JP2000319773A - Production of selenium layer in x-ray detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the crystallization of selenium layers vapor-deposited on planar substrates, the peeling of the selenium layers, or the like, by suppressing the increase of the temps. of the planar substrates and to film- thicken the selenium layers in an X-ray detector. SOLUTION: The outer circumferential face 5a of a mandrel 2 with the shape of a hexagonal prism deposited in a vacuum deposition tank is mounted with plural pieces of planar glass substrates 8, rotation is executed, selenium 20 is evaporated from a selenium evaporating source 3 arranged in the lower direction of the mandrel 2, and the selenium 20 is discontinuously vapor- deposited on the planar glass substrates 8 to form selenium layers, moreover, a heat medium is passed through a flow passage 4 provided in the proximity of the outer circumference 5a of the mandrel 2 to suppress the increase of the temps. of the planar glass substrates 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a selenium layer formed on a flat substrate such as glass or aluminum in an X-ray detector.

[0002]

2. Description of the Related Art Conventionally, as this type of X-ray detector, for example, a zero radiograph system disclosed in Japanese Patent Application Laid-Open No. 52-36034 is known. In this technique, a selenium layer formed on an aluminum substrate is charged in advance by corona discharge, and an electrostatic latent image on the selenium layer when X-rays are irradiated is imaged by an electrophotographic method. The selenium layer is formed by vapor deposition, an aluminum substrate is attached to a mandrel arranged in a vacuum vapor deposition tank, and selenium is vapor-deposited for about 80 minutes while rotating the mandrel to a thickness of about 300 μm.
m to form a selenium layer.

By the way, it is necessary to increase the quantum efficiency with respect to X-rays in order to increase the sensitivity of the detector. Therefore, it is advantageous to increase the thickness of the selenium layer. For example, the direct conversion method proposed in recent years is about 100-
A 200 μm pixel was provided, and each pixel was provided with a function of collecting charges generated by X-rays, a function of accumulating charges, and an electric switch function of reading the amount of accumulated charges. A selenium layer and an electrode layer were provided on this substrate. Although it has a structure, there are two different photographing modes when photographing for medical use in this method. One is a still image shooting mode for shooting a stationary object, and the other is a moving image shooting mode for shooting a moving object. In the still image shooting mode, the selenium layer can be used even if the sensitivity of the detector is low.
Although it may be about 0 μm, it is necessary to read an image of 30 frames per second in the moving image shooting mode. Therefore, the detector is required to have high sensitivity and the thickness of the selenium layer needs to be about 1000 μm or more.

[0004]

However, in the above-mentioned conventional method for forming a selenium layer, the selenium layer is crystallized during vapor deposition or peels off from the substrate, and the number of appearance defects on the selenium layer surface increases. It was difficult to form a selenium layer in a thick film, and it was not possible to stably form a selenium layer having a thickness of about 1000 μm, which is necessary for the above-described moving image shooting.

Therefore, the inventor of the present application has solved the above-mentioned problem by obtaining the following knowledge, and has found a manufacturing method capable of stably forming a thick selenium layer. It is intended to provide an X-ray detector which is useful in the medical field and various industries when used.

[0006] It is difficult to form a thick selenium layer because the selenium layer is crystallized during vapor deposition, the selenium layer peels off from the substrate, and the appearance defects on the selenium layer surface increase as described above. However, the biggest cause of crystallization of the selenium layer is that the substrate temperature increases when the thickness of the selenium layer deposited on the substrate is increased. That is,
This is because the heat of evaporation from the selenium layer deposited on the substrate is proportional to the film thickness. Therefore, as the selenium layer becomes thicker, the amount of heat received by the substrate increases and the substrate temperature rises. Further, even when the thickness of the selenium layer is constant, if the surface area of the selenium layer is increased, the amount of heat received by the substrate increases, and the substrate temperature increases.

As described above, as the thickness of the selenium layer increases and as the deposition area increases, the substrate temperature rises and crystallization of the selenium layer progresses. Therefore, in order to increase the thickness and area of the selenium layer, the temperature of the selenium evaporation source must be lowered, or the distance between the selenium evaporation source and the substrate must be set large, and the selenium layer deposition rate per unit time must be increased. Is considered to reduce the evaporation heat released from the selenium layer to suppress the rise in the substrate temperature. However, this method requires a long deposition time for one batch, resulting in extremely poor productivity. A problem arises. Further, as the deposition time becomes longer, the appearance defects on the surface of the selenium layer tend to increase, which causes a problem in image quality.

