JP2015021843A - Radiation detector, radiation detection device and radiation analysis device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation detector, a radiation detection device and a radiation analysis device that have irradiation of radiation suppressed with respect to an area other than an irradiation area of a radiation detection element.SOLUTION: A radiation detector comprises: a radiation detection element that has an irradiation area set on a principal surface, and converts an energy of radiation with which the irradiation area is irradiated to an electric signal; and a collimator that is arranged in contact with the irradiation detection element in an area adjacent to the irradiation area, and shields the radiation in the area adjacent to the irradiation area. The collimator is arranged on the radiation detection element at a position where the irradiation with which the principal surface is irradiated and which penetrates inside the radiation detection element enters into an effective area inside the radiation detection element and is not incident to an area surrounding a side surface of the effective area.

Description

  The present invention relates to a radiation detector, a radiation detection apparatus, and a radiation analysis apparatus that detect radiation emitted from a measurement object.

  A radiation detector for detecting radiation is used to analyze radiation specific to the substance, such as X-rays, γ-rays, ultraviolet rays, infrared rays, and visible rays. The radiation detector includes a radiation detection element such as a conversion element that converts radiation energy into an electrical signal.

  Usually, the radiation detection element is set with an irradiation region to which the radiation is irradiated. When radiation is irradiated to a region other than the predetermined irradiation region, the electrical signal converted from the energy of the radiation varies, and the accuracy of the radiation detection result deteriorates. For this reason, it is necessary to block radiation irradiation to the radiation detection element outside the irradiation region. For example, a collimator that shields an area other than the irradiation area is arranged on the radiation detection element, and the irradiation area is set (for example, see Patent Document 1).

JP 2003-315466 A

  However, if there is a gap between the collimator and the radiation detection element, radiation having a large incident angle enters the radiation detection element below the collimator. For example, when an electrode or a bonding wire for taking out an electrical signal from the radiation detection element is arranged on the surface of the radiation detection element, a space for arranging the electrode or the bonding wire is provided on the surface of the radiation detection element. It is necessary to secure it. For this reason, a gap is formed between the collimator and the radiation detection element.

  As a result, when the incident angle of radiation is large, the region passes through the gap between the collimator and the radiation detection element, and the region other than the irradiation region is irradiated with the radiation. As a result, there is a problem that the detection accuracy is lowered.

  In view of the above problems, an object of the present invention is to provide a radiation detector, a radiation detection apparatus, and a radiation analysis apparatus in which irradiation of a region other than the irradiation region of the radiation detection element is suppressed.

  According to one aspect of the present invention, (b) a radiation detection element that sets an irradiation region on the main surface and converts the energy of radiation irradiated to the irradiation region into an electrical signal, and (b) a region around the irradiation region The collimator is disposed on the main surface in contact with and shields radiation around the irradiation area, and the collimator radiates the main surface and enters the inside of the radiation detection element. A radiation detector is provided that is disposed on the principal surface at a position that is incident on the region and not incident on the region surrounding the side surface of the effective region.

  According to another aspect of the present invention, (i) an irradiation region is set on the main surface, and a radiation detection element that converts the energy of radiation irradiated to the irradiation region into an electrical signal, and a region around the irradiation region A radiation detector having a collimator arranged in contact with the main surface and shielding radiation around the irradiation area, and (b) a first-stage FET for amplifying the converted electric signal. The collimator irradiates the main surface. The radiation detecting apparatus is arranged on the main surface at a position where the radiation that enters the inside of the radiation detecting element is incident on the effective area inside the radiation detecting element and is not incident on the area surrounding the side surface of the effective area. Provided.

  According to still another aspect of the present invention, (a) an irradiation region is set on the main surface, and a radiation detection element that converts the energy of radiation irradiated to the irradiation region into an electrical signal, and a region around the irradiation region A radiation detector having a collimator disposed on the main surface in contact with the shield and shielding radiation around the irradiation area, and (b) a signal analyzer for analyzing the energy of the radiation using the converted electrical signal. The collimator is disposed on the main surface at a position where the radiation that is irradiated onto the main surface and enters the inside of the radiation detection element enters the effective area inside the radiation detection element and does not enter the area surrounding the side surface of the effective area. A radiation analysis apparatus is provided.

  According to the present invention, it is possible to provide a radiation detector, a radiation detection device, and a radiation analysis device in which irradiation of radiation to regions other than the radiation region of the radiation detection element is suppressed.

