JP4054168B2 - Imaging device and operation method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a photoconductive type imaging device, particularly with high sensitivity and high resolution with greatly improved photoelectric conversion efficiency and spectral sensitivity characteristics while suppressing an increase in dark current, an increase in afterimage and a deterioration in resolution. The present invention relates to a photoconductive imaging device capable of obtaining a high-quality image with high S / N and an operation method thereof.
[0002]
[Prior art]
It is known that when a high electric field is applied to amorphous selenium, a charge avalanche multiplication phenomenon occurs inside. A high-sensitivity image pickup tube of the avalanche multiplication method using this phenomenon or an amorphous selenium thin film is applied to 2 layers. A high-sensitivity solid-state imaging device laminated on a three-dimensional solid-state scanning IC substrate has been disclosed (Japanese Patent Application Nos. 7-29507, 63-174480, 7-192663).
[0003]
Since the avalanche multiplication phenomenon in amorphous selenium requires a high electric field of 5 × 10 ⁷ V / m or more, the injection of charges (holes) from the electrode to the amorphous selenium is prevented, and dark current is prevented. As a means for suppressing this, for example, a method of providing a cerium oxide thin film between a positive electrode and amorphous selenium is known.
[0004]
Moreover, since the band gap of amorphous selenium is about 2 eV and corresponds to photon energy with a wavelength of 620 nm, longer wavelength light is not absorbed and photoelectric conversion does not occur. On the other hand, because the human long-wavelength light visibility limit is approximately 750 nm, even if the above imaging device using amorphous selenium is used for a color camera, for example, the sensitivity to red light is insufficient and the color tone is faithfully reproduced. It is not possible to obtain a high-quality image. In order to solve this problem, at least one of Te, Sb, Cd, and Bi is added to a part of the amorphous selenium film (light incident side) to reduce the band gap, thereby reducing the light absorption edge. A method of shifting to the long wavelength side and extending the spectral sensitivity characteristic to the long wavelength side is known (Japanese Patent Laid-Open No. 62-004871).
[0005]
[Problems to be solved by the invention]
However, if the amount of the material added to amorphous selenium is too large or the addition region is not appropriate, problems such as a problem of spectral sensitivity characteristics, an increase in dark current and afterimage, and deterioration of resolution characteristics occur.
[0006]
An object of the present invention is to provide an imaging device that realizes spectral sensitivity characteristics suitable for a color camera and further high-efficiency photoelectric conversion characteristics in a state where the above problems are suppressed. Another object of the present invention is to apply a voltage that causes charge avalanche multiplication within the carrier multiplication layer to the translucent electrode made of the conductive thin film while suppressing the above problem. An object of the present invention is to provide an operation method of an imaging device that realizes a spectral sensitivity characteristic suitable for a color camera that can be used and a photoelectric conversion characteristic with higher efficiency.
[0007]
[Means for Solving the Problems]
In the present invention, in order to achieve the above object, a translucent electrode made of a conductive thin film, a hole injection blocking layer formed on the surface of the translucent electrode, and a surface of the hole injection blocking layer A hole injection blocking auxiliary layer made of a selenium-based amorphous semiconductor formed on the surface and a large portion of incident visible light formed on the surface of the hole injection blocking auxiliary layer are absorbed and converted into charges. An optical carrier generation layer made of a selenium-tellurium-based amorphous semiconductor and a carrier formed of a selenium-based amorphous semiconductor for avalanche multiplication of the generated optical carrier formed on the surface of the optical carrier generation layer In an imaging device, comprising: a multiplication layer; and a charge injection blocking type photoelectric conversion unit having a function of accumulating the multiplied carriers as signal charges, and means for reading the accumulated signal charges , The optical carrier Tellurium concentration of A generating layer, and more than 20 wt% 13 wt% or more and 0.1μm or 0.2μm or less the film thickness. When the density and film thickness are within the above ranges, dark current, afterimage increase and resolution degradation are suppressed, sensitivity to long wavelength light is kept within the human visibility limit, and long wavelength light cut filter when used in color cameras. Is unnecessary.
