JP2009009779A - Image display device - Google Patents

Abstract

An image display apparatus is provided that is highly reliable and has little afterimage by suppressing fluctuations in device characteristics of an anodized film constituting a thin film electron source.
A signal wiring is a lower electrode, an electron acceleration layer made of an anodic oxide film formed by anodizing the surface of the signal wiring, and an electron emission electrode are formed by laminating the electron acceleration layer. In the thin-film electron source comprising the upper electrode 13, the anodic oxide film constituting the electron acceleration layer is a capacitive element in which charge injection and emission occur before and after voltage application, and the emission temperature activation energy at the time of charge emission is reduced to 0. .5 eV or less.
[Selection] Figure 1

Description

  The present invention relates to an image display device, and is particularly suitable for an image display device also called a self-luminous flat panel display using a thin film electron source array.

  A thin-film electron source is basically a structure in which three types of thin films, an upper electrode, an electron acceleration layer, and a lower electrode, are stacked. By applying a voltage between the upper electrode and the lower electrode, a vacuum is applied from the surface of the upper electrode. To emit electrons. Thin-film electron sources include metal-insulator-metal (MIM), metal-insulator-metal (MIS), metal-insulator-semiconductor (MIS), metal-insulator- There are thin-film electron sources such as semiconductor-metal type.

Regarding the MIM type, for example, Patent Document 1, Patent Document 2, Patent Document 3 and the like, for the metal-insulator-semiconductor type, the MOS type is described in Non-Patent Document 1, and for the metal-insulator-semiconductor-metal type, the HEED type. Are described in Non-Patent Document 2 and the like, EL type is described in Non-Patent Document 3 and the like, and porous silicon type is described in Non-Patent Document 4 and the like.
JP-A-7-65710 j.Vac.Sci.Technol.B11 (2) p.429-432 (1993) high-efficiency-electro-emission device, Jpn, j, Appl, Phys, vol. 36, pp. 939 Applied Physics Vol.63, No.6, 592 Applied Physics Vol. 66, No. 5, p. 437

  Such electron sources are arranged in a plurality of rows (for example, in the horizontal direction) and a plurality of columns (for example, in the vertical direction) to form a matrix, and a large number of phosphors arranged corresponding to each electron source are arranged in a vacuum to display an image. A device can be configured. The MIM type electron source uses a film (anodized film: AO film) formed by an anodic oxidation method in which aluminum constituting the lower electrode serving as a signal wiring is treated in an electrolytic solution as a thin film used for the electron acceleration layer.

  Generally, impurity ions from the electrolytic solution are taken into the anodic oxide film. When a voltage is applied to the MIM type electron source and charge injection occurs, the impurities in the anodic oxide film cause trapping of charges and cause fluctuations in device characteristics. Since fluctuations in device characteristics reduce the reliability of the image display device, it is required to reduce impurities in the anodized film as much as possible.

  In addition, in the image display device, when a specific part of the screen is displayed at an arbitrary luminance, the luminance information becomes a history, and after that, even if the luminance signal of the screen changes, a phenomenon called so-called afterimage occurs. There are things to do. As described above, when the charge trapped in the defect by the charge injection is released, the device characteristics fluctuate, but the afterimage phenomenon also occurs by the release of the same trapped charge.

  An object of the present invention is to provide a highly reliable image display apparatus with little afterimage by controlling variations in device characteristics of an anodized film constituting a thin film electron source.

  In order to achieve the above object, the present invention re-emits the charge once injected into the anodic oxide film in the anodic oxide film constituting the electron acceleration layer of the thin film type electron source represented by the MIM type electron source. Control the speed appropriately.

  Impurities in the anodic oxide film are reduced, and an image display device realizing high reliability can be provided.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will be described below in detail with reference to the drawings of the examples. Here, an image display apparatus using an MIM type electron source will be described as an example. However, the present invention is not limited to the MIM type electron source, and can be similarly applied to an image display apparatus using a thin film type electron source having an anodized film. In particular, the present invention is effective for a hot electron type using a thin electron emission electrode and emitting only a part of the device current in a vacuum, or a surface conduction electron source.

