JP2002022837A - X-ray imaging apparatus and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an emitted light by a phosphor from invading adjacent pixels to contribute to improving a resolution. SOLUTION: The X-ray imaging apparatus includes an array substrate where unit pixels each comprising a capacitor 30 for storing signal charges and a TFT 20 for reading out signal charges from the capacitor 30 are arranged in matrix on a glass substrate 10, a photoelectric conversion film 106 set on the array substrate to be connected electrically to the capacitor 30 of each pixel for converting light into electrical signals, and a phosphor film 102 set on the photoelectric conversion film 106 for converting X rays into light. The phosphor film 102 is separated for every pixel with having a reflecting member 103 embedded between adjacent pixels for reflecting X rays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray imaging apparatus used for a medical X-ray diagnostic apparatus or the like, and more particularly to an indirect conversion type X-ray imaging apparatus that converts X-rays into light and detects the light.

[0002]

2. Description of the Related Art In recent years, in the medical field, the medical data of patients has been put into a database for the purpose of promptly and accurately performing treatment. There is also a demand for creating a database for X-ray image data, and digitization of X-ray images is desired. Conventionally, a medical X-ray diagnostic apparatus uses a silver halide film for imaging, but in order to digitize the image, it is necessary to develop the photographed film and scan it again with a scanner or the like. It was hanging. On the other hand, a method of directly digitizing an image using a CCD camera of about 1 inch has been realized.
However, for example, when taking a picture of the lungs, 40 cm x 40 c
In order to photograph an area of about m, an optical device for condensing light is required, and the size of the device has become a problem.

Therefore, recently, an X-ray imaging apparatus has been developed in which an X-ray image is not captured by a silver halide film but is captured by an image sensor. This device consists of a pixel electrode, a storage capacitor, TF
A photoelectric conversion unit is provided on an array substrate in which unit pixels of T are arranged in a matrix so as to be electrically connected to pixel electrodes, and a phosphor that emits light by X-ray irradiation is provided thereon. . Then, when X-rays enter the phosphor while a bias voltage is applied to the photoelectric conversion film, light excited by the phosphor enters the photoelectric conversion film, causing current to flow and accumulating signal charges in the storage capacitance of the pixel. Is done. The stored signal charges can be read out as pixel information by sequentially driving the TFTs.

However, this type of device has the following problems. That is, in an indirect conversion type X-ray imaging apparatus in which incident X-rays are converted into visible light by a phosphor and the converted light is converted into electric charges by the photoelectric conversion film of each pixel,
There is a problem that light from the phosphor is scattered and reaches adjacent pixels, so that the resolution is deteriorated. In an X-ray imaging apparatus having a conventional structure, a photosensitive film (photoelectric conversion film) for converting fluorescent light excited by X-rays into an electric signal is formed directly on an array substrate, and on this array substrate, on another substrate. The formed X-ray excited phosphor film was stuck. In this case, since gaps are formed between the phosphor film and the photosensitive film, light reaches adjacent pixels through these gaps and the like. Therefore, stray light reaches adjacent pixels,
Spatial resolution was greatly degraded.

[0005] A direct conversion type X-ray imaging apparatus for directly converting X-rays incident on pixels into electric charges has also been developed.
However, as a direct conversion type X-ray photosensitive film, amorphous S
Although heavy metal compounds such as PbI ₂ having a high absorption coefficient of e and X-rays are used, these materials have a fatal drawback of adversely affecting the human body. Therefore, it is not suitable for an X-ray imaging apparatus used in a medical field.

[0006]

As described above, conventionally, in an indirect conversion type X-ray imaging apparatus utilizing light emission of a phosphor, the light emitted from the phosphor is scattered and reaches an adjacent pixel. However, there is a problem in that the metal is deteriorated.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent light emission by a phosphor from invading adjacent pixels, thereby contributing to improvement in resolution. An object of the present invention is to provide an indirect conversion type X-ray imaging apparatus that can be obtained.

[0008]

(Structure) In order to solve the above problem, the present invention employs the following structure.

That is, the present invention provides an array substrate in which unit pixels each having a signal storage section for storing signal charges and a signal reading section for reading out the stored signal charges are arranged in a matrix, and the array substrate A photoelectric conversion film, which is provided on the photoelectric conversion film so as to be electrically connected to the signal storage unit of each pixel and converts light into an electric signal; and a phosphor, which is provided on the photoelectric conversion film and converts X-rays into light. An X-ray imaging apparatus comprising a film and a phosphor film, wherein the phosphor film is separated for each pixel, and a member that reflects or absorbs X-rays is embedded between adjacent pixels.

