JPH11287864A - Semiconductor x-ray detecting device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor X-ray detecting device, which generates more paired electron-holes inside a photoconductive layer, and which can output more electric signals. SOLUTION: A glass substrate 40 is provided. A plurality of pixel electrodes 46 which are installed on the glass substrate 40 so as to receive X-ray photons in units of pixels are provided. Capacitors 24 which are installed at the pixel electrodes 46 in order to store electric charges by the X-ray photons received by the pixel electrodes 46 are provided. Transistors 26 which read out and control the electric charges stored in the capacitors 24 are provided. A photoconductive layer 57 which is formed so as to cover the transistors 26, the capacitors 24 and the pixel electrodes 46 is provided. An electrode 60 for electric-field generation installed to cover the photoconductive layer 57 is provided. A lead foil sheet 10 in a prescribed thickness is installed on the front side of the photoconductive layer 57. A lead foil sheet 20 in a prescribed thickness is installed on its rear face side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor X-ray detecting apparatus suitable for application to an X-ray photographing system for acquiring a local X-ray transmission image of a subject and a method of manufacturing the same. Specifically, a plate-shaped lead member having a predetermined thickness is provided on the front side and the rear side of the photoconductive layer for guiding the X-ray photons, and more electron / hole pairs are generated in the photoconductive layer to generate an electric signal. A large number of outputs can be made, and transmitted X-rays can be reduced.

[0002]

2. Description of the Related Art Conventionally, a medical X-ray imaging system for X-ray imaging of a relatively wide area such as the chest of a human body, as well as an industrial X-ray imaging system for precision inspection of aggregates such as industrial products and building materials. X-ray imaging systems are used. At present, a widely used method is to use a fluorescent intensifying screen (a film which emits blue or green light by irradiating with X-rays to form a film on a emulsion surface of a photographic material in which a silver halide emulsion is coated on both sides of a polyester support). An X-ray image is exposed to the emulsion surface) to obtain an X-ray image by so-called screen / film system, or by directly exposing the X-ray without using an intensifying screen to obtain an X-ray image. Gaining systems are known.

[0003] The former is mainly used for medical applications where the exposure dose is required to be as small as possible, and the latter is often used in industries where the exposure dose does not matter, but rather on sharpness. These methods are very excellent in the quality of X-ray images, but use a silver halide photographic light-sensitive material, and therefore must be subjected to development processing in order to observe the X-ray images.

In recent years, a stimulable phosphor has been used in some cases instead of the above screen / film system to detect an image signal by X-rays. The stimulable phosphor accumulates energy corresponding to the amount of irradiation with X-rays, and when irradiated with light of a specific wavelength (for example, laser light) after the irradiation, the stimulable phosphor responds to the accumulated energy. Light emission is obtained.

[0005] According to the X-ray imaging system using the stimulable phosphor, the stimulable phosphor is arranged on the affected part of the subject, and then the affected part of the subject is irradiated with X-rays. Then, the X-rays transmitted through the affected part reach the stimulable phosphor. Thereby, an image is accumulated in the stimulable phosphor. Furthermore,
Excitation light is scanned over the stimulable phosphor on which the X-ray transmission image is recorded, and light generated by the stimulable light emitted from the phosphor scanned by the excitation light is read, and the light is converted into an electric signal. Is done. After image processing of the electric signal, a lesion is diagnosed from the X-ray image.

However, according to the X-ray imaging system using the stimulable phosphor, a means for irradiating the stimulable phosphor on which the X-ray transmission image has been recorded with excitation light, a means for scanning the excitation light, In addition, the means for erasing the residual electric charge and the like hinder the simplification and weight reduction of the X-ray detection means and the X-ray imaging system.

In this method, an X-ray image can be observed with a cathode ray tube (CRT) or the like using the obtained electric signal. There is a disadvantage that the image quality, particularly sharpness, is significantly inferior to the method using a silver photographic film.

Therefore, recently, an X-ray imaging system equipped with semiconductor detecting means for directly converting X-ray photons into an electric signal has been developed. In this system, X-ray photons transmitted through a subject are directly converted into electric signals by semiconductor detecting means. The electric signal is generated by electron-hole pairs generated in the photoconductive layer by X-ray irradiation, and is obtained by applying a predetermined electric field to the electron-hole pairs and separating the electric charges. By reading out the charges collected by this electric field, X-ray image information can be obtained.