FIG. 1 is a diagram illustrating the principle of an MIM type electron source. The operation of the MIM type electron source is as follows. In other words, the electron acceleration layer (tunnel insulating layer) 12 is interposed between the upper electrode 13 and the lower electrode 11. A drive voltage Vd is applied between the upper electrode 13 and the lower electrode 11 so that the electric field in the tunnel insulating layer 12 is about 1 M to 10 MV / cm. As a result, electrons near the Fermi level in the lower electrode 11 pass through the barrier due to a tunnel phenomenon, and are injected into the conduction band of the insulating layer 12 that is the electron acceleration layer to become hot electrons and flow into the conduction band of the upper electrode 13. . Among these hot electrons, those that reach the surface of the upper electrode 13 with energy equal to or higher than the work function φ of the upper electrode 13 are released into the vacuum. An Au—Al ₂ O ₃ —Al structure is typically known as an MIM type electron source.

  Next, details of the rear substrate constituting the image display device of the present invention will be described with reference to the manufacturing process of FIGS. Further, FIG. 13 shows a flow from manufacturing the image display device shown in FIG. 12 by bonding the front substrate described in FIG. 11 to the rear substrate obtained by the manufacturing process described in FIGS. 2 to 10 are plan views of one full-color pixel (1 pixel: red, green, and blue sub-pixels: composed of sub-pixels) and along the line AA ′ in this plan view. The cross section and the cross section along the BB 'line are shown.

  First, as shown in FIG. 2, a metal film 11P for a lower electrode (signal wiring) 11 is formed on an insulating back substrate 10 such as glass. Aluminum (Al) or an aluminum alloy (for example, an alloy of aluminum and neodymium (Nd): Al—Nd) is used as the material of the metal film 11P. The reason for using Al is that a good quality insulating film can be formed by anodic oxidation. Here, an Al—Nd alloy doped with 2% by weight of Nd was used. For film formation, for example, a sputtering method is used. The film thickness was 300 nm.

  After the formation of the metal film 11P, a stripe-shaped lower electrode 11 is formed by a patterning process and an etching process (FIG. 3... P-1). The electrode width of the lower electrode 11 varies depending on the size and resolution of the image display device, but is approximately the pitch of the subpixel, approximately 100 to 200 μm. For the etching, for example, wet etching with a mixed aqueous solution of phosphoric acid, acetic acid, and nitric acid is used. Since this electrode has a wide and simple stripe structure, resist patterning can be performed by inexpensive proximity exposure or printing.

  Next, a protective insulating layer (field insulating layer) 14 and a tunnel insulating layer 12 are formed to limit the electron emission portion and prevent electric field concentration on the edge of the lower electrode 11. First, a portion to be an electron emission portion on the lower electrode 11 shown in FIG. 4 is masked with a resist film 25, and the other portion is selectively thickly anodized (chemical conversion treatment) to form the protective insulating layer. When the formation voltage is 100 V, the protective insulating layer 14 having a thickness of about 136 nm is formed. Thereafter, the resist film 25 is removed and the surface of the remaining lower electrode 11 is anodized. For example, if the formation voltage is 6 V, an insulating layer (electron acceleration layer) 12 having a thickness of about 10 nm is formed on the lower electrode 11 (FIG. 5... P-2 in FIG. 13).

In general, oxide film growth in the case of using an anodic oxidation method is performed by conduction of metal ions and oxygen ions with a high electric field applied to a thin film. When Al metal is used for the base substrate, Al ³⁺ and O ²⁻ ions (or OH ⁻ ions) move in opposite directions in the film by this electric field. O ²⁻ ions that reach the base substrate / film interface react with Al to form a new oxide, and Al ³⁺ ions that reach the solution / film interface react with H ₂ O to form a new oxide. The Al ₂ O ₃ film formed by this anodic oxidation method has a two-layer structure consisting of an outer layer containing electrolyte anions and a pure metal oxide. It also contains a hydrating oxide called pseudoboehmite

  The ratio of the electrolyte anion layer to the metal oxide, the anion content in the electrolyte anion layer, and the amount of hydratable oxide are the type and composition of the electrolyte during anodization (in this example, an aqueous ammonium tartrate solution), anodization It is known that the temperature changes depending on the temperature at the time, the oxidation current density at the time of anodic oxidation (the growth rate is proportional to the current density according to the Faraday law when the oxide film growth is almost ionic current), and the like.