Here, preferred embodiments of the present invention include the following.

(1) The photoelectric conversion film is formed of amorphous Si.

(2) The photoelectric conversion film is formed of an organic material.

(3) A pixel electrode electrically connected to the signal storage section is arranged for each pixel on the uppermost layer of the array substrate (first substrate).

(4) The photoelectric conversion film and the phosphor film are provided on a substrate (second substrate) different from the array substrate, and have a pixel electrode on the uppermost layer which is electrically connected to the photoelectric conversion unit. Things.

(5) The pixel electrodes on the first and second substrates are electrically connected by connecting columns.

(6) The member embedded between the pixels of the phosphor film is a fluid material in which particles that reflect or absorb X-rays are dispersed in a resin or a polymer.

According to the present invention, in a method of manufacturing an X-ray imaging apparatus, a unit pixel comprising a signal accumulating section for accumulating signal charges and a signal reading section for reading out the accumulated signal charges is formed in a matrix on a first substrate. Forming an array substrate arranged on the second substrate, forming a phosphor film for converting X-rays into light on the second substrate, and etching the phosphor film so as to separate the phosphor film into pixels. Forming a groove;
A step of burying and forming a member that absorbs or reflects X-rays in the groove, a step of forming a photoelectric conversion film that converts light into an electric signal on the phosphor film, and a signal accumulation unit of the first substrate. Connecting the first and second substrates by connection columns so that the photoelectric conversion film of the second substrate is electrically connected to the first substrate.

(Function) According to the present invention, since the phosphor film is separated for each pixel and a member for reflecting or absorbing X-rays is embedded between adjacent pixels, the phosphor film is formed by incidence of X-rays. Fluorescence excited by the film can be prevented from reaching adjacent pixels. For this reason, the resolution can be prevented from deteriorating due to stray light, and a high resolution can be realized. Also,
Since this is an indirect conversion method in which X-rays are converted into light by a phosphor, there is no need to use a material that is not suitable for the human body such as heavy metal or Se used in the direct conversion method, and safety can be improved.

Further, by forming the photoelectric conversion film with an organic film, it is possible to realize a low-cost, large-screen imaging device. Furthermore, by using a fluorescent material as a member to be embedded between adjacent pixels of the phosphor film, light generated by the phosphor can be more effectively guided to the photoelectric conversion film, and the sensitivity can be improved. Become.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
FIG. 5 is a sectional view of an element structure showing one pixel portion of the X-ray imaging apparatus according to the embodiment.

On a first glass substrate 10, a gate electrode 1
1, a thin film transistor (TFT) 20 including a gate insulating film 13, a semiconductor layer 14, a source / drain electrode 15, a stopper insulating film 16, and the like, and a capacitor (signal storage) including a lower electrode 12, a capacitor insulating film 13, an upper electrode 15, and the like. Part) 20 is formed. One of the source and the drain of the TFT 10 as a signal readout unit and the capacitor 20
Are electrically connected to each other, and a protective insulating film 17 and a planarizing layer 18 are formed thereon, and a pixel electrode 19 is formed thereon so as to be electrically connected to the upper electrode of the capacitor 30. Is formed. The above-mentioned one pixel portion is arranged in a matrix to constitute an array substrate.

On the other hand, a metal reflection film 101 and a phosphor film 102 are formed on a second glass substrate 100. The phosphor film 102 is etched in the depth direction between adjacent pixels, and a groove formed by this etching is filled with a reflective material 103 that reflects X-rays. Phosphor film 102
On the reflective material 103, an ITO film 104 as a transparent electrode is formed. On the ITO film 104, an n-type organic film 105, an i-type organic film 106,
A p-type organic film 107 is formed, and a pixel electrode 108 is formed thereon.
Are formed. The pixel electrode 108 is connected to the pixel electrode 19 on the array substrate by a connection pillar 109 made of a conductor.

