JP4287885B2 - Mesh structure - Google Patents

Description

The present invention relates to a mesh structure.

  In recent years, with the progress of semiconductor microfabrication technology, vacuum microelectronic technology that integrates a large number of micron-order cold cathode structures on a substrate such as a semiconductor attracts attention. Field emission electron source array with a micro cold cathode structure obtained by these technologies can be expected to have planar electron emission characteristics and high current density, and does not require a heat source such as a heater unlike a hot cathode. Therefore, expectation is gathered as an electron source for a next-generation flat display, a sensor, and a flat-type imaging device of a low power consumption type.

  As a vacuum apparatus using such a field emission type electron source array, the field emission type electron source display device shown in Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4, and Patent Document 5 are shown. A field emission type electron source imaging device, a light emitting element disclosed in Patent Document 6, and the like are known.

  In general, a field emission electron source device using such a field emission electron source array includes a front panel 101, a back panel 105, and a side peripheral device 104, as shown in FIG. It is fixed and fixed by a sealing material 109 such as frit glass or indium, and the inside is kept in a vacuum.

  On the inner surface of the front panel 101, for example, an anode electrode 102 that transmits incident light from the outside is formed, and a target 103 is formed on the surface thereof. In general, the target 103 is a phosphor layer in which phosphors emitting three colors are regularly arranged when used as a field emission electron source display device, and when used as a field emission electron source imaging device. Is a photoelectric conversion film for converting incident light into signal charges.

  On the inner surface of the back panel 105, a plurality of cold cathode elements (emitters) 107, an insulating layer formed around each cold cathode element 107, a gate electrode for applying a voltage for extracting electrons from the cold cathode element 107, and the like A semiconductor substrate 106 on which a field emission electron source array in which peripheral elements 108 made of these are integrated and integrated is formed. By landing the electron beam emitted from the cold cathode element 107 on the target 103, the field emission electron source display device emits a phosphor to display an image, and in the field emission electron source imaging device, the image is projected on the photoelectric conversion film. An image formed as incident light can be read.

  As a field emission electron source, generally, a cold cathode device having a sharp tip is formed on a semiconductor substrate, an insulating layer is formed around the cold cathode device, and a gate electrode is formed on the insulating layer. A typical example is a Spindt type in which voltage is applied between the gate electrode and electrons are emitted from the tip of the cold cathode device. In addition, an MIM (Metal Insulator Metal) type in which an insulating layer is formed between the cathode electrode and the gate electrode, and voltage is applied to the insulating layer to emit electrons by the tunnel effect, between the cathode electrode and the emitter electrode. SCE (Surface Conduction Electron Source) type that emits electrons from the minute gap by applying a voltage between these electrodes, or carbon such as DLC (Diamond Like Carbon) or CNT (Carbon Nanotube) as the electron source A field emission electron source using a system material can be given as an example.

  A field emission electron source including such a cold cathode has a very small amount of electron emission from each cold cathode element, so that it can be used as a field emission electron source display device or field emission electron source imaging. When used as an apparatus, a cell (electron source cell) having a plurality of field emission electron sources as a unit is formed, and an amount of current necessary for performing a predetermined operation is secured.

  The cells are arranged on a plane, for example, in a matrix. Specifically, a plurality of emitter lines extending in the vertical direction are arranged at equal pitches in the horizontal direction, and a plurality of gate lines extending in the horizontal direction are arranged at equal pitches in the vertical direction. A cell is arranged at each position where the gate line intersects. When the field emission electron source device is driven, an emitter line and a gate line are sequentially selected, whereby an electron beam is sequentially emitted from a cell at a position where the selected emitter line and gate line intersect. In this specification, a cell that emits an electron beam in this manner is hereinafter referred to as a “designated cell”. As described above, the field emission electron source display device can display an image, and the field emission electron source imaging device can read the image formed.

  In the field emission electron source, electrons are emitted by a strong electric field formed between the cold cathode device and the gate electrode, so that electrons spread from each cold cathode device to a predetermined spread (this spread angle is referred to as a “divergence angle”). For example, in the case of a Spindt-type field emission electron source, it is about 30 degrees).

  In the vacuum apparatus using such a field emission type electron source, as shown in FIG. 26, the field emission type electron source array is installed on the back panel 105 of the vacuum vessel, and the electrons from the field emission type electron source array are arranged. In general, a target 103 that performs a predetermined operation by landing a beam is formed on the front panel 101. Here, the distance from the field-emission electron source array to the target 103 is uniquely determined by the distance between the back panel 105 and the front panel 101 on which they are provided.

  That is, in such a conventional field emission electron source device, the distance between the field emission electron source array installed on the back panel 105 and the target 103 formed on the front panel 101 is the front panel 101 and Depending on the accuracy of the joining portion between the back panel 105 and the side surface peripheral device 104, it greatly varies with respect to the ideal design distance.

  For example, when the front panel 101 and the rear panel 105 are joined to the side surface peripheral device 104 using frit glass, the frit glass is supplied in various amounts, or is generated in the process of baking and welding at about 400 ° C. Shrink or the like causes variations in the distance between the field emission electron source array installed on the back panel 105 and the target 103 formed on the front panel 101.

  In addition, when the front panel 101 and the rear panel 105 are joined to the side peripheral device 104 by low-temperature sealing using a soft metal such as indium, indium is removed from the front panel 101 and the side surface during sealing. In order to crush between the peripheral device 104 and between the side peripheral device 104 and the back panel 105, variations in the supply amount of indium and the crushed amount are caused by the field emission electron source array installed on the back panel 105. Variation in the distance from the target 103 formed on the front panel 101 is generated.

  The variation in the distance between the field emission electron source array and the target 103 is about several hundred microns to several millimeters.

  As described above, in the conventional field emission electron source device, the distance between the field emission electron source array installed on the back panel 105 and the target 103 formed on the front panel 101 can be managed with high accuracy. It is difficult. Then, electrons are emitted from each cold cathode element with a divergence angle of about 30 degrees. Therefore, the variation in the distance between the field emission electron source array and the target 103 causes the variation in the extent of the electron beam spot formed by the electron beam on the target 103 (that is, the spot diameter). This is a very inconvenient problem for a field emission type electron source display device and a field emission type electron source imaging device that require a uniform image.

  In order to realize a high-definition field emission electron source display device and a high-definition field emission electron source imaging device, it is necessary to sufficiently reduce the size of the cells on the field emission electron source array. In this case, the distance between the field emission electron source array and the target 103 must be sufficiently small, and the error must be managed to be, for example, about several tens of microns or less. However, in the conventional field emission electron source device, there is a possibility that the distance between the field emission electron source array and the target 103 may vary from several hundred microns to several millimeters. It is difficult to realize a display device and a high-definition field emission electron source imaging device.

  Further, in the conventional field emission electron source device, when the inside of the vacuum vessel is evacuated, the front panel 101 is pressurized by the external pressure and curved. Since the target 103 is formed on the inner surface of the front panel 101, the distance from the field emission electron source array differs between the central portion and the peripheral portion of the target 103 due to the curvature of the front panel 101. As a result, The diameter of the electron beam spot formed on the target 103 is different between the central portion and the peripheral portion of the target 103.

  As a result, when used as a field emission electron source display device, there is a difference in image quality displayed between the center of the screen and the periphery of the screen, and when used as a field emission electron source imaging device, the screen center and screen There is a difference in image quality between the surroundings.

  Unlike FIG. 26, Patent Document 1 and Patent Document 5 show a vacuum apparatus using a field emission electron source array in which a shield grid electrode is provided between a field emission electron source array and a target.

  FIG. 27 shows a cross-sectional view of a field emission electron source device used as a field emission electron source imaging device disclosed in Patent Document 5.

  The vacuum vessel 118 includes a translucent front panel 115, a back panel 117, and a side peripheral device 116 that also serves as a spacer portion for holding a mesh-shaped shield grid electrode 120, which are sealed with frit glass. The material 133 and a sealing material 119 made of indium are fixed and fixed, and the inside is kept in a vacuum.

  On the inner surface of the front panel 115, a photoelectric conversion target 114 is formed which includes an anode electrode 113 that transmits incident light 111 from the outside and a photoelectric conversion film 112 formed on the surface.

  On the inner surface of the rear panel 117, there are a cold cathode element 124, a cathode conductor 125 that supplies a potential to the cold cathode element 124, and an insulating layer 126 formed on the cathode conductor 125 so as to surround the cold cathode element 124. On the insulating layer 126, a field emission electron source array 129 is formed which includes a gate electrode 128 arranged so as to surround the periphery of the cold cathode element 124.

  A shield grid electrode 120 is disposed between the photoelectric conversion target 114 and the field emission electron source array 129. A voltage higher than the voltage applied to the gate electrode 128 is applied to the shield grid electrode 120.

  The shield grid electrode 120 includes a plurality of through holes 120a. The plurality of through holes 120a and the plurality of cold cathode elements 124 have a one-to-one correspondence, and the center of the through hole 120a is located directly above the tip of the cold cathode element 124 that emits the electron beam.

  An electron beam is emitted from the tip of the cold cathode element 124 at a divergence angle of about 30 degrees. Of the electron beams, only the electron beam emitted almost directly above passes through the through-hole 120a corresponding to the cold cathode element 124 of the shield grid electrode 120 and reaches the photoelectric conversion target 114, and the others. The electron beam emitted obliquely is absorbed by the shield grid electrode 120.

  Patent Document 5 states that the spread of the electron beam reaching the photoelectric conversion target 114 can be reduced in this way.

  However, in order to allow only the electron beam emitted from the cold cathode element 124 to be emitted almost directly up to the photoelectric conversion target 114, the size of the cold cathode element 124 and the adjacent cold cathode element 124 are reduced. The relative relationship among the distance between the cathode elements 124, the distance from the field emission electron source array 129 to the shield grid electrode 120, the opening diameter of the through-hole 120a of the shield grid electrode 120, and the thickness of the shield grid electrode 120 is set strictly. There is a need.

  For example, if the cold cathode element 124 is made smaller and the distance between the adjacent cold cathode elements 124 is made smaller, the distance between the adjacent through-holes 120a of the shield grid electrode 120 needs to be made smaller. However, in this case, the electron beam emitted from the tip of the cold cathode element 124 with a divergence angle of about 30 ° is not only the corresponding through hole 120a arranged right above the cold cathode element 124 but also the through hole. There is a possibility of passing through the through hole 120a in the vicinity of 120a and reaching the photoelectric conversion target 114.

  Further, even when the distance from the field emission electron source array 129 to the shield grid electrode 120 is increased, the electron beam emitted at a divergence angle of about 30 ° from the tip of the cold cathode element 124 is the cold cathode element 124. There is a possibility that the photoelectric conversion target 114 may be reached through the through hole 120a in the vicinity of the through hole 120a as well as the corresponding through hole 120a arranged immediately above the through hole 120a.

  Further, when the number of cold cathode elements 124 is larger than the number of through holes 120 a of the shield grid electrode 120, some of the plurality of cold cathode elements 124 formed in the field emission electron source array 129. The center of the through hole 120a is not located directly above the tip of the cold cathode element 124. Accordingly, among the electron beams emitted from the cold cathode element 124, the electron beam emitted almost directly above cannot be passed through the through-hole 120a but is absorbed by the shield grid electrode 120, and is inclined. There is a possibility that the electron beam emitted toward the photoelectric conversion target 114 passes through the through-hole 120 a located other than directly above the cold cathode element 124.

  In this way, unless the relative relationship between the dimensions of the constituent elements is set strictly, it is impossible to reduce the spread of the electron beam reaching the photoelectric conversion target 114. As a result, there arises a problem that the imaging pixel size is enlarged.

  In addition, when the field emission electron source device shown in FIG. 27 is applied to a flat-type imaging device that performs VGA (horizontal direction 640 dots × vertical direction 480 dots) imaging, the following problem occurs. Conceivable.

  In a VGA planar imaging device, pixels of 640 dots in the horizontal direction and 480 dots in the vertical direction are arranged, and the total number of pixels is 310,000 dots. If 100 cold cathode elements 124 are arranged in one pixel (dot), the total number of cold cathode elements 124 is 31 million, which is enormous. When the diagonal size of the planar imaging device is 1 inch (2.54 cm), the horizontal size of the field emission electron source array is 1.275 cm, and the vertical size of the field emission electron source array is 0. 956 cm, and the size of one dot is 0.02 mm (= 20 μm). If 100 cold cathode elements 124 are arranged in the form of lattice points in one dot, it is necessary to arrange 10 in one direction. In order to form the through-hole 120a in the shield grid electrode 120 corresponding to the cold cathode element 124 on a one-to-one basis, the inner diameter of the through-hole 120a needs to be 2 μm or less.

  In this case, if the thickness of the shield grid electrode 120 is 1 μm or less, it seems possible to form the through hole 120 a having an inner diameter of 2 μm or less. However, if the thickness of the shield grid electrode 120 is 1 μm or less, there is a high possibility that the strength of the shield grid electrode 120 will be insufficient or that it will be bent. On the other hand, if the thickness is greater than 1 μm, it is impossible to form a through-hole 120 a having an inner diameter of 2 μm or less in a metal plate such as nickel, copper, or aluminum described in Patent Document 5 as a material for the shield grid electrode 120. it is conceivable that. After all, it is considered almost impossible to form the through-hole 120a corresponding to the cold cathode element 124 in the shield grid electrode 120.

  Even if the through-hole 120a having an inner diameter of 2 μm or less can be formed, and the problem of insufficient strength or bending can be solved, the field emission electron source array 129 and the shield grid electrode 120 are then highly accurate. There is a problem that it must be aligned.

  That is, in order to displace the center of the through-hole 120a directly above the tip of the cold cathode element 124, the relative positional relationship between the field emission electron source array 129 and the shield grid electrode 120 is 0.1 μm or less. It must be managed with accuracy. However, the current general assembly accuracy limit is about 1 μm, and from this point of view, it is difficult to realize a planar imaging device using the field emission electron source device shown in FIG. It is done.

  In addition, as shown in FIG. 27, when one cold cathode element 124 is made to correspond to one pixel, a current amount required to operate one pixel is supplied from one cold cathode element 124. There is a need to. However, considering that the current emission characteristics of the field emission cold cathode device are on the order of nanoamperes, it is difficult to realize a field emission electron source device in which only one cold cathode device 124 is arranged in one pixel. It is thought that.

  Conversely, when a plurality of cold cathode elements 124 are made to correspond to one pixel, and one through hole 120a of the shield grid electrode 120 is made to correspond to one pixel, the position is not directly below the center of the through hole 120a. The tip of the cold cathode element 124 corresponding to the through hole 120a is located. Therefore, as described above, among the electron beams emitted from the cold cathode element 124, the electron beam emitted almost directly above cannot be passed through the through hole 120a and is absorbed by the shield grid electrode 120. There is a possibility that the electron beam emitted obliquely passes through the through hole 120a constituting the adjacent pixel and reaches the photoelectric conversion target 114. Accordingly, in this case as well, it is considered difficult to realize a field emission electron source device. That is, in the field emission type electron source device of FIG. 27, it is very difficult to efficiently reach the photoelectric conversion target 114 by passing the electron beam from the cold cathode element 124 only through the through-hole 120a disposed immediately above. It is difficult to.

  Furthermore, the field emission type electron source device of FIG.

  As shown in FIG. 27, an insulating back panel 117 on which a field emission electron source array 129 is formed, and a front panel 115 on which a photoelectric conversion target 114 facing the field emission electron source array 129 is formed. Are joined between these outer peripheral portions via a side peripheral device 116, and the inside of the vacuum vessel 118 is maintained at a high vacuum.

  At this time, a low melting point frit glass as a sealing material 133 is applied between the back panel 117 and the side surface peripheral device 116, and the back panel 117 and the side surface peripheral device 116 are fired at a temperature of about 400 ° C. To hold the inside of the vacuum vessel airtight. The low melting point frit glass is also used when the shield grid electrode 120 is positioned and fixed on the step portion 121 of the side surface peripheral device 116. Therefore, the distance between the field emission electron source array 129 and the shield grid electrode 120 is the thickness of the low melting point frit glass between the back panel 117 and the side peripheral device 116 and the step portion 121 of the side peripheral device 116 and the shield grid. It depends on the thickness of the low melting point frit glass between the electrode 120 and the electrode 120.

  Therefore, the parallelism and distance between the field emission electron source array 129 and the shield grid electrode 120 vary.

