PROCESS FOR PRODUCING ZINC OXIDE THIN-FILM AND PRODUCTION APPARATUS
|Posted date||Mar 29, 2019|
|International application number||2006JP305244|
|International publication number||WO 2007020729|
|Date of international filing||Mar 16, 2006|
|Date of international publication||Feb 22, 2007|
|Title||PROCESS FOR PRODUCING ZINC OXIDE THIN-FILM AND PRODUCTION APPARATUS|
|Abstract||A method of forming on the surface of a flexible base material, such as a plastic, a highly transparent zinc oxide thin-film of high conductivity without essential requirement of impurity doping; and a thin-film production apparatus therefor. There is provided a method of forming a zinc oxide thin-film through reaction of oxygen radicals with zinc atoms on the surface of a base material disposed in a film forming chamber having been evacuated to vacuum, wherein the density of crystal defects being defects of an atomic arrangement of zinc oxide thin-film is controlled by the temperature of the base material to thereby achieve formation of a zinc oxide thin-film. For intentionally disordering of the regularity of the atomic arrangement of zinc oxide thin-film, it is preferred that film formation be conducted while maintaining the temperature of the base material at 400°C or below.|
|Outline of related art and contending technology||
Background of the Invention
0002: Digital camera, a video DVD, a plasma display panel, an organic EL panel is a transparent electrode film such as an electronic portion of the article is essential, the transparent electrode film of indium tin oxide film is widely used (In dium Tin Oxide). And apply force, as well as the expensive indium is not a problem and come to the plant of the resource, an urgent need to be converted to other materials.
0003: Acid in a chemically stable substance i spoon zinc for a long time and also be harmless substances are used, the advantage of low environmental load. A zinc oxide thin film of a method for producing the main, spa ttaringu method, metal organic chemical vapor deposition method, a spray heating method and the like. Sputtering is the most widely used, non-uniform electrical resistivity of the film is observed, particularly at low temperatures during film deposition and uneven authored, a problem will be.
0004: Metal-organic chemical vapor deposition method and a large amount of waste gas is generated, the size of the environmental load!/, And, the other is in a problem. In addition, the spray thermal decomposition method is to obtain a film of high quality should be at least about 550 °C and, a low-temperature film formation is such a problem that cannot.
0005: I with an acid other than the above method according to the technique for forming a thin film zinc spoon, molecular beam epitaxial growth method is ((Molecular Beam Epitaxy, MBE) (non-patent document 1, see Non-Patent Document 2). However, these non-patent document discloses a zinc oxide thin film is formed, both at the time of the 400 °C on the film at high temperature and u, a heat-resistant plastic or the like in the case of a base material cannot be applied is such a problem. In addition, the transparent electrode film in order to reduce the electrical resistivity of the film doped with an impurity must be a problem.
0006: Further, by using an atmospheric pressure glow discharge plasma is a technique for forming a zinc oxide thin film see patent documents 1, as disclosed by Patent Document 2. However, any inert gas may be used to generate a plasma by the market, i ^ M Ω resistance of a thin film zinc spoon acid equal to or greater than the force which results in a problem.
0007: Further, disclosed by these documents and a thin film of zinc acid i spoon method, a vacuum pressure of a film forming chamber installed in the temperature of the substrate is heated to or above 400 °C, and let the reaction being a zinc oxide, for the user in the film. In addition, these methods can be ensured sufficient conductivity of a V, it is, the impurity needs to be doped during film formation.
1 Note the non-Japanese documents: Plasma assisted MBE growth ana characterization of hexagonal ZnO on GaAs(l l l l), Proceeding of 1st Asia-Pacific Workshop on Widegap Semiconductor s, 153-156 (2003)
Patent Document 2: MBE growth and optical properties of ZnO on GaAs(l l l l) substrates, phys. Stat.sol. (b), 241, 591- 594 (2004)
Patent Document 1: Japanese Patent Application 2003-89875
Patent Document 2: #112001-271167
An object of the present invention to offer a footpad
0008: Is a main object of the present invention, such as a flexible plastic such as high transparency and the surface of the substrate
, And doped with impurities is not an essential requirement of the high conductivity of the formed thin film of zinc acid i arsenate, vico display using the thin film device and the like to provide.
0009: Further, it is an object of the present invention without using a complicated device, the high speed characteristic can be a zinc oxide thin film layer is formed to provide a thin-film production apparatus i spoon acid to the zinc can.