Therefore, in the process according to this example, in order to reduce the amount of anions in the outer anion layer as much as possible, the anodization current density at the time of anodization is controlled by lowering the current density. In this embodiment, anodization current density 2 .mu.A / cm ² during the anodization, 10 .mu.A / cm ^2, to form three types of anodic oxide film is changed from 50 .mu.A / cm ^2.

  Next, heat treatment is performed in order to desorb moisture taken in from the electrolytic solution during the chemical conversion treatment. In this embodiment, heat treatment (annealing) is performed in each atmosphere of air, vacuum, and nitrogen.

  Next, an upper bus electrode film serving as a power supply line to the upper electrode 13, an interlayer insulating film (second protective insulating film) 15 formed thereunder, a first metal layer (upper bus electrode) 26, a second The metal film 27 is formed by, for example, a sputtering method (FIG. 6... P-3 in FIG. 13). As the interlayer insulating film 15, for example, a silicon nitride film is used, and the film thickness is 100 nm. When there is a pinhole in the protective insulating layer 14 formed by anodic oxidation, the interlayer insulating film 15 fills the defect and plays a role of maintaining insulation between the lower electrode 11 and the upper bus electrode 26.

  Chromium (Cr) was used as the material of the upper bus electrode 26, and aluminum-neodymium (Al—Nd) alloy was used as the material of the second metal film 27. In addition to this, molybdenum (Mo), tungsten (W), titanium (Ti), niobium (Nb), or the like can be used as the material of the upper bus electrode 26. As a material for the second metal film 27, aluminum (Al), copper (Cu), chromium, a chromium alloy, or the like can be used in addition to an aluminum-neodymium (Al—Nd) alloy. Here, the film thickness of the upper bus electrode 26 is 10 nm, and the film thickness of the second metal film 27 is several nm.

  Subsequently, the upper bus electrode 26 and the second metal film 27 are processed and formed so as to be orthogonal to the lower electrode 11 by a photoetching process. The wet etching etchant (etching agent) is phosphoric acid, acetic acid, etc., when aluminum-neodymium (Al-Nd) is used, such as ammonium cerium nitrate aqueous solution when chromium is used for the upper bus electrode 26. A mixed aqueous solution of nitric acid is used (FIGS. 7 and 8).

Subsequently, the interlayer insulating film 15 made of SiN in the opening portion of the scanning electrode 21 is processed to open the electron emission portion where the electron acceleration layer 12 is exposed. This electron emission portion is formed at a part of the intersection of a space sandwiched between one lower electrode 11 in the pixel and two scanning electrodes orthogonal to the lower electrode 11. This etching can be performed, for example, by dry etching using an etchant mainly composed of CF ₄ or SF ₆ (FIG. 9).

  Next, a conductive thin film 13P for the upper electrode is formed. As this film formation method, for example, sputtering film formation is used. As the conductive thin film 13P, for example, a laminated film of iridium (Ir), platinum (Pt), and gold (Au) is used, and the film thickness is several nm, for example, 5 nm. The conductive thin film 13 </ b> P is separated in a self-aligned manner by the second metal film 27 formed by etching back on the adjacent scanning line side of the upper bus electrode 26 to become the upper electrode 13. The separated portion is indicated by an arrow C in the B-B ′ cross section of FIG. 10. The upper electrode 13 is supplied with power in contact with the chromium film of the upper bus electrode 26 and the Al—Nd film of the second metal film 27 (P-4 in FIG. 13).

  An image display device (display panel) is configured by bonding the front substrate to the rear substrate thus manufactured through a spacer. Hereinafter, an example of the structure of the image display device in which the front substrate is manufactured and the manufactured front substrate and back substrate are bonded together will be described.

  FIG. 11 is a diagram for explaining a method of manufacturing the front substrate. A black matrix 120 for increasing the contrast of a display image is formed on an insulating substrate 110 preferably made of glass (P-5 in FIG. 13). The black matrix 120 applies a solution obtained by mixing polyvinyl alcohol (PVA) and sodium dichromate to the insulating substrate 110. Then, using a mask, the portion other than the portion left as a black matrix is irradiated with ultraviolet rays to be exposed. Unexposed PVA is removed, and a black matrix solution in which graphite powder is dissolved is applied and dried to form a film. It is formed by lifting off the PVA with a black matrix coating on the PVA.

