JPH11281747A - Semiconductor radiation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor radiation detector the cell density of which can be improved by leaps and bounds, by reducing the dead space among cells. SOLUTION: A semiconductor radiation detector is constituted in such a way that bias electrodes 2 and 3 and signal electrodes 4 are arranged against a plurality of semiconductor cells for detecting radiation arranged in the X- direction, so that the electrodes 4 may be shared by their adjacent paired semiconductor cells 1, and relatively low and high bias voltages may be impressed respectively upon the bias electrodes 2 and 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation semiconductor detector mounted on a gamma camera or the like.

[0002]

2. Description of the Related Art For example, in a gamma camera, a radiation detector includes a radiation isotope (R) injected into a subject.
It is one of the most important components of the forefront for detecting gamma rays from I), and it is not an exaggeration to say that this performance affects the performance of the entire camera, such as the spatial resolution and energy resolution, as well as the counting characteristics. .

At present, the mainstream is a scintillation-type detector. As is well known, light generated by a scintillator (phosphor) due to the incidence of gamma rays is densely arranged on the back of the detector. Photomultiplier tube (PM
T) or a structure for detection by a photodiode array, which was not only very large and heavy, but also low in energy resolution.

On the other hand, a semiconductor detector which has recently been spotlighted is a semiconductor detector, which directly detects gamma rays, and thus has a conventional scintillation which undergoes a two-stage conversion process of gamma rays-light-electricity. Since the conversion efficiency into an electric signal is higher than that of the type detector and the gamma rays can be individually detected by the semiconductor cells, it is expected that the energy resolution and the counting ability are remarkably improved.

As well known in the art, the structure and detection mechanism of this semiconductor detector are as follows. For example, electrodes are formed on a compound semiconductor such as CdTe (cadmium telluride), and a bias electrode plate and a signal electrode plate are formed on both surface electrodes. When a gamma ray is applied to such a structure with a bias voltage applied, a large number of pairs of electrons and holes are generated, each of which is induced when moving to the positive and negative electrodes. The induced charge is accumulated in a charge amplifier provided on the positive electrode side, and is output as a signal proportional to energy.

The device has a structure in which a bias electrode and a signal electrode are formed on the front surface and the back surface, respectively, and the elements are separated vertically and horizontally to form a two-dimensional array, and gamma rays incident through the bias electrode are detected. In many cases, semiconductor cells are vertically arranged substantially parallel to the direction of gamma ray incidence so that the distance in the direction of absorbing gamma rays can be made sufficiently long and the cell density (spatial resolution) can be increased. A structure arranged in an array is considered.

[0007] However, in such a vertical type, 1
Compared to the conventional horizontal type, in which a single plate forms an array structure by element separation, the arrangement accuracy is reduced due to the physical disposition of cells, that is, the dead space between modules and between cells in a module is reduced. The problem was that the size was not uniform and produced unique artifacts. Furthermore, it is necessary to sandwich an electrode layer, an insulating layer, and the like between adjacent cells, and furthermore, to provide a margin for adjusting the above-described nonuniformity, it is necessary to increase a dead space between cells to some extent. Therefore, there was a limit to the improvement in cell density.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a radiation semiconductor detector capable of reducing dead space between cells and dramatically improving cell density.

[0009]

According to a first aspect of the present invention, a radiation semiconductor detector according to the present invention comprises a bias electrode and a bias electrode for each of a plurality of radiation detecting semiconductor cells arranged along a predetermined direction. A signal electrode and a signal electrode are arranged such that the signal electrode is shared by adjacent pairs of semiconductor cells, and a first bias voltage and a second bias voltage are alternately applied to the bias electrode along the arrangement direction. It is characterized by having been constituted.

In the radiation semiconductor detector according to the present invention, a bias electrode and a signal electrode are provided for each of a plurality of radiation detecting semiconductor cells arranged along a predetermined direction. The signal electrodes are individually provided for the semiconductor cells, and the bias electrodes are arranged so as to be shared by adjacent pairs of semiconductor cells. (Operation) According to the present invention as set forth in claims 1 and 2, since the semiconductor cells are arranged vertically in a direction substantially parallel to the incident direction of radiation, the distance in the direction in which radiation is absorbed is made sufficiently long to achieve energy resolution. And the counting ability can be improved, and the cell density (spatial resolution) can be increased.

