Radiation detection device and radiation ct device

Abstract

To appropriately protect a detection unit of a radiation detection device.SOLUTION: A radiation detection device comprises: a substrate; a first electrode that is located on the substrate; a semiconductor layer that is located on the first electrode, and that generates electric charges according to radiation incident on the radiation detection device; second electrodes that are located on the semiconductor layer, and each have a first surface in contact with the semiconductor layer and a second surface on an opposite side of the first surface; and an insulating layer that is in contact with the second surfaces of the second electrodes.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a radiation detection device and a radiation CT device. [Background technology]

[0002] Known radiation detection devices include one type that converts radiation into light using a scintillator and then converts the light into electric charges in a semiconductor layer, and another type that converts radiation into electric charges in a semiconductor layer. In the type that converts radiation into electric charges in a semiconductor layer, electrodes are arranged to sandwich the semiconductor layer, and the semiconductor layer and the electrodes form a sensor unit. Patent Document 1 proposes improving the moisture resistance of a semiconductor layer in a radiation detection device that directly converts radiation into electric charges in a semiconductor layer by covering the side surface of the semiconductor layer with an organic layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 7,223,982 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the side surface of the semiconductor layer is protected from the outside air. However, the electrodes constituting the detection unit may also be deteriorated due to oxidation or the like when exposed to the outside air. An object of some aspects of the present invention is to provide a technique for appropriately protecting the detection unit of a radiation detection device. [Means for solving the problem]

[0005] In view of the above problem, there is provided a radiation detection device comprising: a substrate; a first electrode located on the substrate; a semiconductor layer located on the first electrode, the semiconductor layer generating charges in response to radiation incident on the radiation detection device; a second electrode located on the semiconductor layer and having a first surface in contact with the semiconductor layer and a second surface opposite the first surface; and an insulating layer in contact with the second surface of the second electrode. Effect of the Invention

[0006] By the above means, the detection unit of the radiation detection device is appropriately protected. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of the configuration of a radiation detection apparatus according to some embodiments. [Diagram 2] FIG. 1 is a schematic diagram illustrating an example of the configuration of a radiation detection apparatus according to some embodiments. [Diagram 3] FIG. 1 is a block diagram illustrating an example of the configuration of a radiation CT apparatus according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0009] With reference to FIG. 1, a configuration example of a radiation detection device 100 according to some embodiments will be described. The radiation detection device 100 has a function of detecting incident radiation. When the radiation detection device 100 is used to generate a radiation image, the radiation detection device 100 may be called a radiation imaging device. The upper diagram of FIG. 1 shows a side cross-sectional view of the radiation detection device 100. The lower diagram of FIG. 1 shows a plan view of the radiation detection device 100. In the plan view, the outlines of components hidden by other components are indicated by dashed lines. In addition, in the plan view, in order to make the arrangement of the insulating layer 106 easier to understand, the sealing member 107 is omitted and its outline is indicated by dashed lines.

[0010] The radiation detection device 100 has a substrate 101 and a detection unit 102 located on the substrate 101. The surface of the substrate 101 on which the detection unit 102 is arranged is called the top surface (the upper surface in the side cross-sectional view). The surface of the substrate 101 opposite to the top surface is called the bottom surface (the lower surface in the side cross-sectional view). The surfaces of the substrate 101 connecting the top surface and the bottom surface are called side surfaces (the left and right surfaces in the side cross-sectional view). When the substrate 101 has a rectangular parallelepiped shape, the substrate 101 has four side surfaces. The substrate 101 may be, for example, a printed circuit board (which may also be called a printed circuit board).

[0011] The detection unit 102 has an upper electrode 103, a semiconductor layer 104, and a lower electrode 105. The semiconductor layer 104 is sandwiched between the upper electrode 103 and the lower electrode 105. In a side cross-sectional view, the lower electrode 105 is located on the substrate 101, the semiconductor layer 104 is located on the lower electrode 105, and the upper electrode 103 is located on the semiconductor layer 104.

[0012] The radiation detection device 100 has an individual lower electrode 105 for each pixel. In the example shown in FIG. 1, the radiation detection device 100 has pixels arranged in 4 rows and 4 columns. Therefore, the radiation detection device 100 has a total of 16 lower electrodes 105 arranged in 4 rows and 4 columns. The number of pixels included in the radiation detection device 100 is not limited to this example, and the radiation detection device 100 typically has more pixels. The upper electrode 103 is commonly arranged across multiple pixels. In the example of FIG. 1, the radiation detection device 100 has one common upper electrode 103 for 16 pixels. Alternatively, the radiation detection device 100 may have an individual (i.e., a total of 16) upper electrodes 103 for each pixel.