  Next, phosphors of three colors are formed (P-6 in FIG. 13). First, an aqueous solution in which PVA and sodium dichromate are mixed with red phosphor particles is applied to the insulating substrate 110 and dried. After irradiating the part forming the red phosphor with ultraviolet rays to expose it, the unexposed part is removed with running water. In this way, the red phosphor 111 is patterned. Similarly, a green phosphor 112 and a blue phosphor 113 are formed. Here, the phosphor pattern has a stripe shape as shown in FIG. For example, Y2O2S: Eu (P22-R) for red, ZnS: Cu, Al (P22-G) for green, and ZnS: Ag, Cl (P22-B) for blue can be used as the phosphor.

  Next, after filming with a film of nitrocellulose or the like, aluminum is vapor-deposited to a film thickness of, for example, 75 nm as a metal back 114 (P-7 in FIG. 13). The metal back 114 functions as an acceleration electrode. Thereafter, the insulating substrate 110 is heated to about 400 ° C. in the atmosphere to thermally decompose organic substances such as a filming film and PVA. In this way, the front substrate is completed.

  12A is a cross-sectional view corresponding to the line A-A ′ of FIG. 11 in a state where the back substrate is bonded to the front substrate. FIG. 12B is a cross-sectional view corresponding to the line B-B ′ in FIG. 11 in a state where the rear substrate is bonded to the front substrate. A spacer 40 is interposed between the front substrate 110 and the rear substrate 10, and a sealing frame 116 is sealed with a frit glass 115 around the periphery (P-8 in FIG. 13) and sealed (P-9 in FIG. 13). . This sealing is preferably performed in the atmosphere in order to remove the organic binder contained in the frit glass 115 and to reduce the cost by eliminating equipment and troubles such as gas replacement.

The height of the spacer 40 is set so that the distance between the front substrate 110 and the rear substrate 10 is 1 to 5 mm, preferably about 1 to 3 mm. In FIG. 12B, for the sake of explanation, each scanning line (second metal film 27) is planted. However, in practice, the number of spacers 40 is reduced as long as the mechanical strength can withstand, for example, every 1 cm. Provide. Note that the degree of vacuum inside the sealed interior is about 10 ⁻⁵ Pa. The above manufacturing process is summarized in FIG.

  The degree of vacuum is maintained by activating the sealed getter material in the sealed interior. In the case of an evaporation type getter material mainly composed of barium (Ba), a method of forming a getter material film by high frequency induction heating can be employed. Further, a non-evaporable getter material containing zirconium (Zr) as a main component can also be used.

  In this embodiment, the distance between the front substrate 110 and the rear substrate 10 is 1 to 3 mm, and the acceleration voltage applied to the metal back 114 can be 3 to 6 kV. Thereby, the fluorescent substance for cathode ray tubes can be used for a fluorescent substance.

FIG. 14 is a diagram for explaining the result of confirming the effect of reducing the electrolyte anion by performing SIMS (secondary ion mass spectrometry) well-known in the depth direction analysis on the anodized film manufactured in the example of the present invention. is there. In FIG. 14, the anion reduction effect is shown by comparison of carbon element content for convenience. The horizontal axis indicates the depth (nm) from the surface of the anodic oxide film in the oxide film cross-sectional direction, and the vertical axis indicates the carbon content (atm / cm ³ ) calculated from SIMS analysis. In this embodiment, an example of an anodic oxide film thickness of 10 nm is shown.

  Curve A shows the case where the current density is 50 μA / cm 2 and curve B shows the case where the current density is 10 μA / cm 2. From FIG. 14, it can be seen that the carbon content on the side close to the surface, that is, the anion layer existing region is decreased by the reduction in current density. Further, the peak of 8 to 12 nm from the surface corresponds to the vicinity of the interface between the underlying Al electrode and the anodic oxide film, and is considered to be a false peak peculiar to SIMS depth analysis, and is excluded from the evaluation this time.