  As a result, the spread (focus characteristic) of the electron beam on the photoelectric conversion target 114 differs for each field emission electron source device, or even on one photoelectric field emission electron source device. Depending on the position, the spread of the electron beam varies. Therefore, when used as a field emission type electron source imaging device, captured images vary from device to device or partially in the captured image.

  Furthermore, the field emission type electron source device of FIG.

  The shield grid electrode 120 disposed between the field emission electron source array 129 and the photoelectric conversion target 114 is in the form of a thin film. For example, a thin film copper mesh is fixed to a metal holding frame by applying tension. Or a metal or alloy film such as Ni, Cr, Cu, Ag, Co or the like on the surface of an insulating material such as glass or ceramic provided with a large number of through-holes, by vacuum deposition, sputtering, or chemical plating. It is created by forming by etc.

  However, in the shield grid electrode 120 in which a thin-film copper mesh is fixed by applying tension to a holding frame made of metal, the tension distribution is likely to vary. For example, if the tension is different between the central portion and the peripheral portion of the copper mesh, the shape of the through hole 120a and the distance between adjacent through holes 120a are different between the central portion and the peripheral portion of the copper mesh. In such a case, it becomes difficult to dispose the center of the through hole 120a directly above the tips of all the cold cathode elements 124 of the field emission electron source array 129. That is, the relative positional relationship between the tip of the cold cathode element 124 and the center of the through-hole 120a is partially shifted, so that the amount of electron beam reaching the photoelectric conversion target 114 is changed between the central portion and the periphery of the photoelectric conversion target 114. It varies from part to part or varies locally. Therefore, when used as a field emission type electron source display device, the luminance distribution varies, and when used as a field emission type electron source imaging device, there arises a problem that the captured image becomes non-uniform.

  Further, in the shield grid electrode 120 in which a metal or alloy film is formed on the surface of a glass having a large number of through holes, the glass itself has a large amount of gas adsorption, and even if the metal film as described above is formed on the surface. There is a problem that gas is easily emitted due to collisions of electron beams during driving of the field emission electron source device.

  Further, when the glass is made thin and a large number of fine through-holes 120a are formed on the glass, the mechanical strength of the glass is dramatically deteriorated, and there is a problem that the glass is easily broken. In particular, if many electron beams are allowed to reach the photoelectric conversion target 114, it is necessary to reduce the distance between the adjacent through holes 120a, and the mechanical strength further deteriorates.

  Further, in the shield grid electrode 120 in which a metal or alloy film is formed on the surface of the ceramic provided with a large number of through holes, the ceramic requires a firing step, and the distance between adjacent through holes 120a is reduced. Are difficult, and the mechanical strength is insufficient as in the case of glass.

  Although the shield grid electrode provided in the field emission electron source device has been described above, the mesh structure having a plurality of through holes typified by such a shield grid electrode has the above-described field emission electron source. It is also used for various purposes other than equipment. For example, by making the thickness of the mesh structure sufficiently larger than the diameter of the through-hole, atoms, molecules, light, etc. are passed from one surface to the other surface, and directivity is imparted in the traveling direction thereof. There are applications as a collimator and as a particle filter that sorts particles by particle size by adjusting the diameter of the through holes of the mesh structure.

  In many cases, the mesh structure used for such an application is formed by forming a through-hole in a base material such as metal, glass, or ceramic, as described above. However, the use of such a substrate causes the following problems.

  In other words, when metal is used as the material for the mesh structure, it is necessary to deeply drill holes in the metal structure. Can not do it.

In addition, when glass is used as the material for the mesh structure, it is difficult to drill holes, and there are concerns about outgassing in a vacuum and insufficient mechanical strength as described above.
When ceramic is used as the material for the mesh structure, there are the following problems. That is, it is difficult to reduce the interval between the through holes from the viewpoint of ensuring mechanical strength. Further, since a large number of through holes cannot be formed, when used as a collimator, the amount of atoms, molecules, or light on the emission side is drastically reduced with respect to the amount on the incident side. In general, ceramics tend to have dimensional variations due to firing, and it is difficult to control the through-hole size with high accuracy. For this reason, the filter must determine the through-hole diameter with high accuracy for the particle size. It is also unsuitable for use.
JP-A-9-270229 JP-A-9-69347 JP-A-6-111735 JP 2000-251808 A JP 2000-48743 A JP 2002-313263 A

  The present invention aims to solve the above-described conventional problems.

  That is, an object of the present invention is to provide a mesh structure that has mechanical strength, has little gas emission even in a vacuum, and can form through holes with high dimensional accuracy.

Mesh structure of the present invention has a through-hole of the multiple. Through the through hole, light, electrons, atoms, ions, or molecules can pass from one surface to the other surface. The mesh structure is made of a material containing silicon, and the material containing silicon includes silicon having a crystal structure . The mesh structure includes an N-type or P-type doped silicon layer and an insulating layer made of SiO ₂ .

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the mesh structure which has a mechanical strength, has little gas discharge | emission in a vacuum, and can form a through-hole with a dimensional accuracy.

  The mesh structure according to the first preferred embodiment of the present invention has a plurality of through holes formed one-dimensionally. Through the through hole, light, electrons, atoms, ions, or molecules can pass from one surface to the other surface. The mesh structure is made of a material containing silicon, and the material containing silicon includes silicon having a crystal structure.

  In the first preferred embodiment, since the mesh structure is made of a material containing silicon and the material containing silicon contains silicon having a crystal structure, the through hole can be processed using a fine processing technique used in a semiconductor. Become. Therefore, the through-hole shape and the through-hole diameter of the mesh structure can be controlled with high accuracy. Therefore, for example, a particle filtering function using the through hole can be easily realized.

  Moreover, through holes deeper than the diameter can be easily processed in the mesh structure by the semiconductor microfabrication technology, the mesh structure with a filter function for selecting particles, the traveling direction of atoms, molecules, light, etc. A mesh structure having a collimator function for imparting directivity can be manufactured at low cost.

  Furthermore, since a high-purity silicon plate used in semiconductors can be used, a mesh structure with a collimator function that imparts directivity to atoms, molecules, electrons, etc. without the concern of outgassing in a vacuum is easy. Can get to.

  In the mesh structure according to the second preferred embodiment of the present invention, in the first preferred embodiment, the thickness of the partition wall separating the plurality of through holes is smaller than the opening diameter of the through holes.

  According to the second preferred embodiment, since the ratio (opening ratio) of the opening area of the through hole to the surface of the mesh structure can be increased, a collimator that imparts directivity to atoms, molecules, electrons, light, etc. When used as a collimator, it is possible to provide a collimator having a large ratio (transmission rate) of the amount of atoms, molecules, electrons, light, etc. on the exit side to the amount of atoms, molecules, electrons, light, etc. on the incident side.

  A field emission electron source device according to a third preferred embodiment of the present invention includes a field emission electron source array, a target that performs a predetermined operation with an electron beam emitted from the field emission electron source array, and the electric field. A mesh structure disposed between the emission electron source array and the target and having a plurality of through holes through which the electron beams emitted from the field emission electron source array pass. Each of the plurality of through holes has an opening on the field emission electron source array side and an electron beam passage path continuous from the opening. The mesh structure is made of a material containing silicon doped in N-type or P-type.

  According to the third preferred embodiment, the mesh structure can be produced by a MEMS (Micro Electro Mechanical System) technique, which is a semiconductor technique, using a silicon substrate. As a result, it is possible to perform deep digging with a high aspect ratio and high-precision fine processing required when creating a mesh structure.

  For example, when considering a field emission type electron source imaging device having a VGA (horizontal direction 640 dots × vertical direction 480 dots) and an external diagonal size of 1 inch, the size of one cell is about 20 μm square. In the case of a field emission electron source device in which one cell is composed of a large number (for example, 100) of cold cathode elements (emitters), the opening diameter of the through holes of the mesh structure is, for example, about 16 μm. Sub-micron order accuracy is required for the production. Also, high accuracy is required in assembling the mesh structure and the field emission electron source array. Therefore, by using the ultra-fine processing technology of semiconductor technology, high-precision forming of the mesh structure and high-precision assembly of the mesh structure and the field emission electron source array are possible, and as a result, the electric field with excellent quality is obtained. An emission electron source device can be provided.

  In addition, it is preferable that part or all of the field emission electron source array is formed on a silicon substrate using a semiconductor technique in order to ensure reliability such as accuracy. In addition, the semiconductor technology is now generalized, and a large number of devices that perform this are on the market, which is advantageous in terms of cost.

  Therefore, since the mesh structure is formed using the silicon substrate, the thermal expansion coefficient of the mesh structure and the substrate on which the field emission type electron source array is formed can be made substantially equal, which is advantageous in thermal expansion. It is. That is, it is possible to prevent the field emission electron source device from being broken due to thermal expansion. In addition, since the baking temperature such as baking for outgassing during the assembly of the field emission electron source device can be increased, the reliability of the obtained device can be improved.

In a field emission electron source device according to a fourth preferred embodiment of the present invention, in the third preferred embodiment, the mesh structure comprises an N-type or P-type doped silicon layer and an insulating layer made of SiO _2. Including layers.

In general, a silicon substrate used in semiconductor technology is often a substrate made of pure silicon or an SOI (Silicon On Insulator) substrate having an SiO ₂ layer as an insulating layer sandwiched therebetween. Since SOI substrates that are frequently used worldwide can be obtained relatively inexpensively, according to the fourth preferred embodiment, an inexpensive field emission electron source device can be provided.

  In a field emission electron source device according to a fifth preferred embodiment of the present invention, in the third preferred embodiment, among the surface on the field emission electron source array side and the surface on the target side of the mesh structure. A conductive thin film is formed on at least one of the above.

  Suitable materials for the conductive thin film include aluminum, gold, copper, tantalum, molybdenum, titanium, and the like. Forming such a thin film of a conductive material by a technique such as sputtering, vacuum deposition, or CVD used in the semiconductor manufacturing process is that the device used can be obtained at a low cost by the development of semiconductor technology, This is preferable because the film formation technology has already matured and has been established.

  In a field emission electron source device according to a sixth preferred embodiment of the present invention, in the third preferred embodiment, the mesh structure is formed on a base layer that constitutes most of the mesh structure and on a surface of the base layer. And a thin film layer having a lower resistance than the base layer. Here, the base layer constitutes “the majority” of the mesh structure when the thickness ratio of the base layer is 90% or more in a region (trimming portion 9 described later) where a plurality of through holes are formed in the mesh structure. It means that there is.

  According to the sixth preferred embodiment, the resistance of the surface portion of the mesh structure made of N-type or P-type high-resistance silicon can be lowered. Thereby, it is possible to provide a field emission type electron source device in which potential fluctuation due to local collision of electron beams is unlikely to occur.

  In a field emission electron source device according to a seventh preferred embodiment of the present invention, in the third preferred embodiment, the mesh structure is provided between at least two electrode layers and the at least two electrode layers. And at least one intermediate layer.

  According to the seventh preferred embodiment, the potentials of at least two electrode layers can be set independently and freely, such as different or the same. As a result, the potential of the electrode layer and the degree of freedom of the structure are improved, so that the electron beam absorption and removal action in the mesh structure can be adjusted, the electron beam can be focused, and the focusing action can be adjusted. Is easily possible.

  By using a mesh structure having such a function, for example, by reducing the electron beam spot on the target, a high-resolution field emission electron source display device or a high-resolution field emission electron source imaging device can be obtained. Can be provided. Further, by guiding the electron beam from the field emission electron source array to the target while suppressing the spread, a field emission electron source device with less manufacturing variation can be provided.

  In the field emission electron source device according to an eighth preferred embodiment of the present invention, in the seventh preferred embodiment, the at least one intermediate layer is an insulating layer, and the at least two electrode layers pass through the electron beam. At least two potential spaces are formed on the path.

  According to the eighth preferred embodiment, by applying different potentials to at least two electrode layers, the electron beam incident on the mesh structure is given a desired focusing action, or the mesh structure absorbs and removes the electron beam. The trimming action to be performed can be freely controlled, and the electron beam from the field emission electron source array can be effectively guided to the target.

  In the field emission type electron source device according to a ninth preferred embodiment of the present invention, in the seventh preferred embodiment, one of the at least two electrode layers has the electric field with respect to the at least one intermediate layer. A first electrode layer disposed on the emission electron source array side to which a first voltage is applied; the other one is disposed on the target side with respect to the at least one intermediate layer; A second electrode layer to which a voltage is applied. The at least one intermediate layer is a high resistance layer having a higher resistance value than the first and second electrode layers.

  According to the ninth preferred embodiment, the function and effect of the seventh preferred embodiment are provided, and the mesh structure can be easily manufactured.

As the mesh structure including at least two electrode layers, for example, an SOI substrate in which a SiO ₂ layer as an insulating layer is formed on a silicon substrate may be used. However, since the SOI substrate includes layers of different materials such as a silicon layer and an insulating layer, it has the following problems. For example, if a through hole is to be formed in an SOI substrate by etching, the silicon layer is easy to etch, but the insulating layer is difficult to etch. Further, local stress concentration occurs in the vicinity of the boundary between the silicon layer and the insulating layer, and the substrate is cracked during etching.

  On the other hand, in the mesh structure according to the ninth preferred embodiment, for example, a through hole is formed by etching in a high resistance silicon substrate, and then both surface layers are doped with N-type or P-type material on both sides. It can be easily created by making the resistance low. Alternatively, N-type or P-type material is doped on both sides of a high-resistance silicon substrate to form a low-resistance surface layer on both sides, and through holes are created in the silicon substrate where the intermediate layer remains high-resistance by etching. You may do it.

  Alternatively, after a through hole is formed by etching in a high resistance substrate, a metal or other low resistance film may be formed on both surfaces by electrolytic etching or the like.

  Thus, the mesh structure according to the ninth preferred embodiment is easy to create. Moreover, the electron beam from the field emission electron source array can be absorbed and removed by colliding with the side wall of the electrode layer portion having a low resistance in the electron beam passage path, so that the potentials of at least two electrode layers are independent of each other. And by setting freely, the effect similar to said 7th preferable form can be acquired.

  In the field emission electron source device according to a tenth preferred embodiment of the present invention, in the seventh preferred embodiment, the field emission electron source with respect to the at least one intermediate layer of the at least two electrode layers. When the voltage applied to the first electrode layer disposed on the array side is V1, and the voltage applied to the second electrode layer disposed on the target side with respect to the at least one intermediate layer is V2, V1 > V2 is satisfied.

  According to the tenth preferred embodiment, the electron beam emitted from the field emission electron source array is accelerated by the relatively high voltage V1 applied to the first electrode on the field emission electron source array side and meshed. After entering the through-hole of the structure, it is decelerated by the relatively low voltage V2 applied to the second electrode while passing through the electron beam passage.

  For example, among the electron beams emitted from the designated cell of the field emission electron source array, the direction of the velocity vector indicating the traveling direction of the electron beam incident on the through hole at a position other than directly above the designated cell is Since the direction differs from the extending direction of the electron beam passage, most of them collide with the side wall of the electron beam passage and are absorbed and removed. In addition, since the electron beam is decelerated as it travels from the first electrode side toward the second electrode side along the electron beam passage path, the electron beam is more likely to collide with the side wall of the electron beam passage path.

  Also, among the electron beams emitted from the designated cell of the field emission electron source array, the velocity vector representing the traveling direction of the electron beam incident on the through hole located immediately above the designated cell passes through the electron beam. An electron beam having a velocity vector in a divergence direction different from the extending direction of the path collides with the side wall of the electron beam passing path and is absorbed and removed. In addition, since the electron beam is decelerated as it travels from the first electrode side toward the second electrode side along the electron beam passage path, the electron beam having such a divergence velocity vector is placed on the side wall of the electron beam passage path. It becomes easier to collide.

  By such a trimming action of the mesh structure, only the electron beam emitted from the designated cell in the substantially vertical direction passes through the mesh structure, travels in the substantially vertical direction from the mesh structure, and reaches the target.

  Therefore, even if the distance from the field emission electron source array to the mesh structure and the distance from the mesh structure to the target are slightly different from the design value, the spread of the electron beam on the target (spot diameter) Hardly changes.

  In other words, when frit glass or indium is used to join the back panel to the side panel and the side panel to the front panel, as described above, the distance between the back panel and the front panel can be managed with high accuracy. Difficult to do. According to the 10th preferable form of this invention, even if it is a case where the distance of a back panel and a front panel differs from a design value by assembly variation, the change of the spot diameter of an electron beam on a target can be suppressed. .