Further, in the first aspect, the signal electrode is shared by the adjacent pair of semiconductor cells, and in the second aspect, the bias electrode is shared by the adjacent pair of semiconductor cells. By forming electrodes and signal electrodes, it is possible to reduce the spacing between cells, that is, dead space, compared to a simple vertical type where a bias electrode and a signal electrode are required between all cells. Can,
As a result, the cell density (spatial resolution) can be increased (shorter), and sensitivity degradation due to the presence of a dead zone can be prevented.

Further, in the first aspect, the signal electrode is shared by the adjacent pair of semiconductor cells, and in the second aspect, the bias electrode is shared by the adjacent pair of semiconductor cells. By forming electrodes and signal electrodes, the distance between cells, that is, the dead space, is reduced as compared with the conventional vertical type in which both the bias electrode and the signal electrode are required between all cells. As a result, the cell density (spatial resolution) can be significantly increased, and the sensitivity can be prevented from deteriorating due to the presence of the dead zone.

In the second aspect, the signal electrode is provided individually for each semiconductor cell, so that signal interference does not occur between adjacent semiconductor cells. However, in the first aspect, the signal electrode is used together with the bias electrode. Therefore, it is necessary to determine which of the adjacent semiconductor cells has received the radiation. This determination can be realized as follows.
The first bias voltage and the second bias voltage are alternately applied to the bias electrodes along the arrangement direction. That is, the first bias voltage is applied to one of the adjacent semiconductor cells sharing the signal electrode, and the second bias voltage is applied to the other, so that a difference occurs in the charge-up time. The higher the bias voltage, the faster this charge-up time. Therefore, it is possible to determine which of the adjacent semiconductor cells has received the radiation from the charge-up time.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a radiation semiconductor detector according to the present invention will be described in detail with reference to the drawings. Here, the distribution of the radioisotope (RI) in the body administered to the subject is shown as a planar image, a SPECT image,
The following description will be given as a radiation semiconductor detector provided in a nuclear medicine diagnostic apparatus (gamma camera) for imaging as a PET image, but the application of the radiation semiconductor detector is not limited to this gamma camera, and X-ray computed tomography The present invention may be applied to a device (commonly called a CT scanner) or other fields such as nondestructive inspection.

FIG. 1 is a plan view of the radiation semiconductor detector according to the present embodiment, FIG. 2 is an enlarged schematic view of a part of FIG. 1, FIG. 3A is a front view of FIG. FIG.
FIG. A two-dimensional array of semiconductor cells 1 of a compound semiconductor such as CdTe (cadmium telluride), which can directly detect gamma rays emitted from RI in the subject as an electric signal, includes a motherboard 11.
Are formed by mounting a plurality of modules 15 that constitute a one-dimensional array of the semiconductor cells 1.

Each of the semiconductor cells 1 has a bias electrode 2
(Or 3) and the signal electrodes 4 correspond one by one,
The bias electrodes 2 and 3 and the signal electrode 4 are inserted one by one between the cells so as to be shared between adjacent pairs of semiconductor cells 1 in the X direction in the module 15. Glued.

That is, the plurality of semiconductor cells 1 are changed alternately so that the surfaces on the signal take-out side face each other and the surfaces on which a negative voltage is applied for applying a reverse bias face each other. The signal electrodes 4 are inserted between the signal extraction sides, and the bias electrodes 2 and 3 are alternately arranged along the X direction between the negative voltage application sides.
Is to be inserted.

As shown in FIG. 4A, the cell 1 and the electrodes 2, 3, and 4 are mounted on a positioning substrate 71 whose surface is formed to be uneven for mounting. Even if this substrate 71 is used, it is practically unavoidable that the arrangement interval between the cell 1 and the electrodes 2, 3 and 4 varies, but this variation is reduced by the bias electrodes 2 and 3 and the signal electrodes 4 and 3. Can be absorbed by adjusting the thickness of the conductive adhesive 27 that adheres to the cell 1.

The reason why the bias electrodes are distinguished by reference numerals 2 and 3 in spite of their similarity in structure is that the bias voltage applied to each is different. That is, the bias voltage H is applied to one bias electrode 2.
V1 is applied, and a bias voltage HV2 is applied to the other bias electrode 3. Bias voltage HV
1, HV2 are both negative voltages, | HV1 |> | HV2
|. The bias electrodes 2 and 3 are provided alternately in the X direction, and apply different bias voltages to the adjacent semiconductor cells 1 in the X direction that share the signal electrode 4, that is, adjacent semiconductors that share the signal electrode 4. Cell 1
The bias voltage HV1 is applied to one of the cells, and the bias voltage HV2 is applied to the other cell 1. In addition, the channel of the cell 1 having the higher bias voltage of the adjacent pair of cells 1 sharing the signal electrode 4 is denoted by A.
The channel of the cell 1 having the lower bias voltage is referred to as a B channel.