It is a typical sectional view showing the structure of the radiation detector concerning a 1st embodiment of the present invention. It is a typical top view showing the structure of the radiation detector concerning a 1st embodiment of the present invention. It is a schematic diagram for demonstrating the influence on the spectrum characteristic of an incomplete carrier collection signal. It is a schematic diagram which shows the structure of the radiation detector of a comparative example. It is a graph which shows the relationship between the distance between a measurement object and a radiation detector, and an analysis result. It is a schematic diagram which shows the structural example of the radiation detection apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic diagram which shows the example of the first stage FET circuit of the radiation detection apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic diagram which shows the structural example of the radiation analyzer which concerns on the 3rd Embodiment of this invention.

  Embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description.

  Further, the embodiments described below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the embodiments of the present invention include the material, shape, structure, arrangement, etc. of components. Is not specified as follows. The embodiment of the present invention can be variously modified within the scope of the claims.

(First embodiment)
As shown in FIG. 1, the radiation detector 1 according to the first exemplary embodiment of the present invention has an irradiation region 110 set on the main surface 111 and converts the energy of the radiation L1 irradiated to the irradiation region 110 into an electrical signal. And a collimator 20 that is disposed in contact with the radiation detection element 10 in a region adjacent to the irradiation region 110 and shields the radiation L1 in the region adjacent to the irradiation region 110. The collimator 20 is a region (hereinafter, referred to as “radiation L1” which is irradiated onto the main surface 111 and enters the radiation detection element 10 enters the effective area 101 inside the radiation detection element 10 and surrounds the side surface of the effective area 101). It is arranged on the radiation detection element 10 at a position where it is not incident on the “incomplete carrier collection region 102”.

  The collimator 20 prevents the radiation L1 from entering the radiation detection element 10 from around the irradiation region 110 of the radiation detection element 10. That is, the irradiation area 110 is defined on the main surface 111 as an area where the collimator 20 is not disposed.

  As the radiation detection element 10, a PIN type semiconductor device or the like can be adopted. For example, the radiation detection element 10 includes a semiconductor substrate 11 whose both surfaces are defined by a main surface 111 and a back surface 112 opposite to the main surface 111, and the first main electrode 12 and the back surface 112 disposed on the main surface 111. And a second main electrode 13 disposed on the surface.

For example, a first electrode region 120 is formed in the irradiation region 110 by adding a p-type impurity such as boron (B) to part of the main surface 111 of the semiconductor substrate 11. Then, the first main electrode 12 that is electrically connected to the first electrode region 120 is disposed outside the first electrode region 120. The first main electrode 12 is insulated and isolated from the region of the semiconductor substrate 11 other than the first electrode region 120 by an insulating film 14 disposed on the main surface 111 of the semiconductor substrate 11. A silicon oxide (SiO ₂ ) film or the like can be used for the insulating film 14. In the present embodiment, the insulating film 14 is not disposed in the irradiation region 110 in order to avoid X-ray absorption as much as possible.

  A passivation film 15 is disposed on the insulating film 14 as the uppermost layer of the radiation detection element 10 so that the main surface 111 is stabilized when a voltage is applied to the first main electrode 12. As the passivation film 15, for example, a laminated film of a PSG film and a BSG film can be employed. A collimator 20 is disposed directly on the passivation film 15.

  The first main electrode 12 is embedded in the passivation film 15. As described above, since the first main electrode 12 is embedded in a part of the upper part of the radiation detection element 10, no gap is generated between the radiation detection element 10 and the collimator 20. This prevents the radiation L1 from entering the radiation detection element 10 through the gap between the radiation detection element 10 and the collimator 20.

  On the other hand, an n-type impurity such as phosphorus (P) or arsenic (As) is added to the back surface 112 of the semiconductor substrate 11 to form the second electrode region 130. The second main electrode 13 is disposed on the second electrode region 130. For the first main electrode 12 and the second main electrode 13, for example, a metal thin film such as aluminum (Al) can be used.

  Below, operation | movement of the radiation detector 1 shown in FIG. 1 is demonstrated.

  A voltage is applied between the first main electrode 12 and the second main electrode 13 to form a depletion layer (I layer) in the semiconductor substrate 11. For example, the potential of the second main electrode 13 is set to 100V, and the potential of the first main electrode 12 is set to 0V.