In order to solve the above-mentioned problems, in the present invention, by increasing the temperature of the flat substrate during vapor deposition, the selenium layer can be easily made thicker and the vapor deposition area can be increased, and the vapor deposition time can be reduced. Provided is a method for producing a thick selenium layer which has high productivity by reducing the length and has few appearance defects on the surface of the selenium layer.

[0009]

According to a first aspect of the present invention, there is provided a method of manufacturing a selenium layer in an X-ray detector, comprising the steps of: A plurality of planar substrates are attached to the peripheral surface of the substrate, and selenium is intermittently vapor-deposited on the planar substrate to form a selenium layer. At the time of the vapor deposition, the temperature of the planar substrate is suppressed by passing a heat medium into the support. It is characterized by the following.

According to a second aspect of the present invention, there is provided a method for manufacturing a selenium layer in an X-ray detector, wherein a flow path of a heat refrigerant is formed inside the support at a position close to a mounting surface of a flat substrate. It is characterized by being.

According to a third aspect of the present invention, there is provided a method of manufacturing a selenium layer in an X-ray detector, wherein the support is a rotatable polygonal column-shaped mandrel, and a flat substrate is mounted on a peripheral surface of the mandrel. And selenium is intermittently vapor-deposited on a flat substrate by directional evaporation from a selenium evaporation source arranged facing the peripheral surface of the mandrel.

According to a fourth aspect of the present invention, in the method of manufacturing a selenium layer in an X-ray detector, the polygonal prism mandrel is a hexagonal prism.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a selenium layer in an X-ray detector, wherein the length of each side of the peripheral surface of the polygonal column-shaped mandrel is 250 mm or more. .

According to a sixth aspect of the present invention, in the method for manufacturing a selenium layer in an X-ray detector, the temperature of a heat medium passed through the inside of the support is set to 60 ° C. or less, and the flat substrate is cooled during selenium deposition. It is characterized by doing.

According to a seventh aspect of the present invention, in the method for manufacturing a selenium layer in an X-ray detector, the flat substrate is a flat glass substrate having an electrode film or a thin film transistor circuit formed on a glass plate. It is characterized by.

Further, according to a method of manufacturing a selenium layer in an X-ray detector according to claim 8 of the present invention, a selenium layer having a thickness of 200 μm or more is formed on the flat glass substrate.
An electrode layer is provided on the selenium layer.

According to a ninth aspect of the present invention, there is provided a method for manufacturing a selenium layer in an X-ray detector, wherein a voltage of 10 V is applied between the flat glass substrate and the electrode layer per 1 μm of the selenium layer. Dark current value is 0.1 nA / cm ^{2 to} 6
nA / cm ² .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for manufacturing a selenium layer in an X-ray detector according to the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 show a positional relationship between a rotatable mandrel 2 and a selenium evaporation source 3 installed in a vacuum evaporation tank. The mandrel 2 is formed of a hollow column having a regular hexagonal cross section, and is rotatably supported by a rotating shaft 7 protruding from the fixed wall 6. A flow path 4 for circulating the heat medium is formed inside the hexagonal wall along the outer peripheral surface 5a. A heat medium circulating between a supply pipe and a discharge pipe (not shown) flows through the flow path 4, and can control the temperature of the six flat substrates 8 attached to the outer peripheral surfaces 5 a of the mandrel 2. . A selenium evaporation source 3 is provided below the mandrel 2. The selenium evaporation source 3 is constituted by an upward-opening container extending in parallel along the mandrel 2, and the selenium 20 put in the container evaporates upward from an opening on the upper surface to form a flat substrate 8 attached to the mandrel 2. It is deposited on the surface from below.
Therefore, when the inside of the vacuum evaporation tank is maintained at a predetermined degree of vacuum and the selenium evaporation source 3 is raised to a predetermined temperature while rotating the mandrel 2 to evaporate the selenium 20, the six flat glass substrates 8 have Since the selenium 20 is deposited when it reaches the lower surface position facing the selenium evaporation source 3 and is not deposited when it is at a position outside the selenium evaporation source 3, intermittent deposition is possible as a result. By performing such intermittent vapor deposition, heat is radiated from the flat glass substrate 8 while the flat glass substrate 8 is not facing the selenium evaporation source 3, and the substrate temperature falls.