  Further, by evacuating the inside of the vacuum vessel composed of the back panel, the side peripheral device, and the front panel, the front panel is pushed by the atmospheric pressure and distorted in a curved shape. As a result, the distance between the rear panel and the front panel is different between the central portion and the peripheral portion. According to the 10th preferable form of this invention, even in such a case, it can suppress that the spot diameter of the electron beam on a target differs in a center part and a peripheral part.

  Therefore, according to the 10th preferable form of this invention, the field emission type electron source display device which can display uniform image quality, and the field emission type electron source imaging device which can image uniform image quality can be provided.

  Furthermore, according to the 10th preferable form of this invention, the thickness of a mesh structure can be made thin compared with a 3rd preferable form.

  That is, among the electron beams incident on the through-holes of the mesh structure, an electron beam having a velocity vector representing the traveling direction thereof is different from the extending direction of the electron beam passage path is changed from the first electrode side to the second direction. Since the vehicle is decelerated as it proceeds toward the electrode side, it is more likely to collide with the side wall of the electron beam passage path than when the vehicle is not decelerated. In other words, after such an electron beam is incident on the electron beam passage path, the distance until the electron beam collides with the side wall of the electron beam passage path is shorter than that when the electron beam is not decelerated. Therefore, a desired trimming action can be obtained even if the mesh structure is thin.

  When the thickness of the mesh structure is reduced, it is possible to reduce the proportion of the electron beam incident on the through hole located immediately above the designated cell that is absorbed and removed by the mesh structure. Thereby, the amount of electron beams reaching the target can be increased. As a result, the luminance can be increased in the field emission type electron source display device having the phosphor on the target, and the electron beam reaching the target in the field emission type electron source imaging device having the photoelectric conversion film on the target. Since a sufficient amount can be secured, the afterimage can be reduced.

  In the case of a field emission type electron source imaging device, the following effects can be obtained in addition to the above.

  In the field emission type electron source imaging device, the potential of the photoelectric conversion film provided on the target during operation is determined by the arrival of the electron beam to the target and the reading of the holes, and the cold cathode element of the field emission type electron source array. It drops until it becomes almost equal to the potential. However, according to the tenth preferred embodiment, since the difference between the potential V2 of the second electrode layer on the target side of the mesh structure and the potential of the target can be set small, the electron beam on the target side of the mesh structure The potential difference between the emission part and the target is reduced. Therefore, the electron beam after exiting the mesh structure is not extremely decelerated or accelerated, and a strong electric field lens is not formed near the electron beam exit part. The trajectory hardly changes. Therefore, the electron beam that has passed through the electron beam passing path of the mesh structure without being absorbed and removed proceeds in the vertical direction after reaching the target even after exiting the mesh structure.

  Therefore, even when the distance between the back panel and the front panel is different from the design value due to assembly variations, the field emission type that can suppress the change in the spot diameter of the electron beam on the target and can capture a uniform image quality An electron source imaging device can be provided.

  In a field emission electron source device according to an eleventh preferred embodiment of the present invention, in the seventh preferred embodiment, the field emission electron source with respect to the at least one intermediate layer of the at least two electrode layers. The electrode layer disposed on the array side is a first electrode layer, the electrode layer disposed on the target side with respect to the at least one intermediate layer is a second electrode layer, and of the length of the electron beam passage path, When the length occupied by the first electrode layer is T1, and the length occupied by the second electrode layer is T2, T1 << T2 is satisfied.

  According to the eleventh preferred embodiment, the voltage gradient formed by the voltage V1 applied to the first electrode layer and the voltage V2 applied to the second electrode layer is brought close to the field emission electron source array, and The area occupied by the second electrode layer in the electron beam passage path can be increased. As the voltage gradient approaches the field emission electron source array, the deceleration region in the electron beam passage path approaches the field emission electron source array side. In addition, since the area occupied by the second electrode layer is increased, the range in which the electron beam is absorbed and removed is expanded. Therefore, among the electron beams incident on the through holes of the mesh structure, an electron beam having a velocity vector representing the traveling direction thereof is different from the extending direction of the electron beam passing path, and is decelerated at a relatively early stage. It is absorbed and removed by colliding with the side wall. Therefore, the electron beam can be trimmed efficiently.

  Therefore, the traveling direction of the electron beam emitted from the mesh structure can be made to follow the vertical direction. Therefore, even if the distance between the back panel and the front panel differs from the design value due to assembly variations, or even when the front panel is pressed by atmospheric pressure and distorted in a curved shape, the spot diameter of the electron beam on the target Can be further suppressed.

  Therefore, according to the eleventh preferred embodiment of the present invention, it is possible to provide a field emission type electron source display device capable of displaying a more uniform image quality and a field emission type electron source imaging device capable of imaging a more uniform image quality. .

  The field emission electron source device according to a twelfth preferred embodiment of the present invention further includes a substrate on which the field emission electron source array is formed in the third preferred embodiment. The mesh structure integrally includes a spacer portion that separates the field emission electron source array and the openings of the plurality of through holes. The mesh structure is disposed on the substrate via the spacer portion.

  According to such a twelfth preferred embodiment, the variation in the distance between the field emission electron source array and the opening of the mesh structure on the field emission electron source array side can be reduced and set with high accuracy. For example, in the conventional field emission electron source device shown in FIG. 27, the distance between the field emission electron source array 129 and the shield grid electrode 120 is the same as that of the back panel 117 and the side surface on which the field emission electron source array 129 is formed. Bonding accuracy with the peripheral device 116 (ie, thickness variation of the low melting point frit glass 133), bonding accuracy between the stepped portion 121 of the side surface peripheral device 116 and the shield grid electrode 120 (ie, thickness variation of the low melting point frit glass), and The variation in the manufacturing accuracy of the dimension from the lower surface to the step portion 121 (that is, the dimension variation) of the side surface peripheral device 116 that is bonded to the back panel 117 varies.

  On the other hand, in the twelfth preferred embodiment of the present invention, since the mesh structure is integrally provided with the spacer portion, the field emission electron source array and the opening of the mesh structure on the field emission electron source array side are arranged. This distance varies depending on two variations, namely, the adhesion accuracy between the field emission electron source array and the spacer portion and the manufacturing accuracy (ie, dimensional variation) of the thickness of the spacer portion. That is, there is no adhesion part by the low melting point frit glass with the least accuracy. Therefore, the distance accuracy between the field emission electron source array and the opening of the mesh structure on the field emission electron source array side is improved.

  Moreover, according to the 12th preferable form of this invention, the mechanical strength of a mesh structure improves.

  That is, for example, when considering a field emission electron source imaging device having a VGA (horizontal direction 640 dots × vertical direction 480 dots) and an outer diagonal size of 1 inch, the size of one pixel is about 0.02 mm as described above. Become. The thickness of the mesh structure is about 0.02 mm to 0.2 mm because it is considered appropriate to be about 1 to 10 times the size of one pixel in consideration of its function. As described above, the size of the mesh structure is slightly larger than 12 mm × 10 mm, and considering that a large number of through holes are formed in this mesh structure, the mechanical strength of the mesh structure is very high. small. Accordingly, it is very difficult to handle the mesh structure alone in the assembly process of the field emission electron source device because of its insufficient mechanical strength.

  However, in the twelfth preferred embodiment of the present invention, the mesh structure is integrally provided with a frame-shaped spacer portion around the mesh structure. Therefore, since the spacer portion improves the mechanical strength of the mesh structure, the problem of difficulty in handling the mesh structure alone in the assembly process of the field emission electron source device is solved.

  In a field emission electron source device according to a thirteenth preferred embodiment of the present invention, in the twelfth preferred embodiment, the spacer portion and the substrate are bonded using a conductive material, and the conductive material is used as the conductive material. Power is supplied from the substrate to at least a part of the mesh structure.

  According to the thirteenth preferred embodiment, voltage supply to the mesh structure can be performed from the substrate on which the field emission electron source array is formed, and wire bonding for voltage supply becomes unnecessary. Therefore, the expense for wire bonding can be omitted, and occurrence of defects such as wire collapse when wire bonding is performed can be avoided.

  In a field emission electron source device according to a fourteenth preferred embodiment of the present invention, in the seventh preferred embodiment, the field emission electron source with respect to the at least one intermediate layer of the at least two electrode layers. When the voltage applied to the first electrode layer disposed on the array side is V1, and the voltage applied to the second electrode layer disposed on the target side with respect to the at least one intermediate layer is V2, By driving one or both of the voltage V1 and the voltage V2 while driving the field emission electron source device, an electron beam passing through the plurality of through holes of the mesh structure and traveling toward the target Vary the amount.

  According to the fourteenth preferred embodiment, an effective imaging operation can be performed particularly in a field emission type electron source imaging device having a photoelectric conversion film on a target.

  That is, in a field emission type electron source imaging device having a photoelectric conversion film on a target, the amount of electron-hole pairs generated by the image of light incident on the target and formed is determined by the intensity of the incident light. The stronger the incident light, the more electron-hole pairs are generated. Of the generated electron-hole pairs, holes are transported to the electron scanning surface, which is the surface of the target field emission electron source array side (in the case of an avalanche multiplication type photoelectric conversion film using selenium) It is transported and accumulated while being doubled.

  When the target is scanned by an electron beam emitted from the field emission electron source array, the accumulated holes are combined with electrons contained in the electron beam, and an electric signal is read out at the same time. Here, if sufficient electrons do not reach the target, some of the holes accumulated on the electron scanning surface of the target will not be read and will remain until the next scanning.

  For this reason, holes that remain without being read out in the readout scanning of the first frame will be read out by electrons that arrived in the readout scanning of the second frame, and in the captured image, a portion with a strong incident light becomes an afterimage. It will remain.

  In order to solve this problem, a sufficient amount of electron beam reaches the target after the end of the reading scan of the first frame, and the remaining holes that are not read are removed to prepare for the reading scan of the next frame. There is a need. Hereinafter, this operation is referred to as “charge reset”.

  However, if an electrode having an action of removing a part of electrons such as a mesh structure is arranged between the field emission electron source array and the target, a sufficient amount of electron beam is targeted even during the charge reset period. May not be able to reach.

  In the fourteenth preferred embodiment of the present invention, the voltage V1 applied to the first electrode layer and the second electrode layer are applied during driving of the field emission electron source device (specifically, during the charge reset period). By changing one or both of the voltages V2, the amount of the electron beam that passes through the plurality of through holes of the mesh structure and goes to the target is changed. Thereby, the amount of electron beams reaching the target during the charge reset period can be increased, and a sufficient charge reset current can be secured. Thereby, it is possible to provide a field emission type electron source imaging device with little afterimage.

  In a field emission electron source device according to a fifteenth preferred embodiment of the present invention, in the third preferred embodiment, the cross-sectional shape along the direction perpendicular to the extending direction of the electron beam passage path is circular or elliptical. , Each interior angle is a polygon larger than 90 degrees, or a polygon in which adjacent sides are connected by an arc.

  According to the fifteenth preferred embodiment, the mesh structure can be easily manufactured.

  For example, when the edge shape of the opening is a rectangle (or square) whose inner angle is 90 degrees, stress concentrates on the four corners of the edge of the opening, and the four corners are formed when the through hole is formed. The problem that the mesh structure breaks easily occurs.

  As in the fifteenth preferred embodiment, the edge shape of the opening is a circle or an ellipse, a polygon that is a pentagon or more whose inner angle is greater than 90 degrees, or a polygon in which adjacent sides are connected by an arc. Since the stress concentration is relaxed, the mesh structure is not easily broken when the through hole is formed, and the manufacturing is facilitated.

  The easy production of the mesh structure means that the production yield of the mesh structure is improved, and an inexpensive mesh structure can be provided. Therefore, an inexpensive field emission electron source device can be provided.

  Further, since the mechanical strength of the mesh structure is improved, handling of the mesh structure is facilitated, so that the field emission electron source device can be easily assembled. Also from this point, an inexpensive field emission electron source device can be provided.

  In a field emission electron source device according to a sixteenth preferred embodiment of the present invention, in the third preferred embodiment, the field emission electron source array includes a cell including a plurality of electron sources each emitting electrons. Have multiple. The field emission electron source array and the mesh structure are arranged so that the plurality of openings and the plurality of cells correspond one-to-one in the vertical direction. The electron beam emitted from the cell enters the corresponding opening, passes through the electron beam passage, and enters the target.

  According to the sixteenth preferred embodiment, since the central axis of the cell composed of a plurality of electron sources can coincide with the central axis of the opening of the through hole of the mesh structure, emission from the field emission electron source array is possible. Among the generated electron beams, the electron beam that travels in the vertical direction passes through the through holes of the mesh structure most. Accordingly, the amount of electron beam reaching the target is maximized. Thereby, the luminance can be increased in the field emission type electron source display device having the phosphor on the target, and the electron beam reaching the target in the field emission type electron source imaging device having the photoelectric conversion film on the target. Since a sufficient amount can be secured, the afterimage can be reduced.

  In the field emission electron source device according to a seventeenth preferred embodiment of the present invention, in the third preferred embodiment, the field emission electron source array is interposed between the field emission electron source array and the mesh structure. It further has a prefocusing electrode for prefocusing the emitted electron beam.

  According to the seventeenth preferred embodiment, the electron beam emitted from the field emission electron source array is prefocused by the prefocus electrode, so that its spread is narrowed and enters the through hole of the mesh structure.

  Accordingly, the traveling direction of each electron beam approaches a direction parallel to the vertical direction, and approaches a direction parallel to the extending direction of the electron beam passage path of the through hole. Therefore, the electron beam easily passes through the through hole of the mesh structure.

Therefore, in the seventeenth preferred embodiment, the electron beam spot on the target is smaller than in the case where the pre-focusing is not performed, so that a higher-resolution field emission electron source display device or a higher-resolution field emission electron source. An imaging device can be provided.
A driving method of a field emission electron source device according to a preferred embodiment of the present invention includes a field emission electron source array, a target that performs a predetermined operation with an electron beam emitted from the field emission electron source array, and the electric field. A field emission electron having a mesh structure disposed between the emission electron source array and the target and having a plurality of through holes through which the electron beam emitted from the field emission electron source array passes. It is a drive method of a source device. Each of the plurality of through holes has an opening on the field emission electron source array side and an electron beam passage path continuous from the opening. The mesh structure is made of a material containing silicon doped in N-type or P-type. The mesh structure includes at least two electrode layers and at least one intermediate layer provided between the at least two electrode layers. The voltage applied to the first electrode layer disposed on the field emission electron source array side with respect to the at least one intermediate layer of the at least two electrode layers is V1, and the at least one intermediate layer When the voltage applied to the second electrode layer disposed on the target side is V2, one or both of the voltage V1 and the voltage V2 during driving of the field emission electron source device By changing the amount of the electron beam that passes through the plurality of through holes of the mesh structure and travels toward the target.
According to such a preferred embodiment, an effective imaging operation can be performed particularly in a field emission type electron source imaging device having a photoelectric conversion film on a target.
That is, in the driving method according to the preferred embodiment, the voltage V1 applied to the first electrode layer and the second electrode layer during driving of the field emission electron source device (specifically, during the charge reset period) By changing one or both of the applied voltages V2, the amount of the electron beam that passes through the plurality of through holes of the mesh structure and travels toward the target is changed. Thereby, the amount of electron beams reaching the target during the charge reset period can be increased, and a sufficient charge reset current can be secured. Thereby, it is possible to provide a field emission type electron source imaging device with little afterimage.

  Hereinafter, the present invention will be described in detail with reference to embodiments.

(Embodiment 1)
FIG. 1 is a cross-sectional view of a mesh structure according to Embodiment 1 of the present invention and a field emission electron source device including the mesh structure.

  As shown in FIG. 1, the field emission electron source device according to the first embodiment is a vacuum vessel formed by a front panel 1 made of light-transmitting glass, a back panel 5, and a side peripheral device 4. Is provided. The front panel 1 and the side surface peripheral device 4 and the back panel 5 and the side surface peripheral device 4 are fixed and sealed by a vacuum sealing material 7 such as frit glass for high temperature firing or indium for low temperature sealing, The inside of the vacuum vessel is kept in a vacuum. For convenience of the following description, an axis parallel to the normal direction of the front panel 1 and the back panel 5 is referred to as a Z axis.

  On the inner surface of the back panel 5, a semiconductor substrate 6 on which a field emission electron source array 10 is formed is installed. On the semiconductor substrate 6, a mesh structure 8 integrally provided with a spacer portion 8a is installed and fixed. On the inner surface of the front panel 1 facing the mesh structure 8, a translucent anode electrode 2 and a target 3 are formed. The target 3 is a layer that receives electrons emitted from the field emission electron source array and performs a predetermined beneficial operation, and is, for example, a phosphor layer or a photoelectric conversion film.