According to this method, since the diffusion of electrons and hole pairs does not occur due to the application of an electric field, the sharpness of an image is extremely excellent, and an image quality comparable to or exceeding that of a screen film can be obtained. Can be Its excellent image quality requires no method of reading out an image by photoexcitation such as the stimulable phosphor described above.
An X-ray image can be observed on the RT.

[0010] Therefore, an X-ray imaging system provided with a semiconductor detecting means can obtain a sharper image extremely easily than an X-ray image obtained by a conventional screen / film system. And since there is no need to read out an image by light excitation as in a stimulable phosphor system,
The system can be made lighter and smaller.

[0011]

When using a medical X-ray imaging system, it is necessary to reduce the amount of X-ray exposure to the human body in order not to impair reproductive functions. When this semiconductor X-ray detection device is used for X-ray imaging, most of the X-rays pass through the detection device, and there is a possibility that the photographer or his / her cooperator may be exposed to X-rays. .

Therefore, improving the sensitivity of the semiconductor detection device and reducing the amount of X-rays passing through the detection device leads to a reduction in the amount of X-ray exposure to the patient and the radiologist. Further, in an industrial X-ray image inspection, an X-ray generation voltage is extremely high because an X-ray that transmits through a thick iron plate or the like is generated. Therefore, the consumption of the X-ray tube is severe, and it is desired to reduce the tube current as much as possible. For this, X
It is necessary to increase the sensitivity of the line detector.

In view of the above, the present invention has solved the above-mentioned problem, and it is intended to generate more electron-hole pairs in the photoconductive layer so that more electric signals can be output and transmit X-rays. It is an object of the present invention to provide a semiconductor X-ray detection device and a method of manufacturing the same that can be reduced.

[0014]

In order to solve the above-mentioned problems, a semiconductor X-ray detecting apparatus according to the present invention comprises a substrate and a pixel provided on the substrate for receiving X-ray photons in pixel units. A plurality of electrodes, a capacitor provided for each pixel electrode for accumulating electric charge due to X-ray photons received by each pixel electrode, a transistor for reading and controlling the electric charge stored in this capacitor, A photoconductive layer provided so as to cover the pixel electrode; and an electrode for generating an electric field provided so as to cover the photoconductive layer. A plate having a predetermined thickness is provided on the front side and the rear side of the photoconductive layer. A lead member in a shape of a circle is provided.

According to the semiconductor X-ray detection apparatus of the present invention, when the photoconductive layer is irradiated with X-rays through a lead member provided on an electrode for generating an electric field, for example, the X-rays are applied to the lead member. Part is absorbed and this energy causes the secondary X
X-ray photons in the photoconductive layer increase due to the generation of rays, and consequently the same effect as the increase in X-rays can be obtained. Furthermore, the lead member on the rear surface side of the photoconductive layer absorbs X-rays that have passed through the photoconductive layer, so that X-rays that have penetrated the semiconductor X-ray detection device can be reduced.

According to the method of manufacturing a semiconductor X-ray detection device of the present invention, a plurality of pixel electrodes are formed on a substrate to receive X-ray photons on a pixel-by-pixel basis. Forming a capacitor for each pixel electrode for storage, forming a transistor for reading out the charge stored in the capacitor,
Forming a photoconductive layer of a predetermined thickness on the entire surface of the substrate on which the capacitor and the pixel electrode are formed; and forming an electrode for generating an electric field on the substrate on which the photoconductive layer is formed, and then forming a predetermined thickness on the entire surface of the substrate. Forming a first lead member having a thickness;
Forming a second lead member having a predetermined thickness on the entire back surface of the substrate on which the lead member is formed.

According to the method of manufacturing a semiconductor X-ray detector of the present invention, a plate-like lead member having a predetermined thickness can be formed with good reproducibility on the front side and the rear side of the photoconductive layer for guiding X-ray photons.
A high-output and high-sensitivity semiconductor X-ray detector can be manufactured.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a semiconductor X-ray detecting device and a method of manufacturing the same according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an example of a cell structure of a semiconductor X-ray detecting apparatus 100 according to an embodiment of the present invention.
In the present embodiment, a plate-like lead member having a predetermined thickness is provided on the front side and the rear side of the photoconductive layer for guiding X-ray photons, and more electron-hole pairs are generated in the photoconductive layer to generate an electric signal. Is output more, and transmitted X-rays can be reduced.

