrate can be miniaturized, and the pitch of the conductors inserted into the through-holes can be made narrower than before. Since a pixel electrode is formed by inserting a conductor into a through hole of a substrate made of an insulator or a semiconductor, pixel miniaturization can be realized.
In the former invention, the direct conversion layer that directly converts radiation into electric charge is formed on the substrate.
Unlike the former invention, in the latter invention, a direct conversion layer that directly converts radiation into electric charge and a substrate are bonded together. Therefore, the conversion layer is not directly formed on the substrate (for example, vapor deposition), and there is no adverse effect due to heat on the substrate. Therefore, the substrate does not necessarily have heat resistance, and a direct conversion type radiation detector can be realized by bonding the direct conversion layer and the substrate.

1 is a schematic cross-sectional view of a flat panel X-ray detector (FPD) according to Example 1. FIG. It is an equivalent circuit diagram of an integrated circuit (ASIC) for reading. FIG. 3 is a schematic cross-sectional view illustrating a manufacturing process of the flat panel X-ray detector (FPD) according to the first embodiment. 6 is a schematic cross-sectional view of a flat panel X-ray detector (FPD) according to Embodiment 2. FIG. 6 is a schematic cross-sectional view showing a manufacturing process of a flat panel X-ray detector (FPD) according to Embodiment 2. FIG. It is a schematic sectional drawing of the flat panel type X-ray detector (FPD) which concerns on a modification. It is a schematic sectional drawing of the flat panel type X-ray detector (FPD) which concerns on the further modification. It is a schematic sectional drawing of the flat panel type X-ray detector (FPD) which concerns on the further modification. It is a schematic sectional drawing of the flat panel type | mold X-ray detector (FPD) which arranged FIG. 8 in two dimensions. 1 is a schematic cross-sectional view of a substrate made of silicon having a general through silicon via (TSV) and an IC chip used in a three-dimensional mounting package in which a plurality of IC chips are stacked vertically.

Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of a flat panel X-ray detector (hereinafter abbreviated as “FPD” where appropriate) according to the first embodiment, and FIG. 2 is an equivalent circuit diagram of an integrated circuit for reading (ASIC). It is. In Example 1, including Example 2 to be described later, X-rays are taken as an example of radiation, and a readout integrated circuit (ASIC: Application Specific Integrated Circuit) is taken as an example as a readout circuit. explain. Further, as the direct conversion layer, a CZT film such as CdTe (cadmium telluride), ZnTe (zinc telluride) or CdZnTe (cadmium zinc telluride) will be described as an example.

  As shown in FIG. 1, the FPD according to the first embodiment includes an integrated circuit ASIC for reading, a substrate 1 made of silicon having a through silicon via TSV, and a CZT film that directly converts X-rays into charges. 2 and a common electrode 3 for applying a bias voltage. As shown in FIG. 2, the integrated circuit ASIC for reading is electrically connected to the through silicon via TSV (see FIG. 1) side (see FIG. 1) side (X-ray incident surface side). ), A plurality of pixel electrodes 41 are formed, and an electric circuit 42 for accumulating / reading charges collected by each pixel electrode 41 is provided. Each pixel electrode 41 is set in a two-dimensional matrix arrangement within the X-ray detection effective area SA. The substrate 1 (made of silicon) corresponds to the substrate in the present invention, the CZT film 2 corresponds to the direct conversion layer in the present invention, the pixel electrode 41 corresponds to the pixel electrode in the present invention, and the through silicon via TSV Corresponds to the conductor in the present invention, and the integrated circuit ASIC for reading corresponds to the reading circuit in the present invention.

  As shown in FIG. 1, a substrate 1 is laminated on the incident surface side of the readout integrated circuit ASIC, a CZT film 2 is laminated on the incident surface side of the substrate 1, and a common electrode is formed on the incident surface side of the CZT film 2. 3 are formed in a planar shape and stacked. In the first embodiment, the CZT film 2 is formed on the incident surface side of the substrate 1, and the readout integrated circuit ASIC is mounted on the opposite side of the substrate 1 from the CZT film 2 side.