[0008]
In order to achieve another object of the present invention, the translucent electrode made of the conductive thin film is operated by applying a voltage that causes charge avalanche multiplication within the carrier multiplication layer.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Specific embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view showing a flat-type imaging device using a two-dimensional solid-state scanning IC substrate as a means for reading accumulated signal charges according to the first embodiment of the present invention, and FIG. FIG. 1B is a schematic cross-sectional view of the entire imaging device, and FIG. 1B is a schematic cross-sectional view illustrating an enlarged portion corresponding to one pixel in detail. As shown in FIG. 1A, the photoelectric conversion unit 11 is arranged on a two-dimensional solid-state scanning IC substrate 12 for reading accumulated signal charges, in which pixel electrodes 121 are arranged and the surface is smoothed. Provide. As shown in FIG. 1B, the photoelectric conversion unit 11 provided on the two-dimensional solid-state scanning IC substrate 12 on which the pixel electrodes 121 are arranged has a hole injection blocking layer 112 provided on the translucent electrode 111. Further, a hole injection blocking auxiliary layer 113, a photocarrier generation layer 114, and a photocarrier multiplication layer 115 are further provided thereon.
[0010]
That is, in the first embodiment of the present invention, the photoelectric conversion unit 11 includes at least the translucent electrode 111, the hole injection blocking layer 112, the hole injection blocking auxiliary layer 113, the photocarrier generation layer 114, and An optical carrier generation layer 114 made of a selenium / tellurium-based amorphous semiconductor has an average tellurium concentration of 13% by weight to 20% by weight and a film thickness of 0.1 μm to 0.2 μm. And When the tellurium concentration of the carrier generation layer 114 is less than 13% by weight or the film thickness is less than 0.1 μm, the effect of improving the photoelectric conversion efficiency and the spectral sensitivity characteristics becomes insufficient. Conversely, when the density or film thickness exceeds the above range, dark current or afterimage increases, resolution is likely to deteriorate, and the sensitivity to long wavelength light exceeds the human visibility limit, When used for a color camera, a problem such as the necessity of a long wavelength light cut filter occurs.
[0011]
In the imaging device according to the first embodiment of the present invention, the translucent electrode 111 made of a conductive thin film is used while being positively biased with respect to the means for reading the accumulated signal charge. Therefore, a part of the visible light incident from the translucent electrode 111 side is also absorbed by the hole injection blocking auxiliary layer 113, but most of the visible light is absorbed by the photocarrier generation layer 114 and becomes an electron / hole pair. These holes are transferred to the carrier multiplication layer 115, and new electron / hole pairs are generated one after another by the avalanche multiplication effect. The multiplied signal charges (holes) are accumulated for each pixel and sequentially read to achieve a high sensitivity operation.
[0012]
In the imaging device according to the first embodiment of the present invention, the hole injection blocking auxiliary layer 113 is made of a selenium-based amorphous semiconductor containing fluoride and arsenic. As the fluoride, at least one selected from the group consisting of lithium fluoride, sodium fluoride, potassium fluoride, magnesium fluoride, and calcium fluoride is used. These fluorides have a property of forming trap levels for holes in amorphous selenium and acting as positive space charges. The hole injection blocking auxiliary layer 113 utilizes this property, and during operation, the electric field of the hole injection blocking layer 112 is relaxed by the space charge due to the trapped holes, and the holes from the translucent electrode 111 are relaxed. Helps to prevent injection. Therefore, if the amount of fluoride added is too small, or if the film thickness of the added region is too small, the hole injection prevention assisting function will be insufficient, and there is a possibility that dark current and afterimage will increase. On the other hand, if the added amount is too large or the thickness of the added region is too large, an excessive positive space charge is formed in the hole injection blocking auxiliary layer 113 during operation, and the hole injection blocking auxiliary layer 113 as a whole is formed. Therefore, the light absorbed in this region is not converted into signal charges, and the light use efficiency is reduced. For these reasons, it is preferable that the fluoride content is 0.05 to 1% by weight on average and the film thickness is 0.01 to 0.05 μm on average.
