KR19990022217A - Side-emitter field-emission device with simplified anode and method of manufacturing the same - Google Patents

Abstract

Emitting device 10 has a simplified anodic structure 70 with a lateral emitter 100 parallel to the substrate 20. The lateral field- The upper surface of the anode is precisely spaced from the plane of the side emitter and receives electrons emitted by field emission from the edge of the side emitter cathode when an appropriate bias voltage is applied. The apparatus may be configured as a diode, triode tube, or bipolar tube having a control electrode 140 positioned to allow control of current from the emitter to the anode by an electrical signal applied to the control electrode.

Description

Side-emitter field-emission device with simplified anode and method of manufacturing the same

Field emission displays are well known for replacing liquid crystal cell displays because of their low cost of manufacture, low power consumption, low complexity, high brightness, and improved viewing angle range. Microelectronic field emission devices can replace semiconductor devices in many applications and can be manufactured from a wide range of materials without compromising the purity of the material with good performance, but with equipment and processes similar to those used in semiconductor manufacturing . Journal of Micro mechanics and Microengineering Vol.2. No.2 (June 1992) Heinz H, Vacuum Microelectronice-1992. Busta published a paper on vacuum electronics. Solid State Technology Vo. 37 No. Katherine Derbyshire summarized several design operating principles and fabrication methods for field emission devices, and some of the field emission device versus flat panel displays (see, eg, Katherine Derbyshire, November 1999, pp. 55-65, Beyond AMLCDs: Applications. The theory of field emission of electrons from metals is described in R. O. Jenkins and W. G. (eds.), Electron and Ion Release from Solids (Dover Publications, Inc. New York, NY 1965) And Trodden's paper presentation.

The emitter and the cathode are used herein to mean a field-emission cathode in the present specification as a whole. The control electrode is used to represent a similar electrode in function with the control grid in the vacuum-tube triode. Such an electrode is referred to as a gate in the field emission device related technical literature. The ohmic contact is used to indicate an electrical contact that does not cause rectification. The phosphor is used to mean a material characterized as a cathode emitter. In the description of the luminous body, the conventional notation is used, the formula for the host or matrix compound is provided first, followed by the colon (:) and the active substance (the impurity acting on the host crystal to emit light). ZnS: Mn, where zinc sulphide is the host and manganese is the active material.

Microelectronic devices that use field emission of electrons from cold-cathode emitters have been developed for many purposes to use many of their advantages, including high-speed switching, temperature changes and insensitivity to radiation, low power consumption, and the like . In related art, most microelectronic field-emission devices have emitters that are away from the substrate and in a direction perpendicular to the substrate, but sometimes toward the substrate. Examples of such type devices are described, for example, in US Patent No. 3,789,471 to Spindt et al., U.S. Patent No. 4,721,887 to Brodie, U.S. Patent No. 5,127,990 to Pribat et al., U.S. Patent Nos. 5,141,459 and 5,203,731 to Zimmerman, and Derbysbire, . In such a structure, the anode is a transparent screen that is usually parallel to the substrate and accompanies a phosphor that generates the light output of the display device by the cathodoluminescence. Several cold-cathode microelectronic devices are described in U.S. Patent No. 4,728,851 to Lambe, U.S. Patent No. 4,827,177 to Lee et al., U.S. Patent Nos. 5,233,263 and 5,308,439 to Cronin et al. It has an electric field emitter. In the two Cronin et al. Patents, the side field emission and side cathode or side emitters are structures in which the field emitter tips or blade edges are oriented laterally, that is, parallel to the substrate. In such side-cathode structures of the prior art, the anode is crossed at right angles to the substrate and the emitter (as in US Pat. No. 5,233,263 to Cronin et al. And US Pat. No. 5,308,439), in common with the emitter Patent 4,827,177), and a transparent substrate (as in U.S. Patent No. 4,728,851 to Lambe). Device structures and fabrication methods using lateral cathode configurations have been found to have precise control of size, alignment, capacitance and required bias voltage, such as extremely fine cathode magnetic field spot or tip, and between elements.

If the side field-emitting device is used in the display cell of the phosphor-coated anode, a number of problems arise. In some prior art structures, the cathodoluminescence occurs only in the very narrow region of the edge of the anode facing the side emitter. The light emitted from the phosphor can be obscured by opaque electrodes and absorbed within the phosphorescent layer itself or absorbed throughout the screen. Very high anode voltages should be used in some substructure techniques. In the case of a low voltage electron field emitter display (e.g., an anode potential of about 10 volts or less with respect to the emitter), the actual electron penetration into the phosphor is about one nanometer. Thus, in a display using a prior art side field emission display element, the emission of light due to cathodoluminescence occurs at the edge of the phosphor contacting the emitter element. Other electron field emission display devices, such as those of the Spindt type (described in the Spindt et al. Patents, and described in the review by H. H, Busta, cited above), include phosphors facing the phosphor surface facing the observer Generates light on the surface.

