JP2004265933A - Radiation detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein a radiation detector changes its characteristics due to a leakage in a TFT element when a sensor discrete electrode arranged on a TFT changes its potential. <P>SOLUTION: The TFT element has a top gate structure in which a gate electrode layer 17 is arranged on a channel region, a TFT channel is protected by the gate electrode, and the TFT element is never turned ON by a back gate effect even if a potential varies corresponding to the output of the sensor discrete electrode so that the TFT element can be set stable in characteristics. The TFT elements are connected in series, whereby the radiation detector is improved in OFF-state characteristics and capable of having redundancies to failures, such as a short circuit occurring between an upper and a lower member through the intermediary of an gate insulating layer or a short circuit in a semiconductor layer. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a radiation detection device that detects radiation such as X-rays and γ-rays. In particular, the present invention relates to a radiation detection device applicable to a medical image diagnostic device, a nondestructive inspection device, an analysis device using radiation, and the like.
[0002]
[Prior art]
In recent years, with the advancement of liquid crystal TFT technology and the improvement of information infrastructure, it is composed of a photoelectric conversion element and a switch TFT using non-single-crystal silicon, for example, amorphous silicon (hereinafter abbreviated as a-Si). Panel detector (hereinafter abbreviated as FPD) combining a sensor array that has been used and a phosphor that converts radiation into light such as visible light has been proposed, achieving a large area and digitization in the field of medical imaging. Have been.
[0003]
This FPD is capable of instantly reading a radiation image and displaying it on a display instantly. Further, since the image can be directly retrieved as digital information, data is stored or processed or transferred. There is a feature that is said to be convenient. Although various characteristics such as sensitivity depend on the photographing conditions, they are compared with conventional screen film (hereinafter abbreviated as S / F) photographing methods and computed radiography (hereinafter abbreviated as CR) photographing methods. Has been confirmed to be equal or better.
[0004]
FIG. 10 shows an equivalent circuit diagram of one bit of the FPD. FIG. 11 shows a schematic equivalent circuit diagram of 3 × 3 bits. In the figure, 101 and S11 to S33 are photoelectric conversion element portions, 102 and T11 to T33 are transfer TFT portions, 104 and Vg1 to Vg2 are transfer TFT drive wirings, 106 and Sig1 to Sig3 are signal lines, 107 and Vs1 to Sg3. Vs3 is a photoelectric conversion element bias wiring, A is a signal processing circuit, B is a bias power supply, D is a TFT drive circuit, and C is an A / D converter.
[0005]
Radiation such as X-rays enters from the upper part of the paper of FIG. 11 and is converted into light such as visible light by a phosphor (not shown). The converted light is converted into electric charges by the photoelectric conversion units S11 to S33 and stored in the photoelectric conversion element units S11 to S33. Thereafter, the transfer TFT sections T11 to T33 are operated from the TFT drive wiring by the TFT drive circuit D, and the accumulated charges are transferred to the signal lines Sig1 to Sig3, processed by the signal processing circuit A, and further A / D converted. The signal is A / D-converted and output by the unit C.
Basically, the element configuration as described above is generally used. In particular, the photoelectric conversion element is a PIN-type photodetector (hereinafter abbreviated as a PIN-type PD) or a MIS employed by the present inventors. Photodetectors (hereinafter abbreviated as MIS PDs) are common, and various other devices have been proposed.
[0006]
As described above, while commercialization of the FPD has been achieved, various proposals have been made with the aim of further improving the sensitivity. See, for example, SPIE Medical Imaging VI, February 23-27, 1992; A report by E Antonuk et al. Discloses a structure in which a sensor element is stacked on a TFT element. In this proposal, by adopting the above structure, the aperture ratio of the sensor element is improved, and the sensitivity can be improved. At this time, since the TFT element is disposed immediately below the sensor element, unnecessary parasitic capacitance is formed, and therefore, a grounded plane is disposed. However, the specific content is unknown. And the effect is unknown.
[0007]
In addition, the proposal in Patent Document 1 similarly shows a structure in which a sensor element is stacked on a TFT element in order to improve the aperture ratio. In this proposal, an electrode connected to the source-drain electrode of the TFT element covers the TFT element and serves as a sensor individual electrode.
[0008]
On the other hand, the proposal in Patent Document 2 also discloses a structure in which a sensor element is stacked on a TFT element to improve the aperture ratio. This proposal has a structure in which a sensor is stacked on a TFT element via an interlayer film.