  A getter pump (not shown) is installed in the vacuum vessel composed of the front panel 1, the back panel 5, and the side peripheral device 4 to keep the inside at a high vacuum by adsorbing and removing excess gas. Yes.

  FIG. 2 is a schematic perspective view of the mesh structure 8 as viewed from the surface facing the field emission electron source array. The mesh structure 8 is a substantially flat electrode made of a silicon substrate doped N-type or P-type using MEMS technology, which is a semiconductor processing technology, and has a thin trimming portion 9 at the center and a trimming portion. 9 is provided with a frame-shaped spacer portion 8a which is formed continuously around the trimming portion 9 and is thicker than the trimming portion 9. A plurality of through holes are formed in the trimming portion 9.

  The spacer portion 8a separates the function of improving the mechanical strength of the single mesh structure 8 from the field emission electron source array and the openings of the plurality of through holes formed in the trimming portion 9, and between them. The function of maintaining the distance with high accuracy is provided.

  FIG. 3 is a partially enlarged perspective view of the trimming portion 9 of the mesh structure 8. The trimming unit 9 is formed with a large number of through holes 90 penetrating the front and back of the trimming unit 9 through which the electron beams emitted from the field emission electron source array pass. A large number of through-holes 90 are arranged in lattice points.

  FIG. 4A is a partially enlarged cross-sectional view of the trimming portion 9 in the Z-axis direction. Each through-hole 90 includes an opening 91 formed on the surface of the trimming portion 9 on the field emission electron source array side, and an electron beam passage path 92 continuous from the opening 91 in the thickness direction of the trimming portion 9. . In the present specification, the opening 91 means a portion of the through-hole 90 that is included on the surface of the trimming portion 9 on the field emission electron source array side, and does not include the Z-axis direction component. Further, the electron beam passing path 92 means a portion between the front and back surfaces of the trimming portion 9 in the through hole 90.

  The length of the electron beam passage 92 is sufficiently larger than the diameter D of the opening 91. Here, the length of the electron beam passage path 92 means the length along the electron beam passage path 92. Therefore, when the electron beam passage path 92 is bent, it becomes longer than the thickness of the trimming portion 9 in the Z-axis direction.

  Since the length of the electron beam passage path 92 is sufficiently larger than the diameter D of the opening 91, the extending direction of the electron beam passage path 92 (in this embodiment) of the electron beams emitted from the field emission type electron source array (this embodiment) In the embodiment, the electron beam traveling in a direction that makes a large angle with respect to the Z-axis direction) can be absorbed by the side wall of the electron beam passage 92 and absorbed and removed. For example, when the diameter D of the opening 91 is 16 μm and the length of the electron beam passage path 92 is 100 μm, an electron beam traveling in a direction that forms an angle of about 9.2 degrees or more with respect to the Z axis is used. It can be absorbed and removed by colliding with the side wall.

  FIG. 5 is an exploded perspective view of the field emission electron source device according to the first embodiment. An example of a method for assembling the field emission electron source device will be briefly described with reference to FIG.

  A frit glass 7a is provided on the back panel 5, and an annular side surface outer peripheral device 4 is placed thereon and baked at a high temperature of about 400 ° C. so that the back panel 5 and the side surface outer peripheral device 4 are frit glass. It joins via 7a.

  The spacer portion 8a of the mesh structure 8 and the semiconductor substrate 6 are bonded by a bonding method such as anodic bonding or eutectic bonding. The semiconductor substrate 6 on which the mesh structure 8 is mounted is placed and fixed to the portion surrounded by the side peripheral device 4 on the back panel 5 by die bonding.

  Power feeding to the trimming unit 9 is performed from the semiconductor substrate 6 through a joint portion between the spacer portion 8a of the mesh structure 8 and the semiconductor substrate 6 and the spacer portion 8a. A wiring pattern on the semiconductor substrate 6 for supplying power to the mesh structure 8 is connected to a wiring pattern formed on the back panel 5 by wire bonding (not shown). Thereby, the power supply to the mesh structure 8 can be performed from the outside of the vacuum vessel.

  A field emission electron source array in which a plurality of cells are arranged in a matrix is formed on the semiconductor substrate 6. Each cell includes a plurality (for example, 100) of cold cathode elements (emitters).

  The plurality of cells of the field emission electron source array on the semiconductor substrate 6 and the plurality of through holes 90 of the mesh structure 8 have a one-to-one correspondence. An axis parallel to the Z axis passing through the center of each cell passes through the approximate center of the through hole 90 of the mesh structure 8 corresponding to this cell (for example, in this embodiment, the Z axis passing through the center of the cell). The semiconductor substrate 6 and the mesh structure 8 are aligned with high accuracy so that the amount of misalignment of the center of the through hole 90 with respect to the axis parallel to the axis is about 3 μm or less.

  The back panel structure composed of the back panel 5, the side peripheral device 4, the mesh structure 8, and the semiconductor substrate 6 assembled in this manner is out of gas at a temperature of about 120 ° C. to 350 ° C. in a vacuum apparatus. It is baked for the sake of

  The back-panel structure that has been baked is joined and integrated in a vacuum by the front panel 1 and a metal ring 7b to which indium is adhered, thereby forming a vacuum container whose inside is sealed in a vacuum.

  As shown in FIG. 6, the field emission electron source array formed on the semiconductor substrate 6 includes a cold cathode element (emitter) 15 with a sharpened tip and an insulation formed around the cold cathode element 15. A large number of emitter portions including a layer 13 and a gate electrode 12 provided on the insulating layer 13 and having an opening surrounding the cold cathode element 15 are integrated.

  If the field emission electron source array is a flat-type imaging device that performs imaging of, for example, VGA (horizontal direction 640 dots × vertical direction 480 dots), the vertical and horizontal dimensions are 20 μm at each pixel position arranged in a matrix. About one cell is arranged. A plurality of gate electrodes 12 are formed in a stripe shape extending in the horizontal direction (or vertical direction), and a plurality of emitter electrodes 14 are formed in a stripe shape extending in a direction orthogonal to the longitudinal direction of the gate electrode 12. When viewed from the direction parallel to the Z-axis, one cell is arranged at each intersection point of the plurality of gate electrodes 12 and the plurality of emitter electrodes 14. In each cell, a plurality of cold cathode elements 15 are arranged substantially uniformly in a region where the vertical and horizontal dimensions on the emitter electrode 14 are all about 10 μm.

  A plurality of cold cathode elements 15 in the same cell is applied with a pulsed emitter potential that drops from a reference potential of 30 V to 0 V, for example, and the gate electrode 12 formed on the insulating layer 13 surrounding the cold cathode elements 15 is applied to the gate electrode 12. For example, a pulsed gate potential that rises from a reference potential of 30 V to an intermediate 60 V is applied. Electrons are emitted from the tip of the cold cathode device 15 due to a potential difference formed between the cold cathode device 15 and the gate electrode 12.

  The gate electrode 12 and the emitter electrode 14 are connected to the wiring pattern formed on the back panel 5 so as to connect the inside and outside of the vacuum vessel. The emitter potential applied to the cold cathode element 15 and the gate potential applied to the gate electrode 12 are supplied from the outside of the vacuum vessel via this wiring pattern.

  A medium voltage of about 150 to 500 V, which is slightly higher than the maximum voltage applied to the gate electrode 12, is applied to the mesh structure 8. The distance from the field emission electron source array to the surface of the plurality of through holes formed in the trimming portion 9 of the mesh structure 8 on the field emission electron source array side is about 100 μm.

  If the voltage applied to the mesh structure 8 is too high, there may be a problem with the withstand voltage characteristics between the mesh structure 8 and the field emission electron source array. Further, when used as a field emission type electron source imaging device, the withstand voltage characteristic with the target 3 may also be a problem. On the other hand, if the voltage applied to the mesh structure 8 is too low, the effect of accelerating the electron beam emitted from the field emission electron source array is diminished, and the divergence angle of the electron beam is increased. There is a possibility that the amount of electron beam passing through 8 is reduced, and the amount of current of the electron beam cannot be secured sufficiently. For this reason, the inventors have confirmed through experiments that the preferred value of the voltage applied to the mesh structure 8 is in the above range.

  The target 3 is arranged away from the mesh structure 8 by about 150 to several hundred μm. A transparent anode electrode 2 is formed between the front panel 1 and the target 3. High voltage, for example, about several hundred volts to several kV, which is higher than the voltage applied to the mesh structure 8, is applied to the anode electrode 2 via the electrode 43 (see FIG. 5) penetrating the front panel 1.

  When a predetermined voltage is applied to each of the cold cathode element 15 and the gate electrode 12 of the field emission electron source array, an electron beam 11 a is emitted from the cold cathode element 15. The electron beam 11a is incident on the opening 91 of the through-hole 90 of the mesh structure 8 having a thickness of about 100 μm, separated from the field emission electron source array by about 100 μm in the Z-axis direction, and passes through the electron beam continuously from the opening 91. Pass through the path 92. Then, the electron beam 11b emitted from the mesh structure 8 reaches the target 3 separated from the mesh structure by about 150 to several hundred μm.

  As shown in FIG. 7, the electron beam 11a emitted from one cell (designated cell) of the field emission electron source array travels toward the mesh structure 8 with a predetermined divergence angle, and the mesh structure 8 enters the plurality of through-holes 90 formed in 8.

  Of the electron beam 11a emitted from the designated cell, the electron beam traveling obliquely with respect to the Z axis and passing through the designated cell and entering the through-hole 90 at a position deviating from a straight line parallel to the Z axis passes through the designated cell. It collides with the side wall of the electron beam passing path 92 of the hole 90 and is absorbed and removed.

  On the other hand, of the electron beam 11a emitted from the designated cell, the electron beam 11a travels substantially parallel to the Z axis and passes through the designated cell and is positioned on a straight line parallel to the Z axis (hereinafter referred to as “designated cell”). The electron beam that has entered the through-hole 90 (referred to as “a through hole corresponding to”) passes through the electron beam passage 92 that extends parallel to the Z-axis, exits the mesh structure 8, and reaches the target 3. The divergence angle of the electron beam 11b emitted from the mesh structure 8 is small and the traveling direction is substantially uniform, and the cross-sectional area in the direction perpendicular to the traveling direction does not increase in the process of reaching the target 3.

  As described above, in the field emission electron source device according to the first embodiment, the electron beam 11b having a small divergence angle can be incident on the target 3 as compared with the case where the mesh structure 8 is not provided. Therefore, the spot diameter of the electron beam on the target 3 can be reduced. Accordingly, a high-definition image can be displayed on a field emission electron source display device having a phosphor on a target, and a high-definition image can be displayed on a field emission electron source imaging device having a photoelectric conversion film on a target. Can be imaged.

  Further, since the divergence angle of the electron beam 11b emitted from the mesh structure 8 is small, for example, when the distance between the back panel 5 and the front panel 1 varies due to an assembly error, or when the back panel 5 and / or the front panel is caused by atmospheric pressure. Even when 1 is curved and deformed, the spot diameter of the electron beam on the target 3 hardly changes. Accordingly, it is possible to provide a field emission type electron source display device capable of displaying uniform image quality and a field emission type electron source imaging device capable of imaging uniform image quality.

  Next, the mesh structure 8 will be described in detail.

  The mesh structure 8 can be produced by a micro electro mechanical system (MEMS) technology, which is a semiconductor technology, using a silicon substrate. That is, it is possible to form a through hole 90 as shown in FIG. 3 by performing fine processing using a semiconductor technique on a silicon substrate doped with N-type or P-type to reduce resistance.

  Thus, by producing the mesh structure 8 by the MEMS technology which is a semiconductor technology using a silicon substrate, there are the following advantages.

  First, it becomes possible to perform microfabrication on the order of micron and submicron using semiconductor technology. Accordingly, for example, in the case of a VGA field emission electron source device including a large number (for example, 100) of cold cathode elements 15 in one cell of about 20 μm square, the opening diameter D of the opening 91 of the mesh structure 8 is, for example, It becomes about 16 μm, and the molding accuracy needs to be on the order of submicrons. Such a microfabrication is possible if the MEMS technology is used.

  Second, high precision is also required in assembling the mesh structure 8 and the field emission electron source array. By using the MEMS technology, high-precision molding of the mesh structure 8 and high-precision assembly of the mesh structure 8 and the field emission electron source array become possible, and a field emission electron source device with excellent quality is obtained. Can do.

  Thirdly, by using a silicon substrate, it is possible to make the thermal expansion coefficient the same as that of the semiconductor substrate 6 on which the field emission type electron source array similarly produced using the silicon substrate is formed.

  In order to ensure reliability such as accuracy, it is preferable to create a part or all of the field emission type electron source array using a silicon substrate by a semiconductor technology, and the semiconductor technology is also generalized at present. Many devices that are needed are also on the market, which is advantageous in terms of cost.

  It is advantageous in terms of thermal expansion that the material of the mesh structure 8 is the same as the material of the substrate on which the field emission electron source array is formed. For example, the breakdown due to thermal expansion of the field emission electron source device. In addition, baking such as baking for outgassing during the assembly of the field emission electron source device can be performed at a high temperature.

  The mesh structure 8 is integrally formed with a spacer portion 8a, and the spacer portion 8a of the mesh structure 8 is directly installed on the semiconductor substrate 6 on which the field emission electron source array is formed. Thereby, the distance accuracy between the field emission electron source array and the mesh structure 8 can be improved. As a result, the role of the spacer portion 8a for maintaining the distance between the field emission electron source array and the openings 91 of the plurality of through holes 90 formed in the trimming portion 9 of the mesh structure 8 with high accuracy is effective. Can be demonstrated.

  The thickness Hs of the spacer portion 8a of the mesh structure 8 is preferably about 50 to 150 μm (optimally about 100 μm) when, for example, the vertical and horizontal dimensions of one cell of the above-described field emission electron source array are about 20 μm. Here, as shown in FIG. 7, the thickness Hs of the spacer portion 8a is the distance between the field emission electron source array side surface of the trimming portion 9 of the mesh structure 8 and the field emission electron source array. means.

  In this case, from the viewpoint of the dimension margin in the MEMS processing and the mechanical strength of the trimming portion 9, the distance between the openings 91 adjacent in the vertical and horizontal directions (that is, the thickness of the wall between the adjacent electron beam passage paths 92) is 4 μm ±. It is preferable to be in the range of 2 μm. Therefore, when the vertical and horizontal dimensions of each cell are 20 μm, the shape of the opening 91 of the through hole 90 of the mesh structure 8 is a quadrangle whose side is about 16 μm. The thickness of the trimming portion 9 (that is, the dimension in the Z-axis direction of the electron beam passage 92) is about 1.5 to 10 times, more preferably about 6 to 8 times the opening diameter of the opening 91 (in the above example). 100 to 120 μm) is preferable.

  When the thickness Ht of the trimming part 9 is less than 1.5 times the opening diameter of the opening 91, the electron beam incident on the mesh structure 8 at a large incident angle is made to collide with the side wall of the electron beam passage path 92 and absorbed. It becomes difficult to remove. For this reason, among the electron beams 11a emitted from the designated cell, the electron beam travels obliquely with respect to the Z axis, and passes through the designated cell and enters the through-hole 90 at a position deviating from a straight line parallel to the Z axis. Also passes through the through-hole 90 of the mesh structure 8 and reaches the target 3. Therefore, the spot diameter of the electron beam on the target 3 is enlarged.

  When the thickness Ht of the trimming portion 9 exceeds 10 times the opening diameter of the opening 91, the amount of electron beam that passes through the through-hole 90 of the mesh structure 8 and reaches the target 3 is remarkably reduced. There is a possibility that the amount of electron beam necessary for performing the above cannot be secured.

  The reason why there are optimum values for the thickness Hs of the spacer portion 8a and the thickness Ht of the trimming portion 9 is as follows.

  The thickness Hs of the spacer portion 8a means the distance from the field emission electron source array to the opening 91 of the through hole 90 formed in the trimming portion 9 (see FIG. 7).

  When the thickness Hs of the spacer portion 8a is thick, the mechanical strength of the mesh structure 8 alone can be increased.