[0013]
Arsenic added to the hole injection blocking auxiliary layer 113 is for improving the thermal characteristics. If the amount is too small, the effect cannot be obtained. On the other hand, since arsenic added to amorphous selenium forms a trap level for electrons, if it is too much, the hole trap level due to fluoride is offset and the hole injection blocking assist function is lowered. For this reason, the arsenic content of the hole injection blocking auxiliary layer 113 is preferably 0.5% by weight or more and 5% by weight or less on average.
[0014]
FIG. 2 is a schematic diagram of an imaging device using an electron gun that emits a scanning electron beam as a means for reading accumulated signal charge according to the second embodiment of the present invention. FIG. 2A is a schematic cross-sectional view of the entire imaging device. As shown in FIG. 2A, a photoelectric conversion unit 21 is provided on an electron gun 22 that emits a scanning electron beam. FIG. 2B is a plan view of the photoelectric conversion unit viewed from the electron beam scanning side (electron gun 22 side). FIG. 2C is a schematic cross-sectional view of the photoelectric conversion unit 21. As shown in FIG. 2C (illustrated upside down from FIG. 1), a translucent electrode 211 made of a conductive thin film is provided on a translucent face plate 210, and a hole injection blocking layer is formed thereon. 212, a hole injection blocking auxiliary layer 213, a photocarrier generation layer 214 for absorbing most of incident visible light and converting it into optical carriers, and a carrier multiplication layer 215 are laminated. As shown in FIG. 2B, reference numeral 200 denotes a line indicating the boundary of the electron beam scanning region. The inner side of the line 200 is a scanning region and the outer side is a non-scanning region. As shown in FIG. 2 (c), an additional layer 216 for stabilizing the surface potential of the non-scanning region is further formed in the portion corresponding to the non-scanning region on the carrier multiplication layer. A scanning electron beam landing layer 217 is provided over the entire surface. This scanning electron beam landing layer 217 also serves as an electron injection blocking layer.
[0015]
In the second embodiment, by providing the additional layer 216, the entire thickness of the non-scanning region is increased, and the carrier multiplication layer is operated by applying a voltage high enough to cause a charge avalanche multiplication phenomenon. Even in this case, the electric field does not reach an avalanche multiplication in the non-scanning region, and an excessive increase in surface potential is suppressed. As a result, the occurrence of ripple-like image defects, image polarity reversal, electrode reflection images, image distortion, and the like is greatly suppressed. As shown in FIG. 2A, the electron gun 22 includes a mesh electrode 221, a cathode 222, an electrode 223 for deflecting and converging an electron beam, an indium ring 228, a metal ring 229, and a housing 227. In the drawing, 224 is a scanning electron beam during operation, 20 is incident light, 201 is a lens, 202 is a power source, 203 is a load resistor, 204 is a signal output terminal, 210 is a translucent face plate, 21 is a photoelectric conversion unit, 218 Is an electrode pin.
[0016]
The photoelectric converter 21 according to the second embodiment (FIG. 2) differs from the first embodiment (FIG. 1) mainly in that the translucent face plate 210, the additional layer 216, and the scanning electron beam landing layer 217. The other is composed of the same components.
[0017]
In the photoelectric conversion part of FIGS. 1 and 2, in order to prevent tellurium from being diffused by heat or an electric field at the interface between the photocarrier generation layer and the avalanche multiplication layer, amorphous selenium is mainly used, and the average is 1 It is preferable to provide a tellurium diffusion prevention layer having a film thickness of 0.01 μm or more and 0.5 μm or less containing arsenic in an amount of 10% by weight or less. This tellurium diffusion preventing layer can further improve the thermal stability. However, if the arsenic content or the film thickness is less than the above value, a sufficient diffusion preventing effect cannot be obtained, and if it is too much, a dark current and an afterimage increase and a good quality image cannot be obtained.