Means for solving the problem
0010: Inventors, as a result of study for many years, a zinc atom and the oxygen radicals and acid is carried out at a low temperature, the regularity of the atomic arrangement of the zinc oxide is impaired, as a result, visible light is scattered at the lattice defect portion, the transparency is decreased, the regularity of atomic arrangement of the zinc acid i spoon is disturbed even when the crystal defect density can be equal to or smaller than a predetermined density, the visible light region can be secured to be not the transparency of the, a new discovery.
0011: Further, the atomic arrangement of the thin film of zinc acid i spoon intentionally to disrupt the regularity, crystal defects can be the source of the carrier, the carrier from the source to generate a large number of carriers becomes possible. In this way, while ensuring transparency, and high electric conductivity without doping impurities of the spoon acid i can be a thin film zinc, a new discovery.
0012: The present invention, the pressure in the vacuum film forming chamber and the surface of the substrate disposed within the lead atoms in the oxygen radical and the sub-reaction method of forming a zinc oxide thin film may be!, And, the arranging of the original zinc oxide thin film which is a defect of the crystal defect density by controlling the temperature of the substrate, thus the zinc oxide thin film according to the present invention and. In this case a crystal defect primarily occurs in oxygen vacancies. And a source of generation of crystal defects in addition to the carrier, further acid-type dopant is doped to lower the resistance of the thin film can be zinc, doping amount of the dopant, the dopant in the film and the spoon zinc acid i the ratio of zinc atom in the range of 1 to 1000 as the pair 10-1 pair can be controlled is preferable. Dopants include aluminum, gallium, indium, chlorine is preferably
0013: Zinc oxide thin film of the atomic arrangement is deliberately disturb the regularity, the temperature of the base film 400 °C or less is preferable. Zn + 0 i *→ZnO zinc acid represented by the film formation reaction of the spoon is as mentioned below from the exothermic reaction, on the fact that the range of 0 °C.-400 ° C. is the temperature of the substrate and suitable control, while ensuring the transparency by this, the conductivity and high acid i can be a thin film zinc spoon.
0014: The method of controlling the temperature of the substrate, the distance between the substrate and the oxygen radical generating sources, and the original child source Z or zinc can be adjusted by the distance between the substrate and is preferred. Oxygen radical-generating source, a zinc atom to suppress the influence of radiant heat from the source, the temperature of the substrate can be controlled.
0015: Serving as a source of oxygen radicals, oxygen plasma is generated in the quartz tube is filled to, oxygen plasma and an oxygen radical having a force cell, such a force is supplied to the oxygen radical to the substrate in the case of using oxygen plasma cell system, the temperature of the quartz tube is at least about 350 °C or more, an acid is possible to increase the supply amount of 400 °C or more is required. As a result, the radiant heat from the substrate by 400 °C or more depending on the conditions being heated. However, oxygen plasma cell and the substrate a predetermined distance if the distance or more, the oxygen plasma to suppress the influence of radiant heat of such power cells can be identified have to be, an increase in the temperature of the substrate can be prevented.
0016: Also, the supply of zinc atoms to the substrate of the solid zinc is evaporated in the case of using the method of supplying, solid zinc was evaporated to 300 °C or more of zinc is at least the temperature of the crucible need to be heated, the increase of the supply amount of a zinc atom!] Is 400 °C or more is necessary. As a result, the zinc from the crucible by radiant heat from the substrate is 400 °C or more depending on the conditions is heated. Therefore zinc crucible by controlling the separation of the substrate, the influence of heat radiation from the zinc crucible can be controlled. That is, oxygen plasma and the zinc crucible of cell congestion to the force influence of the substrate due to heat radiation, and the substrate can be controlled by adjusting a distance is suitable.
0017: Substrate and a zinc atom and an oxygen radical source and the distance between the source, an oxygen radical, equal to or less than the mean free path of the sub-lead atoms is preferred. The source of oxygen radicals to the substrate and a zinc atom source of the force affected by the radiated heat at a temperature below the desired set can be adjusted to the distance, the distance is longer than the mean free path, part of oxygen radicals and Z or a zinc atom before reaching the substrate contact is lost energy , not be able to reach the substrate surface. In addition, the reaction at the surface of the substrate has arrived as will be reduced. Therefore, the influence of radiant heat can be adjusted to the desired temperature range and at a distance, a distance of less than the mean free path and is preferred set U,.
0018: To a desired temperature by forced cooling means to control the temperature of the substrate is suitable. The substrate holder so as to be arranged around the pipe, the pipe-like force to the base and the water is recirculated cold the recipe, it is preferable to control the temperature of the substrate.