Next, the device structure of FIG. 1 will be described in more detail according to the manufacturing process. First, on the first glass substrate 10, MoTa, Ta, TaN, Ta / TaNx, Al,
After depositing a metal film such as an Al alloy, Cu, or MoW to a thickness of 300 nm, patterning is performed by photolithography to form a pattern of the gate electrode 11 and the capacitor lower electrode 12, and further, a Cs line and an address line (not shown). Formed.

Next, 300 nm of SiOx and 50 nm of SiNx are used as the insulating film 13 by the plasma CVD method.
Are stacked, and the undoped a-Si film 14 is further
m, a stopper SiNx film 16 was deposited to a thickness of 200 nm. Subsequently, the stopper SiNx film 16 in the TFT portion is patterned according to the gate by using backside exposure. Further, after depositing an n ⁺ a-Si film (not shown) to a thickness of 50 nm, the n ⁺ a-Si and a-Si in the TFT portion were etched to form a-Si islands.

Next, Mo 50 nm / Al 350 nm /
After sputtering 50 nm of Mo or 20 nm of Mo, patterning into a desired pattern was performed to form source / drain electrodes, capacitor upper electrodes, and wirings 15 serving as signal lines. With this, the switching TFT
20 and the capacitor 30 are manufactured, and a protection diode TFT (not shown) is manufactured.

Next, SiNx was deposited to a thickness of 200 nm as a protective insulating film 17. In addition, BCB
To form a flattening layer 18 having a thickness of 1 to 5 μm, preferably 3 μm, to flatten the surface. Then, TFT2
After forming contact holes to the source electrodes of the TFTs 0, 30 and the protection diode TFT (not shown), an ITO film having a thickness of 100 nm was formed as the pixel electrode 19. At this time, the ITO pixel electrode 19 is
0, the capacitor 30 and the like are planarly covered.

On the other hand, a second glass substrate different from the first glass substrate 10
A metal reflective film 1 of Al or the like is formed on the entire surface on the glass substrate 100.
01 is formed to a thickness of 100 nm to 1 μm. The reflective film 101 may be a metal having a high X-ray transmittance of 90% or more and a high visible light reflectance of 50% or more. Further, the substrate 100 is not limited to glass, and a metal substrate may be used.

Next, Gd ₂ O ₂ S is formed on the reflection film 101;
The phosphor film 102 of Pr (GOS) has a thickness of 50 μm to 1 mm,
Preferably, it is formed to a thickness of 100 to 300 μm. Then, a groove is formed by selectively etching the phosphor film 102 in accordance with the pixel pattern. The etching for forming the groove may be wet etching or dry etching. For wet etching, the etchant may be selected in accordance with the phosphor, when the phosphor GOS or the like, can be etched by HC1, HNO _3, HF, or a mixture. After etching,
It is preferable to improve the crystallinity of the phosphor film 102 by annealing at about 1000 ° C.

Next, a reflecting material 103 that reflects fluorescence is buried in a groove provided in the phosphor film 102. Since the fluorescence from the phosphor film 102 has a large visible light range, light having this wavelength may be reflected. The material to be filled in the groove is preferable because a fluid material is simple in process. For example,
A reflective or scattering material such as silver paint or TiO _{2 in} which silver is dispersed in an epoxy resin may be dispersed in a polymer. Further, graphite, pigment, and the like may be dispersed in the polymer. These fluid materials are flattened with a squeegee or the like after the application. Further, a metal may be embedded. As a method thereof, a metal may be buried in the groove by vapor deposition, sputtering, or the like, and then polished and flattened.

Next, the phosphor film 102 and the reflection material 10
3 on the ITO film 1 as a transparent conductive film by sputtering
04 is formed to a thickness of about 100 nm. Here, before forming the ITO film 104, the phosphor film 102 and the reflective material 1 are formed.
03, a transparent insulating film may be provided.

Next, a hole transport layer (n-type organic film) 105 is formed on the ITO
A thickness of 1 μm, a photoelectric conversion film (i-type organic film) 106 as an organic photosensitive film is applied to a thickness of 1 to 100 μm, and an electron transport layer (p-type organic film) 107.
Using an oxadiazole derivative, 0.1 to 50 μm,
Preferably, it is applied and formed to a thickness of about 10 to 30 μm. Here, the thickness of the organic photosensitive film is preferably about 5 μm, but the light generated in the phosphor film 102 (GOS has a wavelength of about 5 μm).
00 nm). The organic photosensitive film is obtained by mixing 40% by weight of diphenylhydrazine with polycarbonate. A dye or pigment such as diphenylhydrazine is mixed in an amount of 1 to 40 mol%, preferably 1 mol%.