[0013] In the semiconductor layer 104, the surface on which the upper electrode 103 is disposed is called the top surface (the upper surface in the side cross-sectional view). In the semiconductor layer 104, the surface opposite the top surface is called the bottom surface (the lower surface in the side cross-sectional view). In the semiconductor layer 104, the surfaces connecting the top surface and the bottom surface are called the side surfaces (the left and right surfaces in the side cross-sectional view). When the semiconductor layer 104 has a rectangular parallelepiped shape, the semiconductor layer 104 has four side surfaces facing in different directions.

[0014] In the upper electrode 103, the surface on which the semiconductor layer 104 is disposed is called the bottom surface (the bottom surface in the side cross-sectional view). In the upper electrode 103, the surface opposite the bottom surface is called the top surface (the top surface in the side cross-sectional view). In the upper electrode 103, the surfaces connecting the top surface and the bottom surface are called the side surfaces (the left and right surfaces in the side cross-sectional view). When the upper electrode 103 has a rectangular parallelepiped shape, the upper electrode 103 has four side surfaces facing in different directions.

[0015] In the lower electrode 105, the surface on which the semiconductor layer 104 is disposed is called the top surface (the upper surface in the side cross-sectional view). In the lower electrode 105, the surface opposite the top surface is called the bottom surface (the lower surface in the side cross-sectional view). In the lower electrode 105, the surfaces connecting the top surface and the bottom surface are called the side surfaces (the left and right surfaces in the side cross-sectional view). When the lower electrode 105 has a rectangular parallelepiped shape, the lower electrode 105 has four side surfaces facing in different directions. As shown in FIG. 1, the side surfaces of the lower electrode 105 have steps.

[0016] The lower surface of the upper electrode 103 is in contact with the upper surface of the semiconductor layer 104. In the example shown in FIG. 1, the upper surface of the semiconductor layer 104 has the same shape as the lower surface of the upper electrode 103. In a plan view of the upper surface of the substrate 101, the outer edge of the upper surface of the semiconductor layer 104 coincides with the outer edge of the lower surface of the upper electrode 103. Therefore, the entire lower surface of the upper electrode 103 is in contact with the entire upper surface of the semiconductor layer 104. Alternatively, the lower surface of the upper electrode 103 may be smaller than the upper surface of the semiconductor layer 104. Furthermore, alternatively, the upper electrode 103 may extend to the side surface of the semiconductor layer 104 and be in contact with at least a part of the side surface of the semiconductor layer 104.

[0017] The upper surface of the lower electrode 105 contacts the lower surface of the semiconductor layer 104. In a plan view with respect to the upper surface of the substrate 101, the upper surface of the lower electrode 105 is smaller than the lower surface of the semiconductor layer 104. Therefore, the entire upper surface of the lower electrode 105 contacts a part of the lower surface of the semiconductor layer 104.

[0018] The semiconductor layer 104 generates charges in response to radiation incident on the radiation detection device 100. The semiconductor layer 104 may generate charges in response to radiation incident on the semiconductor layer 104. In this case, the semiconductor layer 104 may be composed of a compound semiconductor such as cadmium zinc telluride.

[0019] The upper electrode 103 and the lower electrode 105 are each made of a conductive material, and may each be made of a metal such as copper.

[0020] At least a portion of the detection unit 102 is covered by an insulating layer 106. A specific arrangement of the insulating layer 106 will be described below. The insulating layer 106 covers a portion of the upper surface of the upper electrode 103. The portion of the insulating layer 106 that covers a portion of the upper surface of the upper electrode 103 contacts the upper surface of the upper electrode 103. The portion of the upper surface of the upper electrode 103 that is not covered by the insulating layer 106 is used for connecting the wire 110.

[0021] The insulating layer 106 includes a portion covering the side surfaces of the upper electrode 103. The portion of the insulating layer 106 covering the side surfaces of the upper electrode 103 is in contact with the side surfaces of the upper electrode 103. In the example shown in FIG. 1, the insulating layer 106 covers all four side surfaces of the upper electrode 103. Alternatively, the insulating layer 106 may cover only some of the four side surfaces of the upper electrode 103.

[0022] The insulating layer 106 includes a portion covering the side surfaces of the semiconductor layer 104. The portion of the insulating layer 106 covering the side surfaces of the semiconductor layer 104 is in contact with the side surfaces of the semiconductor layer 104. In the example shown in FIG. 1, the insulating layer 106 covers all four side surfaces of the semiconductor layer 104. Alternatively, the insulating layer 106 may cover only some of the four side surfaces of the semiconductor layer 104.