0019: The regularity of atomic arrangement of the zinc oxide film is intentionally disturbed as another method, a zinc atom or an acid radical and Z control the amount of supply to the substrate, a zinc oxide thin film which is a defect of the atomic arrangement is preferable that a crystal defect density control,. Per cent the surface of the substrate, a zinc atom is larger than the supply amount of the supplied oxygen radicals, or oxygen radicals by supplying reduced, and the reaction of the oxygen-deficient. Thus, the concentration of crystal defects can be of the linear force.
0020: Crystal defects of the 1 X 1018 pieces/cm3 from 5 X 1021 pieces/cm3 can be controlled, and the minimum impurity electric resistivity without dough 1 X 10 -4 Ω cm or less, 80% or more in the visible light transmittance that can be secured.
Incidentally, a high transmittance of the electromagnetic wave shielding material or the like is not required, the crystal defect density 5 X I 021 pieces/cm3 or more high conductivity by acid i may be a thin film zinc spoon.
0021: Oxygen radicals and oxygen radicals supplied from a source of zinc atoms and zinc atoms supplied from a source substrate to a reaction on the surface and is suitable for controlling the ratio. In the surface of the substrate, Zn (zinc) (oxygen radical) + 0 * when the reaction occurs→ZnO, unreacted zinc atom is attached to the substrate to cause crystal defects (lattice defects). Of the lead atoms and the supply amount of oxygen radicals Kross supplied by adjusting the ratio of the amount, the degree of density of crystal defects can be controlled. Thus, not doped with an impurity of high conductivity can be a thin film lead acid i 匕 亜. Zinc atoms and the oxygen radical supply amount is controlled, the temperature of the zinc crucible, oxygen plasma cell power control, or zinc crucible capacity, the capacity of the cell can be adjusted to the oxygen plasma.
0022: I after a thin film of zinc acid spoon to repair the crystal defect density in the heat treatment in consideration of the processes during deposition and crystal defect density and is suitable for the control.
· Transparent electronic devices electrically the electrode film is, after the film formation, heat treatment must be different in some cases through the processes. For example, a transparent electrode film is used for a plasma display, an amino group using a silver paste, the probe electrode in the course of formation, about 3 time, are exposed to the heat treatment of 500 °C. Therefore, such a force in the heat treatment processes, the change in the crystal defect density of the zinc oxide thin film (the oxygen vacancy is repaired) due. Therefore, the carrier-generating source is decreased, the conductivity is decreased. Therefore, after the repair the crystal defect density in the thermal processes (the vacancy density in an acid) is taken into account in advance, by forming a zinc oxide thin film, the final desired transmittance and the conductivity of a zinc oxide thin film can be formed.
0023: The present invention, the film forming chamber and the vacuum pressure of which, disposed within the chamber in which film exits the fuel cell oxygen radicals having fine pores and the cell with oxygen plasma, the film formation chamber arranged to generate the vapor of zinc and the zinc crucible, the film forming chamber is disposed within the lead atoms and the oxygen radicals to the surface by the reaction of the nitrite and a zinc oxide thin film are formed one substrate holder for holding a substrate and a zinc acid i in the spoon thin film-manufacturing device,
Z and the substrate the oxygen radical source and a zinc atom or an oxygen radical source and the distance between the mean free path of a zinc atom selected from the group Z or less, and a zinc atom or an oxygen radical source and the source of Z to the influence of radiation heat from a means capable of maintaining 400 °C and.
0024: The substrate holder temperature equal to or smaller than 400 °C is provided with a temperature control means and features. The substrate holder may be mounted on a temperature control means, the temperature of the substrate can be freely and easily controlled, thereby adjusting the reaction rate of zinc acid i spoon can be a thin film. As a result, the supplied oxygen radicals and a zinc atom, zinc atom remaining unreacted be generated due to lattice defects, the density of lattice defects can be controlled.
0025: The apparatus for manufacturing a zinc oxide thin film, doped with doping material was found in a suitable means. Thin film zinc acid i when the spoon impurity, for example aluminum, gallium, indium, chlorine and the like to further reduce the electrical resistivity by doping can be
0026: The cell Z or oxygen plasma and the zinc crucible is heated, the oxygen plasma cell or the zinc from the crucible to the substrate of a radiation to control the effects of the radiation plate is preferred.
The cell is oxygen plasma, the ring-shaped electrodes of the capacitive coupling type is preferred. Using the ring-shaped electrode in a capacitive-coupled, plasma ICP (Inductive coupling plasma) than can be generated easily. Also, for example, oxygen plasma outside of a cell may be provided with a ring-shaped electrode, the generation of the plasma intensity adjustment, and it is preferable that the maintenance becomes easy.
The effect of the invention
0027: According to the present invention, a flexible plastic or the like and the surface of the transparent substrate, the impurity doping is not an essential requirement for the high transmittance is regrettable a high conductivity can be formed as a thin film zinc i arsenate acid. In addition, without using a complicated device, a zinc oxide thin film at a high speed can be formed.