Next, about 100 n is formed on the p-type organic film 107.
m of Al or MgAg or the like to form a pixel electrode 10
8 is formed.

Next, connection pillars 109 are formed from a conductive adhesive resin such as epoxy containing a dye or a pigment or an adhesive electron transport material, and these are connected to the pixel electrodes 19 on the first glass substrate 10. Pixel electrode 10 on second glass substrate 100
8 and the two substrates 10 and 100 are bonded and connected. Finally, the address electrodes and the signal electrodes of the first glass substrate 10 are connected to peripheral driving circuits, and the X-ray imaging device of the present embodiment is completed. The resistance of the connection electrode 109 may be 100 MΩ or less.

FIG. 2 is a diagram showing a circuit configuration of the X-ray imaging apparatus of the present embodiment. One pixel is composed of the TFT 1 (20), the pixel electrode 2 (19, 108 and the phosphor film 102, the photoelectric conversion film 106), and the capacitor 3 (30). It is in the form of an array. A bias voltage is applied to the photoelectric conversion film of the pixel electrode 2 by a power source (not shown). The TFT 1 is connected to a signal line 6 and a scanning line 7, and is turned on and off by a scanning line driving circuit (gate driver) 8. The end of the signal line 6 is connected to an amplifier 9 for signal detection through a changeover switch. In addition, the protection T
An FT 4 is provided, and the TFT 4 is biased by a power source (not shown).

In this configuration, the charge generated in the photoelectric conversion film by the light emission of the phosphor film is stored in the capacitor 3, and the charge stored in the capacitor 3 is driven by driving the scanning line 7 to turn on the TFT1. The signal is read out to the signal line 6. After being amplified by the amplifier 9, it is extracted outside.

FIG. 3 is a plan view showing a configuration of one pixel of the X-ray imaging apparatus of the present embodiment. One pixel includes a reading TFT 1, a pixel electrode 2, a protection diode (not shown),
It comprises a Cs auxiliary electrode 5, a signal readout line (signal line) 6, and a gate line (scanning line) 7. However, in FIG.
The protective film, the common electrode, the phosphor film, the photoelectric conversion film, and those disposed outside the pixel are omitted. As an example of the function, the capacitor 3 includes the pixel electrode 2 and the auxiliary electrode 5 for Cs. The switching TFT 1 may be used as the protection diode.

FIG. 4 is a side sectional view showing the overall configuration of the X-ray imaging apparatus according to the present embodiment. The peripheral portions of the two substrates 10 and 100 are hermetically sealed with an epoxy resin 40 or the like. As a result, deterioration of element characteristics due to moisture can be prevented. In order to release heat from the pixel portion, the metal reflection film 101 on the entire surface of the second substrate 100 is preferably made of a metal having good heat conductivity. Copper may be used instead of Al.

The organic photosensitive film 106 is formed by mixing Alq ₃ , azo pigment, squarylium pigment, phthalocyanine pigment, oxytitanium, titanylphthaloanine pigment, and perylene pigment with polyvinyl butyral and polycarbonate. The thickness of the organic photosensitive film 106 depends on the reflective material 1
It is effective for making the characteristics uniform that the thickness is larger than the size of the unevenness at the end of the pixel 03. For this reason, about 0.3 to 3 μm is optimal. If the thickness is too large, the carrier transport characteristics slightly deteriorate. Before forming the ITO film 104, a transparent insulating film such as SiO ₂ which transmits fluorescence may be provided.

As described above, according to the present embodiment, a groove is formed in the phosphor film 102 in accordance with the pixel pattern, and the reflecting member 103 is buried in the groove. Can be prevented from reaching adjacent pixels. For this reason, the resolution can be prevented from deteriorating due to stray light, and a high resolution can be realized.
In addition, since the reflection member 103 reflects the scattered light from the phosphor film 102 and guides the scattered light to the photoelectric conversion film 106, the sensitivity can be improved. Further, by forming the photoelectric conversion film 106 with an organic film, a large-screen imaging device can be realized at low cost.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention.
FIG. 2 is a sectional view of an element structure showing one pixel portion of the X-ray imaging apparatus according to the embodiment. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

This embodiment is different from the first embodiment described above in that amorphous Si (a-Si) is used as a photoelectric conversion film instead of an organic film. Hereinafter, description will be given according to the manufacturing process.