As described above, in the present invention, intermittent deposition of selenium 20 on the six flat substrates 8 and the flow channel 4 formed in the This is achieved by circulating the heat medium through the heat exchanger. In particular, since the flow path 4 is provided at a position close to the outer peripheral surface 5a of the mandrel 2, the heat medium having a low temperature is circulated so that the inner peripheral surface 5
a can be uniformly cooled.
The flat substrate 8 attached to the substrate a is uniformly cooled from the back side. When the thickness of the selenium layer increases, the amount of heat received by the flat substrate 8 also increases, so that it is necessary to set the temperature of the heat medium low. However, by setting the temperature of the heat medium to 60 ° C. or less as described later. Even when the thickness is increased, selenium does not crystallize.

Although the size of the mandrel 2 is not particularly limited, the X-ray flat detector used for medical purposes is 250 mm × 250 mm to 500 mm × 500 m.
Since a size of m is required, the width dimension W and the length dimension L of the outer peripheral surface 5a of the mandrel 2 are desirably 250 mm or more in order to cope with this.

In the present invention, as the flat substrate on which selenium is deposited, it is preferable to use a glass plate having a smooth-polished surface as a base substrate. Then, ITO (Indium Tin Oxid) is formed on the entire upper surface of the glass plate.
e) A flat glass substrate on which an electrode film is provided, a flat glass substrate on which a plurality of strip-shaped electrode films are arranged in parallel, and a flat glass substrate on which a large number of thin film transistor circuits are mounted in a matrix are used. Selenium is deposited on a flat glass substrate from above. The thin film transistor circuit has a charge collecting electrode, a charge storage capacitor, and a thin film transistor arranged in a pixel of 100 to 200 μm square. In addition to a glass plate, a metal plate such as an aluminum plate or a nickel plate can also be used. However, since these have conductivity, a selenium layer can be directly formed thereon. Further, a circuit board using an active element other than the thin film transistor can be used as a flat substrate. In any case, the thickness of the planar substrate is not particularly limited.

The selenium 20 deposited in the present invention includes not only selenium alone but also an alloy of selenium and arsenic, an alloy of selenium and tellurium, and the like.

The cross-sectional shape of the mandrel 2 is not limited to the above regular hexagonal shape as long as it is a polygonal shape having a peripheral surface on which the flat substrate 8 can be mounted. When mounting the planar substrate 8,
If the shape is a heptagon or more, the diameter of the mandrel 2 becomes too large, and it is difficult to install the mandrel 2 in a vacuum evaporation tank. In addition, since the selenium film thickness variation tends to increase in one flat substrate 8 below the pentagonal shape, the hexagonal shape is preferable in consideration of the size of the mandrel 2 and the selenium film thickness variation.

FIG. 3 shows another embodiment of the mandrel 2 in which the cross-sectional shape of the inner peripheral surface 5b is formed of a regular decagonal hollow column. A flow path 4 for circulating the heat medium is formed all around the wall of the mandrel 2, and the heat medium is circulated in the flow path 4 to be attached to the inner peripheral surface 5 b of the mandrel 2. 10 flat substrates 8
Can be cooled. Further, in this embodiment, the selenium evaporation source 3 is arranged upward at the center of the mandrel 2, and the selenium 20 is deposited while rotating the mandrel 2, so that the ten flat substrates 8 are 3
The selenium 20 is deposited when rotated to the upper surface position facing it, and is not deposited when located at other positions, so that intermittent deposition is possible.

Next, an embodiment in which an X-ray detector is formed using a flat substrate on which a thick selenium layer is formed by the above-described manufacturing method will be described. FIG. 4 is an overall configuration diagram of the X-ray detector 10. Among them, reference numeral 8 denotes the above-mentioned flat glass substrate, on which a number of pixels 12 composed of a thin film transistor circuit are mounted on the upper surface of a glass plate 11. Reference numeral 13 denotes a flat glass substrate 8 by the above-described manufacturing method.
The selenium layer 14 formed thereon is an electrode layer.