  However, the distance from the field emission electron source array to the trimming unit 9 increases, and the spread of the electron beam on the surface of the trimming unit 9 on the field emission electron source array side increases. As a result, the amount of electron beam incident on the through hole 90 corresponding to the designated cell of the field emission electron source array is reduced, and as a result, the amount of electron beam passing through the through hole and reaching the target 3 is reduced. As a result, in a field emission electron source display device having a phosphor on the target, it becomes difficult to display an image having a desired luminance because the amount of electron beam that excites the phosphor becomes small, and photoelectric conversion is performed on the target. In a field emission type electron source imaging device provided with a film, a sufficient current for reading out holes generated in the photoelectric conversion film cannot be secured, resulting in an increase in afterimage.

  On the other hand, when the thickness Hs of the spacer portion 8a is small, it is possible to secure the amount of electron beam that reaches the target 3 through the through hole 90 corresponding to the designated cell of the mesh structure 8.

  However, the mechanical strength of the single mesh structure 8 decreases. As a result, for example, when assembling a field emission electron source device, there is a possibility that the mesh structure 8 is broken and the yield is lowered.

  When the thickness Ht of the trimming portion 9 is small, the amount of electron beam that passes through the mesh structure 8 and reaches the target 3 increases.

  However, of the electron beam 11a emitted from the designated cell of the field emission type electron source array, the electron beam 11a travels obliquely with respect to the Z axis and enters the through hole 90 arranged around the through hole corresponding to the designated cell. The transmitted electron beam also passes through the through-hole 90 and reaches the target 3. That is, the electron beam 11a incident on the through hole other than the through hole corresponding to the designated cell is absorbed and removed by the side wall of the electron beam passage path 92 of this through hole, and only the electron beam 11b emitted from the through hole corresponding to the designated cell. Trimming action of the mesh structure 8 that makes the target reach the target 3 is weakened. As a result, the spot diameter of the electron beam on the target 3 is enlarged. Therefore, it is difficult to display a high-definition image in a field emission electron source display device having a phosphor on a target, and a high definition in a field emission electron source imaging device having a photoelectric conversion film on a target. It becomes difficult to capture an image.

  On the contrary, when the thickness Ht of the trimming portion 9 is thick, the electron beam incident on the through hole 90 arranged around the through hole corresponding to the designated cell passes through the through hole 90 and reaches the target 3. Can be prevented.

  However, the amount of electron beam passing through the through hole 90 corresponding to the designated cell and reaching the target 3 is reduced. Therefore, in a field emission electron source display device having a phosphor on a target, it becomes difficult to display an image having a desired luminance because the amount of electron beam for exciting the phosphor is reduced, and a photoelectric conversion film is formed on the target. In the field emission type electron source imaging device provided with the above, since it becomes impossible to secure a sufficient current for reading out the holes generated in the photoelectric conversion film, the afterimage increases.

  8A, FIG. 8B, FIG. 9A, and FIG. 9B are diagrams showing simulation results in the field emission electron source device according to Embodiment 1 of the present invention.

  8A and 8B show the case where a voltage of 300 V is applied to the mesh structure 8, and FIGS. 9A and 9B show the case where a voltage of 225 V is applied to the mesh structure 8. Shows the case.

  As described above, the simulation corresponds to VGA, one cell size is 20 μm square, the opening 91 of the through-hole 90 of the mesh structure 8 is a square with a side of 16 μm, and the distance from the mesh structure 8 to the target 3 is A field emission electron source device having a thickness of 150 μm was used.

  The thickness Hs of the spacer portion 8a (ie, the distance from the field emission electron source array to the opening 91 of the through hole 90 of the trimming portion 9) Hs was changed from 25 μm to 125 μm at intervals of 25 μm. In the thickness of each spacer portion 8a, the thickness Ht of the trimming portion 9 was changed from 25 μm to 150 μm at intervals of 25 μm.

  8A and 9A show the calculation results of the ratio (unit:%) of the electron beam that passes through the mesh structure 8 and reaches the target 3 among the electron beams emitted from the designated cell. It is the graph which showed. The horizontal axis indicates the value obtained by normalizing the thickness Ht of the trimming portion 9 by the diameter D (= 16 μm) of the through-hole 90 of the mesh structure 8, and the vertical axis reaches the target 3 among the electron beams emitted from the designated cell. The ratio of the electron beam (electron beam arrival rate, unit:%) is shown.

  FIGS. 8B and 9B show one side centered on a point where a straight line passing through the center of the designated cell and parallel to the Z-axis intersects the target 3 among the electron beams emitted from the designated cell. Is a graph showing a result of calculating a ratio (unit:%) of an electron beam reaching a square area of 40 μm. The horizontal axis indicates the value obtained by normalizing the thickness Ht of the trimming portion 9 by the diameter D (= 16 μm) of the through-hole 90 of the mesh structure 8, and the vertical axis indicates the above-described target 3 of the electron beam emitted from the designated cell. The ratio of the electron beam reaching the area (electron beam concentration rate, unit:%) is shown.

  The simulation was performed for a field emission electron source imaging device in which the target 3 includes a photoelectric conversion film. However, when the target 3 is a field emission electron source display device including a phosphor, the voltage applied to the target 3 is different. Other than that, the same applies. Accordingly, the ratio of the electron beam passing through the mesh structure 8 and reaching the target 3 is the same as that in FIGS. 8A and 9A in the case of the field emission electron source display device. . The ratio of the electron beam that reaches a predetermined region on the target 3 is higher than that in the field emission type electron source imaging device because the voltage of the target 3 is higher than that in the field emission type electron source imaging device. Compared with (B) and FIG. 9 (B), the ratio of the electron beam reaching the predetermined region on the target 3 becomes higher.

  8A and 9A, as the ratio of the thickness Ht of the trimming portion 9 to the diameter D of the through hole 90 (ratio Ht / D) increases, the ratio of the electron beam reaching the target 3 is as follows. is decreasing.

  On the surface of the trimming unit 9 facing the field emission electron source array, one opening 91 (a square having a side of 16 μm) is formed in a region corresponding to one cell (a square having a side of 20 μm). Therefore, the area ratio (aperture ratio) of the opening 91 on the surface of the trimming portion 9 facing the field emission electron source array is (16 μm × 16 μm) / (20 μm × 20 μm) × 100 = 64%.

  In the region where the ratio Ht / D is 1.5 or more (the thickness Ht of the trimming portion 9 is 25 μm or more), the ratio of the electron beam reaching the target 3 is point D (FIG. 8A and FIG. 9A). Except for the case where the spacer portion 8a has a thickness Hs of 25 μm and the trimming portion 9 has a thickness Ht of 25 μm), the opening ratio of the trimming portion 9 is sufficiently smaller than 64%. When the thickness Hs of the spacer portion 8a is 50 μm or more, the ratio of the electron beam reaching the target 3 is sufficiently smaller than 64% that is the aperture ratio of the trimming portion 9 regardless of the thickness Hs of the spacer portion 8a.

  This means the following: That is, 64% of the electron beam emitted from the designated cell enters the through hole 90 of the trimming unit 9. A part of the electron beam incident in the through hole 90 collides with the side wall of the electron beam passage 92 and is absorbed and removed, and cannot pass through the mesh structure 8. That is, when the ratio of the electron beam that reaches the target 3 is smaller than 64%, which is the aperture ratio of the trimming portion 9, this means that the trimming action of the mesh structure 8 is functioning effectively. .

  At the point D, when the thickness Hs of the spacer portion 8a is increased, the ratio of the electron beam that reaches the target 3 becomes smaller than 64% that is the aperture ratio of the trimming portion 9. Thus, under the condition of point D, the electron beam trajectory is bent by the electric field lens formed in the vicinity of the opening 91 on the surface side of the trimming unit 9 facing the field emission electron source array. It is considered that the ratio of the beam is larger than 64% that is the aperture ratio of the trimming portion 9. Therefore, if the voltage applied to the mesh structure 8 is lowered under the condition of the point D to weaken the electric field lens, the ratio of the electron beam reaching the target 3 becomes less than 64%, and the trimming action of the mesh structure 8 is achieved. It is thought that can be demonstrated.

  As described above, although there are some differences depending on the voltage condition applied to each part, if the ratio Ht / D is approximately 1.5 or more, the electron beam is formed on the side wall of the electron beam passage path 92 of the through-hole 90 of the mesh structure 8. Can be absorbed and removed.

  Next, a suitable range of the thickness Ht of the trimming portion 9 will be considered. The range of the thickness Ht must be set so as to satisfy the following conditions. First, a part of the electron beam is removed and absorbed by the side wall of the electron beam passage path 92 of the mesh structure 8, and an electron beam having a divergence angle smaller than the divergence angle of the electron beam emitted from the designated cell is meshed. It is necessary to emit light from the body 8 toward the target 3. Second, it is necessary to secure an electron beam amount necessary for performing a desired operation on the target 3.

  Assume that the divergence angle of the electron beam emitted from the designated cell follows a Gaussian distribution, and an electron beam having a divergence angle of 1σ (68.27% of the total) or more is absorbed and removed by the mesh structure 8. For this purpose, the ratio of the electron beam that passes through the mesh structure 8 out of the electron beam emitted from the designated cell is multiplied by the aperture ratio (64%) of the trimming portion 9 by 68.27% corresponding to 1σ. It is preferable that it can be reduced to 43.7% or less, and it is preferable that the ratio Ht / D is 1.5 or more from FIG. 8 (A) and FIG. 9 (A).

  Further, in order to perform a desired operation in the target 3, it is considered that the ratio of the electron beam reaching the target 3 among the electron beams emitted from the designated cell needs to be 5% or more. For this purpose, the ratio Ht / D is preferably 10 or less from FIGS. 8 (A) and 9 (A).

  From the above, the thickness Ht of the trimming portion 9 is preferably 1.5 times or more and 10 times or less the opening diameter D of the through hole 90.

  However, in order to obtain sufficient resolution, for example, 40% or more of the electron beams emitted from the designated cell must reach a square area of 40 μm on one side on the target 3. 8B and FIG. 9B, the thickness Ht of the trimming portion 9 needs to be three times or more the opening diameter D of the through hole 90.

  In addition, it is necessary that 10% or more of the electron beams emitted from the designated cell reach the target 3 because the field emission type electron source array has a relatively poor electron beam emission capability. 8A and 9A, the thickness Ht of the trimming portion 9 needs to be 8 times or less the opening diameter D of the through hole 90.

  Thus, the preferable range of the thickness Ht of the trimming portion 9 varies depending on the application of the field emission electron source device, the type of the field emission electron source array, and the like.

  In the embodiment described above, the field emission electron source has been described as an example of the Spindt type including the cold cathode element 15 having a sharp tip and the gate electrode 12 in which the opening surrounding the tip is formed. The field emission electron source is not limited to this. For example, an MIM (Metal Insulator Metal) type in which an insulating layer is formed between a cathode electrode and a gate electrode, and voltage is applied to the insulating layer to emit electrons by a tunnel effect, a minute amount is formed between the cathode electrode and the emitter electrode. An SCE (Surface Conduction Electron Source) type that emits electrons from a minute gap by applying a voltage between these electrodes, or a carbon-based material such as DLC (Diamond Like Carbon) or CNT (Carbon Nanotube) as an electron source It may be a field emission electron source using

  A field emission type electron source device that is an electron source in which an electron beam is spread and is emitted in a field and that requires a reduction in the spot diameter of the electron beam on the target 3 effectively exhibits the effects of the present invention. Therefore, it is particularly preferable that the present invention is applied.

  An example of a field emission electron source using a carbon-based material such as CNT (Carbon Nanotube) is shown in FIG. 10 (see, for example, Patent Document 6).

  A CNT layer 59 made of an infinite number of carbon nanotubes (CNT) is formed on the substrate. A focusing electrode 60 is formed so as to surround the CNT layer 59. A gate electrode 61 for extracting electrons from the CNT layer 59 is formed above the CNT layer 59. An infinite number of electron beam passage holes are formed in the gate electrode 61. The planar view shape of the cell made of carbon nanotubes is a quadrangle. A plurality of cells are arranged in a matrix in the vertical and horizontal directions. The plurality of cells arranged in the vertical direction are electrically connected to each other to form an emitter line. The gate electrode 61 is disposed on a plurality of cells arranged in the horizontal direction to form a gate line. By selecting one of the plurality of emitter lines and one of the plurality of gate lines, the electron beam 11a is emitted from the cell located at the intersection of the selected emitter line and gate line.

  When the gate electrode 61 is thin, the amount of the electron beam 11a emitted from the cell increases, and the divergence angle increases. When the gate electrode 61 is thick, the amount of the electron beam 11a emitted from the cell decreases. The divergence angle becomes smaller.

  The present invention can also be applied to a field emission electron source device provided with a field emission electron source using such CNTs. In particular, it is preferable to apply to the case where the gate electrode 61 is thin and the amount of the electron beam 11a emitted from the cell is large and the divergence angle is large, since the effect of the present invention is effectively exhibited. In that case, the through holes 90 of the mesh structure 8 are arranged on the upper side in the Z-axis direction of the cells so as to correspond one-to-one with the cells, and the openings of the through holes 90 have the same size as the cells. Is preferred.

  In the above embodiment, the distance from the field emission electron source array to the opening 91 of the through hole 90 of the trimming unit 9 is about 100 μm, the thickness of the trimming layer 9 is about 100 μm, and the mesh structure 8 to the target 3. However, the present invention is not limited to this, and these distances can be freely set depending on the application of the field emission electron source device and the type of the field emission electron source. Needless to say, you can.

  Furthermore, in the above embodiment, the target 3 covers the anode electrode 2, but the present invention is not limited to this. For example, the anode electrode 2 may be larger than the target 3. Alternatively, the target 3 may include phosphors of three colors, and the phosphors of these three colors may be alternately formed on the surface of the anode electrode 2. In this case, a light absorption layer such as a black matrix may be provided between adjacent phosphors. Furthermore, a monochromatic or tri-color filter layer is provided between the anode electrode 2 and the target 3 or between the anode electrode 2 and the front panel 1, and a phosphor layer or a color layer corresponding to the color of the color filter layer is provided. A photoelectric conversion film layer may be formed as the target 3.

  In the above-described embodiment, the example in which the mesh structure 8 is created by the MEMS technology, which is a semiconductor technology, using a silicon substrate has been shown. For example, it may be created by etching a metal plate, or after forming the through hole 90 in an insulator such as glass, a metal film may be formed on the surface by vapor deposition or coating such as sputtering or CVD.

  Alternatively, the trimming part 9 created by semiconductor technology using a silicon substrate and the spacer part 8a made of a material such as silicon, metal, glass or the like are joined and integrated to create a mesh structure 8 You may do it.

  Further, in the above embodiment, the mesh structure 8 having the spacer portion 8a integrated therein is shown in order to reduce the assembly error of the distance from the field emission electron source array to the trimming portion 9, but the present invention has been described. Is not limited to this. For example, as shown in FIG. 11, a step 24a may be provided on the inner peripheral surface of the side surface outer peripheral device 24, and the mesh structure 25 having no spacer portion may be supported by the step 24a. Also in this case, it is possible to obtain a trimming action in which an electron beam incident on a through hole other than the through hole corresponding to the designated cell is absorbed and removed by the side wall of the electron beam passage path of the through hole.

  The inner diameter of the electron beam passage path 92 in the through-hole 90 of the mesh structure 8 does not need to be constant in the Z-axis direction as shown in FIG. By changing the inner diameter of the electron beam passage 92 in the Z-axis direction, the trimming action of the mesh structure 8 can be adjusted. For example, as shown in FIG. 4B, when the inner diameter of the electron beam passage 92 is smaller on the exit side than on the electron beam entrance side, the divergence angle of the electron beam 11b exiting the through hole 90 of the mesh structure 8 is obtained. Can be made smaller, which is preferable.

  The cross-sectional shape along the direction perpendicular to the Z-axis of the electron beam passage path 92 of the through-hole 90 of the mesh structure 8 is not limited to a quadrangle as in the above example. For example, it may be a circle, an ellipse, a polygon whose inner angle is larger than 90 degrees, or a polygon in which adjacent sides are connected by an arc (see, for example, FIG. 14B described later). By adopting these shapes, local stress concentration in the mesh structure can be prevented, and a high-strength mesh structure can be obtained. For example, the cross-sectional shape of the electron beam passage path 92 may be a hexagon or a circle, and the trimming portion 9 may have a honeycomb structure.

  Furthermore, in the above embodiment, the shape of the front panel 1 as viewed from the Z-axis direction is circular, but the present invention is not limited to this, and may be, for example, a quadrangle.