[0009]
[Patent Document 1]
US Patent No. 5,498,880 [Patent Document 2]
JP 2000-156522 A
[Problems to be solved by the invention]
However, in the above-described conventional example, the structure is such that the channel portion of the TFT is subjected to potential fluctuations in various forms, and it is unclear specifically in the description that the shield is disposed.
[0011]
That is, in the conventional FPD having a laminated structure, the individual electrode of the sensor element acts as the back gate electrode of the TFT element, and the potential fluctuation of the individual electrode causes a problem such as leakage of the TFT element. Causes quality degradation.
[0012]
For example, when an area having a large sensor output and an area having a small sensor output are adjacent to each other, crosstalk appears such that the boundary is blurred. In addition, there is a problem that the sensor saturation output decreases and the dynamic range decreases.
[0013]
Accordingly, it is an object of the present invention to suppress the characteristic fluctuation due to the leak of the TFT element even when the individual electrode of the sensor element arranged on the TFT element fluctuates in potential, and to achieve an improvement in sensitivity. .
[0014]
[Means for Solving the Problems]
The radiation detection device of the present invention is a radiation detection device in which a plurality of pixels each including a sensor element that converts radiation into an electric signal and a plurality of thin film transistors connected to the sensor element are arranged.
The plurality of thin film transistors are connected in series and use the same gate wiring, the electrodes of the sensor element connected to the plurality of thin film transistors are arranged on the plurality of thin film transistors, and the plurality of thin film transistors are formed on a substrate. And a top gate structure in which a semiconductor layer, a gate insulating layer, and a gate electrode layer are sequentially stacked.
[0015]
The present invention adopts a structure in which a TFT element is protected by a gate electrode without disposing a complicated shield structure on the TFT by using a top gate structure for the TFT element. An object of the present invention is to obtain stable TFT characteristics without turning on a TFT element due to a back gate effect due to a potential change. That is, the image quality can be greatly improved.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0017]
(Embodiment 1)
As a first embodiment of the present invention, a photoelectric conversion device in which a transfer TFT element and a reset TFT element are arranged in each pixel, and a radiation detection device will be described. The present embodiment is an indirect radiation detection device in which a wavelength converter for converting radiation into light such as visible light is disposed on a photoelectric conversion device, and the converted light is read by the photoelectric conversion device. The photoelectric conversion element of the photoelectric conversion device can be used together with a MIS PD or a PIN PD.
[0018]
FIG. 1 shows an equivalent circuit diagram of one bit (one pixel) of the photoelectric conversion device. In the figure, 1 is a photoelectric conversion element section, 2 is a transfer TFT section, 3 is a reset TFT section, 4 is a transfer TFT drive wiring, 5 is a reset TFT drive wiring, 6 is a signal line, 7 is a bias wiring, and 8 is a reset wiring. It is.
[0019]
The outline of the driving method will be described with reference to FIG. Radiation such as X-rays is wavelength-converted by a wavelength converter such as a phosphor, and is incident on the photoelectric conversion element unit 1. The incident light is photoelectrically converted and stored in the photoelectric conversion element unit 1.
[0020]
Thereafter, an ON voltage is applied to the gate electrode of the transfer TFT section 2 from the transfer TFT drive wiring 4 to turn on the transfer TFT section 2, an electric signal is transferred from the photoelectric conversion element to the signal line 6, and the read IC is attached separately. Is read. After the reading, an OFF voltage is applied to the gate electrode of the transfer TFT unit 2 from the transfer TFT drive wiring 4, the transfer TFT unit 2 is turned off, and a series of read operations is completed.
[0021]
Next, an ON voltage is applied to the gate electrode of the reset TFT section 3 from the reset TFT drive wiring 5 and a reset voltage is applied to the reset wiring 8 to reset the photoelectric conversion element section 1. Thereafter, an OFF voltage is applied to the gate electrode of the reset TFT section 3 from the reset TFT drive wiring 5, and the process ends.
[0022]
In the above, the description has been made using a one-bit equivalent circuit for the sake of simplicity. However, in practice, each pixel (one bit) is two-dimensionally arranged, and the transfer TFT and reset TFT part of each pixel are commonly used. It is connected to the drive wiring, and also commonly connected to signal lines and the like.
[0023]
FIG. 2 shows a schematic plan view of one pixel. 2, the same components as those in FIG. 1 are denoted by the same reference numerals. FIG. 3 is a sectional view showing an AA 'section of FIG. FIG. 3 shows a reduced width between the transfer TFT unit 2 and the reset TFT unit 3.