The electrode layer 14 is formed by depositing or sputtering gold, silver, aluminum, or another conductive material. The thickness of the electrode layer 14 is 0.05 μm or more.
It is in the range of 3.0 μm.

The X-ray detector 10 constructed as described above
In the above, a DC high voltage 15 is applied between the electrode layer 14 and the plane substrate 8 and the selenium layer 13 is irradiated with X-rays 16 so that charges corresponding to the X-ray intensity are converted into electrostatic latent images as selenium layers 13 Occurs during. This charge is DC high voltage 15
Moves through the selenium layer 13 to the flat glass substrate 8 side,
It is stored in each corresponding pixel 12. The stored charges are sequentially read by the thin film transistor of each pixel 12 to form an image.

In the X-ray detector 10, the space between the flat glass substrate 8 and the selenium layer 13 and the selenium layer 13
A charge injection blocking layer (not shown) made of an organic film such as a polycarbonate resin is provided on at least one of the selenium layer 13 and the electrode layer 14 when a voltage is applied.
It is possible to effectively prevent charge injection into the inside. Since the polycarbonate resin has good adhesiveness, the flat glass substrate 8
When provided between the selenium layer 13 and the selenium layer 13, the selenium layer 13 also has an effect of effectively preventing the thick selenium layer 13 deposited thereon from peeling off from the flat glass substrate 8.

[0029]

As described above, according to the method for manufacturing a selenium layer in an X-ray detector according to the present invention, the selenium layer is formed while suppressing the temperature rise of the flat substrate. Even if the selenium layer is deposited thick,
Crystallization of the selenium layer, separation of the selenium layer from the substrate, and the like were prevented, and a high-quality thick selenium layer with few appearance defects on the selenium layer surface was obtained.

Further, according to the manufacturing method of the present invention, it is not necessary to reduce the film forming rate when forming a thick selenium layer. Method.

When an X-ray detector is manufactured using a selenium layer according to the manufacturing method of the present invention, a high-quality large-screen image can be obtained. This is useful as a line detector.

[0032]

EXAMPLE 1 A regular hexagonal prism-shaped mandrel 2 and a selenium evaporation source 3 as shown in FIGS. 1 and 2 were placed in a vacuum evaporation tank. The size of the outer peripheral surface 5a of the mandrel 2 is 300 mm (W) ×
400 mm (L) and a size of 270 on each outer peripheral surface 5a.
Each of the flat substrates 8 mm × 300 mm and 1.1 mm thick was mounted. The flat substrate 8 used was Corning Co., Ltd. product number 7059 in which an ITO electrode film was formed on the upper surface of a glass plate. A heating medium at 60 ° C. was circulated in the flow path 4 formed inside the mandrel 2. The container of the selenium evaporation source 3 was made of stainless steel, and a predetermined amount of selenium 20 was put in the container. Distance H between selenium evaporation source 3 and flat substrate 8
Was set to 200 mm and the mandrel 2 was rotated at 6 RPM. A selenium layer having a thickness of 200 μm was intermittently deposited from a selenium evaporation source 3 set at 290 ° C. while maintaining a predetermined degree of vacuum. The deposition time at this time was 85 minutes.

Example 2 In Example 1, the thickness of the selenium layer was 400 μm.
Then, a selenium layer was deposited by the same method except that the temperature of the heat medium was changed to 40 ° C. The deposition time at this time was 190 minutes.

Example 3 In Example 1, the thickness of the selenium layer was 700 μm.
Then, a selenium layer was deposited by the same method except that the temperature of the heat medium was changed to 25 ° C. The deposition time at this time was 280 minutes.

Example 4 In Example 1, the thickness of the selenium layer was 1000 μm.
Then, a selenium layer was deposited by the same method except that the temperature of the heat medium was changed to 15 ° C. The deposition time at this time was 440 minutes.

Example 5 In Example 1, the thickness of the selenium layer was 1300 μm.
Then, a selenium layer was deposited by the same method except that the temperature of the heat medium was changed to 0 ° C. The deposition time at this time was 530 minutes.