Such a cell array is composed of insulating resin 25
Is mounted on the multilayer substrate 21. The multilayer substrate 21
An HV1 layer, an HV2 layer, and a signal layer are stacked,
The bias electrode 2 is on the HV1 layer, and the bias electrode 3 is on the HV2 layer.
The signal electrode 4 is electrically connected to the signal layer.

As shown in FIGS. 5A and 5B, in order to improve the spatial resolution, the semiconductor cell 1 has an insulating separation layer 29 in the Y direction such that each of the cells forms two channels. Are electrically separated into two pieces, and each piece is provided with two signal electrodes 4 individually connected to each other while maintaining an insulating state with each other by an insulating connecting material 23. (See FIGS. 2 and 3 (b)). Note that FIG.
In (b), 31 is an insulating resin for maintaining insulation between cells adjacent in the Y direction. The insulating separation layer 29 is formed by performing an ion implantation process on a semiconductor crystal.

As another embodiment of the semiconductor cell 1, as shown in FIG. 5C, for example, instead of the insulating separation layer 29, a semiconductor crystal is cut to form a groove 30, and the whole is in a U-shape. The cutout groove 30 may be used to maintain the insulation of the signal electrode 4. Of course, the signal electrode 4 is provided on the side where the cut groove 30 is formed, and the bias electrode 2 or 3 is provided on the side where the cut groove 30 is not formed. The cut groove 30 may be filled with an insulating resin, or may be opened in a hollow state. Grooves 30 are formed in a square semiconductor crystal by etching to form a U-shaped semiconductor crystal. By using the semiconductor cells 1 provided with the cut grooves 30 in this manner, the number of semiconductor cells to be mounted on a semiconductor module having a required number of channels can be reduced as compared with a case where a cell array is formed by individually separated semiconductor cells 1. Therefore, the number of assembly steps of the module can be reduced, and the module can be easily and accurately formed. In FIG. 5C, one groove 30 is provided to divide the signal electrode into two. However, the number of grooves may be increased to a plurality and the number of signal electrodes 4 may be further increased.

As described above, since the signal electrode 4 is shared between the adjacent cells together with the bias electrodes 2 and 3, even if a gamma ray is incident on any of the adjacent semiconductor cells 1 (in any of the AB channels). A signal current is extracted from the same signal electrode 4. Therefore, a device is required to determine which of the adjacent semiconductor cells 1 has received the gamma ray.

First, as described above, the bias voltage HV1 is applied to one of the adjacent pairs of semiconductor cells 1,
A bias voltage HV2 is applied to the other cell 1. When the bias voltage is different as shown in FIG.
As shown in (b), the time required to charge up the charge amplifier differs. Specifically, the maximum time it takes to charge-up is represented by _{^{d 2 / (μ h · V}} ). Incidentally, V is the potential difference between the electrodes, d is the semiconductor cell 1 in the thickness between the electrodes, mu _h represents the mobility of holes, respectively. As a configuration for determining which of the adjacent semiconductor cells 1 receives the gamma ray based on the difference in the charge-up time, for example, as shown in FIG. 7, the output of the charge amplifier 43 is divided into two systems. Then, one of them is shaped as usual by a low-speed waveform shaping circuit 45 and then taken out as an energy signal from a peak hold circuit (P / H) 46, and the other is shaped as a high-speed waveform shaping circuit 47.
After that, the output is compared with two types of comparison voltages Vref (H) and Vref (L) by comparators 49 and 51, and the comparison voltage Vre
The output of the comparator 49 of f (H) is directly sent to the AND circuit 55,
The output of the other comparator 51 is supplied to the AND circuit 55 via the delay circuit 53 having a delay time Δt.