[0018]
As described above, the gist of the present invention is the most suitable spectral sensitivity characteristic for a color camera in an imaging device that enhances sensitivity using an avalanche multiplication phenomenon in an amorphous semiconductor layer mainly composed of selenium. In order to realize high-efficiency photoelectric conversion characteristics, the structure of the amorphous semiconductor layer, particularly the tellurium content and film thickness of the photocarrier generation layer are limited to the optimum range.
[0019]
Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.
A method of manufacturing an imaging device using a two-dimensional solid-state scanning IC substrate as means for reading signal charges according to the first embodiment of the present invention shown in FIG. 1 will be described.
[0020]
First, a two-dimensional solid-state scanning IC substrate 12 in which a pixel electrode 121 and a MOS type switching circuit are formed on a single crystal silicon substrate is formed using a normal LSI process. Subsequently, on the MOS type two-dimensional solid-state scanning IC circuit board 12 in which the pixel electrodes are arranged on the array, an electron injection blocking layer having a thickness of 0.1 μm made of antimony trisulfide (see FIG. (Not shown in FIG. 1), and a carrier multiplication layer 115 having a thickness of 2 μm made of amorphous selenium is formed thereon. On this carrier multiplication layer 115, selenium and arsenic triselenide are simultaneously evaporated from separate boats by a vacuum deposition method, and a film thickness of 0.1% to 10% by weight of arsenic on average is obtained. A tellurium diffusion prevention layer (not shown in FIG. 1) made of a selenium amorphous semiconductor having a thickness of 01 μm or more and 0.1 μm or less is formed. In addition, selenium and tellurium are simultaneously evaporated from separate boats by a vacuum deposition method, and the film thickness is 0.1 μm or more and 0.2 μm or less containing tellurium of 13 wt% or more and 20 wt% or less on average. A photocarrier generation layer 114 made of a selenium / tellurium-based amorphous semiconductor is formed. Further, as a hole injection blocking auxiliary layer 113, selenium, arsenic triselenide, and lithium fluoride are simultaneously evaporated from separate boats by a vacuum deposition method, and an average of 0.5 wt% or more 5 A selenium-based amorphous semiconductor layer having a thickness of 0.01 μm or more and 0.04 μm or less containing 0.5% by weight or less of arsenic and 0.05% by weight or more and 1% by weight or less of lithium fluoride on average and 0.5% by weight on average A selenium-based amorphous semiconductor layer having a film thickness of 0.01 μm or less and containing arsenic in an amount of 5% to 5% by weight is formed. Next, a 15 nm-thick hole injection blocking layer 112 made of cerium oxide is formed thereon by a vacuum deposition method, and further a 20 nm-thick translucent electrode 111 mainly composed of indium oxide is formed thereon by a high-frequency sputtering deposition method. To obtain a planar imaging device.
[0021]
As shown in FIG. 2, the imaging device according to the second embodiment of the present invention is configured by using an electron gun that emits a scanning electron beam as means for reading signal charges. The photoelectric converter 21 is different from the first embodiment (FIG. 1) in three points: a translucent face plate 210, an additional layer 216, and a scanning electron beam landing layer 217. Hereinafter, a method for manufacturing an imaging device configured using the electron gun according to the second embodiment of the present invention will be described in detail.
First, a translucent electrode 211 mainly composed of indium oxide having a diameter of 14 mm and a film thickness of 30 nm is formed on one side of a face plate 210 made of translucent glass having a size of 2/3 inch by high-frequency sputtering deposition. Next, a hole injection blocking layer 212 made of cerium oxide having a diameter of 14 mm and a film thickness of 20 nm is formed thereon by vacuum deposition, and further a hole injection blocking auxiliary layer 213 is formed thereon as a hole injection blocking auxiliary layer 213. A film thickness of 0.01 μm or more and 0.04 μm including the following amorphous selenium layer, an average of 0.5% to 5% by weight of arsenic and an average of 0.05% to 1% by weight of fluoride. A composite layer composed of the following selenium-based amorphous semiconductor layer is formed. Further formed thereon is a photocarrier generation layer 214 made of a selenium-based amorphous semiconductor layer having a film thickness of 0.1 μm or more and 0.2 μm or less containing tellurium of 13 wt% or more and 20 wt% on average. A tellurium diffusion prevention layer comprising a selenium-based amorphous layer containing an arsenic film having a thickness of 0.01 μm or more and 0.5 μm or less containing an arsenic of 1 wt% to 10 wt% on average (shown in FIG. 2C) A carrier multiplication layer 215 having a thickness of 25 μm and made of an amorphous semiconductor mainly containing selenium is formed thereon.