  As shown in FIG. 2, the readout integrated circuit ASIC includes the pixel electrode 41 and the storage / readout electrical circuit 42 as described above. The electric circuit 42 for accumulation / reading includes a capacitor 42A, a TFT (thin film field effect transistor) 42B as a switching element, a gate line 42a, a data line 42b, and the like, and one capacitor 42A and one for each pixel electrode 41. The TFTs 42B are connected in association with each other.

  A gate driver 43, a charge / voltage conversion amplifier 44, a multiplexer 45, and an A / D converter 46 are arranged and connected around the storage / readout electric circuit 42. These gate driver 43, charge voltage conversion amplifier 44, multiplexer 45 and A / D converter 46 are also incorporated in the integrated circuit ASIC for reading.

  As shown in FIG. 1, the substrate 1 has a through hole VIA, and the conductor functions as the silicon through electrode TSV by inserting the conductor into the through hole VIA. Further, the through silicon via TSV is mounted as a pixel electrode 41 associated with a pixel in the X-ray detection effective area SA. Outside the X-ray detection effective area SA, the through silicon via TSV is mounted as an extraction electrode 11 for extracting a digital value in the A / D converter 46 (see FIG. 2). Wire bonding 12 (two in FIG. 1) is mounted on the incident surface side of the substrate 1 at the end. The A / D converter 46 is electrically connected to the extraction electrode 11 via a wiring (not shown) formed on the side opposite to the CZT film 2 side of the substrate 1, and the CZT film 2 side (incident surface) of the substrate 1. The lead electrode 11 is electrically connected to the wire bonding 12 through wiring (not shown) formed on the side). The through hole VIA corresponds to the through hole in this invention.

  In FIG. 1, two wire bonds 12 are mounted, but the number of wire bonds 12 is not particularly limited. There may be only one wire bonding 12 or three or more.

  The pitch of the pixel electrodes 41 on the readout integrated circuit ASIC side is the same as the pitch of the through silicon vias TSV on the substrate 1 side, and each pixel electrode 41 on the readout integrated circuit ASIC side is on the substrate 1 side. It is mounted so as to correspond to each through silicon via TSV. As described above, when the readout integrated circuit ASIC is adopted as the readout circuit, the pitch of the pixel electrodes 41 can be designed to be 10 μm or less in the same manner as the pitch of the through holes VIA.

  When X-rays are detected by the FPD, a bias voltage is applied from a bias supply power source (not shown) to a common electrode 3 for applying a bias voltage via a lead wire (not shown) for supplying a bias voltage. With the bias voltage applied, charges are generated in the CZT film 2 with the incidence of X-rays. The generated charges are once collected by the pixel electrode 41 (collection electrode). Actually, an electron / hole pair generated in proportion to the incident energy of X-rays is generated, and a bias voltage is applied to the common electrode 3 to cause the electron or hole (hole) to drift to the substrate 1. The silicon through electrode TSV (pixel electrode 41) is used for collection. Electric charges collected (consisting of electrons and holes) are taken out as X-ray detection signals for the respective pixel electrodes 41 by the storage / readout electric circuit 42.

  Specifically, the charges collected by the pixel electrode 41 are temporarily stored in the capacitor 42A. Then, a read signal is sequentially applied from the gate driver 43 to the gate of each TFT 42B through the gate line 42a. By giving the read signal, the TFT 42B to which the read signal is given shifts from OFF to ON. As the data line 42b connected to the source of the shifted TFT 42B is sequentially switched and connected by the multiplexer 45, the charge accumulated in the capacitor 42A is read from the TFT 42B via the data line 42b. The read charge is amplified by the charge / voltage conversion amplifier 44 and sent to the A / D converter 46 as an X-ray detection signal for each pixel electrode 41 by the multiplexer 45 to convert from an analog value to a digital value.