[0024]
First, the transfer TFT unit 2 will be described. In FIG. 3, 11 is a substrate, 12 is a polycrystalline semiconductor layer, 13 is a source-drain region, 14 is an offset region composed of a low-concentration region of the same conductivity type as the source-drain region 13, 15 is a gate insulating layer, 16 Is a transfer TFT gate drive wiring, 17 is a gate electrode, 18 is an interlayer insulating layer, and 19 is a source-drain electrode. The transfer TFT unit 2 includes two TFTs connected in series, and two gate electrodes 17 of the two TFTs are commonly connected to the transfer TFT drive wiring 4. Each TFT has an LDD structure.
[0025]
The reset TFT section 3 is formed in the same structure as the transfer TFT section 2, and 21 is a reset TFT gate drive wiring and 22 is a reset wiring. The reset TFT unit 3 also includes two TFTs connected in series, and two gate electrodes of the two TFTs are commonly connected to a reset TFT drive wiring 5. Each TFT has an LDD structure.
[0026]
In FIG. 3, reference numeral 23 denotes an interlayer insulating layer, reference numeral 24 denotes a sensor individual electrode, reference numeral 25 denotes a MIS type PD (laminated structure of an insulating layer, a semiconductor layer, and an ohmic contact layer), reference numeral 26 denotes a transparent electrode, and reference numeral 27 denotes a sensor bias wiring. The electric signal from the MIS type PD 25 is transferred to the drain electrode 19 connected to the sensor individual electrode 24, and is read out from the signal line 6 connected to the source electrode 19 via the transfer TFT unit 2.
[0027]
Note that a phosphor (not shown) is disposed on a photoelectric conversion element unit (here, a MIS type PD) to constitute a radiation detection device. By adopting the above-described configuration, a channel portion of each TFT is shielded by the gate electrode against a potential change of the sensor individual electrode 24 connected to the MIS type PD.
[0028]
Note that one of the transfer TFT unit and the reset TFT unit may be configured to include two TFTs connected in series.
[0029]
As a result, the image quality is remarkably improved, for example, the TFT leak according to the light output of the sensor individual electrode 24 can be reduced. In addition, regardless of the pixel size, the aperture ratio achieves approximately 100%, and the area occupied by the TFT increases with miniaturization. However, regardless of this, the aperture ratio can be secured, and a large structural advantage is obtained. It becomes.
[0030]
Furthermore, by connecting a plurality of TFTs in series, the TFT characteristics, especially the OFF characteristics, are improved, and there is also redundancy against defects such as short-circuiting between the upper and lower sides via the gate insulating layer and short-circuiting in the semiconductor layer. It is also possible to have the nature.
[0031]
(Embodiment 2)
As a second embodiment of the present invention, a radiation detecting apparatus in which a transfer TFT element and a reset TFT element are arranged in each pixel will be described. The present embodiment is a direct radiation detection device that converts radiation directly into an electric signal using a-Se or the like.
[0032]
FIG. 4 shows a 1-bit equivalent circuit diagram. The same components as those in FIG. 1 are denoted by the same reference numerals. Here, 1 indicates a radiation conversion element unit. In the figure, reference numeral 1 denotes a radiation conversion element, which is a direct type in which radiation is directly converted into an electric signal. 2 is a transfer TFT portion, 3 is a reset TFT portion, 4 is a transfer TFT drive wire, 5 is a reset TFT drive wire, 6 is a signal line, 7 is a bias wire, and 8 is a reset wire. 9 is a storage capacitor for the directly converted charges.
[0033]
The basic operation is substantially the same as in the first embodiment. The radiation is directly converted into electric charges by the radiation conversion element unit 1, stored in the storage capacitor 9, and read by the transfer TFT unit 2. Thereafter, in the reset operation, the radiation conversion element unit 1 (here, a direct conversion member) is used. The storage capacitor 9 is reset at the same time.
[0034]
FIG. 5 is a schematic plan view of one pixel. 5, the same components as those in FIG. 4 are denoted by the same reference numerals. FIG. 6 is a sectional view showing an AA 'section of FIG. FIG. 6 shows a reduced width between the transfer TFT unit 2 and the reset TFT unit 3.