A brief description of the drawings
0028: [Fig. 1] a zinc oxide thin film manufacturing apparatus of the present invention shown in overall configuration.
[Fig. 2] is a detailed view of the cell oxygen plasma
[Fig. 3] the film forming chamber with respect to the details of the thin-film production apparatus i acid zinc spoon of the present invention.
[Fig. 4] Example 1 trial is an external view of the cell the oxygen plasma.
[Fig. 5] a ring-shaped to change the distance between the discharge electrodes when the potential distribution of a simulation of the situation of the present invention.
[Fig. 6] oxygen plasma discharge electrode of a capacitively coupled type high-frequency power to the cell (13.56MHz, + 500V to the upper electrode, lower electrode - 500V) is supplied to the emission spectrum of the plasma generated is a graph showing the characteristics.
[Fig. 7] is widely used as a transparent substrate film onto a glass substrate with a thin film of zinc acid-spoon i ' is a view showing the property.
[Fig. 8] the film forming temperature and resistivity, and is a view showing the relationship between the carrier density.
[Fig. 9] the vertical axis indicates the resistivity, carrier density, X-ray excited photoelectron spectroscopy was measured with the oxygen and an!/, A!/, The number of zinc atoms are bound to each other and the relationship between the (pitch names of a non-unit) is a view showing.
[Fig. 10] PET (polyethylene terephthalate) film on the substrate i indicated in the characteristic of the zinc acid and the spoon of the present invention.
[Fig. 11] PC (polycarbonate) film on a substrate of the thin film of zinc acid spoon characteristics i shaded and unshaded.
[Fig. 12] PVC (polyvinyl chloride) film on a substrate of a zinc oxide thin film in the characteristics.
[Fig. 13] PP (polypropylene) film on the substrate and the characteristic of the zinc acid i spoon of the present invention shown in
[Fig. 14] is formed and doped with gallium zinc/zinc gallium acid i spoon and the supply ratio of the thin film-resistance rate is a graph illustrating the relationship between the.
[Fig. 15] the carrier density of the gallium and the supply ratio of the zinc such as Z is a graph showing the relationship of the present invention.
[Fig. 16] a polyethylene terephthalate (PET) and glass, polycarbonate (PC) for use as a substrate, the temperature of the substrate and the low-temperature (90 °C), and gallium dopant are formed in the thin film of zinc/gallium acid i dumbbell spoon the supply ratio of the resistivity and the like is a graph illustrating the relationship.
1 Zinc oxide film forming apparatus
1A Base material of the film forming chamber
10 Substrate holder
11 Oxygen plasma cell
12 Zinc crucible
13 Dopant crucible
14 Elevator mechanism base 15 cooling mechanism
16 Substrate-rotating mechanism