  Further, the digital value in the A / D converter 46 is extracted by the extraction electrode 11 and extracted to the outside (for example, an image processing circuit) through the wire bonding 12. For example, when an FPD is provided in an X-ray fluoroscopic apparatus, an X-ray detection signal is sent to an image processing circuit at a subsequent stage, image processing is performed, and a two-dimensional X-ray fluoroscopic image is output. Each pixel electrode 41 in the two-dimensional matrix array corresponds to each pixel in an X-ray image (here, a two-dimensional X-ray fluoroscopic image). By extracting the X-ray detection signal, an X-ray image (in this case, a two-dimensional X-ray fluoroscopic image) corresponding to the two-dimensional intensity distribution of the X-ray projected onto the X-ray detection effective area SA can be created. That is, the FPD according to the first embodiment, including a second embodiment described later, can detect a two-dimensional intensity distribution of X-rays projected on the X-ray detection effective area SA. It is a detector.

  In this way, the FPD is provided with the CZT film 2 as a direct conversion layer formed on the substrate 1 to directly convert X-rays into electric charges, and the CZT film 2 directly converts X-rays into electric charges. Thus, the flat panel X-ray detector (FPD) is configured to detect X-rays. Further, the readout integrated circuit ASIC reads out the electric charge as a detection signal (X-ray detection signal).

  Next, a method for manufacturing the flat panel X-ray detector (FPD) according to the first embodiment will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view illustrating a manufacturing process of the flat panel X-ray detector (FPD) according to the first embodiment.

  First, as shown in FIG. 3A, an infinite number of through silicon vias TSV are mounted on a substrate 1 made of silicon, and in the X-ray detection effective area SA, each of the infinite number of through silicon vias TSV is a pixel. (Pixel) respectively. A CZT film 2 is deposited on the substrate 1 as shown in FIG. Further, a common electrode 3 is deposited on the CZT film 2. After the CZT film 2 and the common electrode 3 are formed by vapor deposition, a readout integrated circuit ASIC is mounted on the back side of the substrate 1 (the side opposite to the incident side) as shown in FIG.

  Since the CZT film 2 and the common electrode 3 are mounted after vapor deposition, it is possible to avoid damage to the integrated circuit ASIC for reading due to heat of vapor deposition. Since the heat generated during the vapor deposition of CdTe is 600 ° C. or higher, in order to prevent damage to the silicon through silicon via TSV during the vapor deposition, a melting point such as tungsten (melting point is 3422 ° C.) as a conductor inserted into the through hole VIA. It is preferable to use a high metal.

  Generally, the detection efficiency is 100% for X-rays around 10 KeV, but depending on the physical properties of the direct conversion layer, the detection efficiency may be 10% or less for X-rays of several tens of KeV. . The CZT film 2 typified by CdTe, ZnTe, CdZnTe, etc. has high detection efficiency even for X-rays of several tens of KeV. On the other hand, X-ray fluoroscopic images using X-rays of several tens of KeV are necessary for industrial nondestructive inspection. In Example 1, including Example 2 to be described later, the number used in industrial nondestructive inspection and the like by adopting a CZT film 2 typified by CdTe, ZnTe, CdZnTe, etc. as a direct conversion layer. There is also an effect that it is possible to realize a flat panel X-ray detector (FPD) having high detection efficiency and high sensitivity even for X-rays with a high energy level such as 10 KeV.

  According to the flat panel X-ray detector (FPD) described above, the through hole VIA of the substrate 1 can be miniaturized, and the pitch of the conductor (silicon through electrode TSV in each embodiment) inserted into the through hole VIA. Can be made narrower than before. Since the pixel electrode 41 is formed by inserting a conductor (silicon through electrode TSV) into the through hole VIA of the substrate 1 made of silicon, the pixel can be miniaturized. In Example 1, the CZT film 2 is formed on the substrate 1 as a direct conversion layer that directly converts X-rays into electric charges.