Example 6 A selenium layer was deposited in the same manner as in Example 1 except that the flat glass substrate was changed to an aluminum substrate.

Example 7 In Example 6, the thickness of the selenium layer was 400 μm.
Then, a selenium layer was deposited by the same method except that the temperature of the heat medium was changed to 55 ° C.

Example 8 In Example 6, the thickness of the selenium layer was set to 700 μm.
Then, a selenium layer was deposited by the same method except that the temperature of the heat medium was changed to 45 ° C.

Example 9 In Example 6, the thickness of the selenium layer was 1000 μm.
Then, a selenium layer was deposited by the same method except that the temperature of the heat medium was changed to 35 ° C.

Example 10 In Example 6, the thickness of the selenium layer was 1300 μm.
Then, a selenium layer was deposited by the same method except that the temperature of the heat medium was changed to 20 ° C.

COMPARATIVE EXAMPLE 1 In order to compare with the above embodiment, in the above embodiment 3,
The heat medium is extracted from the flow path 4 of the mandrel 2 and the outer peripheral surface 5
A selenium layer was deposited by the same method except that the flat substrate 8 was attached to the mandrel 2 having a temperature of 25 ° C.

Comparative Example 2 In Example 3, a flat substrate 8 was attached to the lower surface of the mandrel 2 facing the selenium evaporation source 3 and vapor deposition was continuously performed on the flat substrate 8 from the selenium evaporation source 3 without rotating the mandrel 2. At the same time, a selenium layer was deposited by the same method except that the shape of the selenium evaporation source 3 was reduced to reduce the amount of selenium 20 sprayed. The deposition time at this time was 48 minutes.

Comparative Example 3 In Example 4, a flat substrate 8 was mounted on the lower surface of the mandrel 2 facing the selenium evaporation source 3, and the evaporation was continuously performed on the flat substrate 8 from the selenium evaporation source 3 without rotating the mandrel 2. At the same time, a selenium layer was deposited by the same method except that the shape of the selenium evaporation source 3 was reduced to reduce the amount of selenium 20 sprayed. The deposition time at this time was 70 minutes.

COMPARATIVE EXAMPLE 4 In the above-mentioned Example 3, the heating medium was extracted from the flow path 4 of the mandrel 2, the temperature of the outer peripheral surface 5a was adjusted to 25 ° C., and the flat substrate was placed on the lower surface of the mandrel 2 facing the selenium evaporation source 3. 8 and continuously depositing from the selenium evaporation source 3 onto the flat substrate 8 without rotating the mandrel 2,
A selenium layer was deposited by the same method except that the shape of the selenium evaporation source 3 was reduced to reduce the amount of selenium 20 sprayed. The deposition time at this time was 48 minutes.

Comparative Example 5 A selenium layer was deposited in the same manner as in Comparative Example 1 except that the temperature of the evaporation source was lowered to 250 ° C. The deposition time at this time was 590 minutes.

Table 1 below shows the thickness of the selenium layer, the temperature of the heat medium, the type of the flat substrate, the vapor deposition method, and the state of the selenium layer after the vapor deposition in the above Examples and Comparative Examples.

[0048]

[Table 1] 〇: Good crystallization of the selenium layer and no peeling of the selenium layer from the flat substrate, and no appearance defects on the surface of the selenium layer. ×: At least one of the following (1) to (4) is observed. (1) Crystals are generated in the selenium layer at the interface with the flat glass substrate. (2) Crystals are generated on the selenium layer surface. (3) Separation of the selenium layer from the flat glass substrate. (4) There are many appearance defects on the selenium layer surface.