In FIG. 1, a semiconductor X-ray detecting apparatus 100 includes a glass substrate (dielectric substrate) 40 as a substrate.
The substrate electrode 42, the pixel electrode 46, and the insulating layer ｛(Si
A capacitor (capacitance: C) 24 is formed by depositing a dielectric layer # 44 such as O ₂ ). This capacitor 24 accumulates the electric charge due to the X-ray photons received by the pixel electrode 46. For this purpose, a capacitor 24 is also provided for each pixel electrode 46.

A switching transistor (hereinafter simply referred to as a transistor) 26 is provided adjacent to the capacitor 24.
Is provided as in the conventional case. The charge stored in the capacitor 24 is read and controlled by the transistor 26. The transistor 26 has a configuration in which a gate electrode 50, a drain electrode 54, and a source electrode 56 are respectively formed as shown in the figure, and the source electrode 56 is connected to the pixel electrode 46 of the capacitor 24.

On the upper surfaces of the capacitor 24 and the switching transistor 26, a charge generation unit 22 having a predetermined thickness is provided. In the present invention, a photoconductive inorganic compound having a high X-ray absorptivity and a photoconductive property is used as the photoconductive layer 57 constituting the charge generation section 22. In this example, amorphous selenium having a thickness of about 500 μm or the like is used as the photoconductive layer 57. Amorphous selenium is deposited on the upper surfaces of the capacitor 24 and the transistor 26.

This photoconductive layer (amorphous selenium layer) 5
Further, a dielectric layer 58 and a surface electrode 60 as an electrode for generating an electric field are respectively formed on the upper surface of 7 as in the prior art. At this time, a polyethylene terephthalate resin having a thickness of about 0.5 to 9 μm is used for the dielectric layer 58.

A lead foil plate 10 as a first lead member is formed on the surface electrode 60. This lead foil plate 10
May be used as the surface electrode 60 by plating with metal copper or the like. The thickness of the lead foil plate 10 is 0.01 to 0.0
It is preferably about 5 mm. This thickness is such a value that X-rays can easily pass through the lead foil plate 10, and furthermore, when the X-rays pass through the lead foil plate 10, a part of the thickness is absorbed to make it easier to generate secondary X-rays. That's why. In this example, the surface electrode 60
May be formed of a lead member to serve also as the lead foil plate 10. Further, a lead foil plate 10 may be provided instead of the dielectric layer 58.

Further, in this example, a lead foil plate 20 as a second lead member is adhered and formed below the glass substrate 40.
The thickness of the lead foil plate 20 is preferably about 0.05 to 0.5 mm. Thus, the lead foil plate 10 on the surface electrode 60
A thicker one is used for the lead foil plate 20 under the glass substrate 40. The lead foil plate 20 has a thickness of up to about 10 mm, depending on the size of the semiconductor X-ray detector 100. If the thickness is more than necessary, portability is hindered. This thickness is to prevent the X-rays from easily passing through the lead foil plate 20. Depending on the irradiation energy of the X-rays, it is sufficient that the X-rays do not leak to the outside. In this example, the pixel electrode 46 may be formed of a lead member so that the lead foil plate 20 is also used.

The glass substrate 40 has a thickness of 0.5 μm.
A resin member of about m to 2 cm may be used. If the resin member is thin and insufficient in strength, another substrate may be further provided below the lead foil plate 20. Thereby, the semiconductor X
The structural strength of the line detection device 100 can be increased.

In the semiconductor X-ray detection apparatus 100, X-ray photons incident on the photoconductive layer 57 via the lead foil plate 10 are directly converted into electric signals. This electric signal is due to an electron-hole pair generated in the photoconductive layer 57 by X-ray irradiation. When a predetermined electric field is applied to the electron-hole pairs, charge separation is performed. The electric field at this time is generated by a predetermined potential applied from the power supply 28 to the surface electrode 60 and the substrate electrode 42.