  In the first embodiment, a read circuit (read integrated circuit ASIC in each embodiment) that reads out charges as a detection signal is provided, and the read circuit (read integrated circuit ASIC) is used as a direct conversion layer (CZT film) of the substrate 1. 2) It is preferable to mount on the side opposite to the side. Since the readout circuit (readout integrated circuit ASIC) is mounted on the side opposite to the direct conversion layer (CZT film 2) side of the substrate 1, the direct conversion layer (CZT film 2) is formed on the substrate 1 (for example, It is possible to prevent a failure of the reading circuit (reading integrated circuit ASIC) due to heat during vapor deposition.

  In the first embodiment, the substrate 1 is silicon. That is, the substrate 1 is made of silicon having a through silicon via (TSV). Since silicon has heat resistance, even if the conversion layer (CZT film 2) is directly formed on the silicon by vapor deposition, there is no adverse effect due to heat.

Next, Embodiment 2 of the present invention will be described with reference to the drawings.
FIG. 4 is a schematic cross-sectional view of a flat panel X-ray detector (FPD) according to the second embodiment. The portions common to the above-described first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  Similar to the first embodiment described above, the FPD according to the second embodiment includes an integrated circuit ASIC for reading, a substrate 1, a CZT film 2, and a common electrode 3, as shown in FIG. In the second embodiment, a support substrate 5 having transparency to X-rays is further provided on the uppermost surface side (incident surface side).

The support substrate 5 preferably has a small X-ray absorption coefficient. For example, a material such as glass, ceramic (Al ₂ O ₃ , AlN), or silicon can be used, but a conductive material such as a graphite substrate can be used. The common electrode 3 can be omitted by using.

  Next, a method for manufacturing a flat panel X-ray detector (FPD) according to the second embodiment will be described with reference to FIG. FIG. 5 is a schematic cross-sectional view illustrating a manufacturing process of a flat panel X-ray detector (FPD) according to the second embodiment.

  First, the common electrode 3 is deposited on the support substrate 5 shown in FIG. 5A, as shown in FIG. 5B, and the CZT film 2 is further deposited. In the case of Example 1 described above, the CZT film 2 and the common electrode 3 are deposited in this order, whereas in the case of Example 2, the common electrode 3 and the CZT film 2 are deposited in this order. Thus, the order of vapor deposition in Example 1 mentioned above and the order of vapor deposition in Example 2 are reversed. As described above, when the support substrate 5 is formed of a conductive material such as a graphite substrate, only the CZT film 2 is formed without forming the common electrode 3.

  After the common electrode 3 and the CZT film 2 are formed by vapor deposition, as shown in FIG. 5B, the substrate 1 having the through silicon via TSV and the CZT film 2 are directly faced to face each other. As shown in FIG. 5C, the substrate 1 and the CZT film 2 are bonded together. Note that the order of mounting the integrated circuit ASIC for reading is not particularly limited. As shown in FIG. 5 (b), an integrated circuit ASIC for reading may be mounted in advance on the back surface side (opposite side to the incident surface side) of the substrate 1 before bonding, or the substrate 1 after bonding. An integrated circuit ASIC for reading may be mounted on the back surface side (the side opposite to the incident surface side).

  According to the flat panel X-ray detector (FPD) described above, the through hole VIA of the substrate 1 can be miniaturized in the same manner as in the first embodiment, and the conductors inserted into the through holes VIA (each embodiment). Then, the pitch of the through silicon vias TSV) can be made narrower than before. Since the pixel electrode 41 is formed by inserting a conductor (silicon through electrode TSV) into the through hole VIA of the substrate 1 made of silicon, the pixel can be miniaturized. Unlike Example 1 described above, in Example 2, a direct conversion layer (CZT film 2 in each example) that directly converts X-rays into electric charges and a substrate 1 are bonded together. . Therefore, the conversion layer (CZT film 2) is not directly formed on the substrate 1 (for example, vapor deposition), and the substrate 1 is not adversely affected by heat. Therefore, the substrate 1 does not necessarily have heat resistance, and a direct conversion type flat panel X-ray detector (FPD) can be realized by bonding the direct conversion layer (CZT film 2) and the substrate 1 together. .

