TWI248626B - Method for fabricating a field emission device - Google Patents

Abstract

A method for fabricating a field emission device includes the following steps: providing a working plate; depositing a layer of catalyst on the working plate; forming an array of carbon nanotubes on the layer of catalyst; depositing a cathode on the top of the array of carbon nanotubes; removing the working plate and exposing the bottom of the carbon nanotubes array to an exterior.

Description

1248626 _ Case No. _ 9·7708___ Year Month Day Amendment 5, Invention Description (1) "'" 'Technical Field of the Invention The present invention relates to a method for preparing a field emission element, and more particularly to a nano-breaking A method of preparing a tube array field emission element. [Prior Art] Nano carbon official is a new type of carbon material, which was discovered in 1991 by the researcher, "HeUcal of graphitic carbon\ S Iijima, Nature? Vol.354, P56 (1 9 9 1 ). The carbon nanotubes have excellent electrical conductivity and have a tip surface area close to the theoretical limit (the smaller the tip surface area, the more concentrated the local electric field), so the best carbon emission is known. The material is straight and has a very low field emission voltage (less than 1 〇〇V), which can transmit a very large density, and the current is extremely stable, which is very suitable for field emission; as shown in the twelfth figure, Dai Hongjie , Fan Shoushan et al., US 6' 232, No. 706, discloses a nano-carbon nanotube field emission device and a pot method. The preparation method of the device is formed on the surface of the substrate 21; the square deposition catalyst layer 230, directly to the catalyst Layer 23 〇 substrate 21 ° nano carbon tube gamma as a field emission element, f tube bundle 200 0 height can reach 3 〇. Micron, Nai 2 is not used for field emission display. S 1 morning and evening growth and should Too half μ μ Ϊ square / to generate nano carbon Is not exactly the same height, no portion eight meters long stone anti officer, the other end portion of the knife = not on the same plane where a Shu "is not particularly sharp wood and stone trans official emission lines of the concave surface as shown in FIG XII

Page 6 1248626 Amendment 曰 Case No. 92107708 V. INSTRUCTIONS (2) Carbon tube array table © ' When electrons are emitted, it is easy to produce electron emission unevenness, which leads to the disadvantage of uneven display. X, therefore, it is necessary to provide a kind of preparation for electronic emission.卞力 [Contents] An object of the present invention is to provide a method for preparing a field emission element having a flat end surface and uniform electron emission. χ In order to achieve the object of the present invention, the present invention provides a field emission device, a method comprising the steps of: providing a substrate, the substrate; forming a catalyst on the surface of the substrate; and introducing a carbon source gas, ί Array; anti-two action τ 'carbon source gas to generate nano carbon tip to form a cathode electrode, · remove the substrate, compared with the prior art, the present invention and the right column emission end in the same plane, thus 4 carbon nanotubes Array [Embodiment] τ-current electrons are hooked. Referring to the first figure, the main step 1 of the method of the present invention provides a substrate, and the substrate has a back-end V-curve. When a material such as high-temperature glass is used, which is capable of being subjected to nano-tubes, oxidized stone, etc. Step 2' forms a flat surface on the surface of the substrate, which can be mechanically polished or chemically polished. * - The smaller the degree, the better, so that the subsequent steps are too much I soil & the surface is flat, flat growth; ~ mussel / The township does not have carbon tubes can start from the same plane 1248626 ~ Γ - 921 ° 770 ^ - year 曰 曰 _ _ 5, invention description (3) ---------- Step 3, on the base Forming a catalyst layer on the surface, forming a catalyst layer on the surface by a chemical deposition method, the catalyst is generally a transition metal =, ruthenium, Nl or an alloy thereof, and the deposition thickness is 10 nm, preferably 3 to 5 na;; The catalyst layer can be further annealed at a temperature of 300 ° C to 400 ° C to facilitate the formation of the catalyst nanoparticle; and the lower carbon dioxide array is grown by chemical vapor deposition. The array of eunuchs generally consists of: introducing carbon source gas and heating to Should warm

: too ̄ ̄ ̄ catalyzed by the catalyst, the carbon source gas chemical reaction, the raw eight = anthrax array, the temperature of the growing carbon nanotube array depends on the carbon source gas into: I catalyst material and t, generally 700 Around °c; the length of the carbon nanotube array = can be determined according to requirements, generally 10 microns ~ 500 microns. Because the surface formed by step J above is flat, &, the carbon nanotube array is grown on the same plane, the growth surface of the carbon nanotube array is flat; step 5, the cathode electrode is formed, and the snow is formed at the top of the carbon nanotube array. The electrode is generally deposited by a chemical deposition method to form a cathode electrode. The cathode electrode may further include a resistor negative feedback layer as needed; ^Step 6, the substrate is removed, the substrate may be removed by chemical etching, and the substrate is removed. The carbon official array grows to form a field-emitting element whose emission surface is flat.