  Here, the afterimage phenomenon and the inspection method will be briefly described using examples. FIG. 15 is a diagram for explaining the afterimage phenomenon of a display (image display device) using the thin film electron source of the present invention. First, as shown in FIG. 15A, the entire screen of the image display device is set to a halftone display 31 state. Here, half the maximum brightness is defined as halftone. A portion indicated by reference numeral 32 is a white display scheduled range. The white display scheduled range 32 is arbitrary.

  Next, as shown in FIG. 15B, the white display scheduled range 32 is displayed with the maximum luminance. (The portion of the white display 33 in which “TEST” is displayed in white in the drawing) For example, the state is held for 1000 seconds in this state.

  Next, the white display 33 portion is returned to the original halftone display state. Ideally, the background portion (halftone display location 31) and the portion displaying the character should have the same luminance, but the portion displaying the maximum luminance may not have the same luminance. This behavior is mainly caused by fluctuations in diode characteristics during operation. FIG. 16 shows a typical current-voltage (IV) characteristic of the thin film electron source in the present invention. In the image display apparatus using the thin film electron source of the present invention, a region where the current and the emission current change exponentially with respect to the applied voltage is used.

  When charge injection by voltage application occurs, the IV curve apparently gradually shifts to the positive voltage side (FIG. 16 (a)). The variation depends on the total injected charge. That is, the larger the charge injection amount, the greater the fluctuation amount. For example, in an element to which a higher voltage corresponding to the maximum luminance is applied, the variation proceeds more than an element to which a lower voltage corresponding to the halftone luminance is applied. When the same voltage is applied to elements with different degrees of fluctuation, the diode current of the element with more advanced fluctuation becomes smaller. As a result, when the image display device is turned on, a luminance difference is generated between the two.

  This voltage shift gradually returns to the original state of the IV characteristics before the charge injection by stopping the charge injection (FIG. 16B). This is a phenomenon that occurs when charges once injected into a thin film are re-emitted from defects in the film. Note that the more the charge injection is, that is, the higher the voltage is applied and the higher luminance is maintained at a higher current, the larger the voltage shift amount is.

  Even if only a certain part on the screen is in the maximum luminance state, that is, when more charges are injected, if this charge discharge phenomenon occurs at high speed, even if it is changed to the halftone luminance state, The halftone brightness can be displayed immediately. However, when the charge emission decrease is slow, the luminance on the screen does not instantaneously become the intermediate luminance even when the maximum luminance state is changed to the halftone luminance state. When this delay time is long, the time for sensing as an afterimage becomes long.

FIG. 17 shows the result of the charge emission characteristic evaluation after charge injection into the thin film for the thin film electron source obtained in the present invention. The measurement of charge emission characteristics is based on voltage-current measurement, which is a well-known method for measuring the electrical characteristics of a thin film. First, the current-voltage characteristics are measured with the charge injected into the thin film. After the arbitrary time has elapsed, measure the current-voltage characteristics again. Here, the current-voltage characteristic is shifted by discharging the charge from the thin film. For example, if the charge trapped in the film is an electron, in the negative direction (left direction in the figure)
When the trapped charge is a hole, it shifts in the positive direction (right direction in the figure). FIG. 17 shows voltage-current characteristics immediately after charge injection and after being left for 1024 seconds without applying a voltage thereafter.

As shown in FIG. 17, the voltage is shifted in the left direction due to re-emission of electrons. The amount of charge and the amount of voltage shift generally have the following relationship.
(Equation 1)
Q = ε ₀ εS / d | ΔV |
Here, ε _{0 is} the dielectric constant of vacuum, ε is the relative dielectric constant of the insulating film, S is the area of the insulating film, d is the insulating film thickness, and ΔV is the voltage shift amount. In calculation, the amount of emitted charges is obtained by dividing the amount of emitted charges: Q by the amount of elementary charges (1.602e ^-19 C).

The release rate of charge in the thin film is determined by the activation energy of charge release. For example, the activation energy can be obtained by evaluating the temperature dependence of the amount of emitted charges. The smaller the activation energy, the easier the charge in the thin film is released.
The activation energy of charge release was derived based on the following Arrhenius equation.
(Equation 2)
k = A x exp (−Ea / RT)
Here, k: reaction rate, A: frequency factor (a constant independent of temperature), Ea: activation energy,
R: Boltzmann constant, T: absolute temperature (K).