From the results of the above example, it is found that the selenium layer is not crystallized even if the selenium layer has a large thickness and the deposition area is large, there is no appearance defect on the selenium layer surface, and the film is formed on a flat glass substrate. It turns out that it is also possible. Looking at the relationship between the film thickness and the deposition time, in the case of Example 1, the film thickness was 2 mm.
The deposition time is 85 minutes for 00 μm, and in the case of Example 3, the deposition time is 280 minutes for 700 μm. Comparing the two embodiments, the deposition time is about 3.3 times, which is almost equal to the film thickness of 3.5 times. In addition, comparing Example 1 and Example 5, the deposition time is about 6.2 times the film thickness of 6.5 times, which is almost the same. From this, in the manufacturing method of the present invention, even when the film thickness is formed as thick as 700 μm or 1300 μm, the selenium layer can be formed at substantially the same film formation rate as when the film thickness is 200 μm. Therefore, even when a thick selenium layer is formed, it is not necessary to reduce the film forming rate as in the related art, so that the vapor deposition time per batch is short and the productivity is good. On the other hand, when Example 1 and Comparative Example 5 are compared, the film thickness is 3.5 times, while the vapor deposition time is 6.9 times longer, and as a result, the vapor deposition per batch is performed. Time is long and productivity is poor.

Example 11 A selenium layer was vapor-deposited in the same manner as in Example 2 above, except that the evaporation source was selenium-arsenic (concentration: 0.3% by weight) and the evaporation source temperature was changed to 310 ° C.

Example 12 A selenium layer was vapor-deposited in the same manner as in Example 3 except that selenium / arsenic (concentration: 0.03% by weight) was used as the vapor deposition material and the temperature of the vaporization source was changed to 310 ° C.

In Embodiments 11 and 12,
Observation of the state of the selenium layer after vapor deposition showed that there was no crystallization of the selenium layer and no peeling of the selenium layer from the planar substrate, and there was no appearance defect on the surface of the selenium layer. Further, the production method of the present invention can also be used in the case of a selenium / arsenic alloy used as a deposition material.

Example 13 In Example 3, the size of the outer peripheral surface 5a of the mandrel 2 was set to 500 mm (W) × 500 mm (L), the size of the flat substrate 8 was set to 480 mm × 480 mm, and the temperature of the heat medium was changed. A selenium layer was deposited in a similar manner except that the temperature was increased to 15 ° C. and the amount of selenium sprayed to the evaporation source was increased.

Observation of the state of the selenium layer after vapor deposition in Example 13 showed that there was no crystallization of the selenium layer and no peeling of the selenium layer from the flat substrate, and there was no appearance defect on the surface of the selenium layer. .

Example 14 Next, the electrical characteristics of the thick selenium layer manufactured in the above example were measured, including variations. As shown in FIG. 5, as shown in FIG. 5, nine equally circular electrode layers 14 a are formed on the upper surface of the selenium layer 13 in each of Examples 1 to 13 and partial X-ray Flat detector 1
9 were fabricated on one thick selenium layer 13. The electrode layer 14a is formed by depositing gold to a thickness of 0.1 μm. A current extraction electrode 17 having a diameter of about 30 mm is provided at the center, and a ring-shaped ground electrode 18 is provided on the outer periphery.

The X-ray flat panel detector 10 manufactured in the embodiment 14 is set in a dark box where light is shielded, and the flat substrate 8 and the electrode layer 14a are applied to the nine detectors 10 in each embodiment.
The dark current when a voltage of 10 V was applied per 1 μm of the thickness of the selenium layer 13 was measured. What is dark current
This is a current flowing to the detector 10 when X-rays are not irradiated. If the dark current is large, the S / N ratio becomes small and a good image cannot be obtained. As a result of the measurement, any of Examples (1 to
13) The dark current value per unit area is 0.1
was nA ^/ cm ² ~6nA ^/ cm 2 and smaller range that can be used as an X-ray flat panel detector. Further, the X-ray current when X-rays were irradiated was at a level at which a current corresponding to the thickness of each selenium layer 13 was obtained and usable. From this, the selenium layer 13 of each example manufactured by the manufacturing method of the present invention is:
It shows that the electric characteristics are in a range that can be used as a flat panel detector, and that the variation in the flat substrate 8 is small.

Example 15 In Example 4 described above, a flat glass substrate on which an ITO electrode film was formed was replaced with a TFT matrix substrate having a size of 100 mm × 100 mm (a thin film transistor circuit comprising pixels of 150 μm square was arranged in a matrix on a glass plate). A selenium layer was formed in the same manner except that the selenium layer was changed to a selenium layer. After the selenium layer was deposited, it was taken out of the vacuum deposition tank, and a 0.1 μm-thick gold electrode layer was deposited on the selenium layer in another deposition tank to produce an X-ray detector 10 as shown in FIG.