FIG. 8A shows a waveform shaping circuit 47 when a gamma ray enters the A channel having a higher bias voltage.
8 shows the output waveforms of the comparators 49 and 51, and FIG.
(B) shows the output waveform of the waveform shaping circuit 47 and the outputs of the comparators 49 and 51 when a gamma ray enters the B channel having the lower bias voltage. When gamma rays enter the A channel having a higher bias voltage, the charge-up time is relatively short, and the time difference between the outputs of the comparators 49 and 51 rising to the “H (1)” level is relatively short. Due to the delay of Δt, the two input terminals of the AND circuit 55 are both supplied with the “H” level at the time t1, and as a result, the output of the AND circuit 55 becomes the “H” level. On the other hand, B
When gamma rays enter the channel, the charge-up time is relatively long, and the time difference between the outputs of the comparators 49 and 51 rising to the "H (1)" level is relatively long.
Despite the delay time Δt, the “H” level is supplied to one of the two input terminals of the AND circuit 55 at the time t1, but the “L (0)” level is supplied to the other input terminal. Supplied with. Therefore, in this case, the output of the AND circuit 55 becomes "L" level.

As described above, which of the two adjacent cells 1 sharing the signal electrode 4 receives the gamma ray can be determined by the output level of the AND circuit 55, and the AB channel is distinguished by this output. An address indicating the incident position can be output from the encoder 57.

As described above, by sharing the bias electrode and the signal electrode between the adjacent cells, one bias or signal electrode may be interposed between the adjacent cells, and one cell may be interposed between the adjacent cells. The undetectable space between adjacent cells, that is, the dead space can be dramatically shortened, and the X-direction can be reduced. Spatial resolution (cell density) can be dramatically improved. In addition, this spatial resolution is obtained by dividing one cell into two channels.
That is, the cell density can be substantially doubled.

When the bias voltage differs depending on the channel, the detection sensitivity characteristic may slightly change with time due to the difference in the bias voltage for each channel. In order to prevent such characteristic fluctuation, the bias electrode 2
Instead of constantly applying a relatively high voltage or a relatively low voltage to each of the bias electrodes 3, a relatively high voltage and a relatively low voltage are periodically applied to the bias electrode 2 on the order of several seconds or tens of seconds. And the bias electrode 3 may be periodically switched between a relatively low voltage and a relatively high voltage, as opposed to the bias electrode 2.

In the above description, the signal electrode and the bias electrode are shared by two adjacent cells. FIG. 9A is a front view, and FIG. 9B is a side view. As described above, only the bias electrode 61 is shared,
Even if the signal electrodes 63 and 65 are provided individually, and the signal currents of the signal electrodes 63 and 65 are separately taken out of the substrate 69 in different layers, the spatial resolution is higher than in the conventional case where both electrodes are provided separately. Is to improve. In this case, the configuration for determination as shown in FIG. 7 is not necessary. However, the signal electrodes 63 and 65 are connected by an insulating connecting member 67 with the insulating layer 66 interposed therebetween, and the signal electrodes 63 and 65 are connected.
It is necessary to maintain an insulation state between five.

In this case, the signal electrodes 63, 65
As shown in FIG. 9 (a), the portions of the leads are bent away from each other, and separately extended from both sides as shown in FIG. 9 (c), so that the distance between the electrodes is reduced. It is possible to earn money. In this case, a total of four signal electrodes 63 and 65 and two bias electrodes 61 are used.
Before mounting the semiconductor, it is advisable to secure and fix the mechanical accuracy with the insulating connecting member 67 before mounting the semiconductor device so that the assembly efficiency of the electrodes can be improved. Of course, in this method, since the signal electrodes are separately provided, the same bias voltage may be applied to adjacent cells 1.

With the configuration in which the signal electrodes are adjacent to each other, the signal of the signal electrode is less likely to be affected by noise due to the bias voltage of the bias electrode as compared with the configuration in which the signal electrode and the bias electrode are adjacent. , And a good signal having a high S / N ratio can be obtained. In addition, since it is hard to be affected by noise, the distance between the electrodes can be reduced.

Next, a more specific mounting structure of the above-described two-dimensional array will be described. As shown in FIG. 10, one module 15 has a matrix size of, for example, 160 × 16. By arranging the modules 15 in the XY directions, a two-dimensional array having a larger matrix size is formed as described above.

FIG. 11A is a view of one module 15 as viewed from above where a gamma ray enters.
(B) shows a front view thereof. In addition, the multilayer substrate 2
12 is shown from the front in FIG. 12 and from the side in FIG. Cells 1 arranged neatly on substrate 71
Thereafter, the low-temperature solder 73 is used for surface mounting on the multilayer substrate 21. A charge amplifier array 75 is mounted on the rear surface of the multilayer substrate 21. Then, the multilayer substrate 21
Are supported by a heat pipe 77 which also serves as a support column.