  In the above embodiment, the mesh structure 8 is installed on the semiconductor substrate 6 on which the field emission electron source array 10 is formed. However, the present invention is not limited to this, and for example, on the back panel 5. Alternatively, a Spindt-type field emission electron source array may be directly formed using a semiconductor processing technique, and the mesh structure 8 may be installed on the back panel 5 on which the field emission electron source array is formed.

  Further, in the above-described embodiment, assuming a field emission electron source device corresponding to VGA, the size of one cell of the field emission electron source array is set to about 20 μm square, and the size of each part corresponding to this is set. Although illustrated, this invention is not limited to this. For example, in the case of a field emission electron source device corresponding to SVGA and SXGA, the size of one cell is smaller than the above, and the dimensions of the other parts must be reduced accordingly.

  In the above embodiment, an example is shown in which the cells of the field emission electron source array and the through holes 90 of the mesh structure 8 correspond one-to-one. However, the present invention is not limited to this. For example, one through hole 90 of the mesh structure 8 may correspond to a plurality of cells of the field emission electron source array. For example, one through hole 90 of the mesh structure 8 can correspond to a total of four cells, two in the vertical direction and two in the horizontal direction. In this case, the center of the opening 91 of the through hole 90 corresponding to the cell is slightly shifted from the straight line passing through the center of the cell and parallel to the Z axis. Therefore, an electron beam that travels in a slightly oblique direction with respect to the Z axis out of the electron beam emitted from the designated cell is incident on the through hole 90 and reaches the target 3, so that attention must be paid to the driving method.

  Furthermore, the voltage applied to each part shown in the above embodiment is merely an example, and the optimum value differs depending on the application of the field emission electron source device, the size of each part, etc., and it must be changed as appropriate. Not too long.

  As described above, in the first embodiment, in a field emission electron source device including a field emission electron source array and a target that performs a beneficial operation, a through hole is provided between the field emission electron source array and the target. A mesh structure 8 made of a material containing silicon and having an electron beam passage 92 that is sufficiently longer than the diameter of 90 openings 91 is disposed. Of the electron beam emitted from the designated cell of the field emission electron source with a spread, the electron beam incident on the through holes 90 other than the through hole 90 arranged on the straight line passing through the center of the designated cell and parallel to the Z axis is Then, it collides with the side wall of the electron beam passage 92 of the mesh structure and is effectively absorbed and removed. By the trimming action of the mesh structure 8, only the electron beam directed to the target 3 having a velocity vector in a direction parallel to the Z-axis direction is selectively extracted from the electron beams emitted from the designated cell. Therefore, the spread of the electron beam emitted from the mesh structure 8 can be reduced. As a result, the spot diameter of the electron beam reaching the target 3 is reduced, and a high-definition field emission electron source device can be realized.

  In addition, by creating the mesh structure 8 using a microfabrication technique used in semiconductor manufacturing, a field emission electron source device with high accuracy and less variation can be realized. In addition, since the mesh structure 8 is manufactured using a silicon substrate in the same manner as the semiconductor substrate 6, the temperature of the heating process in the manufacturing process can be increased and gas can be sufficiently discharged. Therefore, it is possible to realize a field emission type electron source device that emits less gas and has high withstand voltage characteristics.

  Furthermore, since the mesh structure according to the first embodiment can be manufactured by a MEMS technology, which is a semiconductor processing technology, using a silicon substrate, a plurality of through holes can be formed in the mesh structure with high accuracy and uniform distribution. Therefore, when a tension is applied and fixed to a field emission electron source device like a conventional metal mesh structure (for example, a copper mesh), the shape and size of the through hole differs between the central portion and the peripheral portion. There is provided a mesh structure capable of making the amount of electron beams reaching the target uniform regardless of the position on the target when used in a field emission electron source device. be able to.

  The mesh structure made of the material containing silicon having the crystal structure described in the first embodiment can be used for applications other than the field emission electron source device.

  For example, by making the thickness of the mesh structure sufficiently larger than the diameter of the through-hole, it allows atoms, molecules, light, etc. to pass from one surface to the other surface, giving directivity in their traveling direction. Can be used as

  Alternatively, for example, it can be used as a particle filter for selecting particles according to particle diameter by adjusting the diameter of the through holes of the mesh structure.

  That is, it has a plurality of one-dimensionally formed through holes, and a detectable substance such as light, electrons, atoms, ions, or molecules is passed through the through holes from one surface to the other surface. When the mesh structure is made of a material containing silicon having a crystal structure, the through hole can be processed using a fine processing technique used in a semiconductor. Therefore, the through-hole shape and the through-hole diameter of the mesh structure can be controlled with high accuracy. Therefore, for example, a particle filtering function using a through hole can be easily realized.

  Moreover, through holes deeper than the diameter can be easily processed in the mesh structure by the semiconductor microfabrication technology, the mesh structure with a filter function for selecting particles, the traveling direction of atoms, molecules, light, etc. A mesh structure having a collimator function for imparting directivity can be manufactured at low cost.

  Furthermore, since a high-purity silicon plate used in semiconductors can be used, a mesh structure with a collimator function that imparts directivity to atoms, molecules, electrons, etc. without the concern of outgassing in a vacuum is easy. Can get to.

Further, by making the thickness of the partition wall separating the plurality of through holes smaller than the opening diameter of the through holes, the ratio of the opening area of the through holes to the surface of the mesh structure (opening ratio) can be increased. When used as a collimator that gives directivity to atoms, molecules, electrons, light, etc., the amount of atoms, molecules, electrons, light, etc. A collimator having a large ratio (passage rate) can be provided.
In this case, in order to obtain a uniform passing rate regardless of the location, it is preferable that the opening diameters of the plurality of through holes are uniform and the plurality of through holes are regularly arranged.
In the present invention, it is preferable that the thickness of the partition wall separating the plurality of through holes and the opening diameter of the through hole are defined in a cross section including a central axis of each through hole and the through hole closest to the through hole.

(Embodiment 2)
FIG. 12 is a cross-sectional view of a mesh structure according to Embodiment 2 of the present invention and a field emission electron source device including the mesh structure.

  As shown in FIG. 12, the field emission electron source device according to the second embodiment is different from the mesh structure 8 of the first embodiment in that the mesh structure 20 has a three-layer structure. Hereinafter, the description of the same parts as those in the first embodiment will be omitted.

  As shown in FIG. 12, FIG. 13, FIG. 14 (A) and FIG. 14 (B), the mesh structure 20 according to the second embodiment includes a first electrode layer 19 on the field emission electron source array side, and a target. It has a three-layer structure including a second electrode layer 16 on three sides and an insulating layer (intermediate layer) 17 between them. The insulating layer 17 ensures insulation between the first electrode layer 19 and the second electrode layer 16.

  The mesh structure 20 is created by a semiconductor technique using a silicon substrate. An example of the manufacturing method of the mesh structure 20 is demonstrated using FIG. 15 (A)-FIG. 15 (D). As one embodiment, a field emission electron source device in which the size of one cell of a field emission electron source array is about 20 μm square, and the size of a region where a large number of electron sources in one cell are arranged is about 10 μm square. The numerical examples are also shown. However, this numerical example is only an example, and the diameter of the opening 91, the distance from the field emission electron source array to the through-hole 90 of the trimming unit 9, and many electron sources in one cell of the field emission electron source array. When the sizes of the arranged areas are different, it is necessary to change them appropriately.

First, as shown in FIG. 15A, an SOI having an oxide film (SiO ₂ film) 17 ′ to be an insulating layer 17 as an intermediate layer and silicon layers 16 ′ and 18 ′ having desired thicknesses on both sides thereof. Prepare a substrate.

  In one embodiment, the thickness of the silicon layer 16 ′ that becomes the trimming portion 9 can be about 100 μm, and the thickness of the silicon layer 18 ′ that becomes the spacer portion 18 can be about 90 μm. The thickness of the oxide film 17 ′ is preferably 0.5 to 3 μm. In order to ensure a withstand voltage and to satisfactorily etch the silicon layers 16 ′ and 18 ′ and the oxide film 17 ′, the thickness is about 2 μm. Is the best.

  The silicon layer 16 ′ is a layer that becomes the second electrode layer 16. In order to exhibit the function of the second electrode layer 16, an N-type or P-type material is doped in advance to reduce the resistance.

  Next, as shown in FIG. 15B, only the central portion of the silicon layer 18 ′ of the SOI substrate is removed by etching, and the central portion of the SOI substrate is thinned. Thus, the silicon layer 18 ′ remains only around the SOI substrate, and becomes the spacer portion 18.

  Next, as shown in FIG. 15C, a metal such as aluminum, gold, copper, tantalum, molybdenum, or titanium is deposited on the surface on the silicon layer 18 ′ side by vacuum deposition, sputtering, CVD, or the like. Then, a metal thin film 19 ′ to be the first electrode layer 19 is formed.

  Next, as shown in FIG. 15D, a through-hole 90 is formed from the silicon layer 16 ′ side using an etching technique. Thus, the first electrode layer 19 made of the metal thin film 19 ′, the insulating layer 17 made of the oxide film 17 ′, and the second electrode layer 16 made of the silicon layer 16 ′ are formed.

  When the through-hole 90 is formed, depending on the etching characteristics of each layer, the shape of the periphery of the opening 91 on the field emission electron source array side of the through-hole 90 is not as shown in FIG. A) to FIG. 16C may be obtained. However, there is no great difference in the function as the trimming unit 9 in any shape.

  If the metal thin film 19 ′ formed in FIG. 15C is too thick, it is difficult to form the through hole 90 during the etching process in FIG. If the metal thin film 19 ′ is too thin, the effect of guiding the electron beam from the field emission electron source array into the opening 91 of the through hole 90 is weakened. Accordingly, there is an optimum value for the thickness of the metal thin film 19 ′. In the case of the above-described embodiment, the thickness of the metal thin film 19 ′ (first electrode layer 19) is preferably about 2 μm.

  In the second embodiment, since the mesh structure 20 is processed using the SOI substrate and the first electrode layer 19 is formed as described above, the mesh structure is added to the advantages described in the first embodiment. It has the advantage that the body can be manufactured inexpensively.

  The method for creating the mesh structure 20 is not limited to the above.

For example, the step of FIG. 15D for forming the through hole 90 may be performed after the step of FIG. 15A and before the step of FIG. 15B, or a silicon substrate is used without using an SOI substrate. Alternatively, an SiO ₂ film may be formed by performing an oxidation treatment in the middle of the production process.

  The mesh structure 20 produced in this way is installed and fixed on the semiconductor substrate 6 on which the field emission electron source array 10 is provided via a spacer portion 18 provided integrally with the mesh structure 20. The first electrode layer 19 of the mesh structure 20 is applied with the first voltage V1 of about 150 to 500 V, for example, through the semiconductor substrate 6, and the second electrode layer 16 is provided with a voltage supply provided separately. For example, the lower second voltage V2 of about 50 to 200 V is applied through the wire.

  In the designated cell of the field emission electron source array, a pulsed emitter potential that drops from a reference potential of 50 V to 0 V, for example, is applied to a plurality of cold cathode elements 15 (see FIG. 6) in the designated cell, and the gate electrode 12 For example, a pulsed gate potential that rises from a reference potential of 50V to 100V is applied (see FIG. 6).

  The electron beam 11a emitted from the designated cell is accelerated by a medium first voltage V1 of about 150 to 500 V applied to the first electrode layer 19 of the mesh structure 20, and its traveling direction is parallel to the Z axis. The light is incident on the mesh structure 20 while being corrected.

  As shown in FIG. 12, the electron beam 11a emitted from the designated cell passes through the center of the designated cell and is not only located on a straight line parallel to the Z axis. It is also incident on.

  The electron beam accelerated by the first electrode layer 19 is incident on the through-hole 90 of the mesh structure 20 and then applied to the second electrode layer 16 by the first voltage V1 of the first electrode layer 19 of about 50 to 200V. Is also rapidly decelerated by the lower second voltage V2.

  By abruptly decelerating the electron beam, the velocity component of the electron beam in the Z-axis direction becomes small, and the velocity component in the direction orthogonal to the Z-axis becomes relatively large. Therefore, the electron beam easily collides with the side wall of the electron beam passage path 92 in the region of the second electrode layer 16.

  In order to efficiently collide the electron beam with the side wall of the electron beam passage path 92 in the region of the second electrode layer 16, the length occupied by the first electrode layer 19 in the length of the electron beam passage path 92 is defined as T1. It is preferable that T1 << T2 is satisfied when the length occupied by the second electrode layer 16 is T2. Specifically, it is preferable that T2 / T1 ≧ 50 is satisfied. That is, it is preferable that the decelerating electric field by the second electrode layer 16 is disposed in a region near the field emission electron source array in the electron beam passage path 92. However, even if T1> T2, the electron beam can collide with the side wall of the electron beam passage path 92 in the region of the second electrode layer 16 to a lesser extent.

  Thus, in the second embodiment, the electron beam incident obliquely with respect to the longitudinal direction (Z-axis direction) of the electron beam passage path 92 is incident on the electron beam passage path 92 as compared with the first embodiment. It collides with the side wall at an early stage and is absorbed and removed.

  Therefore, in the second embodiment, compared to the first embodiment, the electron beam 11a incident on the through hole other than the through hole corresponding to the designated cell is absorbed and removed by the side wall of the electron beam passage path 92 of this through hole. The trimming action of allowing only the electron beam 11a incident on the through hole corresponding to the designated cell to reach the target 3 can be improved.

  For this reason, in the second embodiment, it is possible to display a higher definition image in the field emission electron source display device in which the target is provided with a phosphor as compared with the first embodiment. In a field emission type electron source imaging device provided with a conversion film, it becomes possible to capture a higher definition image.

  Further, in the second embodiment, compared to the first embodiment, even if the distance from the field emission electron source array to the target varies from the design value due to assembly variation or atmospheric pressure, the electrons on the target 3 Changes in the size of the beam spot can be further suppressed. Accordingly, it is possible to provide a field emission type electron source display device capable of displaying a more uniform image quality and a field emission type electron source imaging device capable of imaging a more uniform image quality.

  In the second embodiment, since the trimming action is improved by changing the velocity vector of the electron beam incident on the mesh structure 20, the thickness Ht of the trimming portion 9 of the mesh structure is improved as compared with the first embodiment. Can be made thinner. Thereby, compared with Embodiment 1, the amount of electron beams that pass through the through-hole 90 corresponding to the designated cell and reach the target 3 can be increased, and the amount of electron beam necessary for the target 3 is ensured. Becomes easier.

  FIG. 17A, FIG. 17B, FIG. 18A, and FIG. 18B are diagrams showing simulation results in the field emission electron source device according to Embodiment 2 of the present invention.

  17A and 17B show a case where a voltage of 300 V is applied to the first electrode layer 19 of the mesh structure 20 and a voltage of 100 V is applied to the second electrode layer 16, and FIG. ) And FIG. 18B show a case where a voltage of 225 V is applied to the first electrode layer 19 of the mesh structure 20 and a voltage of 75 V is applied to the second electrode layer 16.

  Similar to the above-described simulation of the first embodiment, the simulation corresponds to VGA, a square having a cell size of 20 μm square, an opening 91 of the through hole 90 of the mesh structure 20 having a side of 16 μm, and the mesh structure 20 A field emission electron source apparatus having a distance of 150 μm to the target 3 was used.

  The thickness of the first electrode layer 19 was 2 μm, and the thickness of the insulating layer 17 was 2 μm. The thickness of the spacer portion 18a (ie, the distance from the field emission electron source array to the opening 91 of the through hole 90 of the trimming portion 9) Hs was changed from 25 μm to 125 μm at 25 μm intervals. In the thickness of each spacer portion 18a, the thickness Ht of the trimming portion 9 was changed from 25 μm to 150 μm at intervals of 25 μm by changing the thickness of the second electrode layer 16.

  FIGS. 17A and 18A show the calculation results of the ratio (unit:%) of the electron beam that passes through the mesh structure 20 and reaches the target 3 among the electron beams emitted from the designated cell. It is the graph which showed. The horizontal axis indicates the value obtained by normalizing the thickness Ht of the trimming portion 9 by the diameter D (= 16 μm) of the through-hole 90 of the mesh structure 20, and the vertical axis reaches the target 3 among the electron beams emitted from the designated cell. The ratio of the electron beam (electron beam arrival rate, unit:%) is shown.