The device structure described above has a side electron emitter located a certain distance above the anode phosphor. The bias is suitably applied so that the emitted electrons are spread over the top surface of the phosphor and collide on a large area of the phosphor element rather than in the other side electron field-emitting device. Thus, with this new structure, the light beam comes to a place where the viewer can see it directly and is not attenuated by passing through the phosphor as in the case of the conventional structure. The light ray is generated in a portion having a larger cell area than in the conventional structure. The prior art description of the side-emitter field-emission display element provides how to provide bias voltage contact with the phosphor of such a bipolar element. The new structure described herein has metal anode contacts located below the phosphor (implanted) and may have means for connection from the surface for applying the electrical bias to the contact so inserted.

Although the side-emitter type structure has the obvious advantages described above, the side-emitter field-emitter devices so far capable of providing the most accurate control of the size and alignment between the elements have been expensive to manufacture due to the relatively large number of materials and processing steps . These processing steps involved using a conforming layer of the sacrificial material needed to form the spacer to make some size. The present invention eliminates some of the materials and processing steps necessary for fabrication, thus reducing manufacturing time and costs, providing a simple anodic structure, and retaining the inherent automatic alignment of the side cathode structures and side cathode types. This simpler construction and lower cost manufacturing is effective for both field effect devices with phosphorescent anodes used for display elements and phosphorescent field effect devices. Accordingly, the present invention solves several problems in the prior art.

The present invention relates to integrated field emission microelectronic devices, and more particularly, to a side-emitter field emission device having a simple anode structure for use in field emission displays and a simple method for manufacturing such microelectronic devices .

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of a portion of a preferred arrangement of a field emission device made in accordance with the present invention;

2 is a cross-sectional view of a single field-emission device embodiment made in accordance with the present invention;

3 is a cross-sectional view of a single field-emission device selective embodiment.

Figures 4A and 4B are flow diagrams of an embodiment of a manufacturing method performed in accordance with the present invention.

Figures 5a-5b are cross-sectional views corresponding to the results of the method steps of Figures 4a and 4b.

Description of the Related Art [0002]

20: Substrate 30: Insulator layer

40: Reference plane 50: Conductive layer

60: insulator layer 70: anode

75: phosphor layer 80: insulator

90: insulating layer (film) 100: emitter layer

110: blade edge 120: contact portion

130: insulator layer 140: control electrode

160: opening

It is a principal object of the present invention to provide a display device with improved light emission from each cell of a display device. This object is an electronic field emission device structure suitable for use in a display cell. Another object is to direct the light emitted from the phosphor directly to the display. Another object is to provide an electron field-emission device cell structure in which the light-emitting region occupies a larger portion of the cell region than in the prior art devices of the side-emitter type. Another object of the present invention is a metallization structure that allows other features and advantages of the improved side-emitter field emission display to be realized. One particular objective is to provide a bipolar electrical contact structure that does not darken any portion of the phosphor surface of the display cell. The object is to provide an anode contact which can act as a mirror to reflect the light rays reflected towards the observer of the display. It is yet another object of the present invention to provide a display cell anode structure that improves and reduces or eliminates coulomb aging of the phosphor. It is another specific object of the present invention to provide a simplified display cell by having a control electrode configuration that can be made with a single metallization step.

The overall objective of the present invention is to provide an improved display device which retains all the known advantages of a side-emitter field emission device comprising: That is, the cathode edge or tip is extremely limited. Correctly adjust the distance between cathode and anode (to reduce device operating voltage and reduce device-to-device variability). Control the distance between the cathode and the control electrode (control the overlap between the control electrode and the cathode to control the inter-electrode capacitance and precisely control the required bias voltage). Control - electrode and cathode structures and improved alignment density. It is a further object of the present invention in relation to retaining the known advantages of the lateral-emitter field-emission device to provide by a direct structure that reduces the number of interconnections between devices, thus reducing manufacturing costs and increasing device reliability and performance Design flexibility.

It is another important object of the present invention to provide a microelectronic manufacturing technology and apparatus for manufacturing microelectronic devices that are capable of precisely controlling the size and arrangement of the device and producing a direct side-emitter field-emission display cell structure with reproducible acidity and economical production rates. To provide the processing to be used. A primary object of the present invention is to provide a simplified anode structure for a side-emitter field-emission device. It is another principal object of the present invention to provide a self-aligning side-emitter field-emission device, wherein the main purpose is to remove several masks that would have been needed to fabricate the self-aligned side-emitter field- Thus reducing manufacturing time and cost.

In one aspect of the invention, the field-emission device is made of a lateral emitter that is parallel to the substrate and has a simple anodic structure. The side-emitter field-emitter device has a thin-film emitter cathode with a water edge thickness and a discharge blade edge or tip with a small radius of bend. A bipolar device made simple can have one or more control electrodes. The upper surface of the anode is precisely spaced from the plane of the side emitter and receives electrons emitted by field emission from the blade edge or tip of the side-emitter cathode when an appropriate bias voltage is applied. The apparatus may include a diode, a triode tube, and a quadrupole space having one or more control electrodes positioned to allow control of current from the emitter to the anode by an electrical signal applied to the control electrode. In a particularly simple embodiment, a single control electrode is located in one plane above or below the emitter edge. This simplified device is particularly adapted for use in an array comprising field-emission display arrays.