Further, as shown by the broken line in FIG.
A voltage may be supplied between the substrate electrode 42 and the substrate electrode 42. In this case, 0 V (ground line potential) is applied to the lead foil plate 10 and a negative voltage (for example, -1200 V) is applied to the substrate electrode 42. The reason why the lead foil plate 10 is set to 0 V is to prevent electric shock to the subject. The electric charge collected by the electric field is accumulated in the capacitor 24, and the electric charge is read out from the capacitor 24 by the switching transistor 26, thereby obtaining X-ray image information.

As described above, according to the present embodiment, when the photoconductive layer 57 is irradiated with X-rays through the lead foil plate 10 under the surface electrode 60, a part of the X-rays 15 is applied to the lead foil plate 10. Is absorbed, and this energy causes secondary X-rays to be generated from the lead foil plate 10, and the number of X-ray photons in the photoconductive layer 57 is increased. As a result, the same effect as the increase in the X-rays 15 is obtained. Further, the lead foil plate 20 behind the photoconductive layer 57 absorbs the X-rays 15 passing through the photoconductive layer 57, so that the X-rays 15 passing through the semiconductor X-ray detection device 100 can be reduced. .

Next, a method of forming the semiconductor X-ray detection device 100 will be described. In this example, like the method of manufacturing a liquid crystal panel, first, in FIG.
A conductive film having a predetermined thickness is formed on the entire surface of the substrate, a predetermined resist is patterned, and the conductive film is selectively removed using the resist film as a mask. Thus, the gate electrode 50 and the substrate electrode 42 are formed. This film is doped with a desired amount of a desired impurity into polycrystalline silicon or the like to form an electrode structure. A CVD device is used for film growth, and a dry etching device or the like is used for removing unnecessary films.

Thereafter, referring to FIG.
And forming an insulating film on the glass substrate 40 on which the substrate electrode 42 is formed, patterning a predetermined resist,
Using the resist film as a mask, the insulating film is selectively removed. Thereby, the gate insulating film 52 and the dielectric film 44
To form For this film, SiO ₂ or SiN ₃ is used.

Thereafter, in FIG. 2C, the gate insulating film 5
2 and the glass substrate 40 on which the dielectric film 44 is formed,
A conductive film is formed, a predetermined resist is patterned, and the conductive film is selectively removed using the resist film as a mask. Thus, the active layer 51 is formed. This film is doped with a desired amount of n-type or p-type impurities into polycrystalline silicon or the like to form an n-type active layer or a p-type active layer 51.

Thereafter, in FIG. 3A, for example, a conductive film is formed on the glass substrate 40 on which the p-type active layer 51 is formed, a predetermined resist is patterned, and the resist film is selectively used as a mask. Next, the conductive film is removed. This film is doped with a desired amount of n-type impurities in polycrystalline silicon or the like. Thereafter, when the glass substrate 40 is heat-treated, p
An n-type impurity is diffused into the active layer 51 to form a pair of n-channel layers n ^{+ on} both sides above the gate electrode 50. At the same time, a drain electrode 54 and a source electrode 46 are formed, and a pixel electrode 46 extending from the source electrode 46 to a region on the dielectric layer 44 is formed. Thus, an n-type TFT (thin film transistor) 26 having the drain electrode 54 and the source electrode 46 is formed on the left side of FIG. 3A. A capacitor (capacitance: C) 24 having a substrate electrode 42, a dielectric layer 44, and a pixel electrode 46 is formed on the right side thereof.

Thereafter, in FIG. 3B, the n-type TFT 26
And a film thickness 5 on the entire surface of the glass substrate 40 on which the capacitance C is formed.
After forming amorphous selenium of about 00 μm, the amorphous selenium layer (photoconductive layer) 57 on the substrate 40 is flattened. A polisher is used to planarize this layer.

Thereafter, an insulating film and a conductive film are laminated with a predetermined thickness on the entire surface of the glass substrate 40 on which the amorphous selenium layer 57 is formed, and the dielectric layer 58 and the surface electrode 6 are laminated.
0 is formed. Until now, it is based on a conventional manufacturing method.