[0035]
First, the transfer TFT unit 2 will be described. 6, reference numeral 11 denotes a substrate, 12 denotes a polycrystalline semiconductor layer, 13 denotes a source-drain region, 14 denotes an offset region formed of a low-concentration region of the same conductivity type as the source-drain region 13, 15 denotes a gate insulating layer, 16 Is a transfer TFT gate drive wiring, 17 is a gate electrode, 18 is an interlayer insulating layer, and 19 is a source-drain electrode. The transfer TFT unit 2 includes two TFTs connected in series, and two gate electrodes 17 of the two TFTs are commonly connected to the transfer TFT drive wiring 4. Each TFT has an LDD structure.
[0036]
The reset TFT section 3 is formed in the same structure as the transfer TFT section 2, and 21 is a reset TFT gate drive wiring and 22 is a reset wiring. The reset TFT unit 3 also includes two TFTs connected in series, and two gate electrodes of the two TFTs are commonly connected to a reset TFT drive wiring 5. Each TFT has an LDD structure.
[0037]
In FIG. 6, 23 denotes an interlayer insulating layer, 24 is a sensor separate electrode, 29 is a direct conversion member (a-Se, other GaAs, and the like PbI _2), 30 is a sensor upper electrode.
[0038]
Further, the configuration of the storage capacitor 9 is a structure formed using the capacitor lower electrode 28, the interlayer insulating layer 18, and the source-drain electrode 19.
[0039]
In addition, similarly, by adopting the above-described configuration, a channel portion of each TFT is shielded by a gate electrode against a potential change of the sensor individual electrode 24 connected to the direct conversion member 29. Become.
[0040]
As a result, the image quality is remarkably improved, for example, the TFT leak according to the output of the sensor individual electrode 24 can be reduced. Further, regardless of the pixel size, the aperture ratio achieves approximately 100%, which is a great structural advantage for miniaturization.
[0041]
Furthermore, by connecting a plurality of TFTs in series, the TFT characteristics, especially the OFF characteristics, are improved, and there is also redundancy against defects such as short-circuiting between the upper and lower sides via the gate insulating layer and short-circuiting in the semiconductor layer. It is also possible to have the nature.
[0042]
(Embodiment 3)
As a third embodiment of the present invention, a radiation detection device including an AmpTFT (amplification TFT) that receives a charge generated in a photoelectric conversion element at a gate electrode, a transfer TFT that transfers a signal corresponding to the charge, and the like will be described. . The present embodiment is an indirect radiation detecting apparatus in which radiation is temporarily converted into light such as visible light, and the converted light is read by a photoelectric conversion element. The photoelectric conversion element can be used together with a MIS PD or a PIN PD.
[0043]
FIG. 7 shows a 1-bit equivalent circuit diagram of the photoelectric conversion device. The same components as those in FIG. 1 are denoted by the same reference numerals. In the figure, 1 is a photoelectric conversion element section, 31 is an AmpTFT section, 2 is a transfer TFT section, 3 is a reset TFT section, 4 is a transfer TFT drive wiring, 5 is a reset TFT drive wiring, 6 is a signal line, and 7 is a bias wiring. , 8 are reset wirings, and 32 is a transfer TFT bias wiring. The AmpTFT unit 31 also includes two TFTs connected in series.
[0044]
The outline of the driving method will be described with reference to FIG. Radiation such as X-rays is wavelength-converted by a wavelength converter such as a phosphor, and is incident on the photoelectric conversion element unit 1. The incident light is photoelectrically converted and stored in the photoelectric conversion element unit 1.
[0045]
Due to this charge, a potential change occurs in the gate electrode of the AmpTFT 31 according to the amount of incident light. After that, an ON voltage is applied to the gate electrode of the transfer TFT section 2 from the transfer TFT drive wiring 4 to turn on the transfer TFT section 2, and an output corresponding to the amount of incident light is generated via the signal line 6.
[0046]
After reading by the external IC, an OFF voltage is applied to the gate electrode of the transfer TFT unit 2 from the transfer TFT drive wiring 4, the transfer TFT unit 2 is turned off, and a series of read operations is completed.
[0047]
Next, an ON voltage is applied to the gate electrode of the reset TFT section 3 from the reset TFT drive wiring 5 and a reset voltage is applied to the reset wiring 8 to reset the photoelectric conversion element section 1. Thereafter, an OFF voltage is applied to the gate electrode of the reset TFT section 3 from the reset TFT drive wiring 5, and the process ends.
[0048]
In the above, the description has been made using a 1-bit equivalent circuit for simplicity. However, in practice, each pixel (1 bit) is two-dimensionally arranged, and the transfer TFT and reset TFT of each pixel use a common drive. It is connected to wiring, and also commonly connected to signal lines and the like.