  The depletion layer formed in the semiconductor substrate 11 is the effective region 101, and the region surrounding the side surface of the depletion layer is the incomplete carrier collection region 102. In FIG. 1, the boundary between the effective region 101 and the incomplete carrier collection region 102 (hereinafter referred to as “depletion layer boundary surface”) is indicated by reference numeral 103. The radiation L1 that has entered the irradiation region 110 and has passed through the signal boundary surface 104 indicated by the broken line in FIG. 1 does not enter the incomplete carrier collection region 102.

  When the radiation detection element 10 is irradiated with the radiation L1 in a state where the depletion layer is formed in the semiconductor substrate 11, electrons and holes are generated in the semiconductor substrate 11 by the radiation L1 incident on the depletion layer which is the effective region 101. , And detected as a current pulse outside the radiation detection element 10. That is, the energy of the radiation L1 is converted into an electric signal. This electrical signal is output to the outside of the radiation detection element 10 via the first main electrode 12.

  The semiconductor substrate 11 is selected according to the type of radiation L1 such as X-rays, γ-rays, ultraviolet rays, infrared rays, and visible rays. That is, a substrate made of a material that absorbs the radiation L1 to be detected and generates carriers is selected. For example, when detecting X-rays, a silicon (Si) substrate is selected as the semiconductor substrate 11. When detecting γ-rays, a germanium (Ge) substrate or the like can be employed.

  A material that absorbs the radiation L1 is used for the collimator 20 that shields the radiation L1. Furthermore, a material that does not emit an impure line that affects the detection result is selected for the collimator 20. For example, when the radiation L1 is an X-ray, a collimator 20 in which an aluminum (Al) layer, a chromium (Cr) layer, and a tungsten (W) layer are stacked in this order from the radiation detection element 10 side can be employed. Even if an impurity line is generated when X-rays are absorbed by the W layer, the impurity line is absorbed by the Cr layer. At this time, the impure line generated in the Cr layer is absorbed by the Al layer. Even if the impure line generated in the Al layer is incident on the radiation detection element 10, it is a light atom and thus has little influence on the detection result. Thus, by using the stacked collimator 20 in which the material of the lighter atom is arranged on the radiation detection element 10 side, the influence of the impure line generated in the collimator 20 can be suppressed.

  As shown in FIG. 1, it is preferable that the grounded guard ring 16 is in electrical contact with the semiconductor substrate 11 to reduce the capacitance of the first main electrode 12 and improve the resolution. The guard ring 16 disposed on the insulating film 14 is in contact with the semiconductor substrate 11 at the opening formed in the insulating film 14. A contact region 160 to which a p-type impurity is added is formed at a position where the semiconductor substrate 11 is in contact with the guard ring 16. Contact region 160 is disposed in a region where a depletion layer is formed. By grounding the guard ring 16, the range of the p-type region around the first main electrode 12 is reduced, and the resolution of the radiation detector 1 is improved. The guard ring 16 is embedded in the passivation film 15 in the same manner as the first main electrode 12 so that no gap is generated between the radiation detection element 10 and the collimator 20. A metal thin film such as an Al layer can also be used for the guard ring 16.

  FIG. 2 is a plan view of the radiation detection element 10. In FIG. 2, the position of the collimator 20 is indicated by a broken line. 1 is a cross-sectional view taken along the II direction of FIG.

  As shown in FIG. 2, the first main electrode 12 is disposed on the main surface 111 along the outer periphery of the irradiation region 110. The first main electrode 12 is connected between the radiation detection element 10 and the collimator 20 and connected to a signal wiring 121 extending outside the main surface 111. The electrical signal converted from the energy of the radiation L1 and output from the first main electrode 12 is propagated to the outside of the radiation detection element 10 through the signal wiring 121.

  A guard ring wiring 161 that is in electrical contact with the guard ring 16 is disposed between the radiation detection element 10 and the collimator 20 and extends outside the main surface 111. The guard ring 16 is grounded via a guard ring wiring 161.

  The bonding pad 122 for the first main electrode 12 connected to the signal wiring 121 and the bonding pad 162 for the guard ring 16 connected to the guard ring wiring 161 are outside the region where the collimator 20 is disposed, and the radiation detection element. 10 main surfaces 111 are arranged. Below the collimator 20, the signal wiring 121 and the guard ring wiring 161 are embedded in the passivation film 15 in the same manner as the first main electrode 12 and the guard ring 16. That is, the signal wiring 121 and the guard ring wiring 161 are formed as a wiring pattern using a metal thin film. For this reason, the radiation detection element 10 and the collimator 20 can be closely adhered without a gap.