[0022]
Next, an additional layer 216 is formed in the non-scanning region of FIG. 2B by a vacuum evaporation method using an evaporation mask. The additional layer 216 is an amorphous layer mainly composed of a selenium-based amorphous semiconductor layer having a thickness of 0.05 to 0.5 μm and containing selenium having a thickness of 30 μm, containing 0.2% by weight of lithium fluoride on average. It consists of a semiconductor layer. Next, the deposition mask was removed, and antimony trisulfide was deposited in an inert gas atmosphere with a pressure of 0.3 Torr over the entire surface on the scanning side with a diameter of 14 mm to obtain a scanning electron beam landing layer having a thickness of 0.2 μm. An injection blocking layer 217 is formed to obtain the photoelectric conversion unit 21 of the present invention. The photoelectric conversion unit 21 obtained as described above is attached to the housing 227 using the indium ring 228 and the metal ring 229, and the inside is vacuum-sealed to obtain an imaging tube type imaging device.
[0023]
An imaging device in which a photoelectric conversion unit and a MOS type two-dimensional solid-state scanning IC substrate according to a third embodiment of the present invention are bonded to each pixel by an indium bump method will be described. FIG. 3 is a schematic diagram of an imaging device in which the photoelectric conversion unit and the MOS type two-dimensional solid-state scanning IC substrate according to the third embodiment of the present invention are joined to each pixel by an indium bump method. ) Is a schematic cross-sectional view of the entire imaging device, and FIG. 3B is a schematic cross-sectional view showing an enlarged portion corresponding to one pixel. As shown in FIG. 3A, the photoelectric conversion unit 31 and the two-dimensional solid-state scanning IC substrate 32 for reading the accumulated signal charge are joined by indium bumps 326. A translucent face plate 310 is laminated on the photoelectric conversion portion 31, and electrode pins 318 are welded (penetrated) to the translucent face plate 310 to electrically connect the photoelectric conversion portion (that is, the translucent electrode 311). Is connected. As shown in FIG. 3B, a translucent face plate 310, a translucent electrode 311 made of a conductive thin film, a hole injection blocking layer 312, a hole injection blocking auxiliary layer 313, and most of the incident visible light. In this structure, an optical carrier generation layer 314, a carrier multiplication layer 315, an electron injection blocking layer 317, and a second pixel electrode 319 for absorbing and converting light are converted to optical carriers. As shown in the drawing, the two-dimensional solid scanning IC substrate 32 includes a first pixel electrode 321, a source electrode 322, a gate electrode 323, a drain electrode 324, an insulating layer 325, and an indium bump 326. The imaging device according to this embodiment has a configuration in which each first pixel electrode 321 and each second pixel electrode 319 are joined via an indium bump.
[0024]
Next, the manufacturing method of the imaging device joined by the indium bump method according to the third embodiment of the present invention shown in FIG. 3 will be described in detail.
First, a translucent face plate 310 to which the photoelectric conversion unit 31 is bonded and a two-dimensional solid-state scanning IC substrate 32 having indium bumps 326 for each pixel are prepared separately. The two-dimensional solid-state scanning IC substrate is of the MOS type as in the first embodiment, and indium bumps are formed in an array on each of the first pixel electrodes 321 by an ordinary photoresist processing method. The other photoelectric conversion unit 31 has a diameter of 14 mm on one side of a translucent face plate 310 made of glass with a size of 2/3 inch to which electrode pins 318 are previously welded, using the same material and method as in the first embodiment. A transparent electrode 311 mainly composed of indium oxide, a hole injection blocking layer 312, a hole injection blocking auxiliary layer 313, a photocarrier generation layer 314, a carrier multiplication layer 315, and an electron injection blocking layer 317 are formed. On the electron injection blocking layer 317, a gold thin film is formed by a vacuum deposition method by a vacuum deposition method, and a second pixel electrode 319 is formed by a normal photoresist processing method. A MOS-type two-dimensional solid-state scanning IC having a translucent face plate 310 having the photoelectric conversion portion (photoconductive portion) 31 obtained as described above and an indium bump 326 formed on each first pixel electrode 321. The substrate 32 is pressure-bonded to each pixel through an indium bump so as to have the configuration shown in FIG. 3 to obtain a planar indium bump bonded imaging device.