[0049]
FIG. 8 shows a schematic plan view of one pixel. 8, the same components as those in FIGS. 1 and 7 are denoted by the same reference numerals. In the case where three types of TFTs are used as in the present embodiment, conventionally, the aperture ratio is remarkably reduced and sufficient sensitivity cannot be secured, so that it is difficult to design a functional circuit. By arranging the sensor element on the TFT element, it is possible to realize a radiation detection apparatus having a high degree of freedom in design. In other words, a device with high image quality can be realized.
[0050]
(Embodiment 4)
This embodiment describes a case where the TFT structure is an offset structure in the first embodiment. FIG. 9 shows a schematic plan view.
[0051]
As shown in the figure, the offset structure is such that the channel region 12 is wider than the gate electrode 17 of the TFT. In the present embodiment, similar to the LDD structure of the first embodiment, even in the offset structure, the TFT has the same effect such as stabilization of the OFF current.
[0052]
Next, an X-ray diagnostic system using the radiation detection device of each embodiment described above will be described.
[0053]
FIG. 12 shows an application example of the radiation detecting apparatus according to the present invention to an X-ray diagnostic system.
[0054]
The X-rays 6060 generated by the X-ray tube 6050 pass through the chest 6062 of the patient or the subject 6061 and enter the radiation detection device (for example, a device in which a phosphor is arranged before the photoelectric conversion device) 6040 of the present embodiment. The incident X-ray contains information on the inside of the body of the patient 6061. The scintillator emits light in response to the incidence of the X-rays, and this is photoelectrically converted by the photoelectric conversion element to obtain electrical information. This information is converted into digital data, image-processed by an image processor 6070 serving as signal processing means, and can be observed on a display 6080 serving as display means in a control room.
[0055]
Further, this information can be transferred to a remote place by a transmission means such as a telephone line 6090, and can be displayed on a display 6081 such as a doctor room at another place or stored in a recording means such as an optical disk, so that a doctor at a remote place can make a diagnosis. It is also possible. Further, it can be recorded on a film 6110 as a recording medium by a film processor 6100 as a recording means.
[0056]
The embodiments of the present invention have been described above, but the preferred embodiments of the present invention are the following.
[0057]
Embodiment 1 In a photoelectric conversion device in which a plurality of pixels each including a sensor element for converting incident light into an electric signal and a plurality of thin film transistors connected to the sensor element are arranged.
The plurality of thin film transistors are connected in series and use the same gate wiring,
The electrode of the sensor element connected to the plurality of thin film transistors is disposed on the plurality of thin film transistors,
The photoelectric conversion device, wherein the plurality of thin film transistors have a top-gate structure in which a semiconductor layer, a gate insulating layer, and a gate electrode layer are sequentially stacked on a substrate.
[0058]
Second Embodiment In the photoelectric conversion device according to the first embodiment, the plurality of thin film transistors include a plurality of transfer thin film transistors that transfer an electric signal from the sensor element, and a plurality of reset thin film transistors that reset the sensor element. Photoelectric conversion device containing
[0059]
(Embodiment 3) In the photoelectric conversion device according to Embodiment 1, the plurality of thin film transistors include a plurality of amplifying thin film transistors to which an electric signal is input from the sensor element and a plurality of transfer circuits for outputting the electric signal. And a plurality of resetting thin film transistors for resetting the sensor element.
[0060]
(Embodiment 4) The photoelectric conversion device according to any one of Embodiments 1 to 3, wherein the plurality of thin film transistors have a channel region wider than a gate electrode.
[0061]
(Embodiment 5) A radiation detection apparatus comprising: the photoelectric conversion device according to any one of Embodiments 1 to 4; and a conversion body that converts radiation into light on a light incident side of the photoelectric conversion device.
[0062]
(Embodiment 6) In a radiation detection device in which a plurality of pixels each including a sensor element for converting radiation into an electric signal and a plurality of thin film transistors connected to the sensor element are arranged,
The plurality of thin film transistors are connected in series and use the same gate wiring,
The electrode of the sensor element connected to the plurality of thin film transistors is disposed on the plurality of thin film transistors,
The radiation detector according to claim 1, wherein the plurality of thin film transistors have a top-gate structure in which a semiconductor layer, a gate insulating layer, and a gate electrode layer are sequentially stacked on a substrate.
[0063]
(Embodiment 7) The radiation detection device according to embodiment 6, wherein a storage capacitor is connected to the sensor element.