In another aspect of the present invention, new manufacturing processes using process steps similar to those of semiconductor integrated circuit technology are used to generate the novel devices and their arrangement. Various embodiments of the manufacturing process permit the use of conductive or insulating substrates and permit the manufacture of devices with various functions and complexities. The anode is simply manufactured without the use of prior art processes to form spacers made by one coding. The following steps are performed in a preferred manufacturing process for a simple bipolar device. A cathode film is deposited, an insulation film is deposited over the cathode film, and an extremely thin conductive emitter film is deposited on the insulation and a pattern is made. A trench opening is etched through the emitter and the insulator and is stopped at the anode film, thus forming the emission edge of the emitter, automatically aligning, and generating field emission of electrons from the emission edge of the emitter to the anode A means for applying sufficient electrical bias to the emitter and anode is provided. The cathode film comprises a phosphor for an apparatus intended for use in a field emission display. The manufacturing process involves depositing an additional insulator film and depositing additional conductor film for the control electrode that is automatically aligned with the emitter blade edge or tip.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a partial plan view of a preferred embodiment of a field-emission device made in accordance with the present invention; In the simple arrangement of Figure 1, each field-emission device shares an anode with at least one other device, and each anode is shared by two or more devices. The emitter in Figure 1 is also shared by several devices. Such element sharing between these devices is not necessary for use or operation of the present invention, but may be useful for designing and manufacturing higher density arrays (in terms of number of devices per unit area). The basic features of the device to be made in accordance with the present invention can be readily appreciated as only a single device of Fig.

2 is a sectional view of an embodiment of a single field-emission device made according to the present invention. The field-emission device labeled 10 is made on a solid substrate 20. An insulator layer 30 has an upper major surface, which makes a convenient reference plane 40 for the description of other elements. A conductor layer 50 may be used as the inserted contact layer. The conductive layer 50 is placed on a reference plane as shown in FIG. 2 and can be made by planarizing the resulting surface by depositing the conductive layer 50 into the recess formed in the insulator 30.

The upper surface of the conductive layer 50 lies within the reference plane 40. One insulator layer 60 is placed on the reference plane covering the conductive layer 50 and the conductive layer parallel to the plane 40 serves as the anode 70. The preferred manufacturing method herein places the upper surface of the anode 70 under the plane of the side emitter 100. In the case of the embodiment as in Fig. 2 where several devices have independent anodes, the anodes of adjacent devices are isolated and insulated from each other by an area of the insulator 80. Fig. A small portion of the anode 70, which is adjacent to the left in Fig. 2, reaches the left side of the insulator 80. Fig. Such a portion is not included in the structure or operation of the single device of the present invention. The very thin conductivity that forms an insulating layer 90 of a certain thickness is also made parallel to the substrate, thus forming a side emitter. A conductive contact 120 may connect the emitter layer 100 to the interposed contact layer 50. If the device at this time is to have one control electrode 140 on the emitter 100, a conductor layer is made to form two additional layers, an insulator layer 130 and a control electrode 140. In a method of manufacturing such an apparatus (described in detail below), one opening 160 is provided by using a directional etch. Such openings extend through all of the conductor and insulator layers that lie above the anode and below the top surface 70 of the anode. The method of etching the opening 160 forms a blade edge or tip 110 through which the thin film 100 of the side-emitter ends after etching. The blade edge or tip 110 has a very small bending backlash limited to half of the thickness of the extremely thin side-emitter layer 100. The preferred thickness of the side-emitter film 100 is less than about 300 angstroms, which limits the radius of curvature of the side-emitter blade edge or tip to be less than about 150 angstroms. The bending radius is an important factor for generating an electric field in the tip 110 sufficient to generate the cold-cathode field emission so that the bias voltage is applied low, and the bending radius may be less than half of the film thickness. Another factor that is important in determining the effective field to generate field emission is the thickness of the insulator film 90. The degree of film thickness control in the conventional semiconductor integrated processing is sufficient to control the thickness of the insulator film 9 with a desired precision. An apparatus made in accordance with the present invention may be operated with a bias voltage of 10-50 volts or less. In the preferred embodiment of FIG. 2, the anode 70 extends at least partially beneath the side emitter 100. That is, the anode 70 extends through the vertical plane through the emission edge 110 made by the side wall of the opening 160.

The conductive connection to the various electrodes of the inventive device is made in a conventional manner and is therefore not shown in the drawings. Such a conductive connection is made by a vertical stud located on the outboard side of the cross section of FIG. For example, the conductive stud may extend from the emitter 100 or the inserted contact layer 50 to a surface conductive pad to which an emitter bias voltage is applied. A similar electrically conductive connection electrically isolated from the emitter connection may lead to the anode 70 for application of the anode bias voltage. Similarly, if the apparatus of the present invention is a three-electrode vacuum tube or a bipolar vacuum tube having a control electrode, a conductive connection is required to apply control signals to the control electrode 140. The arrangement of the device described above may be reversed (R5EVERSE) since the emitter connection is directly connected to the surface pad and the inserted contact layer 50 is used for the anode contact. Of course, in order to cause field emission of electrons, the polarity of the applied bias voltage must be an anode with respect to the emitter of the anode. Devices made on the same substrate do not have to have conductive connections in physically identical arrangements. Some devices may have embedded anode contacts, while other devices on the same substrate may have embedded emitter contacts. Such an arrangement allows a compact and efficient circuit arrangement in the circuit where the emitter of one device is connected to the anode of another device. With this arrangement, the dissimilar connections that are placed on the same plane and are not connected are held electrically side by side so that the insulator is sandwiched between them.