Further, the lower structure of the multilayer substrate 21 is shown in a front view in FIG. 14 and a side view in FIG.
The output terminal of the multilayer board 21 is taken out to the motherboard 11 via the connector 81. The seat pipe 77
A cooling mechanism such as a cooling fin is provided through the motherboard 11, and is fixed to a cooling plate 81 made of, for example, copper having a large heat capacity with a nut 89.

In the above description, the bias electrodes 2 and
Although the HV1 layer and the HV2 layer for applying the bias voltage to 3 are formed in the multilayer substrate 21, at least one of the HV1 layer and the HV2 layer is formed as shown in FIGS.
An insulating layer 8 is provided on the front side of the cell array where gamma rays are incident.
5 may be transferred to the HV layer 87 formed.

Further, as shown in FIGS. 16A and 16B, the bias electrodes 2 and 3 may be connected in the module by common electrodes 91 and 93 in the Y direction. Further, two channels are configured by one cell by providing two signal electrodes 4 in one cell 1. However, as shown in FIG. 16B, one signal electrode 4 is provided in one cell 1. It is also possible that one cell constitutes one channel. It is needless to say that the present invention is not limited to the above-described embodiment, but can be implemented with various modifications.

[0037]

According to the present invention, it is possible to provide a radiation semiconductor detector capable of reducing dead space between cells and dramatically improving cell density.

[Brief description of the drawings]

FIG. 1 is a diagram of a radiation semiconductor detector according to a preferred embodiment of the present invention, as viewed from above where gamma rays are incident.

FIG. 2 is a diagram showing a part of the semiconductor cell array of FIG. 1 in detail.

3A is a front view of FIG. 2, and FIG. 3B is a side view of FIG.

FIG. 4A is a schematic diagram showing an arrangement of cells and electrodes in a module, and FIG. 4B is a diagram showing a manner in which a conductive adhesive for bonding cells and electrodes absorbs variations in an array.

5A is a perspective view showing an electrode of one semiconductor cell in FIG. 2, FIG. 5B is a plan view of one electrode, and FIG. 5C shows a groove for insulation between channels of the semiconductor cell; FIG.

6A is a diagram illustrating a dependency of a charge-up time on a bias electrode, and FIG. 6B is a diagram illustrating a difference in output waveform between adjacent cells due to the dependency of FIG.

FIG. 7 is a configuration diagram for discriminating an incident cell using the difference in FIG. 6B.

8A shows output waveforms of the two comparators in FIG. 7 when gamma rays enter a cell on a relatively high bias voltage side, and FIG. 8B shows gamma rays on a cell on a relatively low bias voltage side. FIG. 8 is a diagram showing output waveforms of the two comparators shown in FIG.

9A is a front view of a cell array of a semiconductor detector as a modification, FIG. 9B is a side view corresponding to FIG.
(C) is a perspective view of the signal electrodes of (a) and (b).

FIG. 10 is a plan view showing a two-dimensional array of the mounted cell array module.

11A is a plan view of one module of FIG. 10, and FIG. 11B is a front view.

FIG. 12 is a front view showing a mounting structure of the module of FIG. 10;

FIG. 13 is a side view of one module of FIG. 10;

FIG. 14 is a front view showing the lower structure of the cell array according to the embodiment.

FIG. 15 is a side view showing the lower structure of the cell array of the embodiment.

16A is a side view of a modification in which a bias electrode is used as a common electrode in a cell array in a module, FIG. 16B is a side view showing a modification in which a bias electrode is used as a common electrode in a cell array in a module,
Moreover, a side view of a modification in which one cell is not divided into two channels.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Semiconductor cell, 2 ... Bias electrode, 3 ... Bias electrode, 4 ... Signal electrode, 5 ... Insulating layer, 11 ... Motherboard, 13 ... Effective field of view, 15 ... Semiconductor module, 17 ... Connection terminal.