[0023] The insulating layer 106 includes a portion covering a part of the lower surface of the semiconductor layer 104. The portion of the insulating layer 106 covering a part of the lower surface of the semiconductor layer 104 is in contact with the lower surface of the semiconductor layer 104. In the example shown in FIG. 1, the insulating layer 106 is in contact with the entire portion of the lower surface of the semiconductor layer 104 that is not in contact with the lower electrode 105. As described above, the insulating layer 106 extends from above the detection unit 102 to the side of the detection unit 102, and further extends below the detection unit 102.

[0024] The insulating layer 106 may be made of, for example, an inorganic material. Specifically, the insulating layer 106 may be made of an oxide, a nitride, or an oxynitride. More specifically, the insulating layer 106 may be made of silicon nitride, silicon oxide, silicon oxynitride, or aluminum oxide. The insulating layer 106 may be made of a single layer, or may be made of a laminate including a plurality of layers. When the insulating layer 106 is made of a laminate, each of the plurality of layers may be made of the same material or may be made of different materials. The insulating layer 106 may be made of, for example, an organic material. Furthermore, the insulating layer 106 may be a laminate of an inorganic material and an organic material.

[0025] By covering a part of the detection unit 102 with the insulating layer 106, the part of the detection unit 102 can be isolated from the outside world (for example, the air inside the housing of the radiation detection device 100). This makes it possible to suppress deterioration of the detection unit 102 due to the influence of the outside world. In this way, the insulating layer 106 protects the detection unit 102 from the outside world, and therefore the insulating layer 106 may be called a protective layer or an insulating protection layer.

[0026] An electrode 109 and an electrode 111 are formed on the upper surface of the substrate 101. The lower electrode 105 (specifically, its lower surface) is coupled to the substrate 101 (specifically, its electrode 109) by a bump 108. Since the bump 108 is conductive, the electrode 109 and the lower electrode 105 are electrically connected to each other. The bump 108 is formed of, for example, solder. The electrode 109 is electrically connected to another circuit mounted on the substrate 101 or another circuit mounted on a substrate different from the substrate 101 through a wiring formed on the substrate 101. When the radiation detection device 100 is used, a signal corresponding to the charge generated in the semiconductor layer 104 is transmitted to the other circuit through this wiring.

[0027] One end of the wire 110 is connected to the electrode 111 of the substrate 101. The other end of the wire 110 is connected to the upper electrode 103 (specifically, its upper surface). The electrode 111 and the upper electrode 103 are electrically connected to each other through the wire 110. The electrode 111 is electrically connected to another circuit mounted on the substrate 101 or another circuit mounted on a substrate different from the substrate 101 through wiring formed on the substrate 101. When the radiation detection device 100 is in use, a predetermined potential is supplied to the upper electrode 103 from the other circuit.

[0028] The sealing member 107 seals a portion of the upper surface of the upper electrode 103 that is not covered by the insulating layer 106. Furthermore, the sealing member 107 extends from a portion on the side of the semiconductor layer 104 to the upper surface of the substrate 101, thereby sealing the space between the detection unit 102 and the substrate 101. In the example of FIG. 1, a space (in other words, a region where no solid exists) exists between the detection unit 102 and the substrate 101. Alternatively, the space between the detection unit 102 and the substrate 101 may be filled with the sealing member 107. The sealing member 107 is made of, for example, an organic material.

[0029] 1, the insulating layer 106 covers the upper, side, and lower sides of the detection unit 102. Alternatively, the insulating layer 106 may cover only a part of the upper, side, and lower sides of the detection unit 102, for example, only the upper side, only the side, only the lower side, or the other side than the upper side, the other side, and the other side than the lower side. In this case, the part covered by the insulating layer 106 is protected from the outside world.

[0030] A method for manufacturing the radiation detection device 100 will be described. An upper electrode 103 is formed on one surface of a semiconductor layer 104. Then, the semiconductor layer 104 and the upper electrode 103 are covered with an insulating layer 106, and a part of the insulating layer 106 is removed. Then, a lower electrode 105 is formed on the lower surface of the semiconductor layer 104 in a part from which the insulating layer 106 has been removed. Then, the lower electrode 105 and an electrode 109 of the substrate 101 are bonded by a bump 108. Then, a part of the upper electrode 103 of the semiconductor layer 104 that is not covered with the insulating layer 106 is connected to an electrode 111 of the substrate 101 by a wire 110. Then, the detection unit 102 is sealed with a sealing member 107.

[0031] With reference to FIG. 2, a configuration example of a radiation detection device 200 according to some embodiments will be described. The radiation detection device 200 has a function of detecting incident radiation. When the radiation detection device 200 is used to generate a radiation image, the radiation detection device 200 may be called a radiation imaging device. The upper diagram of FIG. 2 shows a side cross-sectional view of the radiation detection device 200. The lower diagram of FIG. 2 shows a plan view of the radiation detection device 200. In the plan view, the outlines of components hidden by other components are indicated by dashed lines. In addition, in the plan view, in order to make the arrangement of the insulating layer 106 easier to understand, the sealing member 207 is omitted and its outline is indicated by dashed lines.