In this embodiment, in FIG. 4A, a lead foil plate 10 having a desired thickness t1 is attached on the surface electrode 60. The lead foil plate 10 is joined with a resin adhesive. The thickness t1 of the lead foil plate 10 is preferably about 0.01 to 0.05 mm. The lead foil plate 10 may be plated with metal copper or the like, and may be attached on the dielectric layer 58 instead of the surface electrode 60. Further, the surface electrode 60 may be formed of a lead member and the lead foil plate 10 may be omitted.

Thereafter, in FIG. 4B, the glass substrate 40
A lead foil plate 20 having a desired thickness t2 is attached to a lower portion of the lead foil plate. The lead foil plate 20 is joined with a resin adhesive. The thickness t2 of the lead foil plate 20 is preferably about 0.05 to 0.5 mm.

Thus, the lead foil plate 10 having a predetermined thickness is provided on the front surface side of the amorphous selenium 57 and on the surface electrode 60, and the lead foil plate 10 having a predetermined thickness is provided on the rear surface side and below the glass substrate 40. X-ray detection apparatus 100 having
Can be manufactured with good reproducibility.

Subsequently, a flat panel detector (Flat Panel Detector) in which the semiconductor X-ray detector 100 is integrated
r, hereinafter referred to as FPD) 4.

A specific example of the FPD is disclosed in Japanese Patent Laid-Open No. 6-342.
098. That is, X transmitted through the subject
The line is absorbed by a photoconductive layer such as an a-Se layer to generate a charge corresponding to the X-ray intensity, and the amount of the charge is detected for each pixel. An example of another type of FPD is disclosed in JP-A-9-9
X-rays are absorbed by a phosphor layer such as an intensifying screen to generate fluorescence, and the intensity of the fluorescence is detected by a photodetector such as a photodiode provided for each pixel, as disclosed in US Pat. There is something. Other means for detecting fluorescence include CCD and C
-There is also a method using a MOS sensor.

In particular, in the FPD of the system disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 6-342098, since the X-ray dose is directly converted into the electric charge amount for each pixel, the sharpness of the FPD is hardly deteriorated and the image having excellent sharpness Therefore, the effect of the X-ray imaging system of the present invention is large and suitable.

Hereinafter, the internal brewing of the FPD 4 will be described with reference to the drawings. FIG. 5 is a circuit diagram showing a panel configuration of the FPD 4. In FIG. 5, the FPD 4 has a vertical length of 35.
cm, 43cm in width, 4cm in thickness, 15cm in weight
It has a flat panel shape of about kg. The FPD 4 includes, in addition to the X-ray imaging panel 13, vertical and horizontal scanning units 30,
32 and a signal processing circuit 34.

The basic configuration of the X-ray imaging panel 13 itself is obtained by integrating the above-described semiconductor X-ray detection device 100 in a matrix (m × n). The conversion cell 14, which is a basic unit, includes, in addition to the charge generation unit 22, a capacitor 24 for storing the generated charge and a TF for extracting the stored charge.
The switching transistor 26 has a T configuration. The charge generation unit 22 has pixel electrodes 46 defined for receiving X-ray photons in pixel units with respect to the X-ray image of the subject, and the pixel electrodes 46 are provided on the glass substrate 40 by m rows × n columns. Its cross-sectional configuration is as shown in FIG.

The above-described transistor 26 is connected to the vertical scanning section 30.
When each transistor 26 is selected in a time-series manner, the electric charge read out from the drain electrode 54 of the selected transistor 26 is signal-controlled via the horizontal scanning unit 32. Output to the processing circuit 34. In the signal processing circuit 34, the original image signal Sorg after amplifying the electric signal is output to image processing means (not shown).

In this example, an X-ray transmitted through a tissue such as a human body is projected on the FPD 4, and an X-ray image is directly converted into an electric signal (original image signal) Sorg and output in the FPD 4. This original image signal Sorg is very sharp.

Subsequently, the first and second lead foil plates 10 and 20
The result of comparing the X-ray detection sensitivity and its blocking property between the case where X is present and the case where X is not present will be described. FIG. 6 is a measurement circuit diagram for evaluating the X-ray detection sensitivity and its blocking property.