FIG. 18 is a diagram illustrating the charge discharge characteristics when the current density during anodic oxidation is set to a high current density. FIG. 19 is a diagram for explaining charge discharge characteristics when the current density during anodic oxidation is set to a low current density. FIG. 18 shows the dependence of the charge discharge amount on the device fabricated with the current density during anodization of 50 μA / cm ² , and FIG. 19 shows the charge of the device fabricated with the current density during anodization of 10 μA / cm ^2. The dependence of the release amount on the standing time is shown. The charge discharge amount is indicated by using the voltage shift amount as described above. In the charge release measurement, the measurement temperature is changed to 30 ° C., 60 ° C., and 90 ° C., and the temperature dependence of the charge release amount is simultaneously shown.

The time for the voltage shift amount to reach 50 mV is calculated as the reaction speed (k) of the Arrhenius equation. FIG. 20 is a diagram for explaining an Arrhenius plot for obtaining the activation energy of charge emission. FIG. 20A shows an Arrhenius plot when the current density during anodization is 50 μA / cm ^2, and FIG. 20B shows the Arrhenius plot when the current density during anodization is 10 μA / cm ^2. .

In this embodiment, 2 .mu.A / cm ² current density during the anodization, 10μA / cm ^2, is varied with 50 .mu.A / cm ^2. The activation energies obtained from the temperature characteristic evaluation were 0.22 eV, 0.50 eV, and 0.66 eV, respectively, and it was found that the device manufactured at a low current density showed lower activation energy. FIG. 21 shows a summary of the current density during anodic oxidation and the activation energy thereof.

  FIG. 22 is a diagram for explaining the panel afterimage characteristics of a panel in which the current density during anodization is changed in the image display device of the present invention. FIG. 22 is a visual evaluation of the afterimage evaluation when the current density during anodic oxidation is changed. In this evaluation method, first, the background screen is set to an intermediate luminance tone, and a video signal (for example, a character) having the maximum luminance is given to an arbitrary portion. After 100 seconds have passed in this state, a video signal having an intermediate luminance tone is applied to the portion that has been given the maximum luminance. Observe the time dependence of the luminance change for that part. The horizontal axis represents the elapsed time (seconds) immediately after returning from the maximum luminance to the intermediate luminance, and the vertical axis represents the ratio (%) of the luminance of the character display portion / background portion.

Ideally, the ratio of the luminance of the character display portion / background portion is 100% immediately after switching, but the character display portion has a lower luminance than the background portion due to variations in element characteristics. However, it is confirmed visually that if the difference from the background is within 5% after 1 second, the difference from the background cannot be recognized. Judging by this criterion, each of 95% arrival time in the image display apparatus fabricated changed current density of the anodic oxide film, 2 .mu.A / in cm ² 0.15 seconds, 10 .mu.A / cm ² at 0.9 seconds, 50 .mu.A / Cm ² is 5 seconds.

Accordingly, there is no problem with an image display device in which an anodized film is formed at an anodic oxidation current density of 10 μA / cm ² or less, but an image display device in which an anodized film is formed at an anodic oxidation current density higher than that has a slow recovery time. The afterimage will be clearly recognized.

  By reducing the current density during anodization, it is estimated that the activation energy of charge emission is reduced and the emission rate is increased, but at least the activation energy of emitted charge is 0.5 eV or less. Therefore, it is possible to manufacture an image display device with good afterimage characteristics.