[0032] The radiation detection device 200 has a substrate 201 and a detection unit 202 located on the substrate 201. The surface of the substrate 201 on which the detection unit 202 is arranged is called the top surface (the upper surface in the side cross-sectional view). The surface of the substrate 201 opposite to the top surface is called the bottom surface (the lower surface in the side cross-sectional view). The surfaces of the substrate 201 connecting the top surface and the bottom surface are called side surfaces (the left and right surfaces in the side cross-sectional view). When the substrate 201 has a rectangular parallelepiped shape, the substrate 201 has four side surfaces. The substrate 201 may be, for example, a semiconductor substrate.

[0033] The detection unit 202 has an upper electrode 203, a semiconductor layer 204, and a lower electrode 205. The semiconductor layer 204 is sandwiched between the upper electrode 203 and the lower electrode 205. In a side cross-sectional view, the lower electrode 205 is located on the substrate 201, the semiconductor layer 204 is located on the lower electrode 205, and the upper electrode 203 is located on the semiconductor layer 204.

[0034] The radiation detection device 200 has an individual lower electrode 205 for each pixel. In the example shown in FIG. 2, the radiation detection device 200 has pixels arranged in 4 rows and 4 columns. Therefore, the radiation detection device 200 has a total of 16 lower electrodes 205 arranged in 4 rows and 4 columns. The number of pixels included in the radiation detection device 200 is not limited to this example, and the radiation detection device 200 typically has more pixels. The upper electrode 203 is commonly arranged across multiple pixels. In the example of FIG. 2, the radiation detection device 200 has one common upper electrode 203 for 16 pixels. Alternatively, the radiation detection device 200 may have an individual (i.e., a total of 16) upper electrodes 203 for each pixel.

[0035] In the semiconductor layer 204, the surface on which the upper electrode 203 is disposed is referred to as the top surface (the upper surface in the side cross-sectional view). In the semiconductor layer 204, the surface opposite to the top surface is referred to as the bottom surface (the lower surface in the side cross-sectional view). In the semiconductor layer 204, the surfaces connecting the top surface and the bottom surface are referred to as the side surfaces (the left and right surfaces in the side cross-sectional view). When the semiconductor layer 204 has a rectangular parallelepiped shape, the semiconductor layer 204 has four side surfaces facing in different directions.

[0036] In the upper electrode 203, the surface on which the semiconductor layer 204 is disposed is referred to as the bottom surface (the bottom surface in the side cross-sectional view). In the upper electrode 203, the surface opposite the bottom surface is referred to as the top surface (the top surface in the side cross-sectional view). In the upper electrode 203, the surfaces connecting the top surface and the bottom surface are referred to as the side surfaces (the left and right surfaces in the side cross-sectional view). When the upper electrode 203 has a rectangular parallelepiped shape, the upper electrode 203 has four side surfaces facing in different directions.

[0037] In the lower electrode 205, the surface on which the semiconductor layer 204 is disposed is referred to as the top surface (the upper surface in the side cross-sectional view). In the lower electrode 205, the surface opposite the top surface is referred to as the bottom surface (the lower surface in the side cross-sectional view). In the lower electrode 205, the surfaces connecting the top surface and the bottom surface are referred to as the side surfaces (the left and right surfaces in the side cross-sectional view). When the lower electrode 205 has a rectangular parallelepiped shape, the lower electrode 205 has four side surfaces facing in different directions.

[0038] 2, the upper surface of the semiconductor layer 204 has the same shape as the lower surface of the upper electrode 203. In a plan view of the upper surface of the substrate 201, the outer edge of the upper surface of the semiconductor layer 204 coincides with the outer edge of the lower surface of the upper electrode 203. Therefore, the entire lower surface of the upper electrode 203 contacts the entire upper surface of the semiconductor layer 204. Alternatively, the lower surface of the upper electrode 203 may be smaller than the upper surface of the semiconductor layer 204. Furthermore, alternatively, the upper electrode 203 may extend to the side surface of the semiconductor layer 204 and contact at least a part of the side surface of the semiconductor layer 204.

[0039] An upper surface of lower electrode 205 contacts a lower surface of semiconductor layer 204. In a plan view with respect to the upper surface of substrate 201, the upper surface of lower electrode 205 is smaller than the lower surface of semiconductor layer 204. Therefore, the entire upper surface of lower electrode 205 contacts a part of the lower surface of semiconductor layer 204.