Referring to the second to eighth figures, the first embodiment of the present invention mainly includes the following steps. As shown in the second figure, 'the metal plate 2〇 with the fine groove 2〇1 is provided as the working plate of the subsequent step, and the fine groove 2〇1 is provided to facilitate the smooth removal of the metal plate 20 after the subsequent steps are completed. In order to make the surface flat, the stone can be used

1248626 ___ Case No. 92107708_Year L Day Tired, bottom _ V. Invention Description (4) The easily removable material is coated with the groove 201 and the surface of the metal plate 2, which serves as the supporting basis for the subsequent steps. As shown in the third figure, the surface of the metal plate 20 is formed by a mineral film, printing or directly using a ready-made template or the like to form a surface smoothed oxidized layer 2 2 as a substrate for growing the carbon nanotube array 30 in a subsequent step. The surface of the enamel layer is required to be smooth and smooth by the mechanical polishing method. The surface flatness requirement is less than 1 micrometer. The thickness is from 1 micrometer to 1000 micrometers, preferably from 1 micrometer to 2 (10) micrometer. The emulsified stone layer 2 2 may also be provided with other insulation. The material is capable of withstanding the temperature required for the growth of the carbon nanotubes (about 700 C). The ruthenium oxide layer 22 can be removed by chemical re-etching. As shown in the fourth figure, the catalyst layer 24 is further deposited on the surface of the ruthenium oxide layer 22, typically iron, cobalt, nickel or alloys thereof. The catalyst layer 24 has a thickness of from 1 to 5 nm, preferably from 3 to 5 nm. Preferably, the catalyst layer 24 is annealed at a temperature of 300 ° C to 400 ° C to facilitate the formation of catalyst nanoparticle. As shown in the fifth figure, the carbon nanotube array 30 is grown on the surface of the yttrium oxide layer 22, and the carbon nanotube array 30 is formed by chemical vapor deposition, and a carbon source gas is introduced under a certain temperature condition, such as Acetylene or ethylene, through the catalytic action of the catalyst layer 24, the carbon source gas undergoes a chemical reaction, so that the carbon nanotube array 30 is formed on the surface of the ruthenium oxide layer 22; the temperature of the growth carbon nanotube array 3 一般 is generally about 70 ° C . Since the surface of the ruthenium oxide layer 22 is flat, the carbon nanotube array 30 can be ensured to grow on the same plane; the length of the carbon nanotube array 3 视 depends on the growth process, generally between micrometers and 1 micrometer. For field emission preferably from 10 microns to 500 microns.

1248626 9210770«

V. Description of the invention (5) As shown in the sixth figure, the nano-carbon negative feedback layer 402 and the cathode electrode are formed by depositing a metal material, a resistor, a metal, etc., and the thickness may be as a seventh. As shown in the figure, the metal stripping is removed, and the carbon nanotube array 3 is removed; the oxygen is removed, and if necessary, the growth surface of the carbon nanotube array 30 is removed by laser bombardment as an emitting element. The carbon nanotube array 3 has a uniform purpose. Further, as shown in the eighth embodiment, the electrode electrode 44 is further passed through the gate electrode, and the gate electrode 44 is formed on the cathode electrode 40. The top of the tube array 30 is deposited to form a resistor - the cathode electrode 40 is a chemically resistive resistor. The negative feedback layer 402 is optionally adapted to the needs of the resistor. The plate 20 and the yttrium oxide layer 2 2 are removed from the ruthenium layer 22. The remaining catalyst layer 24 can be chemically etched to expose the electron-emitting end, thereby forming a long surface of the field, so that the nano-emission can be reached. A grid is formed on both sides of the carbon tube array 30 to control the surface of the carbon nanotube array 3 〇 emission insulating layer 42, separated by insulation

Please refer to the ninth to eleventh steps. Mainly for the second embodiment of the present invention

As shown in the ninth figure, a working plate 11 is provided, and the surface thereof is smoothed by mechanical polishing or the like, preferably, the surface flatness is less than 丨 micrometer, and then the surface thickness of the biO nanometer is formed by the chemical deposition method. Catalyst layer (not shown), the catalyst is generally transition metal iron, cobalt, nickel or its alloy, and then, through the carbon source gas acetylene or ethylene, heated to the reaction temperature (700 C ~ 1000 C), under the action of the catalyst The carbon nanotube array 1 30 is grown on the surface of the working plate 11 , and the obtained carbon nanotube array 丨 3 〇 top is uniform and does not affect the electron emission effect. Because the surface of the working plate 110 is smooth and smooth