In this example, in order to measure the X-ray detection sensitivity of the FPD 4, a copper aluminum filter 2 is disposed between the X-ray tube 1 and the FPD 4 shown in FIG.
Is irradiated on the FPD 4 via the copper aluminum filter 2. The exposure process on the FPD 4 by the X-ray tube 1 is performed by 0.1 second exposure (60 mA exposure). FPD4 during X-ray exposure
Was measured by the ammeter 5 after being amplified by the amplifier.

In this example, in order to measure the X-ray blocking properties of the FPD 4, a dental film (manufactured by Hanshin) 6 was
After attaching to the back of D4 and performing X-ray exposure 20 times,
The dental film 6 was developed and its blackening density was measured. Here, assuming that the blackening concentration increase value is a parameter of X-ray transmission, the higher the concentration, the more the lead foil plate 2
This indicates that the amount of X-ray transmitted through 0 is large.

The X-ray irradiation conditions at that time are as follows.
A tungsten tube is used for the X-ray tube 1. The X-ray generation voltage Vx is 120 kVp, and the copper aluminum filter 6 and the FP
The separation distance L from D4 is 50 cm. Power supply 28 to F
The voltage Vf for generating an electric field supplied to the PD 4 was 1500 V. The thickness of the lead foil plates 10 and 20 was varied in the range of 0 to 2.0 mm.

The presence or absence of the lead foil plates 10 and 20 under the above-mentioned X-ray irradiation conditions was compared with respect to the X-ray detection sensitivity and its blocking property.

FIG. 7 is a table summarizing the comparison results. In this table, when the lead foil plates 10 and 20 are not present, the lead foil plate 10 is attached to the front side of the FPD 4 when the lead foil plate 10 is attached to the front side of the FPD 4. The relative values are shown for the case where the lead foil plate 20 is also mounted on the rear side.

In the comparative example shown in FIG. 7, the process number (1) is a case where the lead foil plates 10 and 20 are not mounted on the FPD. The process numbers (2) to (7) correspond to the case where the lead foil plate 10 is mounted on the front side of the FPD. Processing number (8) to (16)
Fig. 5 shows a case where the lead foil plate 10 is mounted on the front side of the FPD and the lead foil plate 20 is mounted on the rear side.

According to the comparison result of FIG. 7, the processing number (2)
Since the lead foil plate 10 is attached to the FPDs of (1) to (7), a larger current value can be obtained than the FPD of the process number (1). In particular, when the thickness t1 of the lead foil plate 10 is set to 0.
With respect to the FPDs of process numbers (3) to (7) exceeding 03 mm, a current value approximately 2.7 times that of the FPD of process number (1) can be extracted.

Regarding the X-ray blocking property, processing numbers (2) to
(7) Since the lead foil plate 20 is not mounted on the FPD,
Although there is no significant difference from the FPD of the treatment number (1), it is slightly improved as the thickness of the lead foil plate 10 increases.

The FPDs of the processing numbers (8) to (16)
Since the lead foil plates 10 and 20 are attached, the X-ray shielding property is improved as compared with the FPD of the processing number (1). In particular, with respect to the FPDs of process numbers (14) to (15) in which the thickness t2 of the lead foil plate 20 exceeds 1.0 mm, leakage of X-rays to the outside can be almost completely blocked. The FPDs of the processing numbers (9) to (13) are improved by half. Regarding the current value, the FPs of the process numbers (8) to (16)
D is 2.5 to 3 .D compared to the FPD of the process number (1).
It can output 5 times.

As described above, by mounting the lead foil plate 10 having a desired thickness t1 on the front side of the FPD 4, a large amount of current I0 can be taken out, so that the detection sensitivity can be improved. At the same time, by mounting the lead foil plate 20 having a desired thickness t2 on the rear surface side of the FPD 4, X-rays that have passed through the inside of the FPD 4 can be blocked, so that leakage of X-rays to the outside can be reduced.

[0057]

As described above, according to the semiconductor X-ray detection apparatus of the present invention, a plate-like lead member having a predetermined thickness is provided on the front side and the rear side of the photoconductive layer for guiding X-ray photons. It is.