[0040] The semiconductor layer 204 generates charges in response to radiation incident on the radiation detection device 200. The semiconductor layer 204 may generate charges in response to radiation incident on the semiconductor layer 204. In this case, the semiconductor layer 204 may be composed of a compound semiconductor such as cadmium zinc telluride.

[0041] The upper electrode 203 and the lower electrode 205 are each made of a conductive material, and may be made of a metal such as copper.

[0042] At least a portion of the detection unit 202 is covered by an insulating layer 206. A specific arrangement of the insulating layer 206 will be described below. The insulating layer 206 covers a portion of the upper surface of the upper electrode 203. The portion of the insulating layer 206 that covers a portion of the upper surface of the upper electrode 203 contacts the upper surface of the upper electrode 203. The portion of the upper surface of the upper electrode 203 that is not covered by the insulating layer 206 is used for connecting the conductive member 210.

[0043] The insulating layer 206 includes a portion covering the side surfaces of the upper electrode 203. The portion of the insulating layer 206 covering the side surfaces of the upper electrode 203 is in contact with the side surfaces of the upper electrode 203. In the example shown in FIG. 2, the insulating layer 206 covers all four side surfaces of the upper electrode 203. Alternatively, the insulating layer 206 may cover only some of the four side surfaces of the upper electrode 203.

[0044] The insulating layer 206 includes a portion covering the side surfaces of the semiconductor layer 204. The portion of the insulating layer 206 covering the side surfaces of the semiconductor layer 204 is in contact with the side surfaces of the semiconductor layer 204. In the example shown in FIG. 2, the insulating layer 206 covers all four side surfaces of the semiconductor layer 204. Alternatively, the insulating layer 206 may cover only some of the four side surfaces of the semiconductor layer 204.

[0045] The insulating layer 206 includes a portion that covers part of the lower surface of the semiconductor layer 204. The portion of the insulating layer 206 that covers part of the lower surface of the semiconductor layer 204 is in contact with the lower surface of the semiconductor layer 204.

[0046] The upper surface of the substrate 201 includes, in a plan view of the upper surface, a portion that overlaps with the semiconductor layer 204 and a portion that does not overlap with the semiconductor layer 204. The insulating layer 206 includes a portion that covers the portion of the upper surface of the substrate 201 that does not overlap with the semiconductor layer 204.

[0047] The insulating layer 206 includes a portion covering the side surfaces of the substrate 201. The portion of the insulating layer 206 covering the side surfaces of the substrate 201 is in contact with the side surfaces of the semiconductor layer 204. In the example shown in Fig. 2, the insulating layer 206 covers all four side surfaces of the substrate 201. Alternatively, the insulating layer 206 may cover only some of the four side surfaces of the substrate 201.

[0048] Insulating layer 206 includes a portion covering the lower surface of substrate 201. The portion of insulating layer 206 covering the lower surface of substrate 201 contacts the lower surface of semiconductor layer 204. In the example shown in Fig. 2, insulating layer 206 contacts the entire lower surface of substrate 201. As described above, insulating layer 206 extends from above substrate 101 to the side of substrate 101, and further extends below substrate 101.

[0049] The insulating layer 206 may be made of, for example, an inorganic material. Specifically, the insulating layer 206 may be made of an oxide, a nitride, or an oxynitride. More specifically, the insulating layer 206 may be made of silicon nitride, silicon oxide, silicon oxynitride, or aluminum oxide. The insulating layer 206 may be made of a single layer, or may be made of a laminate including multiple layers. When the insulating layer 206 is made of a laminate, each of the multiple layers may be made of the same material or may be made of different materials. The insulating layer 206 may be made of, for example, an organic material. Furthermore, the insulating layer 206 may be a laminate of an inorganic material and an organic material.

[0050] By covering a part of the detection unit 202 with the insulating layer 206, the part of the detection unit 202 can be isolated from the outside world (for example, the air inside the housing of the radiation detection device 200). Therefore, deterioration of the detection unit 202 due to the influence of the outside world can be suppressed. In this way, the insulating layer 206 protects the detection unit 202 from the outside world, and therefore the insulating layer 206 may be called a protective layer or an insulating protective layer.

[0051] The upper surface of the substrate 201 is covered with an insulating layer 211. The insulating layer 211 is in contact with the upper surface of the substrate 201. The insulating layer 211 is also in contact with the side surface of the lower electrode 205. The insulating layer 211 is also in contact with the entire lower surface of the semiconductor layer 204, that is not in contact with the lower electrode 205. The insulating layer 206 and the insulating layer 211 may be considered to constitute an insulating layer that functions as a protective layer.