Claims (20)

[Claims] 1. A bias electrode and a signal electrode are arranged for each of a plurality of semiconductor cells for radiation detection arranged along a predetermined direction such that the signal electrode is shared by adjacent pairs of semiconductor cells. A radiation semiconductor detector characterized in that a first bias voltage and a second bias voltage are alternately applied to the bias electrodes along the arrangement direction. 2. A method according to claim 1, wherein a bias electrode and a signal electrode are provided for each of a plurality of semiconductor cells for radiation detection arranged along a predetermined direction. A radiation semiconductor detector, wherein a bias electrode is arranged so as to be shared by an adjacent pair of semiconductor cells. 3. A method according to claim 1, wherein a time required for charging up a charge amplifier by a difference in a bias voltage applied to an adjacent pair of semiconductor cells sharing the signal electrode is determined.
2. The radiation semiconductor detector according to claim 1, wherein the radiation semiconductor detector is configured to determine which of the adjacent pairs of the semiconductor cells has received the radiation. 4. The radiation semiconductor detector according to claim 1, wherein said signal electrode is constituted by a plurality of electrodes such that one semiconductor cell constitutes a plurality of channels. 5. The radiation semiconductor detector according to claim 4, wherein an insulating layer is formed between said electrodes of said one semiconductor cell by ion implantation. 6. The radiation semiconductor detector according to claim 4, wherein the semiconductor cell has an insulating groove between the signal electrodes. 7. The bias electrode and the signal electrode are bonded to the semiconductor cell with a conductive adhesive in order to absorb variations in arrangement of the semiconductor cell, the bias electrode, and the signal electrode. The radiation semiconductor detector according to claim 1 or 2, wherein 8. The radiation semiconductor detector according to claim 2, wherein adjacent signal electrodes provided individually to said semiconductor cells are bonded with an insulating adhesive. 9. The radiation semiconductor detector according to claim 1, wherein a two-dimensional array is configured by an arrangement structure of said semiconductor cell, said bias electrode and said signal electrode. 10. The radiation semiconductor detector according to claim 9, wherein said two-dimensional array is constituted by using a plurality of module structures in which said semiconductor cells are arranged in a line. 11. The radiation semiconductor detector according to claim 9, wherein said bias electrode is shared across a plurality of semiconductor cells in a direction orthogonal to said predetermined direction. 12. The preamplifier array substrate according to claim 1, wherein a preamplifier array substrate is arranged under the arrangement structure of said semiconductor cell, said bias electrode and said signal electrode at least so as not to protrude from said arrangement structure. Radiation semiconductor detector. 13. The radiation semiconductor detector according to claim 1, wherein cooling means is provided to the array structure of the semiconductor cells via a heat pipe also serving as a support column. 14. A semiconductor device according to claim 1, wherein said first bias voltage supply layer and said second bias voltage supply layer are divided into a front side and a rear side on which radiation of said semiconductor cell is incident. The radiation semiconductor detector according to claim 1 or 2, wherein: 15. An X-ray computed tomography apparatus comprising the radiation semiconductor detector according to claim 1 or 2. 16. A signal electrode, first and second semiconductor members electrically connected to the signal electrode and configured to sandwich the signal electrode, and electrically connected to the first and second semiconductor members. First and second bias electrodes connected to each other and configured to sandwich the first and second semiconductor members; and a bias for applying different bias voltages to the first and second bias electrodes. A radiation semiconductor detector, comprising: a voltage supply unit. 17. A first and a second signal electrode disposed so as to sandwich an insulating layer, and electrically connected to the first and the second signal electrode, wherein the first and the second signal electrode are electrically connected to each other. First and second semiconductor members configured to sandwich the first and second semiconductor members, electrically connected to the first and second semiconductor members, and configured to sandwich the first and second semiconductor members. And a bias voltage supply means for applying a bias voltage to the first bias electrode and the second bias electrode. 18. A PET and SP equipped with the radiation semiconductor detector according to claim 1, 2, 16, or 17.
A nuclear medicine diagnostic apparatus having at least one function with ECT. 19. A nuclear medicine diagnostic apparatus equipped with the radiation semiconductor detector according to claim 1 or 16 and having at least one of PET and SPECT functions, wherein said diagnostic signal is output from said signal electrode. Nuclear medicine diagnosis, comprising: means for determining which of the semiconductor member on the lower bias voltage side and the semiconductor member on the higher bias voltage side has received radiation based on the rise time of the signal. apparatus. 20. A nuclear medicine diagnostic apparatus equipped with the radiation semiconductor detector according to claim 1 or 16 and having at least one of PET and SPECT, wherein said first bias electrode and A nuclear medicine diagnostic apparatus, comprising: voltage switching means for periodically switching a bias voltage applied to each of the second bias electrodes between a relatively high voltage and a relatively high voltage.