Page 10 1248626 --- No. 7708__ years _ month 曰 _ correction _ five, invention description (6) Therefore, the growth surface of the carbon nanotube array 130 is even and even. As shown in the tenth figure, a metal material is deposited on the top of the carbon nanotube array 130 to form a cathode electrode 150, which is electrically connected to the top of the carbon nanotube array 130. As shown in the eleventh figure, the working plate 1 1 〇 is removed, and the carbon nanotube array 130 and the cathode electrode 150 are retained, and the growth surface of the carbon nanotube array 130 is used as the electron emission end face, that is, It can be used as a field emission element for electronic devices such as field emission displays. The growth surface of the carbon nanotube array 130 is consistent with the surface of the working plate 110, and the surface flatness is the same as the surface flatness of the working plate 110, which is less than 1 micrometer, so the electron emission end face of the carbon nanotube array 130 is uniform. In order to achieve uniform electron emission. In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application in accordance with the law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or modifications made by those skilled in the art to the spirit of the present invention are intended to be included in the scope of the following claims.

1248626 _ Case No. 92107708_年月曰 修正 Revision _ Schematic description of the drawings The first figure is a flow chart of the preparation method of the field emission element of the present invention. 2 to 8 are schematic views of steps of the first embodiment of the present invention. The ninth to eleventh drawings are schematic views of the steps of the second embodiment of the present invention. Figure 12 is a schematic diagram of a prior art carbon nanotube field emission device. [Main component symbol description]

Metal plate 20 working plate 1 10 yttrium oxide layer 22 carbon nanotube array 130 catalyst layer 24 cathode electrode 150 carbon nanotube array 30 carbon nanotube bundle 200 cathode electrode 40 fine groove 201 insulating layer 42 vertical substrate 210 peach electrode 44 Porous Shixia 220 Resistance Negative Feedback Layer 402 Catalyst Layer 230

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Claims (1)

1248626 _ Case No. 92107708 VI. Patent application scope i A method for preparing a field emission device, comprising the steps of: providing a working plate having a flat surface; forming a catalyst layer on the surface of the working plate; The carbon source gas is heated to the reaction temperature, and the carbon source gas acts to form an array of carbon nanotubes; the cathode electrode is formed at the top of the carbon nanotube array; the working plate is removed to expose the root end of the nanotube array. 2. The preparation of the field emission element as described in claim 1 of the patent application is directed to the surface of the work plate having a flatness of less than 1 micrometer. 3. The preparation of the field emission element according to claim 1, wherein the working plate is made of a material & material capable of withstanding the growth temperature of the carbon nanotube. 4. The preparation method of the field emission element of the first item of the patent application scope is as follows: The material of the working board is covered with high temperature glass, enamel or oxidized stone. The method for producing a field emission element according to claim 1, wherein the carbon source gas comprises ethyl or ethylene. 6. The method of producing a field emission element according to claim 1, wherein the catalyst is transition metal iron, cobalt, nickel or an alloy thereof. 7. The method of preparing a field emission element according to claim 1, wherein the catalyst layer has a thickness of from 1 nm to 10 nm. 8. The method of producing a field emission element according to claim 7, wherein the catalyst layer has a thickness of from 3 nm to 5 nm. The method of producing a field emission element according to claim 1, wherein the cathode electrode forms a cathode electrode by depositing a metal material. 1248626 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Feedback layer. II. The method of preparing a field emission element according to claim 10, wherein the resistance negative feedback layer is tantalum or an alloy. 1 2 · A method for preparing a field emission element, comprising the steps of: providing a working plate having a flat surface; forming a catalyst layer on the surface of the working plate; introducing a carbon source gas, heating to a reaction temperature, The carbon source gas generates an array of carbon nanotubes under the action of the catalyst; forming a cathode electrode at the top of the carbon nanotube array; removing the working plate to expose the root end of the carbon nanotube array; forming at both ends of the nanotube array a gate. A method of producing a field emission element according to the above aspect, wherein the surface of the working plate has a flatness of less than 1 μm. The method of producing a field emission element according to claim 12, wherein the working plate is made of a material capable of withstanding the growth temperature of the carbon nanotube. The method of producing a field emission element according to claim 12, wherein the carbon source gas is acetylene or ethylene. The method of producing a field emission element according to the above aspect of the invention, wherein the catalyst is transition metal iron, indium, nickel or an alloy thereof. / The method for preparing the field emission element according to claim 12, wherein the thickness of the catalyst layer is 1 to 1 nanometer. ι\·If the preparation of the field emission element described in claim 17 of the patent scope is 1248626 _ case number 92107708_年月日日__ 6. The patent scope method, wherein the catalyst layer has a thickness of 3 nm to 5 Nano. The method of producing a field emission element according to claim 12, wherein the cathode electrode forms a cathode electrode by depositing a metal material. The method for preparing a field emission device according to claim 19, wherein the forming the cathode electrode further comprises a resistance negative feedback layer. Page 15