[0052] The lower electrode 205 (specifically, its lower surface) is electrically connected to a wiring layer 208 formed in the substrate 101 through a plug 212. The wiring layer 208 is electrically connected to other circuits formed in the substrate 201 or other circuits formed in a substrate different from the substrate 201. When the radiation detection device 200 is in use, a signal corresponding to the charge generated in the semiconductor layer 204 is transmitted to the other circuits through the wiring layer 208.

[0053] One end of a conductive member 210 is connected to an electrode 209 formed on the substrate 201. The other end of the conductive member 210 is connected to the upper electrode 203 (specifically, its upper surface). The electrode 209 and the upper electrode 203 are electrically connected to each other through the conductive member 210. The electrode 209 is electrically connected to another circuit formed on the substrate 201 or another circuit formed on a substrate different from the substrate 201 through wiring formed on the substrate 201. When the radiation detection device 200 is in use, a predetermined potential is supplied to the upper electrode 203 from the other circuit.

[0054] The sealing member 207 seals the conductive member 210. Furthermore, the sealing member 207 may cover the upper surface and side surfaces of the semiconductor layer 204. The sealing member 207 is made of an insulating member, and may be an organic or inorganic material. Also, the sealing member 207 may be made of the same material as the insulating layer 206 described above.

[0055] The substrate 201 may have a connection portion for connecting to an external circuit. In a plan view, this connection portion is disposed apart from the semiconductor layer 204. A pad electrode may be used for connection to the external circuit.

[0056] The radiation detection device 200 may have a heat insulating region in a region between the connection portion and the semiconductor layer 204 in a plan view. By having the heat insulating region, heat generated when connecting the pad electrodes is less likely to be transmitted to the semiconductor layer 204. The heat insulating region may include, for example, a heat insulating portion having a lower thermal conductivity than the substrate 201. The heat insulating portion may be realized by making the thickness of the substrate 201 thinner than the rest, that is, by making a part of the substrate 201 hollow, or by providing a member different from the substrate 201 and having a lower thermal conductivity than the substrate 201. When the heat insulating region is formed by thinning the substrate 201, the thickness of the substrate in the heat insulating region is smaller than the thickness of the substrate in a region overlapping with the semiconductor layer 204 in a plan view.

[0057] 2, the insulating layer 206 covers the upper and side surfaces of the detection unit 202. Alternatively, the insulating layer 206 may cover only a part of the upper and side surfaces of the detection unit 202, for example, only the upper surface or only the side surfaces. In this case, the part covered by the insulating layer 206 is protected from the outside world.

[0058] A method for manufacturing the radiation detection device 200 will be described. A lower electrode 205 and an insulating layer 211 are formed on a substrate 201 on which a wiring layer 208, a plug 212, and the like are formed. Then, a semiconductor layer 204 is formed on the lower electrode 205 and the insulating layer 211. As described above, the semiconductor layer 204 generates charges according to the incident radiation. Then, an upper electrode 203 is formed on the semiconductor layer 204. As described above, the upper electrode 203 has a lower surface in contact with the semiconductor layer 204 and an upper surface opposite to the lower surface. Then, an insulating layer 206 is formed in contact with the upper surface of the upper electrode 203. The insulating layer 206 may be formed by, for example, a low-temperature film formation method. Furthermore, when the insulating layer 206 is an inorganic material, it may be formed by, for example, a chemical vapor deposition method (CVD (Chemical Vapor Deposition) method) or an atomic layer deposition method (ALD (Atomic Layer Deposition) method). When the insulating layer 206 is an organic material, it may be formed by a dipping method, a spin coating method, or the like using a resin as a material. As described above, the insulating layer 206 may cover the side surface of the semiconductor layer 204 and a part of the substrate 201. Then, a part of the insulating layer 206 is removed, and the conductive member 210 is formed in the removed part. Then, the detection unit 202 is sealed with a sealing member 207.

[0059] 3 is a block diagram of a radiation CT apparatus in this embodiment. The above-mentioned radiation detection apparatuses 100 and 200 are applicable to detectors of a radiation CT apparatus. Although a case where the radiation detection apparatus 100 is used will be described below, the radiation detection apparatus 200 may also be used. The radiation CT apparatus 30 in this embodiment includes a radiation generation unit 310, a wedge 311, a collimator 312, a radiation detection unit 320, a top plate 330, a rotating frame 340, a high-voltage generator 350, a data acquisition system (DAS) 351, a signal processing unit 352, a display unit 353, and a control unit 354.

[0060] Radiation generating unit 310 is composed of, for example, a vacuum tube that generates X-rays. A high voltage and a filament current are supplied to the vacuum tube of radiation generating unit 310 from high voltage generator 350. X-rays are generated by irradiating thermal electrons from a cathode (filament) toward an anode (target).