[0025]
As shown in FIG. 4, the imaging device according to the fourth embodiment of the present invention is configured using a planar electron source in which a plurality of field emission elements are arranged in two dimensions as means for reading signal charges. Is. FIG. 4 is a schematic view of an imaging device using a planar electron source according to the fourth embodiment of the present invention. This imaging device includes a photoelectric conversion unit 41, a planar electron source 42, a translucent face plate 410, electrode pins 418, a mesh electrode 421, an electron emission plate 422, an indium ring 428, a metal ring 429, a housing 427, a lens 401, a power source 402, a load resistor 403, a signal output terminal 404, and a planar electron source power source 405. In the drawings, reference numeral 40 denotes incident light. As shown in FIG. 4, a photoelectric conversion part 41 is formed on one side of a translucent glass face plate 410 in the same process as in the second embodiment, and an indium ring 428 and a metal ring 429 are used to form a planar electron source housing. Crimp. Next, the inside is evacuated and sealed to obtain a flat vacuum type imaging device.
[0026]
When the characteristic evaluation was performed using the imaging device of the present invention obtained in Embodiments 1 to 4 above, spectral sensitivity suitable for a color camera in a state in which deterioration in resolution and increase in dark current and afterimage were suppressed. It was confirmed that the characteristics were obtained and the photoelectric conversion characteristics were greatly improved.
[0027]
The present invention is not limited to the above-described embodiments, and many changes and modifications can be made. For example, an example in which a MOS type two-dimensional solid scanning IC substrate is used as a means for reading the accumulated signal charge has been described, but a CCD type solid scanning IC substrate can also be used. Similarly, the electron beam generator is not necessarily limited to the electrostatic deflection / electrostatic convergence method. For example, the electromagnetic deflection / electrostatic convergence method, the electrostatic deflection / electromagnetic convergence method, the electromagnetic deflection / electromagnetic convergence method can be used. It can also be used.
[0028]
【The invention's effect】
As described above, according to the present invention, a high spectral sensitivity characteristic suitable for a color camera and a further high-efficiency photoelectric conversion characteristic can be achieved while suppressing an increase in dark current, an increase in afterimage, and deterioration in resolution. A photoconductive imaging device capable of obtaining a high-quality image with high sensitivity and high resolution can be realized.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a flat-plate imaging device using a two-dimensional solid-state scanning IC substrate as a means for reading accumulated signal charges according to the first embodiment of the present invention, wherein FIG. FIG. 2B is a schematic cross-sectional view of the entire imaging device, and FIG. 4B is a schematic cross-sectional view illustrating an enlarged portion corresponding to one pixel in detail.
FIG. 2 is a schematic view of an imaging device using an electron gun that emits a scanning electron beam as a means for reading accumulated signal charges according to the second embodiment of the present invention, in which (a) shows imaging FIG. 2B is a schematic cross-sectional view of the entire device, FIG. 2B is a plan view of the photoelectric conversion unit viewed from the electron beam scanning side (electron gun 22 side), and FIG.
FIG. 3 is a schematic diagram of an imaging device in which a photoelectric conversion unit and a MOS type two-dimensional solid-state scanning IC substrate according to a third embodiment of the present invention are joined to each pixel by an indium bump method. Is a schematic cross-sectional view of the entire imaging device, and (b) is an enlarged schematic cross-sectional view showing a portion corresponding to one pixel.
FIG. 4 is a schematic view of an imaging device using a planar electron source according to a fourth embodiment of the present invention.