As in the first embodiment, the TFT 20, the capacitor 30 and the like are formed on the first glass substrate 10 to produce an array substrate.

On the other hand, Ti is placed on the second glass substrate 200.
O ₂ and the metal higher in admixture reflectance SiO ₂ such as a reflective film 2
07 is formed. The reflective film 207 may have a high X-ray transmittance of 90% or more and a high visible light reflectance of 50% or more. As a method for forming the metal reflection film 201,
TiO ₂ and spin-on-glass may be mixed, applied by a spinner, and then fired. 100n thickness
m to 1 μm. Then, as in the first embodiment, the phosphor film 202 is formed on the metal reflective film 207 by 100 to 100 μm.
It is formed to a thickness of 300 μm, and is etched according to the pixel pattern to form a groove.

Next, a reflecting material 203 that reflects fluorescence is buried in a groove provided in the phosphor film 202. Since the fluorescent light from the phosphor film 202 has a large visible light range, the reflective material 203 may reflect light of this wavelength. The reflective or absorbing material to be filled in the groove is preferable because the flowable material is simple in process. For example, a spin-on glass may be mixed with a heat-resistant metal such as Al or Ta and spin-coated, or a reflective or scattering material such as TiO ₂ may be dispersed in the spin-on glass. Further, graphite may be dispersed in the spin-on glass. These fluid materials are flattened with a squeegee or the like after the application. And 300-800
The spin-on-glass is converted into SiO ₂ by firing at ℃.

Instead of using spin-on-glass as described above, a metal such as Al may be directly buried in the groove. As a method thereof, a metal may be buried in the groove by vapor deposition, sputtering, or the like, and then polished and flattened.

Next, the phosphor film 202 and the reflection material 20
3 on the IT as a transparent conductive film 204 by sputtering.
An O film or a SnO ₂ film is formed with a thickness of about 100 nm. here,
Before forming the transparent conductive film 204 of ITO or the like, the fluorescent film 202 and the reflective material 203 are coated with SiO ₂ that transmits fluorescence.
And the like may be provided.

Next, a p-type a-
An Si (or p-type a-SiC) film 205 is deposited by a 50 nm glow discharge, followed by a non-dove a-Si film 206.
Is deposited to a thickness of 1 to 3 μm, and furthermore, n-type a-Si
(Or n-type a-SiC) film 207 is formed to a thickness of about 50 nm by plasma CVD. Here, the thickness of the a-Si film 206 as a photosensitive film is preferably 2 μm, but the light generated by the phosphor (GOS has a wavelength of about 500 nm).
m).

Next, on the n-type a-Si film 207, about 10
The pixel electrode 208 is formed by forming Mo or Ti having a thickness of 0 nm by sputtering or vapor deposition. Note that the unevenness of the substrate 200 containing a reflective or absorptive material is
Or smaller than the thickness of the p-type a-Si film 205.

Next, connection pillars 109 are formed in the same manner as in the first embodiment, and are connected to the pixel electrodes 19 on the first glass substrate 10 and the pixel electrodes 20 on the second glass substrate 200.
8 and the two substrates 10 and 200 are bonded and connected. Finally, the address electrodes and the signal electrodes of the first glass substrate 10 are connected to peripheral driving circuits, and the X-ray imaging apparatus of the present embodiment is completed.

In the X-ray imaging apparatus thus configured, as in the first embodiment, a groove is formed in the phosphor film 202 according to the pixel pattern, and the reflecting member 2 is formed in the groove.
Since 03 is buried, it is possible to prevent light generated by the phosphor 202 from reaching adjacent pixels. Therefore, the same effect as that of the first embodiment can be obtained.

(Third Embodiment) FIG. 6 shows a third embodiment of the present invention.
FIG. 2 is a sectional view of an element structure showing one pixel portion of the X-ray imaging apparatus according to the embodiment. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the first and second embodiments, the phosphor and the photosensitive film are formed on different substrates, but they may be formed on a TFT array substrate. As an example of a configuration similar to that of FIG. 1, as shown in FIG. 6, a p-type organic film 107, an i-type organic photosensitive film 106, and an n-type organic photosensitive film 106
A type organic film 105 and an ITO film 104 are formed. A phosphor film 102 is formed thereon via a transparent insulating film (not shown). Then, after the phosphor film 102 is separated by wet etching according to the pixel pattern, a reflective or absorbing material 103 is embedded, and a reflective film 101 such as TiO ₂ is formed thereon. Further, this upper portion protects the glass substrate 100 by bonding it to the array substrate 10 with epoxy or the like.