  Similar to the first embodiment described above, the second embodiment includes a read circuit (in each embodiment, a read integrated circuit ASIC) that reads charges as a detection signal, and includes the read circuit (read integrated circuit ASIC). The substrate 1 is mounted on the side opposite to the direct conversion layer (CZT film 2) side.

  Similar to the first embodiment described above, in the second embodiment, the substrate 1 is silicon. That is, the substrate 1 is made of silicon having a through silicon via (TSV).

  The present invention is not limited to the above-described embodiment, and can be modified as follows.

  (1) In each of the above-described embodiments, the radiation is X-rays, and an X-ray detector that detects X-rays is taken as an example, but radiation other than X-rays (α rays, β rays, γ rays) is described. It can also be applied to a direct-conversion type radiation detector that detects).

  (2) The direct conversion type radiation detector (X-ray detector in each embodiment) may be used for medical diagnosis or for non-destructive inspection for industrial use.

  (3) In each of the above-described embodiments, the CZT film 2 represented by CdTe, ZnTe, CdZnTe, or the like has been described as an example of the direct conversion layer. However, the direct conversion layer is not limited to the CZT film. An amorphous direct conversion layer (for example, amorphous selenium) may be employed.

  (4) In each of the above-described embodiments, the readout integrated circuit ASIC is described as an example of the readout circuit. However, the readout circuit is not limited to the readout integrated circuit ASIC. An active matrix substrate may be employed as the reading circuit, and pixel electrodes and the like may be formed on the active matrix substrate by photolithography. In this case, the pitch of the pixel electrodes on the active matrix substrate side is wider than the pitch of the through silicon vias on the substrate side, so that the pitch conversion is performed (the structure of the pitch conversion is not shown).

  (5) In each of the embodiments described above, the readout circuit (the readout integrated circuit ASIC in each embodiment) is mounted on the side opposite to the direct conversion layer (CZT film 2 in each embodiment) side of the substrate. As long as it does not interfere with the incidence of light, it may be mounted on the side surface of the substrate, or even on the incident surface, it may be mounted on the end outside the detection effective area.

  (6) In each of the embodiments described above, the substrate is silicon, but a semiconductor or insulator other than silicon may be employed for the substrate. For example, the same material as that of the support substrate 5 (see FIGS. 4 and 5) in Example 2 described above may be employed.

  (7) In each of the above-described embodiments, as shown in FIGS. 1 and 3 to 5, the wire bonding 12 is mounted on the incident surface (upper surface) side of the substrate 1, and the CZT film 2 on the upper surface of the substrate 1. 6 is drifted to the lower surface and collected by the pixel electrode 41. The X-ray detection signal based on the collected charge is again drawn to the upper surface of the substrate 1 and taken out by the wire bonding 12. The structure which takes out an X-ray detection signal with the lower surface (back surface) of the board | substrate 1 like FIG. 9 may be sufficient.

  (8) For example, as shown in FIG. 6, the wire bonding 12 may be mounted on the lower surface (back surface) of the substrate 1 on which the readout integrated circuit ASIC is mounted. In this case, the extraction electrode 11 (see FIG. 1 and FIGS. 3 to 5) for extracting the X-ray detection signal again on the upper surface of the substrate 1 is not necessary. In addition, also when the support substrate 5 (refer FIG. 4, FIG. 5) like Example 2 is provided, the structure similar to FIG. 6 is employable.