111 Quartz tube
112 Ring-shaped discharge electrode
|Scope of claims||
 真空に減圧された成膜室内に配置された基材表面で酸素ラジカルと亜鉛原子とを反 応させて酸化亜鉛薄膜を製造する方法にお！ヽて、酸ィ匕亜鉛薄膜の原子配列の欠陥 たる結晶欠陥密度を少なくとも前記基材の温度により制御し、成膜することを特徴と する酸化亜鉛薄膜の製造方法。
 真空に減圧された成膜室内に配置された基材表面で酸素ラジカルと亜鉛原子とを反 応させて酸化亜鉛薄膜を製造する方法にお!ヽて、前記酸素ラジカル及び Z又は前 記亜鉛原子の基材表面への供給量を制御し、酸化亜鉛薄膜の原子配列の欠陥たる 結晶欠陥密度を制御し、成膜することを特徴とする酸化亜鉛薄膜の製造方法。
 前記基材表面で酸素ラジカルと亜鉛原子とを反応させて酸化亜鉛薄膜を成膜する 際に、前記基材表面にドーパントを供給し酸ィ匕亜鉛薄膜を成膜することを特徴とする 請求項 1又は 2に記載の酸化亜鉛薄膜の製造方法。
 酸ィ匕亜鉛薄膜中のドーパントと亜鉛原子との比率力 ^対 10～1対 1000の範囲となるよ うに前記ドーパントの供給量を制御することを特徴とする請求項 3に記載の酸ィ匕亜鉛 薄膜の製造方法。
 結晶欠陥密度を 1 X 1018個/ cm3から 5 X 1021個/ cm3の範囲で制御することを特徴とす る請求項 1又は 2に記載の酸化亜鉛薄膜の製造方法。
 前記基材の温度を 400°C以下に保持し成膜することを特徴とする請求項 1から 5のい ずれかに記載の酸化亜鉛薄膜の製造方法。
 酸素ラジカル発生源及び Z又は亜鉛原子発生源と基材との距離を調節することによ り基材の温度を 400°C以下に制御することを特徴とする請求項 6に記載の酸ィヒ亜鉛 薄膜の成膜方法。
 酸素ラジカル発生源及び Z又は亜鉛原子発生源と基材との距離は、酸素ラジカル および Z又は亜鉛原子の平均自由行程以下であり、かつ酸素ラジカル発生源及び 亜鉛原子発生源からの輻射熱による影響を所望の温度以下に保持可能な距離であ ることを特徴とする請求項 7に記載の酸化亜鉛薄膜の製造方法。
 前記基材はプラスチック等のフレキシブル基材であることを特徴とする請求項 1から 8 の!、ずれかに記載の酸化亜鉛薄膜の製造方法。
 前記フレキシブル基材がポリエチレンテレフタレート（PET)、ポリカーボネート (PC)、 ポリビニルクロライト（PVC)、ポリプロピレン (PP)の、ずれかであることを特徴とする請 求項 9に記載の酸化亜鉛薄膜の製造方法。
 請求項 1から 10のいずれかに記載の方法により製造した酸ィ匕亜鉛薄膜を含む電極。
 請求項 1から 10のいずれかに記載の方法により製造した酸ィ匕亜鉛薄膜を含む電子 ディスプレイ素子用、電子工学素子用、タツチパネル素子用、又は太陽電池素子用 基板フィルム、フレキシブルシート、有機又は無機 ELディスプレイ、液晶ディスプレイ
 請求項 1から 10のいずれかに記載の方法により製造した酸ィ匕亜鉛薄膜を含む電磁 波シールド材、又は赤外線遮断シート。
 成膜後の熱処理プロセスで修復される結晶欠陥密度を加味して成膜の際の結晶 欠陥密度を制御することを特徴とする請求項 1又は 2に記載の酸ィヒ亜鉛薄膜の製造 方法。
 真空に減圧された成膜室と、該成膜室内に配置され酸素ラジカルを噴出する微細な 孔を備えた酸素プラズマセルと、前記成膜室内に配置され蒸気の亜鉛原子を生成 する亜鉛るつぼと、前記成膜室内に配置され前記酸素ラジカルと前記亜鉛原子との 反応により表面に酸化亜鉛薄膜が形成される基材を保持する基材ホルダーとを備え た酸化亜鉛薄膜製造装置にお!ヽて、
前記基材と酸素ラジカル発生源及び Z又は亜鉛原子発生源との距離を酸素ラジカ ルおよび Z又は亜鉛原子の平均自由行程以下とし、かつ酸素ラジカル発生源及び Z又は亜鉛原子発生源からの輻射熱による影響を 400°C以下に保持可能な手段を 備えたことを特徴とする酸化亜鉛薄膜製造装置。
 前記基材を 400°C以下に制御可能な基材温度制御手段を更に備えたことを特徴とす る請求項 15に記載の酸ィ匕亜鉛薄膜製造装置。
 ドーパントをドープする手段を更に備えたことを特徴とする請求項 15又は 16に記載 の酸化亜鉛薄膜製造装置。
 前記酸素プラズマセル及び Z又は前記亜鉛るつぼは、該酸素プラズマセル又は該 亜鉛るつぼからの輻射熱の前記基材への影響を制御するための温度制御板を備え
たことを特徴とする請求項 15から 17のいずれかに記載の酸ィ匕亜鉛薄膜製造装置。 前記酸素プラズマセルは、容量結合型のリング状電極を備えたことを特徴とする請求 項 15から請求項 18のいずれかに記載の酸ィ匕亜鉛薄膜製造装置。
|IPC(International Patent Classification)||
National States: AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KM KN KP KR KZ LC LK LR LS LT LU LV LY MA MD MG MK MN MW MX MZ NA NG NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW
ARIPO: BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW
EAPO: AM AZ BY KG KZ MD RU TJ TM
EPO: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU LV MC NL PL PT RO SE SI SK TR
OAPI: BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG
Contact Information for " PROCESS FOR PRODUCING ZINC OXIDE THIN-FILM AND PRODUCTION APPARATUS "
- Yamanashi Industrial Technology Center (In Japanese)企画連携推進部
- URL: http://www.pref.yamanashi.jp/yitc/
- Address: 2094, Ootsu, Kofu, Yamanashi, Japan , 400-0055
- Phone: 81-55-243-6111
- Fax: 81-55-243-6110