With such a configuration, only one substrate is required for device formation, and the process can be simplified.

(Modification) The present invention is not limited to the above embodiments. The order of the photoelectric conversion films is p
-In or nip. This is the same for an organic photosensitive film and an inorganic photosensitive film. Further, the TFT may be formed of a-Si or poly-Si.

In the present invention, metal oxides, metal iodides, and metal sulfides can be used as the phosphor film.
Specifically, Gd ₂ O ₂ S; Tb, CsI, ZnS, Y _x
Gd _{2- x} O ₃ , CdWO _{4 and the} like are preferred. Particle size is 1
The diameter is 100 μm, preferably 3 μm. Since these substances have a large absorption coefficient of X-rays, a thin film can sufficiently absorb X-rays, and the effect of high emission efficiency by X-rays can be obtained.

As the organic photosensitive film material, a material in which at least one of hydrogen, oxygen, and nitrogen is bonded to carbon or silicon, particularly a metal complex thereof can also be used. These substances have a feature that they have high carrier mobility as an organic substance. In particular, TPD, Alq ₃ , polyphenylenevinylene, polyalkylthiophene, polyvinylcarbazole, triphenylene, liquid crystal molecules, metal phthalocyanine, and the like are more preferable because of their high carrier mobility.

When an organic photosensitive film is used, the electron transport layer (p-type organic film) and the hole transport layer (n-type organic film) have a carrier mobility of about 1 to obtain sufficient conductivity. × 10
^-7 cm ² Vsec or more, and preferably a resistivity of about 1 × 10 ⁸ Ωcm or more to prevent an increase in dark current. The electron transporting layer and the hole transporting layer are made of n-type and p-type semiconductors, respectively, and are preferably organic films in terms of manufacturing cost. However, inorganic semiconductors such as Si and GaAs may be used in terms of characteristics. Further, at least one of an oxadiazole derivative and Alq ₃ can be used as the electron transport layer. These substances have the effect of having high electron mobility. Further, as the hole transport layer, TP
At least one of D and diamine can be used.
These substances have the effect of having a high hole mobility. The order of the photosensitive films may be pin or nip, and may be selected according to the driving pulse.

In this embodiment, the first substrate is a TFT
Any material may be used as long as the second substrate is capable of sufficiently transmitting X-rays. Since the phosphor film and the like can be applied and formed at a low temperature, it is possible to use a plastic or the like having low heat resistance. Is also good. By using such a material for the substrate, the entire X-ray imaging apparatus can have plasticity. Furthermore, since it is lightweight, it is easy to carry.

In this embodiment, a-Si is used as Si for forming the TFT, but it may be formed of polysilicon (p-Si). When formed with p-Si, p-Si
The high mobility of the TFT makes it possible to reduce the size of the TFT, so that the effective area of the pixel is enlarged, and the peripheral circuit can be formed on the same glass substrate, thereby reducing the manufacturing cost including the peripheral circuit. There is also. The structure of the TFT may be either above the gate or below the gate.

The protective insulating film and the stopper film (16, 17) of the TFT are made of inorganic SiNx or SiNx.
O ₂ , and also organic polyimides (ε = about 3.3, withstand voltage about 300 V / mm), benzocyclobutene (BCB)
(Ε = about 2.7, withstand voltage about 400V / mm), JSR
Acrylic photosensitive resin HRC (ε = about 3.2) manufactured by
A black resist or the like may be used, and these may be laminated as needed. Fluorine resin also has a small relative dielectric constant (ε =
About 2.1), so it is effective. In addition, although it is not necessary to be photosensitive, a photosensitive material is more effective because patterning is easier.

In addition, various modifications can be made without departing from the spirit of the present invention.

[0063]

As described above in detail, according to the present invention, X
Since the phosphor film that generates fluorescence by the incidence of a line is separated for each pixel, and a member that reflects or absorbs X-rays is embedded between adjacent pixels, light emitted by the phosphor enters the adjacent pixels. Can be prevented. Therefore, the resolution is not degraded due to the stray light, thereby improving the resolution. Further, since a dangerous material such as Se used in the direct conversion type is not used, a highly safe device can be realized.