  In FIG. 2, a region where the signal wiring 121 and the guard ring 16 intersect with each other employs a multilayer wiring structure although not shown, and the signal wiring 121 and the guard ring 16 are insulated and separated.

  Although FIG. 2 shows an example in which the first main electrode 12 and the guard ring 16 are arranged in a circular shape, they may be arranged in a polygonal shape other than a circular shape. However, it is preferable to arrange the first main electrode 12 and the guard ring 16 in a circular shape in order to prevent the electric field from concentrating on the corners.

  By the way, even when the radiation L1 enters the incomplete carrier collection region 102 where the depletion layer in the semiconductor substrate 11 does not spread, electrons and holes are generated in the incomplete carrier collection region 102. Then, when carriers generated in the incomplete carrier collection region 102 near the depletion layer boundary surface 103 move to the effective region 101, they are detected as current signals. An electrical signal generated by such a carrier is referred to as an “incomplete carrier collection signal”. Compared to the case where the carrier generated in the effective area 101 is detected instantaneously, the time required for the imperfect carrier collection signal to move to the effective area 101 passes after the carrier is generated until it is detected. Yes. For this reason, the radiation L1 incident on the incomplete carrier collection region 102 generates large noise in the spectral characteristics indicating the detection result. As a result, the accuracy of detection results deteriorates due to variations in electrical signals. Specifically, a background increase (B) and a ghost peak (P) appear in the spectrum characteristics as indicated by a characteristic S2 indicated by a broken line in FIG. A characteristic S1 indicated by a solid line in FIG. 3 is a spectral characteristic when the influence of the radiation L1 incident on the incomplete carrier collection region 102 is small.

  Consider the case of the radiation detector 1A of the comparative example shown in FIG. The radiation detection element 10 </ b> A used in the radiation detector 1 </ b> A is a PIN type radiation detection element similar to the radiation detection element 10. In the radiation detector 1A, a bonding pad 122A and a bonding wire 123A for extracting an electric signal generated by the radiation detection element 10A to the outside, and a bonding pad 162A and a bonding wire 163A connected to the guard ring 16 are connected to the radiation detection element 10A. Place on the main surface. For this reason, there is a gap between the collimator 20A and the radiation detection element 10A.

  Therefore, when the incident angle of the radiation L1 is large, the radiation L1 enters the incomplete carrier collection region 102 through the gap between the collimator 20A and the radiation detection element 10A. For this reason, an incomplete carrier collection signal is generated and a large noise is generated. Thus, in the measurement using the radiation detector 1A of the comparative example, the detection accuracy is lowered. The “incident angle” is an angle formed by the radiation L1 and the surface normal of the principal surface 111.

  In the measurement using the radiation detector 1A, if an object to be measured is brought closer to the radiation detector 1A in order to increase the signal intensity, the radiation L1 having a large incident angle is increased and the incomplete carrier collection signal is increased. . As a result, as the distance between the object to be measured and the radiation detector 1A is shorter, a larger noise is likely to occur, and problems such as a ghost peak P occurring on the low energy side as shown in FIG.

  FIG. 5 is an analysis result of X-rays emitted from the measurement object when the measurement object is an iron 55 radiation source (Fe55). Specifically, it is a graph showing the result of counting the number of charges detected using the radiation detector 1A for each energy magnitude. The vertical axis is the counted number, and the horizontal axis is the energy channel. That is, FIG. 5 shows the result of counting the number of charges detected by the generation of carriers in the radiation detection element 10A on which the radiation L1 is incident for each magnitude of energy.

  The characteristic A indicated by a solid line in FIG. 5 is an analysis result when the distance between the measurement object and the radiation detection element 10A is shorter than the characteristic B indicated by a broken line. Thus, there is a limit in reducing the distance between the measurement object and the radiation detection element 10A in order to increase the signal intensity.

  As described above, when the radiation L1 enters the incomplete carrier collection region 102, noise is generated and the detection accuracy is lowered. In particular, when there is a gap between the collimator and the radiation detection element, it is difficult to increase the signal intensity by reducing the distance between the measurement object and the radiation detector.

