WO2011061922A1

WO2011061922A1 - Manufacturing method and device for transparent conductive film, sputtering target and transparent conductive film

Info

Publication number: WO2011061922A1
Application number: PCT/JP2010/006713
Authority: WO
Inventors: 富之湯川; 応樹武井; 大士小林; 泰彦赤松; 淳也清田; 健二増澤; 暁石橋
Original assignee: 株式会社アルバック
Priority date: 2009-11-19
Filing date: 2010-11-16
Publication date: 2011-05-26
Also published as: JP6060202B2; CN102666909A; CN102666909B; CN104213085A; KR20180063386A; KR20120070597A; TW201538764A; JP2015158014A; KR20170005149A; JPWO2011061922A1; TWI620827B; JP5726752B2; TWI500786B; TW201124546A; KR20140071502A

Abstract

Disclosed is a transparent conductive film manufacturing method which enables the formation of a transparent conductive film having excellent etching properties and conductivity, without using water vapour. The disclosed manufacturing method for a transparent conductive film comprises a step wherein an indium tin oxide thin film is formed on a substrate by sputtering a target material containing a first component which is formed from indium oxide, a second component which is formed from tin oxide, and a third component which is formed from at least one element, or the oxide thereof, selected from among La, Nd, Dy, Eu, Gd, Tb, Zr, Al, Si, Ti, and B. The method further comprises a step wherein the indium tin oxide thin film is patterned using an etching solution, and a step wherein the indium tin oxide thin film is crystalised by means of heat treatment. Due to the above method the ITO film can be etched by a weak acid immediately after film formation and a desired conductivity can be imparted to the ITO film.

Description

Transparent conductive film manufacturing method, transparent conductive film manufacturing apparatus, sputtering target, and transparent conductive film

The present invention relates to a method for producing a transparent conductive film excellent in etching characteristics, conductive characteristics, etc., a transparent conductive film production apparatus, a sputtering target, and a transparent conductive film.

In the field of manufacturing flat panel displays and solar power generation modules, ITO (Indium Tin Oxide) films mainly composed of indium oxide and tin oxide are widely used as transparent conductive films. The ITO film is formed by a vacuum deposition method, a sputtering method, or the like, and a sputtering target made of ITO is often used in the sputtering method.

Since the ITO film formed at room temperature is in a state where both crystalline and amorphous are mixed, it is difficult to obtain desired conductive characteristics. On the other hand, an ITO film formed at a temperature of 200 ° C. or higher has a high conductive property because it is in a crystalline state. However, the crystallized ITO film has low solubility in a weak acid such as oxalic acid, and it is necessary to use a strong acid such as hydrochloric acid or sulfuric acid as an etching solution. For this reason, it is difficult to ensure a high etching selectivity between the ITO film and its underlying film or other wiring layers.

Therefore, there is known a method for producing a low-resistance ITO film by forming an amorphous ITO film by mixing water vapor into a sputtering gas such as argon and then crystallizing the ITO film by annealing. (See Patent Document 1). According to this method, since etching with a weak acid is possible in a state where the film is formed (as-deposition state), good etching characteristics can be obtained.

JP 2008-179850 A (paragraphs [0023] to [0026])

However, in the method for forming an ITO film described in Patent Document 1, the film adhering to the non-erosion region of the deposition prevention plate or the target is easily peeled off due to the influence of the introduced water vapor, which causes generation of particles. There is a problem. In addition, the introduction of water vapor may hinder the stable exhaust action of the film formation chamber.

In view of the circumstances as described above, an object of the present invention is to provide a method for producing a transparent conductive film, which can form a transparent conductive film having good etching characteristics and conductive characteristics without using water vapor. is there.

Also, an object of the present invention is to provide a transparent conductive film manufacturing apparatus and a sputtering target capable of forming a transparent conductive film having good etching characteristics and conductive characteristics without using water vapor.

In order to achieve the above object, a method for producing a transparent conductive film according to an embodiment of the present invention includes a first component made of indium oxide, a second component made of tin oxide, lanthanum, neodymium, dysprosium, europium, Placing the substrate in a chamber having a target material comprising a third component comprising at least one element selected from gadolinium, terbium, zirconium, aluminum, silicon, titanium, and boron or an oxide thereof. . By sputtering the target material, an indium tin oxide thin film is formed on the substrate.

In order to achieve the above object, a transparent conductive film manufacturing apparatus according to an embodiment of the present invention includes a chamber, a support portion, and a film formation portion.
The chamber is configured to be able to maintain a vacuum state.
The support is for supporting a substrate in the chamber.
The film forming unit includes a first component made of indium oxide, a second component made of tin oxide, and lanthanum, neodymium, dysprosium, europium, gadolinium, terbium, zirconium, aluminum, silicon, titanium, and boron. A target material including at least one selected element or a third component made of an oxide thereof. The film forming unit forms the indium tin oxide thin film on the substrate supported by the support unit by sputtering the target material in the chamber.

To achieve the above object, a sputtering target according to an embodiment of the present invention is a sputtering target for forming a transparent conductive film on a substrate by a sputtering method, and includes a first component, a second component, And a third component.
The first component is made of indium oxide.
The second component is made of tin oxide.
The third component is composed of at least one element selected from lanthanum, neodymium, dysprosium, europium, gadolinium, terbium, zirconium, aluminum, silicon, titanium, and boron, or an oxide thereof.

In order to achieve the above object, a transparent conductive film according to one embodiment of the present invention is a transparent conductive film formed over a substrate by a sputtering method, and includes a first component, a second component, and a first component. 3 ingredients.
The first component is made of indium oxide.
The second component is made of tin oxide.
The third component is composed of at least one element selected from lanthanum, neodymium, dysprosium, europium, gadolinium, terbium, zirconium, aluminum, silicon, titanium, and boron, or an oxide thereof.