[Explanation of symbols]
11, 21, 31, 41 Photoelectric conversion parts 111, 211, 311 Translucent electrodes 112, 212, 312 made of a conductive thin film Hole injection blocking layer 113, 213, 313 Hole injection blocking auxiliary layers 114, 214, 314 Photocarrier generation layer 115, 215, 315 Carrier multiplication layer 12, 32 Two-dimensional solid-state scanning IC substrate 121 Pixel electrode 200 Lines 20, 40 indicating the boundary of the electron beam scanning region Incident light 201, 401 Lens 202, 402 Power source 203, 403 Load resistors 204 and 404 Signal output terminals 210, 310, and 410 Translucent face plate 216 Additional layer 217 Scanning electron beam landing layer and electron injection blocking layer 22 Electron guns 221 and 421 that emit a scanning electron beam Mesh electrode 222 Cathode 223 Electrode 224 for deflecting and converging electron beam 227, 427 Case 228, 428 Indium ring 229, 429 Metal ring 317 Electron injection blocking layer 319 Second pixel electrode 218, 318, 418 Electrode pin 321 First pixel electrode 322 Source electrode 323 Gate electrode 324 Drain electrode 325 Insulating layer 326 Indium bump 405 Planar electron source power supply 42 Planar electron source 422 Electron emission plate 423 Electron beam

Claims (8)

A translucent electrode made of a conductive thin film, a hole injection blocking layer formed on the surface of the translucent electrode, and a selenium-based amorphous semiconductor formed on the surface of the hole injection blocking layer And a selenium-tellurium-based amorphous semiconductor that absorbs most of the incident visible light formed on the surface of the hole injection prevention auxiliary layer and converts it into charges. A photocarrier generation layer and a carrier multiplication layer formed on the surface of the photocarrier generation layer and made of a selenium-based amorphous semiconductor for avalanche multiplication of the generated photocarriers. In an imaging device comprising a charge injection blocking photoelectric conversion unit having a function of storing carriers as signal charges, and means for reading the stored signal charges,
An imaging device, wherein the photocarrier generation layer has a tellurium concentration of 13% by weight to 20% by weight and a film thickness of 0.1 μm to 0.2 μm. The imaging device according to claim 1.
The hole injection blocking auxiliary layer of the photoelectric conversion part contains arsenic in an amount of 0.5 wt% to 5 wt% and a fluoride of 0.05 wt% to 1 wt%, and has a film thickness of 0.01 μm. An imaging device comprising a selenium-based amorphous semiconductor having a thickness of 0.05 μm or less. The imaging device according to claim 2.
An imaging device, wherein the fluoride is at least one selected from the group consisting of lithium fluoride, sodium fluoride, potassium fluoride, magnesium fluoride, and calcium fluoride. The imaging device according to any one of claims 1 to 3,
Tellurium diffusion prevention with a film thickness of 0.01 μm or more and 0.5 μm or less containing mainly 1% by weight to 10% by weight of arsenic between the photocarrier generation layer and the carrier multiplication layer. An imaging device comprising a layer. The imaging device according to any one of claims 1 to 4,
An imaging device characterized in that the means for reading the accumulated signal charge is a two-dimensional solid-state scanning IC substrate, and the two-dimensional solid-state scanning IC substrate and the photoelectric conversion unit are joined to each other. . The imaging device according to any one of claims 1 to 4,
The means for reading the accumulated signal charge comprises an electron gun that emits a scanning electron beam, and the electron gun and the photoelectric conversion unit are provided facing each other in a vacuum container. Imaging device. The imaging device according to any one of claims 1 to 4,
The means for reading the accumulated signal charge comprises a planar electron source in which a plurality of field emission elements are arranged in a two-dimensional manner, and the planar electron source and the photoelectric conversion unit are opposed to each other in a vacuum vessel. An imaging device characterized by being provided. The imaging device according to any one of claims 1 to 7,
A method for operating an imaging device, wherein a voltage that causes charge avalanche multiplication in the carrier multiplication layer is applied to the translucent electrode made of the conductive thin film.

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