Figure 3 shows a cross-sectional view of an alternative embodiment of a field-emission device made in accordance with the present invention. The side-emitter field-emission device of Figure 3 is a diode device or device without a control electrode. The anode 70 of the device shown in Fig. 3 includes a phosphor layer 75 that is part of the anode 70. If the anode phosphor is conductive, the entire anode 70 is made of a phosphor. The anode 70 of FIG. 3 is shown as having a separately marked phosphor film 75. 3 differs from FIG. 2 in that the anode 70 does not extend below the side-emitter 100 emission blade edge or tip 110. Another method of describing the optional structure shown in Figure 3 is to provide an opening 100 in which the sidewall is adapted to create a vertical plane including the side emitter 100 emission edge 110, . However, the vertical extension of the opening 160 is still determined by extending vertically up to the upper surface of the anode 70 (in this embodiment, the upper surface of the phosphor film 75). 3, the minimum vertical extension of the opening 160 is the sum of a certain thickness of the insulator layer 90 and a certain thickness of the side emitter 100. [ The field emission device is made to have a plurality of anodes 70 (not shown in the figure). A useful example of such a structure is to have three anodes per emitter, each having a different phosphor color for each anode. A particularly useful combination is that the three anode devices have red, green and blue phosphors for RGB displays.

The preferred materials of the various structural elements of the side-emitter field-effect device having a simplified anode are described below, together with a description of the novel and preferred manufacturing method.

Novel fabrication methods using steps similar to the fabrication steps used in semiconductor integrated circuit fabrication can be used to generate the devices and arrangements according to the present invention. Various embodiments of the above manufacturing methods permit the use of conductive or insulative substrates and permit the fabrication of devices with various functions and complexities. A novel feature of all the manufacturing method embodiments described herein is that the anode is simply formed without the use of the spacers used in the conventional method (in the prior art method, the speckle was formed by consuming conforming shapes ).

Figures 4A and 4B show a flow diagram of a manufacturing method embodiment formed in accordance with the present invention. Figures 5a-5r show a series of cross-sectional views corresponding to the results of the manufacturing steps of Figure 4a, Figure 4b. In the following description of the preferred process for the production of the field-emitter device, reference is made to Figs. 4A, 4B and 5A-5R, wherein the same or similar process steps and cross- S2, ..., S18. A simple stagnation process outline for the production of the diode device is first described, and then the detailed process, which is further illustrated by the corresponding results of Figs. 5a-5r, shown in Figs. 4a and 4b. Table 1 lists the processing steps shown in Figures 4A and 4B.

In a simple manufacturing process of a diode field-emitter device with a simplified anode, the anode film 70 is deposited 57, the insulator film 90 is deposited 88 over the cathode film, and an extremely thin conductive emitter The film 100 is deposited over the insulator S12 and a pattern is formed and the trench opening 160 is etched through the emitter and the insulator S15 and is terminated at the anode film and thus the emission edge Means for applying sufficient electrical bias to the emitter and anode to form and automatically align the emitter 100 and to generate field emission of electrons from the emissive edge 110 of the emitter 100 to the anode 70, (S18), the anode film 70 deposited in step S7 includes a phosphor film 75 for a device particularly suitable for use in a field-emission display. The phosphor may be any negative-electrode luminescent material and may be selected on the basis of conductive and luminescent coloring.

S1 substrate.

S2 insulation layer.

Pattern and etch S3 recesses.

A conductive material is deposited in the S4 recess to form the inserted contact layer.

S5 is made flat.

S6 Insulation layer is deposited.

S7 Conductive layer is deposited to a certain thickness.

S8 Insulate the insulation layer to a certain thickness.

The conductive layer is deposited to form the S9 control electrode layer.

S10 The insulating layer is deposited to a constant thickness.

S11 Provides conductive contact with the inserted contact layer.

S12 Extremely thin layer of emitter is deposited and patterned.

S13 insulation layer to a predetermined thickness.

S14 If necessary, the control electrode layer is deposited and patterned.

S15 opening below the anode top surface.

S16 Open contact hole with emitter, control electrode (if necessary) and anode contact.

S17 Metal contact is welded.

S18 provides a means for applying appropriate bias and signal voltages.

Blocks of the production processing steps shown in Table I Figs. 4A and 4B.

The fabrication process for the triode, quadrupole tube and the like includes the steps of depositing the additional insulating film 130 and depositing the additional conductive film 140 for the control electrode. The control electrode has a control electrode edge 150 that is automatically aligned with the emitter blade edge or tip 110. In the following detailed description, these additional steps are included as optional steps and are performed only if the control electrodes are included in the feature apparatus structure. The detailed processing of Figs. 4A and 4B, which is illustrated by the results of Figs. 5A-5R, can be modified to create an even simpler device by deleting certain processing steps.

A detailed description of a suitable method for making the field-emission device in conjunction with Figures 4A, 4B, 5A, 5R is provided below.