  FIG. 17B and FIG. 18B show one side centered on a point where a straight line passing through the center of the designated cell and parallel to the Z axis intersects the target 3 among the electron beams emitted from the designated cell. Is a graph showing a result of calculating a ratio (unit:%) of an electron beam reaching a square area of 40 μm. The horizontal axis indicates the value obtained by normalizing the thickness Ht of the trimming portion 9 by the diameter D (= 16 μm) of the through-hole 90 of the mesh structure 20, and the vertical axis indicates the above-described target 3 of the electron beam emitted from the designated cell. The ratio of the electron beam reaching the area (electron beam concentration rate, unit:%) is shown.

  The simulation was performed for a field emission electron source imaging device in which the target 3 includes a photoelectric conversion film. However, when the target 3 is a field emission electron source display device including a phosphor, the voltage applied to the target 3 is different. Other than that, the same applies. Therefore, the same calculation results as in FIGS. 17A and 18A can be obtained for the ratio of the electron beam that passes through the mesh structure 20 and reaches the target 3 also in the field emission type electron source display device. . Since the ratio of the electron beam reaching the predetermined region on the target 3 is higher than that in the field emission type electron source imaging device, the voltage of the target 3 is higher than that in the field emission type electron source imaging device. Compared with (B) and FIG. 18 (B), the ratio of the electron beam that reaches the predetermined region on the target 3 becomes higher.

  Compared with FIGS. 8A and 9A shown in Embodiment Mode 1, the ratio of the electron beam reaching the target 3 is reduced in FIGS. 17A and 18A. This means that in the second embodiment, the ability of the trimming unit 9 to absorb and remove the electron beam is improved as compared with the first embodiment.

  Compared with FIGS. 8B and 9B shown in Embodiment Mode 1, in FIG. 17B and FIG. 18B, an electron beam reaching a predetermined region on the target 3 is obtained. The percentage of is increasing. In particular, when the ratio of the thickness Ht of the trimming portion 9 to the diameter D of the through hole 90 (ratio Ht / D) is 3 or more, and further 4 or more, the electron beam concentration rate is remarkably increased.

  From the above simulation results, as described above, the mesh structure has a three-layer structure, the second voltage V2 of the second electrode layer 16 is set lower than the first voltage V1 of the first electrode layer 19, and the electron beam passes. It can be seen that by decelerating the electron beam in the path 92, the effect of absorbing and removing the electron beam by colliding with the side wall of the electron beam passage path 92 can be increased.

  A suitable range of the thickness Ht of the trimming portion 9 in the second embodiment will be considered from the simulation result. As described in the first embodiment, the minimum value of the thickness Ht of the trimming portion 9 that can reduce the ratio of the electron beam that passes through the mesh structure 8 out of the electron beam emitted from the designated cell to 43.7% or less is It is smaller than the first embodiment. Further, the maximum value of the thickness Ht of the trimming portion 9 that allows the ratio of the electron beam reaching the target 3 among the electron beams emitted from the designated cell to be 5% or more is almost the same as in the first embodiment. (FIGS. 17A and 18A).

  From FIG. 17 (B) and FIG. 18 (B), in order to make 40% or more of the electron beams emitted from the designated cell reach a square region with one side on the target 3 of 40 μm, The ratio Ht / D may be 1.5 times or more. In order to achieve an even higher resolution by causing 40% or more of the electron beams emitted from the designated cell to reach the region on the target 3, the ratio Ht / D should be four times or more. It ’s fine. If the ratio Ht / D is 6 times or more, 90% or more of the electron beams emitted from the designated cell can reach the region on the target 3.

  In the simulation of the second embodiment, the thickness of the first electrode layer 19 is 2 μm and the thickness of the insulating layer 17 is 2 μm, but the thickness of the first electrode layer 19 and the insulating layer 17 is 3 μm, 2 μm, 1 μm,. A similar simulation was performed by changing to 5 μm and the like, and a qualitatively similar result was obtained.

  As described above, in the second embodiment, the mesh structure 20 made of a material containing silicon has a three-layer structure, and the electron beam 11a emitted from the field emission electron source array is converted into the field emission electron source array side. The first voltage V1 of the first electrode layer 19 is accelerated to enter the through-hole 90 of the mesh structure 20, and the electron beam passes by being decelerated by the second voltage V2 of the second electrode layer 16 on the target 3 side. Since the electron beam trajectory is bent in the path 92, the trimming operation can be performed more effectively. Therefore, the spread of the electron beam emitted from the mesh structure 20 can be made smaller than that in the first embodiment. As a result, the spot diameter of the electron beam on the target 3 becomes smaller, and a field emission electron source device with higher definition than in the first embodiment can be realized.

  Alternatively, when it is sufficient if a trimming action similar to that of the first embodiment is obtained, the thickness Ht of the trimming portion 9 of the mesh structure 20 can be reduced. As a result, the amount of electron beam reaching the target 3 can be increased as compared with the first embodiment. As a result, the luminance can be increased in the field emission type electron source display device having the phosphor on the target, and the afterimage can be reduced in the field emission type electron source imaging device having the photoelectric conversion film on the target. it can.

(Embodiment 3)
FIG. 19 is a cross-sectional view of a mesh structure according to Embodiment 3 of the present invention and a field emission electron source device including the mesh structure.

  As shown in FIG. 19, the field emission type electron source device according to the third embodiment has the mesh structure 8 and the first embodiment in the point that the mesh structure 23 has a five-layer structure. 2 different from the mesh structure 20 of FIG. Hereinafter, the description of the same parts as those in the first and second embodiments will be omitted.

  As shown in FIGS. 19 and 20, the mesh structure 23 made of a material containing silicon according to the third embodiment has a second insulating layer 21 on the surface of the mesh structure 20 according to the second embodiment on the target 3 side. And the third electrode layer 22 are provided in this order. A third voltage V3 that is not much different from the second voltage V2 applied to the second electrode layer 16 is applied to the third electrode layer 22.

  In one embodiment, the thickness of the third electrode layer 22 is about 2 μm, which is the same as that of the first electrode layer 19, and the thickness of the second insulating layer 21 between the second electrode layer 16 and the third electrode layer 22 is also about 2 μm. be able to.

  As described in the second embodiment, the electron beam 11 a incident on the through-hole 90 of the mesh structure 23 passes through the first electrode layer 19 and the second electrode layer 16, and thereby reaches the side wall of the electron beam passage path 92. It is effectively absorbed and removed by collision. The electron beam that has not been absorbed and removed has its divergence angle finely adjusted by the third voltage V 3 applied to the third electrode layer 22, and then exits the through hole 90 and reaches the target 3. Thereby, a good spot of the electron beam can be formed on the target 3.

  According to a simulation result performed on the field emission electron source imaging device in which the target 3 includes a photoelectric conversion film, V1> V3 in a state where the potential of the target 3 is settled to the emitter potential after reading one frame. It was confirmed that the spot diameter of the electron beam on the target 3 can be made smaller than that of the second embodiment. At that time, the amount of electron beam passing through the mesh structure 23 and reaching the target 3 was slightly reduced.

  In a field emission type electron source display device having a phosphor in the target, since the potential of the target 3 is higher than the second voltage V2, a better spot of the electron beam is formed on the target 3 when V2 <V3. can do.

  As described above, in the third embodiment, the mesh structure 23 having the five-layer structure in which the third electrode layer 22 for final adjustment of the electron beam is provided on the target 3 side of the mesh structure 20 of the second embodiment. Use. Thereby, the expansion of the electron beam emitted from the mesh structure 23 can be made smaller than that in the second embodiment. As a result, in addition to obtaining the same effect as in the second embodiment, the spot diameter of the electron beam reaching the target 3 becomes smaller, and a field emission electron source device with higher definition than in the second embodiment is realized. can do.

(Embodiment 4)
FIG. 21 is a cross-sectional view of a mesh structure according to Embodiment 4 of the present invention and a field emission electron source device including the mesh structure.

  As shown in FIG. 21, the field emission electron source device according to the fourth embodiment has a focus electrode for prefocusing between a field emission electron source array 10 and a mesh structure 8 made of a material containing silicon. 26 is different from the field emission electron source device according to the first embodiment in that 26 is provided. Hereinafter, the description of the same parts as those in the first embodiment will be omitted.

  The focus electrode 26 has an opening at each position of a plurality of cells arranged in a matrix of the field emission electron source array 10 and includes a plurality of cylindrical bodies surrounding each cell. The focus electrode 26 is supplied with a voltage lower than the voltage applied to the portion of the mesh structure 8 on the field emission electron source array 10 side. Thereby, an electric field penetrating from the mesh structure 8 into the cylindrical body of the focus electrode 26 is formed.

  The electron beam emitted from the cell of the field emission electron source array 10 is prefocused by the electric field formed in the cylindrical body of the focus electrode 26 and then emitted toward the mesh structure 8. Since the electron beam is preliminarily focused by the focus electrode 26, the divergence angle of the electron beam emitted from the focus electrode 26 is smaller than that when the focus electrode 26 is not provided. For this reason, the number of electron beams having a velocity vector with a small angle formed with respect to the Z-axis direction (longitudinal direction of the electron beam passage path 92) increases, and the amount of electron beams passing through the mesh structure 8 increases. Accordingly, the amount of electron beam incident on the through hole 90 corresponding to the designated cell is increased. As a result, the amount of the electron beam reaching the target 3 is increased and the spot diameter of the electron beam is reduced on the target 3 as compared with the case where the focus electrode 26 is not provided.

  As described above, in the fourth embodiment, the electron beam emitted from the field emission electron source array 10 is prefocused by the focus electrode 26 before entering the mesh structure 8. Thereby, compared with Embodiment 1, the amount of electron beams reaching the target 3 can be increased, and the spot diameter of the electron beam on the target 3 can be reduced. Accordingly, it is possible to provide a high-luminance and high-definition field emission electron source display device and a high-definition field emission electron source imaging device with little afterimage.

  Although the focus electrode having a single electrode is shown in the above example, the present invention is not limited to this. For example, a plurality of electrodes may be provided in the Z-axis direction. By applying different voltages to each electrode, an electric field for prefocusing can be formed in the focus electrode. In this case, the voltage applied to the electrode closest to the mesh structure may be lower or the same as the voltage applied to the focus electrode side portion of the mesh structure 8. In the same case, the supply voltage circuit can be shared.

  In the above example, the field emission electron source device described in Embodiment 1 is provided with the focus electrode. However, the present invention is not limited to this, and any of the field emission electron source devices described above or later will be described. The focus electrode described in the embodiment can be provided, and in that case, the same effect as described above can be obtained.

(Embodiment 5)
A mesh structure according to Embodiment 5 of the present invention and a field emission electron source device including the mesh structure will be described with reference to FIG.

  In the fifth embodiment, the first voltage V1 applied to the first electrode layer 19 of the mesh structure 20 made of a material containing silicon and the second electrode layer 16 are applied during driving of the field emission electron source device. This is different from the second embodiment in that one or both of the second voltages V2 are changed. Hereinafter, the description of the same parts as those of the second embodiment will be omitted.

  In the present embodiment, this makes it possible to perform an effective imaging operation particularly in a field emission type electron source imaging device having a photoelectric conversion film on a target.

  That is, in a field emission type electron source imaging device having a photoelectric conversion film on the target 3, the amount of electron-hole pairs generated by the image of light incident on the target 3 and formed is determined by the intensity of the incident light. The stronger the incident light that is determined, the more electron-hole pairs are generated. Of the generated electron-hole pairs, the holes are transported to the electron scanning surface which is the surface of the target 3 on the field emission electron source array 10 side (in the case of an avalanche multiplication type photoelectric conversion film using selenium). It is transported and accumulated while being multiplied by electrons.

  When the target 3 is scanned by the electron beam 11c emitted from the field emission electron source array 10, the accumulated holes are combined with electrons contained in the electron beam, and an electric signal is simultaneously read out. Here, if sufficient electrons do not reach the target 3, some of the holes accumulated on the electron scanning surface of the target 3 are not read out and remain until the next scanning.

  For this reason, holes that remain without being read out in the readout scanning of the first frame will be read out by electrons that arrived in the readout scanning of the second frame, and in the captured image, a portion with a strong incident light becomes an afterimage. It will remain.

  To solve this problem, a sufficient amount of electron beam reaches the target 3 after the end of the reading scan of the first frame, and an operation (charge reset) is performed to remove holes that remain without being read, It is necessary to prepare for the reading scan of the next frame.

  However, if an electrode having an action of removing a part of electrons such as the mesh structure 20 is disposed between the field emission electron source array 10 and the target 3, a sufficient amount of electrons can be obtained even during the charge reset period. There is a possibility that the beam cannot reach the target 3.

  Therefore, in the fifth embodiment, the first voltage V1 and the second electrode layer 16 that are applied to the first electrode layer 19 while the field emission electron source device is being driven (specifically, during the charge reset period). By changing one or both of the second voltages V <b> 2 applied to, the amount of the electron beam 11 c that passes through the plurality of through holes 90 of the mesh structure 20 and travels toward the target 3 is changed. Thereby, the amount of electron beams that reach the target 3 during the charge reset period can be increased, and a sufficient charge reset current can be secured. Thereby, it is possible to provide a field emission type electron source imaging device with little afterimage.

  In particular, it is preferable to increase the second voltage V2 while keeping the first voltage V1 constant during the charge reset period. Thereby, the direction of the velocity vector of the electron beam approaches the Z-axis direction due to the electric field formed in the electron beam passage path 92. As a result, the amount of electron beam passing through the through hole 90 and reaching the target 3 increases. For example, when only the electron beam incident on the through hole 90 corresponding to the designated cell can pass through the mesh structure 20 among the electron beams emitted from the designated cell during normal driving, The electron beam incident on the through hole around the through hole can also pass through the mesh structure 20, and the amount of electron beam that can pass through the through hole 90 corresponding to the designated cell also increases.

  For example, during normal driving (during the readout period), about 250 V is applied to the first electrode layer 19 as the first voltage V1, and about 75 V is applied to the second electrode layer 16 as shown in FIG. Consider a field emission electron source imaging device. In this state, the field emission electron source imaging apparatus sequentially drives the cells of the field emission electron source array 10 to read out the holes accumulated in the target 3.

  Then, during the charge reset period after the reading of holes for one image or one line is completed, the electron beam is emitted from all cells or cells corresponding to one line, and at the same time, the second of the mesh structure 20 The voltage V2 is increased from 75V to about 150V.

  Thereby, the trimming action of the mesh structure 20 is weakened, and the electron beam incident on the through hole 90 around the through hole 90 corresponding to the cell from which the electron beam is emitted also passes through the mesh structure 20 and passes through the target 3. To come to reach. Therefore, the amount of the electron beam reaching the target 3 is remarkably increased as compared with that during normal driving, whereby holes remaining on the electronic scanning surface of the target 3 without being read out during the reading operation can be removed.

  In the above case, during the charge reset period, the first voltage V1 may be decreased at the same time as the second voltage V2 is increased. As a result, the amount of electron beams emitted from the mesh structure 20 can be further increased, although the driving is slightly complicated.

  As described above, the amount of the electron beam that reaches the target 3 during the charge reset period can be increased, so that the amount of electron beam necessary for removing excess holes remaining on the target 3 is ensured. Can do. Therefore, it is possible to provide a field emission type electron source imaging device in which no afterimage remains.

  In addition, according to the fifth embodiment, even if holes remain on the electronic scanning surface of the target 3 at the end of the normal reading period for one image or one line, the target 3 is detected during the subsequent charge reset period. Since the holes can be removed by a large amount of electron beams that reach, the amount of electron beams necessary to remove (read) all the holes during the normal readout period does not reach the target 3 Also good. Therefore, for example, the thickness Ht of the mesh structure 20 can be increased to reduce the spot diameter of the electron beam on the target 3. Alternatively, the cell arrangement and drive circuit of the field emission electron source array 10 can be designed with a margin to improve the reliability.

  As described above, in the fifth embodiment, when the mesh structure 20 includes the first electrode layer 19 and the second electrode layer 16 at different positions in the Z-axis direction, during the readout period and during the charge reset period. One or both of the first voltage V1 applied to the first electrode layer 19 and the second voltage V2 applied to the second electrode layer 16 are made different. Thereby, the amount of electron beams reaching the target 3 can be increased during the charge reset period as compared with the read period, and holes remaining at the end of the read period can be removed.

  Accordingly, it is possible to provide a field emission type electron source imaging device in which no afterimage remains.