[0064]
(Eighth Embodiment) In the radiation detection apparatus according to the sixth or seventh embodiment, the plurality of thin film transistors are a plurality of transfer thin film transistors that transfer an electric signal from the sensor element, and a plurality of reset thin film transistors that reset the sensor element. A radiation detection device including a thin film transistor.
[0065]
(Embodiment 9) In the radiation detecting apparatus according to Embodiment 6 or 7, the plurality of thin film transistors are a plurality of amplifying thin film transistors to which an electric signal is input from the sensor element and a plurality of thin film transistors for outputting the electric signal. And a plurality of reset thin film transistors for resetting the sensor element.
[0066]
(Embodiment 10) The radiation detection device according to any one of Embodiments 6 to 9, wherein the plurality of thin film transistors have a channel region wider than a gate electrode.
[0067]
(Embodiment 11) The radiation detection device according to any of Embodiments 5 to 9,
Signal processing means for processing a signal from the radiation detection device,
Recording means for recording a signal from the signal processing means,
Display means for displaying a signal from the signal processing means,
Transmission processing means for transmitting a signal from the signal processing means,
A radiation source for generating the radiation.
[0068]
【The invention's effect】
As described above, according to the present invention, it is possible to dispose a sensor element on a TFT without disposing a special shield structure. As a result, even when the pixel size is reduced due to high definition, a sufficient aperture ratio, i.e., sensitivity, can be ensured, and a decrease in image quality due to TFT leak can be prevented.
[0069]
Further, by connecting a plurality of TFTs in series to each TFT element, the redundancy of the TFTs can be obtained, the stability of the OFF current can be secured, the operation margin can be secured, and the image quality can be improved.
[0070]
Further, since a plurality of TFTs can be arranged in one pixel, the degree of freedom in circuit design is increased, and driving for improving image quality can be realized.
[Brief description of the drawings]
FIG. 1 is a 1-bit equivalent circuit diagram of a first embodiment.
FIG. 2 is a schematic plan view of the first embodiment.
FIG. 3 is a schematic cross-sectional view taken along the line AA ′ of the first embodiment.
FIG. 4 is a 1-bit equivalent circuit diagram of a second embodiment.
FIG. 5 is a schematic plan view of a second embodiment.
FIG. 6 is a schematic cross-sectional view taken along the line AA ′ of the second embodiment.
FIG. 7 is a 1-bit equivalent circuit diagram of a third embodiment.
FIG. 8 is a schematic plan view of a third embodiment.
FIG. 9 is a schematic sectional view of a fourth embodiment.
FIG. 10 is a schematic equivalent circuit of a conventional one bit.
FIG. 11 is a schematic equivalent circuit of a conventional 3 × 3.
FIG. 12 is a conceptual diagram showing a configuration of an X-ray imaging system using the radiation detection device of the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 photoelectric conversion element section 2 transfer TFT section 3 reset TFT section 4 transfer TFT drive wiring 5 reset TFT drive wiring 6 signal line 7 bias wiring 8 reset wiring 9 storage capacitor 11 substrate 12 polycrystalline semiconductor layer (channel region)
Reference Signs List 13 source-drain region 14 offset region 15 gate insulating layer 16 transfer TFT gate drive wiring 17 gate electrode 18 interlayer insulating layer 19 source-drain electrode 21 reset TFT gate drive wiring 22 reset wiring 23 interlayer insulating layer 24 sensor individual electrode 25 MIS type PD
26 Transparent electrode 27 Sensor bias wiring 28 Capacitor lower electrode 29 Direct conversion member 30 Sensor upper electrode 31 Amp TFT part 32 Transfer TFT bias wiring S11-S33 Photoelectric conversion element part T11-T33 Transfer TFT part Vg1-Vg2 Transfer TFT drive wiring Sig1 to Sig3 Signal lines Vs1 to Vs3 Photoelectric conversion element bias wiring A Signal processing circuit B Bias power supply A / D converter D TFT driving circuit

Claims (1)

In a radiation detection device in which a plurality of pixels each including a sensor element that converts radiation into an electric signal and a plurality of thin film transistors connected to the sensor element are arranged,
The plurality of thin film transistors are connected in series and use the same gate wiring,
The electrode of the sensor element connected to the plurality of thin film transistors is disposed on the plurality of thin film transistors,
The radiation detector according to claim 1, wherein the plurality of thin film transistors have a top-gate structure in which a semiconductor layer, a gate insulating layer, and a gate electrode layer are sequentially stacked on a substrate.

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