The method described in Figures 4a, 4b, 5a, 5r is carried out to make the triode device with two control electrodes. A substrate 20, which may be a silicon wafer, is provided (step S1). An insulating layer 30 is deposited on the substrate (step S2). This is done, for example, by growing a silicon oxide film about 1 micrometer thick on a silicon substrate. One pattern is made on the insulator surface to deposit the front head structure. In a preferred method, a pattern of recesses is created and etched into the surface of the insulator layer (step S3). In step S4, the metal is deposited in the recess to form the inserted contact layer 50 and then is planarized (step S5). The deposited conductive material in step S4 may be a metal such as aluminum, tungsten, titanium, or the like, and may be a transparent conductor such as tin oxide, indium tin oxide, or the like. (In the case of using a common emitter for all devices made on a substrate, In this application, steps S2, S3, S4, and S5 may be omitted, although steps similar to step S2 are necessary to insulate one control electrode from the substrate. The insulating layer 60 is deposited (step S6), which is to chemically vacuum deposit the silicon oxide to a thickness of, for example, about 0.1 to 2 micrometers.

A conductive layer is deposited to a constant thickness and a pattern is formed to form the anode layer 70. If it is not required to be a cathode emitter to act as a light source of the anode 70, the conductive anode layer 70 deposited in step S7 may be a metal film or a conductive film such as indium oxide or indium tin oxide (ITO). If such an apparatus is to be used in a light emitting application such as a display device, the conductive layer may be a conductive phosphor 75 or a mixed layer of a conductive material having a thin film of a phosphor at the upper surface. Suitable phosphors include zinc oxides (ZnO), zinc sulfide (ZnS) and many other compounds as suitable phosphors. Other suitable phosphors include ZnO: Zn; SnO _2: En; ZnGa ₂ O ₄ : Mn; La ₂ O ₂ S: Tb; Y ₂ O ₂ S: Eu; LaOBr: Tb; _{ZnS: Zn + In 2 O 3} ; _{ZnS: Cu, A1 + In 2} O 3; (ZnCd) S: Ag + In ₂ O ₃ and ZnS: Mn + In ₂ O ₃ .

Other suitable phosphorescent materials are described in Advances in Electronics and Electron Physics Vol. (A, 1990) pp. 271-373, which is incorporated herein by reference in its entirety. In case the anode layer 70 is to be patterned, The anode layer 70 is formed in a similar manner to the steps S3, S4 and S5 and a pattern can be made have.

In the next step S8, the insulating layer 90 is deposited with an exactly constant thickness. This constant thickness of the insulating layer 90 is important in determining the proximity distance between the emitter and the anode and is therefore important in determining the electric field generated by the constant applied bias voltage. Step S8 includes chemically vacuum depositing the silicon oxide to a constant thickness in the range of 0.1 to 2 micrometers.

Steps S9 and S10 are performed if control electrode layer 140 is required to be below emitter layer 100. (Such a control electrode layer is shown in 5i-5j but is removed from 5k-5r to explain the selection without the lower control electrode layer.) If necessary, the conductive control electrode layer 140 is deposited in step S9, Is created. In step S10, a certain thickness of insulating layer 130 is deposited on the conductive control electrode layer 140 to insulate it and provide a flat insulating surface parallel to the substrate for the next step. Regardless of whether steps S9 and S10 are performed, a flat insulating surface is provided.

This description of the fabrication method continues with respect to Figures 4b and 5k-r which respectively show the corresponding fabrication steps and corresponding cross-sections of the device. In step S11, the conductive contact 120 is opened by opening an appropriate contact hole to create an ohmic contact with the inserted contact layer 50 and by looking at the conductive material into them (by forming a stud) (50). In step S12, an extremely thin emitter layer 100 is deposited and patterned. Preferred materials for the conductive side-emitter layer 100 are alloys of these, such as titanium, tantalum, molybdenum, or titanium-tungsten alloys. However, many other conductors can be used, such as aluminum, gold, silver, copper, copper-doped aluminum, platinum, palladium, polycrystalline silicon, etc. or transparent thin film conductors such as tin oxide or indium tin oxide (ITO). It is preferable to use a material having a low work function for electron emission. In this regard, the preferred material has a work function that is less than or equal to three electron volts, and the more preferred material has a work function that is less than or equal to one electron volt. The deposition at step S12 is controlled to form a film about 100 to 300 angstroms thick so as to have an emitter blade edge or tip 110 with a radius of curvature of less than 150 angstroms and preferably less than 50 angstroms in its final structure. 2, a side emitter 100 is patterned such that it extends past at least a portion of the anode 70 for fabrication. One insulator 130 is deposited over the emitter layer (step S13) again, which may be a chemical vacuum deposition of silicon oxide, for example, 0.1 to 2 micrometers in thickness. If there are two control electrodes and symmetry about the plane of the emitter layer 100 is desired, then such an insulator layer 130 should be made as thick as the insulator layer 130 deposited in step S10. If the control electrode 140 is to be fabricated, one conductive material is deposited or patterned (step S14) to form the upper control electrode layer 140. The control electrode 140 is deposited and planarized in a recess pattern as in the case of the inserted contact layer 50. [ Steps S4, S9 (if performed), S12, S14 (if performed) are all deposited in at least partial alignment with respect to the deposited and patterned cathode film in step S7.