  On the other hand, in the radiation detector 1 shown in FIG. 1, the first main electrode 12, the signal wiring 121, the guard ring 16, and the guard ring wiring 161 arranged on the main surface 111 of the radiation detection element 10 include radiation. This is a wiring pattern using a wiring layer embedded in a part of the upper part of the detection element 10. For this reason, the area other than the irradiation area 110 of the main surface 111 is closely covered with the collimator 20. As a result, the incidence of the radiation L1 on the incomplete carrier collection region 102 is suppressed. As described above, according to the radiation detector 1, the irradiation of the radiation L1 to the region other than the irradiation region 110 of the radiation detection element 10 is suppressed, and the generation of an incomplete carrier collection signal can be prevented.

  Furthermore, according to the radiation detector 1, since the radiation L1 having a large incident angle is also prevented from entering the imperfect carrier collection region 102, the signal intensity can be increased by reducing the distance between the measurement object and the radiation detector 1. Can be raised. As a result, the detection efficiency can be improved and the detection time can be shortened.

  In order to reduce the incomplete carrier collection signal in the comparative example shown in FIG. 4, a method of reducing the area of the opening of the collimator 20A or a method of increasing the distance between the measurement object and the radiation detection element 10A are considered. It is done. However, these methods limit the incidence of the radiation L1 on the incomplete carrier collection region 102 by narrowing the radiation L1 incident on the radiation detection element 10 to those having a small incident angle. Therefore, the total energy of the radiation L1 incident on the radiation detection element 10A is reduced, and the detection efficiency is lowered. On the other hand, in the radiation detector 1, it is not necessary to reduce the area of the opening of the collimator 20 or increase the distance between the measurement object and the radiation detection element 10, so that the detection efficiency does not decrease.

(Second Embodiment)
FIG. 6 shows an example of a radiation detection apparatus 200 using the radiation detector 1 described above. The radiation detection apparatus 200 includes the radiation detector 1, a first stage FET circuit 210 electrically connected to the radiation detection element 10, and a cold finger 220 that supports the radiation detector 1 and the first stage FET circuit 210 so as to surround the radiation detector 1. FIG. 6 is a cross-sectional view along the traveling direction of the radiation incident on the radiation detector 1. For example, the bonding pad 122 shown in FIG. 2 and the first stage FET circuit 210 are electrically connected by a bonding wire or the like.

  The cold finger 220 supports the radiation detector 1 and the first stage FET circuit 210 and cools the radiation detector 1 and the first stage FET circuit 210. For this reason, for example, as shown in FIG. 6, the cold finger 220 is cooled by the cooling device 250. The cooling device 250 is, for example, a liquid nitrogen dewar, and the cooling medium 251 connected to the cooling device 250 is cooled by liquid nitrogen. The cooling medium 251 is thermally connected to the cold finger 220. For this reason, the cold finger 220 is cooled via the cooling medium 251 made of copper (Cu) or the like having good thermal conductivity. Then, the radiation detection element 10 and the first stage FET circuit 210 that are in contact with the cooled cold finger 220 are cooled.

  The radiation detector 1, the first stage FET circuit 210, and the cold finger 220 are disposed inside the container 230. At the time of radiation detection, the inside of the container 230 is maintained in a vacuum state. The radiation L <b> 1 emitted from the measurement object passes through the incident window 240 arranged in the container 230 and enters the radiation detection element 10. The material of the entrance window 240 is, for example, beryllium (Be) when the radiation L1 is X-ray.

  The electrical signal output from the radiation detection element 10 is received by the first stage FET circuit 210. For example, as shown in FIG. 7, the electric signal I generated in the radiation detection element 10 by the incidence of the radiation L1 is input to the gate electrode of the field effect transistor (FET) of the first stage FET circuit 210. Then, the first stage FET circuit 210 converts and amplifies the electrical signal I of the radiation detection element 10 into a voltage proportional to the energy of the radiation L1, and outputs it as a detection signal ST. By analyzing the detection signal ST output from the first stage FET circuit 210, it is possible to specify the element contained in the measurement object.

  By using the radiation detector 1, generation of an incomplete carrier collection signal in the radiation detection element 10 is prevented, and further, the signal intensity can be increased by reducing the distance between the measurement object 400 and the radiation detector 1. it can. Therefore, according to the radiation detection apparatus 200 according to the second embodiment of the present invention, a decrease in detection accuracy is suppressed and detection efficiency is improved.

(Third embodiment)
The radiation detection apparatus 200 shown in FIG. 7 can be applied to a radiation analysis apparatus 300 as shown in FIG. 8, for example. The radiation analyzer 300 irradiates the measurement object 400 with the excitation radiation L0 output from the radiation source 310, thereby detecting and analyzing the radiation L1 emitted from the measurement object 400.