  Further, the amount of electron beam reaching the target 3 during the readout period may be smaller than the amount necessary for removing (reading out) all the holes. Therefore, for example, the thickness Ht of the mesh structure 20 is reduced. As a result, the spot diameter of the electron beam on the target 3 can be reduced and the resolution can be improved. Alternatively, the cell arrangement and drive circuit of the field emission electron source array 10 can be designed with a margin to improve the reliability.

  In the above example, the case where one or both of the first voltage V1 and the second voltage V2 are changed in the field emission electron source device of the second embodiment has been described. However, the present invention is not limited to this. The same drive may be performed for the field emission electron source device of the third embodiment (FIG. 19) or the other field emission electron source device including a mesh structure including two or more electrodes. In any case, the same effect as described above can be obtained.

  The method of changing the voltage is not limited to the above example. For example, the first voltage V1 may be decreased while the second voltage V2 is kept constant, or the first voltage V1 is decreased and the first voltage V1 is decreased. You may raise 2 voltage V2.

(Embodiment 6)
22 and 23 are partially enlarged cross-sectional views of a mesh structure according to Embodiment 6 of the present invention and a field emission electron source device including the mesh structure.

  The field emission electron source device shown in FIG. 22 includes the shield electrode layer 45 made of a low-resistance thin film on the surface on the target 3 side of the mesh structure 8 made of a material containing silicon. This is different from the field emission electron source device shown in FIG.

  Further, the field emission electron source device shown in FIG. 23 is shown in FIG. 12 of the second embodiment in that a shield electrode layer 45 made of a low-resistance thin film is provided on the surface of the mesh structure 20 on the target 3 side. Different from the field emission electron source device.

  Hereinafter, the description of the same parts as those of the first and second embodiments will be omitted.

  The shield electrode layer 45 can be formed, for example, by depositing a metal thin film on the target side surface of a mesh structure made of a material containing silicon by sputtering, vacuum deposition, chemical plating, or the like. Alternatively, it can be formed by doping an N-type or P-type substance from the target-side surface of the mesh structure made of silicon to a predetermined depth and increasing its concentration. The shield electrode layer 45 is connected to a voltage supply source outside the vacuum container of the field emission electron source device.

  By providing the shield electrode layer 45, among the electron beams 11 b and 11 c that have passed through the mesh structures 8 and 20, the shield electrode layer 45 accurately traps the electron beam that returns without reaching the target 3. Local voltage fluctuations of the mesh structures 8 and 20 can be suppressed.

  That is, most of the electron beams 11 b and 11 c emitted from the mesh structures 8 and 20 reach the target 3, but some may return to the mesh structures 8 and 20 without reaching the target 3. This can cause the following problems.

  For example, when a relatively high resistance material is exposed on the surface of the mesh structures 8 and 20 on the target 3 side, the electron beam that does not reach the target 3 and returns to the mesh structures 8 and 20 is meshed. After the mesh structures 8 and 20 trap the local voltage fluctuation due to the secondary electron emission or the like by colliding with the structures 8 and 20 or when the mesh structures 8 and 20 trap the electrons, the electrons are transferred to the outside in a short time. There is a possibility that voltage fluctuations occur due to not being released. Further, the pulse voltage applied to the gate electrode of the field emission electron source array 10 may be superimposed on the mesh structures 8 and 20.

  When such a phenomenon occurs, the amount of electron beams emitted from the mesh structures 8 and 20 varies due to local variation of the trimming action of the mesh structures 8 and 20. As a result, unevenness in luminance occurs in the field emission type electron source display device, and in the field emission type electron source imaging device, local voltage fluctuation of the mesh structure is transmitted to the surface of the target 3 and noise is superimposed on the output signal. To do.

  On the other hand, according to the sixth embodiment, the surface of the mesh structures 8 and 20 on the target 3 side is covered with the shield electrode layer 45 made of a low-resistance thin film, and the shield electrode layer 45 is an electric field. Since it is connected to a voltage supply source outside the vacuum container of the emission type electron source device, secondary is generated by electrons that are emitted from the mesh structures 8 and 20 and return to the mesh structures 8 and 20 without reaching the target 3. Electron emission is suppressed by the shield electrode layer 45, and electrons trapped in the shield electrode layer 45 can be emitted to the voltage supply source in a short time, so that local voltage fluctuations in the mesh structures 8 and 20 are caused. It never happens.

  In addition, since the shield electrode layer 45 formed on the surface of the mesh structures 8 and 20 on the target 3 side is connected to a voltage supply source outside the vacuum vessel of the field emission electron source device, the field emission electron source array. The pulse voltage applied to the 10 gate electrodes is not superimposed on the shield electrode layer 45 formed on the surface of the mesh structures 8 and 20 particularly on the target 3 side.

  Therefore, there is no problem that the amount of electron beams emitted from the mesh structures 8 and 20 varies due to local variation of the trimming action of the mesh structures 8 and 20. Therefore, luminance unevenness is suppressed in the field emission electron source display device, and noise is superimposed on the output signal due to local voltage fluctuation of the mesh structure being transmitted to the target surface in the field emission electron source imaging device. Does not occur. Therefore, a high-performance field emission electron source device can be provided.

(Embodiment 7)
FIG. 24 is a partially enlarged cross-sectional view of another mesh structure according to Embodiment 7 of the present invention and a field emission electron source device including the mesh structure.

  As shown in FIG. 24, another field emission type electron source device according to the seventh embodiment includes a mesh structure 54 made of a material containing silicon, a high resistance layer 56, and a field emission type of the high resistance layer 56. A low-resistance first electrode layer 55 to which a first voltage formed on the electron source array 10 side is applied, and a low-resistance second electrode to which a second voltage formed on the target 3 side of the high-resistance layer 56 is applied. The field emission type electron source device according to the first embodiment is different from the field emission type electron source device in that the electrode layer 57 is provided. Hereinafter, the description of the same parts as those in the first embodiment will be omitted.

  In the seventh embodiment, the same effect as that of the first embodiment can be obtained, and the mesh structure can be easily manufactured.

For example, when the through hole 90 is formed by etching using an SOI substrate including a silicon layer on both sides of an insulating layer made of SiO ₂ as shown in the second embodiment, the mesh structure differs in the thickness direction. Since the layers of material are stacked, for example, the etching process is easy with a silicon layer, but it is difficult with an insulating layer, and the substrate is etched during the etching process due to local stress concentration due to the difference in material. The problem that it breaks occurs.

  On the other hand, in the seventh embodiment, for example, a through-hole 90 is formed by etching in a high-resistance silicon substrate, and then N-type or P-type material is doped so that both surface layers have low resistance. Thus, the mesh structure 54 can be easily created. Alternatively, the mesh structure 54 may be formed by doping the N-type or P-type material so that both surface layers of the high-resistance silicon substrate have low resistance, and then forming the through holes 90 by etching.

  Alternatively, after the through hole 90 is formed in the high resistance substrate by etching, a metal or other low resistance film may be formed on both surfaces by electrolytic etching or the like.

  Since the mesh structure 54 has the above configuration, the mesh structure 54 can be easily created.

  In addition, among the electron beams emitted from the designated cells of the field emission electron source with a spread, the electron beams incident on the through holes 90 other than the through holes 90 corresponding to the designated cells are transmitted through the electron beam passage path 92 of the mesh structure. The trimming action of effectively absorbing and removing by colliding with the side wall can be obtained as in the first embodiment.

  When the first voltage applied to the first electrode layer 55 is V1, and the second voltage applied to the second electrode layer 57 is V2, V1> V2 may be satisfied. Thereby, the same effect as Embodiment 2 can be acquired.

  That is, by setting V1> V2, a voltage gradient is formed in the high resistance layer 56, which decelerates the electron beam incident on the through hole 90 of the mesh structure 54. Thereby, the velocity component of the electron beam in the Z-axis direction is reduced, and the velocity component in the direction orthogonal to the Z-axis is relatively increased. Therefore, the electron beam easily collides with the side wall of the electron beam passage path 92 in the region of the second electrode layer 16. Therefore, the electron beam 11a incident on the through hole other than the through hole corresponding to the designated cell is absorbed and removed by the side wall of the electron beam passage path 92 of this through hole, and only the electron beam 11a incident on the through hole corresponding to the designated cell is obtained. The trimming effect of reaching the target 3 can be improved.

  Therefore, in the seventh embodiment, the following effects can be obtained as in the second embodiment. That is, even if the distance from the field emission electron source array to the target varies from the design value due to assembly variations and atmospheric pressure, the change in the size of the electron beam spot on the target 3 can be further suppressed. Accordingly, it is possible to provide a field emission type electron source display device capable of displaying uniform image quality and a field emission type electron source imaging device capable of imaging uniform image quality.

  When the first voltage applied to the first electrode layer 55 is V1, and the second voltage applied to the second electrode layer 57 is V2, one of the voltages V1 and V2 during driving of the field emission electron source device or Both may be changed, whereby the same effect as in the fifth embodiment can be obtained.

  That is, in the field emission type electron source imaging device in which the target 3 includes a photoelectric conversion film, by changing one or both of the first voltage V1 and the second voltage V2 during the readout period and the charge reset period, The trimming action of the structure 54 is made different between the readout period and the charge reset period. Thereby, the amount of electron beams reaching the target 3 can be increased during the charge reset period as compared with the read period, and holes remaining at the end of the read period can be removed. Therefore, in the seventh embodiment, similarly to the fifth embodiment, a field emission type electron source imaging device in which no afterimage remains can be provided.

(Embodiment 8)
FIG. 25 is a cross-sectional view of a mesh structure according to Embodiment 8 of the present invention and a field emission electron source device including the mesh structure.

  As shown in FIG. 25, the field emission electron source device according to the eighth embodiment is the field emission type according to the first embodiment shown in FIG. 1 in that the trimming portion 66 of the mesh structure 65 is thinned. Different from electron source device. Hereinafter, the description of the same parts as those in the first embodiment will be omitted.

  In the eighth embodiment shown in FIG. 25, the trimming portion 66 of the mesh structure 65 made of a material containing silicon is thin. Thereby, since the mesh structure 65 can be produced by processing a material containing silicon by the MEMS technology which is a semiconductor processing technology, a plurality of through holes can be formed in the mesh structure with high accuracy and uniform distribution. Therefore, when a tension is applied and fixed to a field emission electron source device like a conventional metal mesh structure (for example, a copper mesh), the shape and size of the through hole differs between the central portion and the peripheral portion. There is provided a mesh structure capable of making the amount of electron beams reaching the target uniform regardless of the position on the target when used in a field emission electron source device. be able to.

  Furthermore, when the semiconductor substrate 6 on which the field emission electron source array 10 is formed is made of a material containing silicon, the semiconductor substrate 6 and the mesh structure 65 are made of the same material, so that the temperature of the heating process in the manufacturing process is increased. Thus, the gas can be sufficiently discharged. Therefore, it is possible to realize a field emission type electron source device that emits less gas and has high withstand voltage characteristics.

  The field of application of the mesh structure and the field emission electron source device of the present invention is not particularly limited, and can be used for, for example, a field emission electron source display device and a field emission electron source imaging device.

FIG. 1 is a cross-sectional view of a mesh structure according to Embodiment 1 of the present invention and a field emission electron source device including the mesh structure. FIG. 2 is a schematic perspective view of a mesh structure used in the field emission electron source device according to Embodiment 1 of the present invention. FIG. 3 is a partially enlarged perspective view showing a through hole formed in a trimming portion of a mesh structure used in the field emission electron source device according to Embodiment 1 of the present invention. 4A and 4B are partially enlarged cross-sectional views in the thickness direction of the trimming portion of the mesh structure used in the field emission electron source device according to Embodiment 1 of the present invention. . FIG. 5 is an exploded perspective view of the field emission electron source device according to Embodiment 1 of the present invention. FIG. 6 is a cross-sectional view showing an example of a field emission electron source array in the field emission electron source device according to Embodiment 1 of the present invention. FIG. 7 is a partially enlarged cross-sectional view of the mesh structure according to Embodiment 1 of the present invention and a field emission electron source device including the mesh structure. 8A and 8B are diagrams showing simulation results in the field emission type electron source device according to Embodiment 1 of the present invention. 9A and 9B are diagrams showing simulation results in the field emission electron source device according to Embodiment 1 of the present invention. FIG. 10 is a cross-sectional view showing another example of a field emission electron source array in the field emission electron source device according to Embodiment 1 of the present invention. FIG. 11 is a cross-sectional view of another mesh structure according to Embodiment 1 of the present invention and a field emission electron source device including the mesh structure. FIG. 12 is a cross-sectional view of a mesh structure according to Embodiment 2 of the present invention and a field emission electron source device including the mesh structure. FIG. 13 is a partially enlarged cross-sectional view in the thickness direction of the trimming portion of the mesh structure used in the field emission electron source device according to Embodiment 2 of the present invention. 14A and 14B are partially enlarged perspective views of a trimming portion of a mesh structure used in the field emission electron source device according to Embodiment 2 of the present invention. 15 (A) to 15 (D) are cross-sectional views showing one step of a method for manufacturing a mesh structure used in the field emission electron source device according to Embodiment 2 of the present invention. 16 (A) to 16 (C) show the vicinity of the opening on the field emission electron source array side of the through hole of the mesh structure used in the field emission electron source device according to Embodiment 2 of the present invention. It is an expanded sectional view showing an example of shape. 17 (A) and 17 (B) are diagrams showing simulation results in the field emission electron source device according to Embodiment 2 of the present invention. 18A and 18B are diagrams showing simulation results in the field emission electron source device according to Embodiment 2 of the present invention. FIG. 19 is a cross-sectional view of a mesh structure according to Embodiment 3 of the present invention and a field emission electron source device including the mesh structure. FIG. 20 is a partially enlarged cross-sectional view in the thickness direction of the trimming portion of the mesh structure used in the field emission electron source device according to Embodiment 3 of the present invention. FIG. 21 is a cross-sectional view of a mesh structure according to Embodiment 4 of the present invention and a field emission electron source device including the mesh structure. FIG. 22 is a partially enlarged cross-sectional view of a mesh structure according to Embodiment 6 of the present invention and a field emission electron source device including the mesh structure. FIG. 23 is a partially enlarged cross-sectional view of another mesh structure according to Embodiment 6 of the present invention and a field emission electron source device including the mesh structure. FIG. 24 is a partially enlarged cross-sectional view of a mesh structure according to Embodiment 7 of the present invention and a field emission electron source device including the mesh structure. FIG. 25 is a cross-sectional view of a mesh structure according to Embodiment 8 of the present invention and a field emission electron source device including the mesh structure. FIG. 26 is a cross-sectional view of a field emission electron source device using a conventional field emission electron source array. FIG. 27 is a cross-sectional view of a field emission electron source device using another conventional field emission electron source array.

Explanation of symbols

1, 101, 115 Front panel 2, 102, 113 Anode electrode 3, 103 Target 4, 24, 104, 116 Side peripheral device 5, 105, 117 Rear panel 6, 106 Semiconductor substrate 7, 109 Sealing material 7a Frit glass vacuum Sealing portion 7b, 119 Indium vacuum sealing portion 8, 20, 23, 25, 54 Mesh structure 8a Spacer portion 9, 66 Trimming portion 10 Field emission electron source array 11a, 11b, 11c Electron beam 12, 128 Gate electrode 13, 17, 21, 126 Insulating layer 14, 125 Emitter electrode layer 15, 107, 124 Cold cathode element (emitter)
16 Second electrode 18 Spacer portion 19 First electrode 22 Third electrode 26 Focus electrode 55 First electrode layer 57 Second electrode layer 65 Mesh structure 43 Voltage supply pin 45 Shield electrode layer 50 Getter 51 First space 52 Second space 56 Resistance layer 59 CNT
60 Focusing electrode 61 Gate electrode 90 Through hole 91 Opening 92 Electron beam passage 108 Peripheral element (gate electrode and insulating layer)
111 Incident light 112 Photoelectric conversion film 114 Photoelectric conversion target 118 Vacuum vessel 120 Shield grid electrode 121 Step 122 Voltage supply terminal 123 Voltage supply lead 129 Field emission electron source array 133 Frit glass sealing portion

Claims (2)

Has multiple through-holes, the through-hole, light, electron, atoms, ions, or molecules in a mesh structure can pass through from one surface to the other surface,
The mesh structure is made of a material containing silicon, we saw including a silicon material including silicon having a crystal structure,
The mesh structure includes an N-type or P-type doped silicon layer and an insulating layer made of SiO ₂ .   The mesh structure according to claim 1, wherein a thickness of a partition wall separating the plurality of through holes is smaller than an opening diameter of the through holes.

Images