In step S15, an opening is provided through which all layers lying on the upper surface of the anode layer 70 are passed. Such openings are made to cross at least a portion of the emitter layer 50 (and with the control electrode layer 140 if necessary) to form the emitter edge 110 of the emitter layer 100 (and If necessary, to make edge 150 of control electrode layer 140). Such steps are performed using conventional directional etching processes, such as reactive ion etching, referred to as trench etching, in the semiconductor manufacturing literature. Step S15 for fabricating the preferred embodiment of FIG. 2 is performed while at least a portion of the insulator 90 covers at least a portion of the anode 70.

In step S16, the contact hole is opened to the emitter, the control electrode and the positive electrode, if necessary. The metal contact is welded to the necessary place in step S17. Optionally, such processing portions (steps S16 and S17) may be performed after step S13 or S14 but before step S15. In this case, the order of the processing steps is as follows. S13, S14 (if used) S16, S17 and then S15 For some display applications (so-called head-up displays) it is desirable to form a device structure using transparent materials for all films Do. The transparent film can be made with an operable and preferred film thickness in the present invention.

In step S18, means are provided for applying an appropriate electrical bias voltage and an appropriate signal voltage (in the case of a device using a control electrode). Such means may include a contact pad selectively provided on the upper surface of the device to make an electrical contact and may optionally include a lead junction such as a tape self-joining, flip-chip or a means for joining Of course, should be provided to supply a conventional bias voltage and control signal to the conventional power supply and source when using the device, which generates a cold-cathode field emission of the electron flow from the emitter edge 110 to the anode 70 If there is an unreacted layer to the top surface of the device, with the exception of the conductive contact studs or contact pads needed to make the electrical contact, if necessary, apply a sufficient voltage magnitude of the correct electrode This concludes the description of the detailed processing described in Figs. 4A, 4B and 5A-r.

It is desirable to have such a space or cavity in the opening 160 if it is desirable to have an electric field-emitting cell that works with a vacuum or low-pressure non-flammable gas.

This can be done by a method analogous to that described in Research Publication No. 305, Publication No. 30510, September 1987, Integrated Circuit Device Size and Ionization Gas Apparatus Suitable for Processing. Such a method can be initiated by etching small auxiliary openings connected to openings not deep enough (such as not to extend deeper to the height of the anode layer 70) just like the openings provided in step S15. Such an auxiliary opening is made in a portion of the cavity remote from the emitter edge region. The opening for the cavity and the auxiliary opening connected thereto are temporarily filled with a sacrificial organic material such as parylene and then flattened. The insulator of the weapon is welded and extends over the entire device surface including the material sacrificed to include the cavity. A hole is made in the insulator of the weapon by reactive ion etching only through the auxiliary opening. The sacrificial organic material is removed from the cavity by plasma etching, such as oxygen plasma etching, operating through the hole. The atmosphere surrounding the device is then removed to empty the cavity. If an inert gas filler (filler) is required, such gas is removed at the desired atmospheric pressure.

The holes and auxiliary holes are then filled by sputtering the inorganic material to fill the holes. If a gettering insert is needed, the hole-fill step consists of two or more smaller steps. The getter material, and then the inorganic insulator is deposited to complete the plug. The plug of the inorganic insulator closes the cavity and keeps vacuum or inert gas inserted. If a ketting agent is used, it is selected to get an undesirable gas such as oxygen or a gas containing sulfur, if used. Said suitable getter material may be an alloy of Ca, BaTi, Th or a getter material known in the art of vacuum tube construction. Such a method for containing a vacuum or gas atmosphere is not described in Figures 4a, 4b, 5a-5r.

Those skilled in the art will appreciate that the integrated array of field-emission devices, such as the array in FIG. 1, provides a variety of interconnections between multiple devices, while the fabrication method described for the plurality of field- Steps may be performed concurrently.

An integrated array of field-effect devices made in accordance with the present invention has each device as described herein, and these devices are arranged as cells comprising at least one emitter and at least one anode per cell. The cells are arranged along rows and columns, for example the anodes are interconnected along the rows along the emitters.

The field emission device structure and manufacturing method of the present invention, in particular, there are many various uses for making a flat panel display device for producing images and for displaying character or graphic information with high resolution. The type of panel display made with the device of the present invention can replace any existing display device including a liquid crystal cell because they are simple to manufacture, cheap to manufacture, low in power consumption, It is expected to be possible.

Display devices made in accordance with the present invention are expected to be used in many new applications such as display devices for virtual systems. In embodiments using transparent substrates and annealing, the display device using the structure of the present invention is particularly useful for an enhanced reality display.

In addition, the sequence of production steps can be changed to some extent for various purposes. Lithographic patterning, deposition, etching, or other fabrication techniques may be used. Functionally equivalent materials can be used to replace the specific materials used in the described embodiments, the preferred sizes can be varied, and other modifications are possible to adapt the device to a variety of uses and conditions.