In Example 15, the state, electrical characteristics, image characteristics and the like of the selenium layer of the X-ray detector were examined. (A) State of selenium layer after vapor deposition The selenium layer was not crystallized and the selenium layer was not peeled off from the flat substrate, and the surface of the selenium layer was good without any appearance defects. (B) Electrical characteristics In a dark box that shields light, 10
v (the polarity is the electrode layer 1 as shown in FIG. 4).
(A negative voltage was applied to the four sides.) Dark current was measured. The dark current per unit area is as small as 3 nA / cm ² , which is a level that can be used as a flat panel detector. Also, the X-ray current is at a usable level. (C) Image characteristics When the image was created, an image without image defects was obtained. Movie shooting was also possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a positional relationship between a mandrel and a selenium evaporation source for performing a manufacturing method according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG. 1;

FIG. 3 is a sectional view showing another embodiment of a mandrel and a selenium evaporation source.

FIG. 4 is a cross-sectional view of an X-ray detector using a selenium layer according to the present invention.

FIG. 5 is a plan view when a large number of small pieces of an electrode layer are arranged on a selenium layer.

[Explanation of symbols]

 2 Mandrel (support) 3 Selenium evaporation source 4 Flow path 5a Outer peripheral surface (peripheral surface) 5b Inner peripheral surface (peripheral surface) 8 Flat glass substrate (flat substrate) 10 X-ray flat panel detector 11 Glass plate 12 Pixel 13 Selenium layer 14 electrode layer 16 X-ray 20 selenium

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiko Shima 1014 Miyaharacho, Kofu City, Yamanashi Prefecture Inside (72) Inventor Naoki Uchida 1014 Miyaharacho, Kofu City, Yamanashi Prefecture Yamanashi Electronics Co., Ltd. F term (reference) 2H013 CZ01 4K029 AA09 BA02 BD00 BD01 CA01 DA08 EA01 EA08 EA09 JA01 JA02

Claims (9)

[Claims] A selenium layer is formed by intermittently depositing selenium on the flat substrate and mounting a plurality of flat substrates on a peripheral surface of a support provided in a vacuum deposition tank. A method for producing a selenium layer in an X-ray detector, wherein a heat medium is sometimes passed through a support to suppress a rise in the temperature of a flat substrate. 2. A method for manufacturing a selenium layer in an X-ray detector according to claim 1, wherein a flow path of a heat refrigerant is formed inside the support at a position close to a mounting surface of the flat substrate. Method. 3. The supporting body is a rotatable polygonal prism-shaped mandrel, and a flat substrate is mounted on the peripheral surface of the mandrel and rotated, and the support is rotated from a selenium evaporation source disposed opposite the peripheral surface of the mandrel. The method for producing a selenium layer in an X-ray detector according to claim 1, wherein selenium is intermittently vapor-deposited on a flat substrate by evaporating the selenium layer. 4. The method for manufacturing a selenium layer in an X-ray detector according to claim 3, wherein said polygonal prism mandrel is hexagonal prism. 5. The method for producing a selenium layer in an X-ray detector according to claim 3, wherein the polygonal columnar mandrel has a length of each side of a vertical surface and a horizontal surface of 250 mm or more. 6. The X-ray detector according to claim 1, wherein the temperature of the heat medium passed through the inside of the support is set to 60 ° C. or less, and the flat substrate is cooled during selenium deposition. Of producing a selenium layer in a vessel. 7. The X-ray detector according to claim 1, wherein the flat substrate is a flat glass substrate having an electrode film or a thin film transistor circuit formed on a glass plate. Method for producing selenium layer. 8. A film having a thickness of 200 μm on the flat glass substrate.
8. The method for producing a selenium layer in an X-ray detector according to claim 7, wherein the selenium layer is formed and an electrode layer is provided on the selenium layer. 9. A dark current value of 0.1 nA / cm ² to ⁶ nA / cm ² when a voltage of 10 V per 1 μm of selenium layer thickness is applied between the flat glass substrate and the electrode layer. The method for producing a selenium layer in an X-ray detector according to claim 8, wherein