[0061] Wedge 311 is a filter that adjusts the amount of radiation irradiated from radiation generating unit 310. Wedge 311 attenuates the amount of radiation so that the radiation irradiated from radiation generating unit 310 to the subject has a predetermined distribution. Collimator 312 is composed of a lead plate or the like that narrows down the irradiation range of the radiation that has passed through wedge 311. The radiation generated by radiation generating unit 310 is shaped into a cone beam via collimator 312 and irradiated to the subject on top board 330.

[0062] The radiation detection unit 320 is configured using the above-mentioned radiation detection device 100. The radiation detection unit 320 detects radiation that has passed through the subject from the radiation generation unit 310, and outputs a signal corresponding to the radiation dose as the DAS 351.

[0063] The rotating frame 340 has an annular shape and is configured to be rotatable. A radiation generating unit 310 (wedge 311, collimator 312) and a radiation detecting unit 320 are arranged facing each other inside the rotating frame 340. The radiation generating unit 310 and the radiation detecting unit 320 are rotatable together with the rotating frame 340.

[0064] The high voltage generator 350 includes a boost circuit, and outputs a high voltage to the radiation generation unit 310. The DAS 351 includes an amplifier circuit and an A / D conversion circuit, and outputs a signal from the radiation detection unit 320 to the signal processing unit 352 as digital data.

[0065] The signal processing unit 352 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and is capable of performing image processing on digital data. The display unit 353 includes a flat display device, and is capable of displaying radiation images. The control unit 354 includes a CPU, a ROM, a RAM, and the like, and controls the operation of the entire radiation CT apparatus 30.

[0066] In the above, there has been described an embodiment in which the radiation detection apparatus 100 is used in the radiation CT apparatus 30. Alternatively, the radiation detection apparatus 100 or the radiation detection apparatus 200 may be used as an area sensor.

[0067] <Summary of the embodiment> <Item 1> 1. A radiation detection device, comprising: A substrate; a first electrode overlying the substrate; a semiconductor layer located on the first electrode, the semiconductor layer generating charges in response to radiation incident on the radiation detection device; a second electrode located on the semiconductor layer and having a first surface in contact with the semiconductor layer and a second surface opposite to the first surface; an insulating layer in contact with the second surface of the second electrode. <Item 2> 2. The radiation detection device according to item 1, wherein the semiconductor layer generates charges in response to radiation incident on the semiconductor layer. <Item 3> 3. The radiation detection device according to claim 1 or 2, wherein the insulating layer comprises an inorganic material. <Item 4> Item 4. The radiation detection device of item 3, wherein the insulating layer comprises an oxide, a nitride, or an oxynitride. <Item 5> Item 5. The radiation detection device of item 4, wherein the insulating layer comprises silicon nitride, silicon oxide, silicon oxynitride, or aluminum oxide. <Item 6> 3. The radiation detection device according to claim 1, wherein the insulating layer comprises an organic material. <Item 7> the second electrode further has a third surface connecting the first surface and the second surface, 7. The radiation detection device according to any one of claims 1 to 6, wherein the insulating layer is further in contact with the third surface of the second electrode. <Item 8> the substrate has a fourth surface on which the semiconductor layer is disposed, a fifth surface opposite to the fourth surface, and a sixth surface connecting the fourth surface and the fifth surface; the fourth surface of the substrate includes a portion that does not overlap the semiconductor layer, 8. The radiation detection device according to any one of claims 1 to 7, wherein the insulating layer covers a portion of the fourth surface of the substrate that does not overlap the semiconductor layer. <Item 9> 9. The radiation detection device of claim 8, wherein the insulating layer further covers the sixth surface of the substrate. <Item 10> 10. The radiation detection device of claim 9, wherein the insulating layer further covers the fifth surface of the substrate. <Item 11> 8. The radiation detection device of claim 1, wherein the first electrode is coupled to the substrate by a bump. <Item 12> the semiconductor layer has a seventh surface in contact with the first electrode, the seventh surface includes a portion that is not in contact with the first electrode, Item 12. The radiation detection device according to item 11, wherein the insulating layer is in contact with a portion of the seventh surface of the semiconductor layer that is not in contact with the first electrode. <Item 13> the substrate has a connection portion for connection to an external circuit, the connection portion being spaced apart from the semiconductor layer in a plan view; 11. The radiation detection device according to any one of claims 1 to 10, further comprising a heat insulating region in a region between the connection portion and the semiconductor layer in a plan view. <Item 14> Item 14. The radiation detection device of item 13, wherein the heat insulating region includes a heat insulating portion having a lower thermal conductivity than the substrate. <Item 15> Item 15. The radiation detection device according to item 14, wherein the insulating portion is hollow. <Item 16> 16. The radiation detection device according to any one of items 13 to 15, wherein the thickness of the substrate in the heat insulating region is smaller than the thickness of the substrate in a region overlapping with the semiconductor layer in a plan view. <Item 17> A radiation detection device according to any one of items 1 to 16, a radiation generating unit that irradiates the radiation detection device with radiation; a signal processing unit that processes a signal output from the radiation detection device; A radiation CT apparatus comprising: <Item 18> forming a first electrode on a substrate; forming a semiconductor layer on the first electrode, the semiconductor layer generating charges in response to incident radiation; forming a second electrode on the semiconductor layer, the second electrode having a first surface in contact with the semiconductor layer and a second surface opposite to the first surface; A method for manufacturing a radiation detection device, comprising forming an insulating layer in contact with the second surface of the second electrode. <Item 19> Item 19. The method of claim 18, wherein the insulating layer is formed by a low-temperature deposition method. <Item 20> 20. The method according to item 18 or 19, wherein the insulating layer is formed by chemical vapor deposition or atomic deposition.