With this configuration, secondary and tertiary X-rays can be generated in the photoconductive layer, so that more electron-hole pairs can be generated in the photoconductive layer.
Therefore, it is possible to read out the charge accumulated in the capacitor by the electric field of the predetermined potential as an original image signal related to the X-ray image of the subject. Thereby, a semiconductor X-ray detector with high sensitivity and high output can be provided.

According to the method of manufacturing a semiconductor X-ray detector of the present invention, a plate-like lead member having a predetermined thickness can be formed with good reproducibility on the front side and the rear side of the photoconductive layer for guiding X-ray photons.
A high-output and high-sensitivity semiconductor X-ray detector can be manufactured.

The present invention is very suitable when applied to an X-ray photography system for acquiring a local X-ray transmission image of a subject.

[Brief description of the drawings]

FIG. 1 shows a semiconductor X-ray detector 100 as an embodiment.
3 is a cross-sectional view showing a cell structure example of FIG.

FIGS. 2A to 2C are process diagrams (part 1) illustrating an example of forming a cross section of the semiconductor X-ray detection apparatus 100. FIGS.

FIGS. 3A and 3B are process diagrams (part 2) illustrating an example of forming a cross section of the semiconductor X-ray detection device 100. FIGS.

4A and 4B are process diagrams (part 3) illustrating an example of forming a cross section of the semiconductor X-ray detection device 100. FIG.

FIG. 5 shows an FPD 4 to which the semiconductor X-ray detection device 100 is applied.
FIG. 3 is a circuit diagram showing a configuration example of the present invention.

FIG. 6 is a block diagram illustrating an example of a measurement circuit when evaluating the FPD 4.

FIG. 7 is a table showing a comparison example of the case where lead foil plates 10 and 20 are present and the case where FPD 4 is not present.

[Explanation of symbols]

Reference numeral 10: lead foil plate (first lead member), 20: lead foil plate (second lead member), 40: glass substrate (substrate), 4
6 ... pixel electrode, 24 ... capacitor (capacity), 2
6 ... transistor, 57 ... amorphous selenium layer (photoconductive layer), 60 ... surface electrode (electrode for generating electric field)

Claims (8)

[Claims] A substrate, a plurality of pixel electrodes provided on the substrate for receiving X-ray photons in pixel units, and a plurality of pixel electrodes for accumulating electric charges by the X-ray photons received by the pixel electrodes. A capacitor provided for each electrode; a transistor for reading and controlling the charge stored in the capacitor; a photoconductive layer provided to cover the transistor, the capacitor and the pixel electrode; and a cover for the photoconductive layer An electrode for generating an electric field provided as described above, and a plate-like lead member having a predetermined thickness is provided on the front side and the rear side of the photoconductive layer. 2. The semiconductor X-ray detection device according to claim 1, wherein the lead member on the front side of the photoconductive layer is thinner than the lead member on the rear side of the photoconductive layer. apparatus. 3. The lead member has a thickness of 0.01-10.
3. A semiconductor X-ray detection apparatus according to claim 2, wherein the X-ray detector has a diameter of 1 mm. 4. The semiconductor X-ray detection apparatus according to claim 1, wherein said lead member also serves as said pixel electrode. 5. The semiconductor X-ray detector according to claim 1, wherein the lead member also serves as the electrode for generating the electric field. 6. The semiconductor X-ray detector according to claim 1, wherein amorphous selenium is used for the photoconductive layer. 7. The lead member according to claim 6, wherein the lead member is provided on the front side or the rear side of the amorphous selenium layer in a state of being in contact with the amorphous selenium layer or not in contact with the amorphous selenium layer. Semiconductor X-ray detector. 8. A step of forming a plurality of pixel electrodes on a substrate for receiving X-ray photons in pixel units, and a capacitor for each pixel electrode for accumulating charges by the X-ray photons received by the pixel electrodes. Forming a transistor for reading out the charge stored in the capacitor; and forming a photoconductive layer of a predetermined thickness on the entire surface of the substrate on which the transistor, the capacitor, and the pixel electrode are formed. Forming an electrode for generating an electric field on the substrate on which the photoconductive layer is formed, and then forming a first lead member having a predetermined thickness on the entire surface of the substrate; and forming the first lead member. Forming a second lead member having a predetermined thickness on the entire rear surface of the substrate.