Claims (36)

a) a substrate having an upper surface making a first plane, b) a field emission electron emitter located at a second plane parallel to and spaced apart from the first plane by a first predetermined distance, the emitter having an emission edge (edge). c) an inserted conductive contact layer having an upper and a lower major surface, wherein one of said upper and lower main surfaces is disposed successively with said first plane, d) a conductive emitter contact spaced from the emissive edge of the emitter, the emitter electrically connecting at least a portion of the inserted conductive contact layer to provide a cathode contact. d) a first insulating layer disposed between the first and second planes and occupying the upper major surface, e) an anode disposed on the first insulating layer upper main surface that is remote from the conductive emitter contact portion and extends upward to a height less than the distance between the first and second planar surfaces from the first insulating layer upper main surface, f) a conductive anode contact electrically connected to the anode, whereby the device has an applied electrical bias voltage, and g) applying said electrical bias voltage as said emitter and said anode so that said applied bias voltage is sufficient to allow a cold-cathode discharge current of electrons to flow from said discharge edge of said electron emitter to said anode The field emission device of the type using a cold cathode field emission power source. The method according to claim 1, b) a conductive control electrode disposed on a third plane remote from the first and second planes, one control electrode edge aligned with the emission edge of the emitter, i) a second insulating layer disposed between the second and third planes to isolate the control electrode from the electron emitter, j) a conductive control electrode contact electrically connected to the control electrode from the conductive emitter contact, the conductive anode contact and away from the control electrode edge, and k) further comprising means for applying a control signal to said conductive control electrode contact to thereby enable said device to be controlled as a triode plate. The field emission display of claim 1, wherein the anode extends at least partially below the emission edge. The field emission display of claim 1, wherein the anode includes a phosphor. The field emission display of claim 1, wherein the electron emitter includes a thin-film structure having a thickness of 300 angstroms or less. The field emission display of claim 1, wherein the emission edge of the electron emitter includes a ballast having a bending radius of less than 150 ohms. The method of claim 4, wherein the phosphor is ZnO: Zn; SnO _2: Eu; ZnGa ₂ O ₄ : Mn; La ₂ O ₂ S: Tb; Y ₂ O ₂ S: Eu; LaOBr: Tb; _{Zns: Zns: Zn + In 2} O 3; ZnS: Cu, Al + In ₂ O ₃ ; (ZnCd) S: Ag + In 2 O 3; And ZnS: Mn + In ₂ O ₃ cold, characterized by consisting of a material selected from the group list in-field emission display device of the type that uses the field emission cathode power. 5. The field emission display of claim 4, wherein the phosphors have different color cathode luminescent properties. 2. The field emission display of claim 1, wherein the phosphors have different luminous properties. The field emission device of claim 4, wherein the phosphor is comprised of three phosphorescent materials characterized by having a cathodoluminescent property of the red, green, and blue portions of the spectrum. Display device. 6. The field emission display of claim 5, wherein the thin film-film structure comprises at least one film having a work function for electron emission of three or less of the total volts. Device. 6. The field emission display of claim 5, wherein the thin film-film structure comprises at least one metal film. A method according to one of claims 1 to 11, wherein the substrate emitter, the anode, the control electrode, and the first and second insulating layers are both transparent to light. Field emission display. (a) providing a substrate, (b) disposing a first insulating layer over the substrate, (c) disposing a first conductive layer over the first insulating layer, thereby providing one anode, the anode having a first predetermined thickness and an upper major surface, (d) disposing a second insulating layer on the anode layer, the second insulating layer having a second predetermined thickness, (e) disposing a second conducting layer, which is only a few hundred angstroms thick, on the second insulating layer and forming a pattern, Thus making it parallel to the lipid, thus forming a side emitter layer, (f) providing an opening through the side emitter layer and through a second insulating layer, thus forming a discharge edge of the side emitter layer, the interstice opening extending to the upper main surface of the anode, and (g) providing a means for applying an electrical bias voltage to the side emitter layer and to the anode layer, wherein the bias voltage to be applied causes the cold-cathode discharge flow of electrons to flow from the emission edge of the side- So as to be sufficient to orient the anode layer toward the anode layer. 14. The method of claim 13, wherein the substrate providing step (a) provides one conductive substrate. 14. The field emission device according to claim 13, wherein the first conductive layer arrangement step (c) includes arranging a phosphor layer and thus forming a positive electrode having at least an upper main surface of the positive electrode including a phosphor How to. 14. The method of claim 13, wherein a second conductive layer lay-up step (9) further comprises extending the second conductive layer in at least a portion of the anode layer. 14. A method according to claim 13, wherein the opening providing step (f) includes leaving at least a portion of the second insulating layer such that the remaining portion covers at least a portion of the anode layer . 15. The method of claim 14, wherein the electrical bias voltage applying means providing step (g) comprises providing electrical contact between the conductive substrate and the side emitter layer, the method comprising applying a bias voltage to the conductive substrate, Thereby providing a means for fabricating a device having a cavity-emitter structure. ≪ Desc / Clms Page number 13 > 15. The method of claim 14, wherein the step of providing electrical bias voltage applying means (g) comprises providing electrical contact between the conductive substrate and the anode layer, applying a bias voltage to the conductive substrate, And providing a means for making the field emission device. 14. The method of claim 13, wherein the substrate providing step (a) (I) providing a conductive substrate, (Ii) placing a third insulating layer on the conductive substrate, and (Iii) disposing a third conductive layer over the third insulating layer to provide an interposed contact layer. ≪ Desc / Clms Page number 13 > 14. The method of claim 13, wherein the substrate providing step (a) (I) provide an insulating substrate, and (Ii) disposing the conductive layer on the insulating substrate to provide an interposed contact layer. ≪ Desc / Clms Page number 12 > 22. The method of claim 21, wherein providing the electrical bias voltage applying means (g) comprises providing means for applying a bias voltage to the third conductive layer. 