It is a principle explanatory view of a MIM type electron source. It is a figure which shows the manufacturing process of the thin film type electron source of this invention. It is a figure following FIG. 3 which shows the manufacturing process of the thin film type electron source of this invention. It is a figure following FIG. 4 which shows the manufacturing process of the thin film type electron source of this invention. It is a figure following FIG. 5 which shows the manufacturing process of the thin film type electron source of this invention. It is a figure following FIG. 6 which shows the manufacturing process of the thin film type electron source of this invention. It is a figure following FIG. 7 which shows the manufacturing process of the thin film type electron source of this invention. It is a figure following FIG. 8 which shows the manufacturing process of the thin film type electron source of this invention. It is a figure following FIG. 9 which shows the manufacturing process of the thin film type electron source of this invention. It is a figure following FIG. 10 which shows the manufacturing process of the thin film type electron source of this invention. It is a figure explaining the manufacturing method of a front substrate. It is sectional drawing along the A-A 'line | wire state of the state which bonded the back substrate to the front substrate. It is sectional drawing along the B-B 'line | wire state of the state which bonded the back substrate to the front substrate. It is a figure explaining the manufacturing process of the image display apparatus of this invention. It is a figure explaining the temperature dependence of the moisture desorption amount in a film | membrane by performing SIMS (secondary ion mass spectrometry) about the anodic oxide film manufactured in the Example of this invention. It is a figure explaining the afterimage phenomenon of the display using the thin film electron source of this invention. It is a figure explaining the relationship between the current-voltage characteristic fluctuation | variation and the afterimage of the thin film electron source of this invention. It is a figure explaining the principle of the electric current-voltage characteristic fluctuation | variation of the thin film electron source of this invention, and charge emission measurement. It is a figure explaining the charge discharge characteristic at the time of making the current density at the time of anodizing high current density. It is a figure explaining the charge discharge characteristic at the time of making the current density at the time of anodizing low current density. It is a figure explaining the Arrhenius plot for calculating | requiring the activation energy of electric charge discharge | release. It is a figure explaining the relationship between the current density at the time of anodization, and the activation energy of charge discharge | release. It is a figure explaining the panel afterimage characteristic of the panel which changed the current density at the time of anodization.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Back substrate (cathode substrate), 11 ... Lower electrode, 12 ... Insulating layer (electron acceleration layer, tunnel insulating layer), 13 ... Upper electrode, 14 ... Protective insulating layer (field Insulating layer), 15 ... Interlayer insulating layer, 25 ... Resist film, 27 ... Scan electrode, 30 ... Spacer, 50 ... Signal line drive circuit, 60 ... Scan line drive circuit, DESCRIPTION OF SYMBOLS 110 ... Front substrate (color filter substrate), 111 ... Red phosphor, 112 ... Green phosphor, 113 ... Blue phosphor, 120 ... Black matrix.

Claims (8)

A large number of signal wirings made of aluminum formed in parallel to each other on the inner surface, and a large number of scanning wirings formed on the signal wirings so as to cross the signal wirings through an interlayer insulating layer and in parallel with each other; One substrate including a thin film electron source array formed in the vicinity of the intersection of the signal wiring and the scanning wiring and including a plurality of electron emission portions arranged in a two-dimensional matrix in an image display area; ,
The other substrate provided with a phosphor screen composed of a plurality of phosphors that are installed opposite to the inner surface of the one substrate, and emit light by excitation by electrons emitted from the thin film electron source array on the inner surface;
The thin-film electron source includes an electron acceleration layer formed of an anodized film formed by anodizing the surface of the signal wiring with the signal wiring as a lower electrode, and an electron emission electrode laminated to cover the electron acceleration layer Consisting of the upper electrode comprising
The anodic oxide film constituting the electron acceleration layer is a capacitive element that generates charge injection and emission before and after voltage application,
An image display device characterized in that an emission temperature activation energy at the time of releasing the injected charge is 0.5 eV or less. In claim 1,
The upper electrode constituting the electron emission electrode of the thin film electron source is a conductive thin film electrically connected to the scanning wiring formed so as to cover the entire surface of the image display region on the scanning wiring, An image display device characterized in that it is electrically separated between adjacent scanning lines. In claim 1,
The image display apparatus according to claim 1, wherein the thin film electron source is disposed at a portion of the scanning wiring that is closer to one side in the width direction. In claim 2 or 3,
The thin film electron source has the conductive thin film as the electron emission electrode on the anodic oxide film constituting the electron acceleration layer disposed in the opening of an interlayer insulating layer that insulates the signal wiring and the scanning wiring. An image display device characterized by being configured. In claim 1,
An image display device, wherein a spacer for regulating a distance between the one substrate and the other substrate is disposed at a portion of the scanning wiring in the width direction that is opposite to the electron emission portion. . In claim 1,
The scanning wiring is pure aluminum or an aluminum alloy, and the upper electrode is a single noble metal or a laminate of two or more noble metals. In claim 6,
An image display device, wherein the aluminum alloy is an alloy of aluminum and neodymium. In claim 6 or 7,
The image display device, wherein the noble metal is iridium, platinum, or gold.