[0068] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0069] 100 Radiation detection device, 101 Substrate, 102 Detection unit, 103 Upper electrode, 104 Semiconductor layer, 105 Lower electrode, 106 Insulating layer

Claims

1. A radiation detection device, comprising: A substrate; a first electrode located on the substrate; a semiconductor layer located on the first electrode, the semiconductor layer generating charges in response to radiation incident on the radiation detection device; a second electrode located on the semiconductor layer and having a first surface in contact with the semiconductor layer and a second surface opposite to the first surface; an insulating layer in contact with the second surface of the second electrode, the substrate has a connection portion for connecting to an external circuit, the connection portion being spaced apart from the semiconductor layer in a plan view; The radiation detection device has a heat insulating region in a region between the connection portion and the semiconductor layer in a plan view.

2. The radiation detection device according to claim 1 , wherein the semiconductor layer generates charges in response to radiation incident on the semiconductor layer.

3. The radiation detection device of claim 1 , wherein the insulating layer comprises an inorganic material.

4. The radiation detection device of claim 3 , wherein the insulating layer comprises an oxide, a nitride, or an oxynitride.

5. The radiation detection device of claim 4 , wherein the insulating layer comprises silicon nitride, silicon oxide, silicon oxynitride, or aluminum oxide.

6. The radiation detection device of claim 1 , wherein the insulating layer includes an organic material.

7. the second electrode further has a third surface connecting the first surface and the second surface, The radiation detection device according to claim 1 , wherein the insulating layer is further in contact with the third surface of the second electrode.

8. the substrate has a fourth surface on which the semiconductor layer is disposed, a fifth surface opposite to the fourth surface, and a sixth surface connecting the fourth surface and the fifth surface; the fourth surface of the substrate includes a portion that does not overlap the semiconductor layer, The radiation detection device according to claim 1 , wherein the insulating layer covers a portion of the fourth surface of the substrate that does not overlap with the semiconductor layer.

9. The radiation detection device of claim 8 , wherein the insulating layer further covers the sixth surface of the substrate.

10. The radiation detection device of claim 9 , wherein the insulating layer further covers the fifth surface of the substrate.

11. The radiation detection device of claim 1 , wherein the first electrode is coupled to the substrate by a bump.

12. the semiconductor layer has a seventh surface in contact with the first electrode, the seventh surface includes a portion that is not in contact with the first electrode, The radiation detection device according to claim 11 , wherein the insulating layer is in contact with a portion of the seventh surface of the semiconductor layer that is not in contact with the first electrode.

13. The radiation detection device according to claim 1 , wherein the heat insulating region includes a heat insulating portion having a thermal conductivity lower than that of the substrate.

14. The radiation detection device according to claim 13 , wherein the heat insulating portion is a cavity.

15. The radiation detection device according to claim 1 , wherein the thickness of the substrate in the heat insulating region is smaller than the thickness of the substrate in a region overlapping with the semiconductor layer in a plan view.

16. A radiation detection device according to any one of claims 1 to 15; a radiation generating unit that irradiates the radiation detection device with radiation; a signal processing unit that processes a signal output from the radiation detection device; A radiation CT device comprising:

17. forming a first electrode on a substrate; forming a semiconductor layer on the first electrode that generates charges in response to incident radiation; forming a second electrode on the semiconductor layer, the second electrode having a first surface in contact with the semiconductor layer and a second surface opposite to the first surface; A method for manufacturing a radiation detection device, comprising forming an insulating layer in contact with the second surface of the second electrode.

18. The method of claim 17 , wherein the insulating layer is formed by a low-temperature film-forming method.

19. The method of claim 17 , wherein the insulating layer is formed by chemical vapor deposition or atomic deposition.

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