  (9) Also, for example, as shown in FIG. 7, the CZT film 2 and the substrate 1 are mounted at the center of the readout integrated circuit ASIC larger than the substrate 1, and the incident surface (upper surface) of the readout integrated circuit ASIC is obtained. The wire bonding 47 may be mounted on the end portion. Also in this case, the extraction electrode 11 (see FIGS. 1 and 3 to 5) for extracting the X-ray detection signal again on the upper surface of the substrate 1 is not necessary. In addition, also when the support substrate 5 (refer FIG. 4, FIG. 5) like Example 2 is provided, the structure similar to FIG. 7 is employable.

  (10) Further, for example, as shown in FIG. 8, the reading substrate 6 may be mounted on the lower surface (back surface) of the reading integrated circuit ASIC. In a normal CMOS process, a readout circuit is formed on a base substrate through a photolithography process such as film formation or etching, and an X-ray detection signal is extracted from the top surface, and X-ray detection is performed from the bottom surface. The signal cannot be extracted. In order to extract the X-ray detection signal from the lowermost surface, not only the substrate 1 but also the integrated circuit ASIC for reading can be provided by providing the through silicon via TSV. Also in this case, the extraction electrode 11 (see FIGS. 1 and 3 to 5) for extracting the X-ray detection signal again on the upper surface of the substrate 1 is not necessary. Furthermore, the structure for extracting the X-ray detection signal in the side surface direction can be omitted. In addition, also when the support substrate 5 (refer FIG. 4, FIG. 5) like Example 2 is provided, the structure similar to FIG. 8 is employable.

  (11) Further, FIG. 9 shows a structure in which FIG. 8 is two-dimensionally arranged. In the structure of FIG. 8 described above, the structure for extracting the X-ray detection signal in the lateral direction can be omitted, so that the four sides of the substrate 1 and the integrated circuit ASIC for reading are free, as shown in FIG. The detectors can be arranged two-dimensionally without any gaps. Further, the image area (image area) can be adjusted depending on the application. Even when the support substrate 5 (see FIGS. 4 and 5) as in the second embodiment is provided, the same configuration as in FIG. 9 can be employed.

DESCRIPTION OF SYMBOLS 1 ... Substrate (made of silicon) 2 ... CZT film 41 ... Pixel electrode VIA ... Through-hole TSV ... Silicon through-electrode ASIC ... Integrated circuit for reading

Claims (6)

A direct conversion type radiation detector for detecting the radiation by directly converting the radiation into an electric charge,
A substrate made of the insulator or semiconductor formed by inserting a conductor into the through-hole in an insulator or semiconductor having a through-hole; and
Direct conversion of the radiation into the charge, and a direct conversion layer formed on the substrate,
The radiation detector, wherein the conductor inserted into the through hole collects the electric charge and is mounted as a pixel electrode associated with a pixel. The radiation detector according to claim 1.
A readout circuit for reading out the electric charge as a detection signal;
A radiation detector, wherein the readout circuit is mounted on a side opposite to the direct conversion layer side of the substrate. The radiation detector according to claim 1 or 2,
The radiation detector, wherein the substrate is silicon. A direct conversion type radiation detector for detecting the radiation by directly converting the radiation into an electric charge,
A substrate made of the insulator or semiconductor formed by inserting a conductor into the through-hole in an insulator or semiconductor having a through-hole; and
A direct conversion layer that directly converts the radiation into the charge,
The conductor inserted in the through hole collects the electric charge and is mounted as a pixel electrode associated with a pixel,
A radiation detector comprising the substrate and the direct conversion layer bonded together. The radiation detector according to claim 4.
A readout circuit for reading out the electric charge as a detection signal;
A radiation detector, wherein the readout circuit is mounted on a side opposite to the direct conversion layer side of the substrate. The radiation detector according to claim 4 or 5,
The radiation detector, wherein the substrate is silicon.

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