[Brief description of the drawings]

FIG. 1 is an element structure cross-sectional view showing one pixel portion of an X-ray imaging apparatus according to a first embodiment.

FIG. 2 is a diagram illustrating a circuit configuration according to the first embodiment.

FIG. 3 is a plan view showing a configuration of a plurality of pixels in the first embodiment.

FIG. 4 is a side view showing the overall configuration in the first embodiment.

FIG. 5 is an element structure cross-sectional view showing one pixel portion of the X-ray imaging apparatus according to the second embodiment.

FIG. 6 is an element structure sectional view showing one pixel portion of an X-ray imaging apparatus according to a modification of the present invention.

[Explanation of symbols]

 1, 20 TFT (signal readout unit) 2 pixel electrode 3 storage capacitor (signal storage unit) 4 protection diode 5 auxiliary electrode line 6 signal readout line 7 gate line (scan line) 8 gate driver circuit 9 Integrating amplifier circuit 10 First glass substrate 11 Gate electrode 12 Capacitor electrode 13 Gate insulating film 14 a-Si layer 15 Wiring 16 SiNx stopper film 17 Protective insulating film 18 Flattening layer 19 ... Pixel electrodes 100 and 200 Second glass substrate 101 and 201 Metal reflective film 102 and 202 Phosphor film 103 and 203 Reflective material 104 and 204 ITO (transparent electrode) 105 n-type organic film 106 Carrier Transport layer 107 p-type organic film 108, 208 pixel electrode 109 connection column 205 p-type a-Si film 206 i-type a-Si film 207 n Type a-Si film

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masami Atsuta 1 Toshiba R & D Center, Komukai Toshiba-cho, Saisaki-ku, Kawasaki-shi, Kanagawa Prefecture No. 1 F-term in Toshiba Nasu Factory (reference) 2G083 AA02 AA10 BB01 CC02 CC10 DD20 EE02 2G088 EE02 FF02 GG13 GG19 GG20 GG21 JJ05 JJ29 JJ37 5F088 AA03 AA20 AB05 BA20 BB03 BB07 EA04 EA08 EA08 EA08 EA08 EA08

Claims (5)

[Claims] 1. An array substrate in which unit pixels each comprising a signal accumulating section for accumulating signal charges and a signal reading section for reading out the accumulated signal charges are arranged in a matrix on a substrate, and the array substrate is provided on the array substrate. A photoelectric conversion film that is provided to be electrically connected to the signal storage unit of each pixel and converts light into an electric signal; and a phosphor film that is provided on the photoelectric conversion film and converts X-rays into light. An X-ray imaging apparatus comprising: the phosphor film is separated for each pixel;
An X-ray imaging apparatus, wherein a member that reflects or absorbs a ray is embedded. 2. An X-ray imaging apparatus according to claim 1, wherein said photoelectric conversion film is formed of amorphous Si or an organic material. 3. A pixel electrode, which is electrically connected to a signal storage unit for each pixel, is disposed on an uppermost layer of the array substrate. Is provided on another photoelectric conversion substrate, and has a second pixel electrode electrically connected to a photoelectric conversion portion on the uppermost layer of the photoelectric conversion substrate, wherein the first and second pixel electrodes are 2. The X-ray imaging apparatus according to claim 1, wherein the X-ray imaging apparatus is electrically connected by a connection pillar. 4. The member embedded in the phosphor film between pixels is a fluid material in which particles reflecting or absorbing X-rays are dispersed in a resin or a polymer. An X-ray imaging apparatus according to claim 1. 5. A step of manufacturing an array substrate on a first substrate, in which unit pixels each including a signal storage section for storing signal charges and a signal reading section for reading the stored signal charges are arranged in a matrix. Forming a phosphor film for converting X-rays into light on the second substrate; forming a groove by etching the phosphor film so as to separate the phosphor film into pixels; A step of forming a member that absorbs or reflects a line, a step of forming a photoelectric conversion film for converting light into an electric signal on the phosphor film, and a step of forming a signal storage portion of the first substrate and a second substrate. Connecting the first and second substrates with connection pillars so as to be electrically connected to the photoelectric conversion film.