22. The method of claim 21, wherein the third conductive layer disposition step further comprises patterning the third conductive layer. 22. The method of claim 21, (A) patterning the insulating layer and selectively etching the insulating substrate to form an opening for the third conductive layer, (B) disposing the third conductive layer in the opening in the insulating substrate. 14. The method of claim 13, (h) a third conductive layer is disposed apart from the first and second conductive layers to form a control electrode layer, (i) further providing an opening through the third conductive layer, thus providing the control electrode layer with a control electrode edge to perform the opening providing step (f) (j) providing the electrical signal to the third conductive layer so that the applied electrical signal is sufficient to control the flow of electrons. < RTI ID = 0.0 > Way. 26. The method of claim 25, (k) disposing a third insulating layer on the second conductive layer, The third conductive layer disposition step is formed after the second conductive layer disposition and pattern formation step (e), and Wherein the opening-providing step (f) comprises providing an opening through the third insulating layer. (a) providing an insulating substrate, (b) disposing a first conductive layer over the substrate, selectively forming a pattern, (c) disposing a first insulating layer on the first conductive layer, Thus providing one anode, said anode having a first predetermined thickness and an upper major surface, (d) disposing a second conductive layer over the first insulating layer, thereby disposing a positive electrode layer, the positive electrode layer having a first predetermined thickness and an upper major surface, (e) disposing a second insulating layer on the anode layer, the second insulating layer having a second predetermined thickness, (f) disposing a third conducting layer, which is only a few hundred angstroms thick, on the second insulating layer and forming a pattern, Thus forming a side emitter layer so as to be parallel to the lipid, (g) providing an opening through the side emitter layer and through a second insulating layer, thus forming a discharge edge of the side emitter layer, the opening extending to the upper main surface of the anode layer, And (h) providing a means for applying an electrical bias voltage to the side emitter layer and to the anode layer, wherein the bias voltage to be applied causes the cold-cathode discharge flow of electrons to flow from the emission edge of the side- So as to be sufficient to turn toward the anode layer. ≪ Desc / Clms Page number 13 > 28. The method of claim 27, wherein the second conductive layer disposition and patterning step (d) comprises arranging and patterning the phosphor and thereby forming an anode with at least the upper main surface of the anode comprising the phosphor A method of providing a field emission device. 28. The method of claim 27, wherein a third conductive layer arrangement and patterning step (f) further comprises extending said third conductive layer in at least a portion of said anode layer. 28. The method of claim 27, wherein step (g) of providing the opening leaves at least a portion of a second insulating layer to cover at least a portion of the anode layer. 28. The method of claim 27, (I) disposing a third insulating layer in the second conductive layer, (Ii) placing the fourth conductive layer so that the fourth conductive layer is separated from the side-emitter layer by the third insulating layer, and (k) providing the opening through the third insulating layer and the fourth conductive layer while providing the opening providing step (g), thereby forming an edge on the fourth conductive layer , And Further comprising means for applying an electrical signal (I) to said fourth conductive layer, such that said electrical signal to be applied is sufficient to control the flow of said electrons. Lt; / RTI > (a) providing a flat substrate, (b) disposing a first insulating layer over the substrate, (c) forming a pattern in the first insulating layer and etching the first insulating layer to form a recess, (d) disposing a first conductive layer in the recess to form an inserted contact layer, (e) disposing a second insulating layer on the inserted contact layer, (f) arranging the second conductive layer to form a positive electrode layer, the positive electrode layer having an upper main surface and a first thickness, (g) disposing a third insulating layer having a second predetermined weight on at least a part of the anode layer, (h) arranging and patterning a third conductive layer having a third thickness, which is only a few hundred angstroms on the third insulating layer, parallel to the substrate, (i) disposing a fourth insulating layer having a fourth thickness of at least a portion of the thin emitter layer, (j) arranging a fourth conductive layer in the fourth insulating layer parallel to the substrate and at least partially aligned with the anode layer, and forming a patterned control electrode layer, (k) providing an opening through the control electrode layer, through the fourth insulating layer, through the thin emitter layer, and through the third insulating layer, thereby extending to the upper major surface of the anode layer Forming an emitter edge of the thin emitter layer and forming a control electrode edge of the control electrode layer, (I) providing means for applying an electrical bias voltage to the thin emitter layer and to the anode layer, wherein the applied bias voltage causes a cold-cathode discharge flow of electrons from the emitter edge to the anode layer , And (m) providing means for applying a signal voltage to the control electrode layer, the signal voltage being sufficient to control the flow of electrons. 33. The method of claim 32, wherein said second conductive layer disposition step (f) comprises placing a layer of phosphor in one layer and thus forming an anode with at least said upper main surface of said anode layer comprising phosphors Wherein said method comprises the steps of: The method of manufacturing a field emission device according to claim 32, wherein said third conductive layer arrangement and pattern formation step (h) further comprises extending said third conductive layer in at least a portion of said anode layer . 33. The method of claim 32, further comprising leaving the opening providing step (k) such that at least a portion of the third insulating layer covers at least a portion of the anode layer. 14. The method of claim 13, further comprising controlling the placement of the second conductive layer such that the second conductive layer disposition step (e) forms a thickness between 100 Angstroms and about 300 Angstroms in both quantities. ≪ / RTI >