  When the radiation L1 enters the radiation detection apparatus 200, as already described, the radiation L1 is detected by the radiation detector 1, and the detection signal ST indicating the magnitude proportional to the energy of the radiation L1 is output from the first stage FET circuit 210. The The radiation L1 has energy specific to the element contained in the measurement object 400. For this reason, the element contained in the measuring object 400 is specified by analyzing the detection signal ST by the signal analyzer 320.

  The radiation analyzer 300 using the radiation detector 1 is, for example, an energy dispersive fluorescent radiation analyzer (EDX) that uses an X-ray source as the radiation source 310 or an energy dispersive type that uses an electron beam source as the radiation source 310. A radiation analyzer (EDS).

  As described above, by using the radiation detector 1, generation of an incomplete carrier collection signal in the radiation detection element 10 is prevented, and further, the distance between the measurement object 400 and the radiation detector 1 is reduced. Signal strength can be increased. Therefore, according to the radiation analysis apparatus 300 according to the third embodiment of the present invention, a decrease in detection accuracy is suppressed, detection efficiency is improved, and detection time can be shortened.

(Other embodiments)
As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, a PIN-type semiconductor element formed by diffusing and drifting lithium (Li) in a Si single crystal in the radiation detection element 10 can also be employed.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

L1 ... Radiation 1 ... Radiation detector 10 ... Radiation detection element 11 ... Semiconductor substrate 12 ... First main electrode 13 ... Second main electrode 14 ... Insulating film 15 ... Passivation film 16 ... Guard ring 20 ... Collimator 101 ... Effective area DESCRIPTION OF SYMBOLS 102 ... Imperfect carrier collection area | region 103 ... Depletion layer interface 110 ... Irradiation area 111 ... Main surface 112 ... Back surface 200 ... Radiation detection apparatus 300 ... Radiation analysis apparatus 310 ... Radiation source 320 ... Signal analysis apparatus 400 ... Measurement object

Claims (7)

An irradiation area is set on the main surface, and a radiation detection element that converts the energy of radiation irradiated to the irradiation area into an electrical signal;
A collimator disposed in contact with the radiation detection element in a region adjacent to the irradiation region, and shielding the radiation in a region adjacent to the irradiation region;
A position where the collimator is irradiated on the main surface and enters the inside of the radiation detection element so that the radiation enters the effective area inside the radiation detection element and does not enter the area surrounding the side surface of the effective area. The radiation detector is arranged on the radiation detection element.   The radiation detection according to claim 1, further comprising a signal wiring layer that is embedded in a part of an upper portion of the radiation detection element between the radiation detection element and the collimator and propagates the electrical signal. vessel. A semiconductor substrate in which the radiation detection element is defined on both sides by the main surface and a back surface facing the main surface;
A first main electrode disposed on the main surface and a second main electrode disposed on the back surface, and applying a voltage between the first main electrode and the second main electrode The radiation detector according to claim 1, wherein a depletion layer region formed in the semiconductor substrate is the effective region.   The radiation detector according to claim 1, further comprising a guard ring electrode that is electrically connected to the semiconductor substrate and disposed on the main surface and grounded. An irradiation area is set on the main surface, a radiation detection element that converts the energy of radiation irradiated to the irradiation area into an electrical signal, and an area adjacent to the irradiation area is disposed in contact with the radiation detection element, A radiation detector having a collimator for shielding the radiation in an area adjacent to the irradiation area;
A first stage FET for amplifying the converted electrical signal,
A position where the collimator is irradiated on the main surface and enters the inside of the radiation detection element so that the radiation enters the effective area inside the radiation detection element and does not enter the area surrounding the side surface of the effective area. The radiation detection apparatus is arranged on the radiation detection element. An irradiation area is set on the main surface, a radiation detection element that converts the energy of radiation irradiated to the irradiation area into an electrical signal, and an area adjacent to the irradiation area is disposed in contact with the radiation detection element, A radiation detector having a collimator for shielding the radiation in an area adjacent to the irradiation area;
A signal analyzer for analyzing the energy of the radiation using the converted electrical signal;
A position where the collimator is irradiated on the main surface and enters the inside of the radiation detection element so that the radiation enters the effective area inside the radiation detection element and does not enter the area surrounding the side surface of the effective area. The radiation analyzer is arranged on the radiation detection element.   The radiation analysis apparatus according to claim 6, further comprising a radiation source that irradiates the measurement object with excitation radiation and emits the radiation from the measurement object.

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