It is the schematic which shows the manufacturing apparatus of the transparent conductive film which concerns on one Embodiment of this invention. It is a process flow explaining the manufacturing method of the transparent conductive film which concerns on one Embodiment of this invention. The X-ray diffraction intensity distribution of the ITO film which concerns on the Example and comparative example of this invention is shown, (A) is a measurement result about the ITO film immediately after film-forming, (B) is about the ITO film after annealing It is a measurement result. The relationship between the specific resistance and oxygen partial pressure of the ITO film | membrane which concerns on the Example and comparative example of this invention is shown, (A) is a measurement result about the ITO film | membrane immediately after film-forming, (B) is after annealing It is a measurement result about this ITO film | membrane. It is an experimental result which shows the relationship between the etching rate of the ITO film | membrane and oxygen partial pressure which concern on the Example and comparative example of this invention. It is an experimental result which shows the visible light transmittance | permeability of the ITO film | membrane which concerns on the Example and comparative example of this invention.

A method for producing a transparent conductive film according to an embodiment of the present invention includes a first component made of indium oxide, a second component made of tin oxide, lanthanum, neodymium, dysprosium, europium, gadolinium, terbium, zirconium, and aluminum. And disposing a substrate in a chamber having a target material including at least one element selected from silicon, titanium, and boron or a third component made of an oxide thereof. By sputtering the target material, an indium tin oxide thin film is formed on the substrate.

According to the method for producing a transparent conductive film, an amorphous indium tin oxide thin film (hereinafter also referred to as “ITO film”) can be formed as it is. Therefore, when the ITO film is patterned by etching, a weakly acidic etching solution such as oxalic acid can be used. In addition, it becomes easy to ensure a high etching selectivity between the base film and other wiring layers, so that good etching characteristics can be obtained.
Furthermore, by crystallization of the ITO film by heat treatment (annealing), good conductive properties can be imparted. Since the heat-treated ITO film has good transmittance characteristics in the visible light region, it can be suitably used as a transparent conductive film for flat panel displays, solar power generation modules and the like.

The substrate on which the ITO film is formed is typically a glass substrate, but may also be a silicon substrate or a ceramic substrate. Further, an organic substrate can be used as long as it has heat resistance with respect to the heat treatment temperature.

The third component is an element group capable of forming an ITO film soluble in a weak acid. In particular, by using dysprosium (Dy) or an oxide thereof as the third component, an ITO film having a specific resistance of 300 μΩ · cm or less and excellent conductive properties can be obtained.

The gas for sputtering the target material can be a mixed gas of argon and oxygen. Argon primarily generates ions that sputter the target material. Oxygen functions as a reactive gas and adjusts the oxygen concentration of the deposited ITO film. By appropriately adjusting the oxygen partial pressure, an ITO film having desired conductive characteristics and etching characteristics can be formed.

The heat treatment temperature (annealing temperature) for crystallizing the ITO film can be 200 ° C. or higher. When the heat treatment temperature is lower than 200 ° C., amorphous and crystal may be mixed in the ITO film. The upper limit of the heat treatment temperature is not particularly limited, and is appropriately set according to the heat resistance of the substrate on which the ITO film is formed.

Meanwhile, a transparent conductive film manufacturing apparatus according to an embodiment of the present invention includes a chamber, a support part, and a film forming part.
The chamber is configured to be able to maintain a vacuum state.
The support is for supporting a substrate in the chamber.
The film forming unit includes a first component made of indium oxide, a second component made of tin oxide, and La, Nd, Dy, Eu, Gd, Tb, Zr, Al, Si, Ti, and B. A target material including at least one selected element or a third component made of an oxide thereof. The film forming unit forms the indium tin oxide thin film on the substrate supported by the support unit by sputtering the target material in the chamber.

A sputtering target according to an embodiment of the present invention is a sputtering target for forming a transparent conductive film on a substrate by a sputtering method, and includes a first component, a second component, and a third component. And ingredients.
The first component is made of indium oxide.
The second component is made of tin oxide.
The third component is composed of at least one element selected from La, Nd, Dy, Eu, Gd, Tb, Zr, Al, Si, Ti, and B or an oxide thereof.

According to the transparent conductive film manufacturing apparatus, an amorphous ITO film can be formed on a substrate by sputtering the target material (sputtering target) having the above structure. Therefore, when the ITO film is patterned by etching, a weakly acidic etching solution such as oxalic acid can be used. In addition, it becomes easy to ensure a high etching selectivity between the base film and other wiring layers, so that good etching characteristics can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Sputtering equipment]
FIG. 1 is a schematic view showing a transparent conductive film manufacturing apparatus according to an embodiment of the present invention. The illustrated apparatus is configured as a sputtering apparatus 100 for forming a transparent conductive film. The sputtering apparatus 100 connects a film forming chamber 101 for forming a transparent conductive film (ITO film) F on the surface of the substrate S, a load / unload chamber 102, and the film forming chamber 101 and the load / unload chamber 102. And a gate valve 103.

The film forming chamber 101 includes a first chamber 11 having a sealed structure and an evacuation system 30 that can evacuate the inside of the first chamber 11. The film forming chamber 101 can be evacuated to a predetermined film forming pressure and can maintain the degree of vacuum. The vacuum exhaust system 30 includes a main pump (turbo molecular pump) 31 and an auxiliary pump (rotary pump) 32 that exhausts the back pressure side.

The film formation chamber 101 has a sputtering cathode 20. The sputtering cathode 20 includes a sputtering target (hereinafter simply referred to as “target”) 21, a magnet unit 22 for forming a magnetic field on the surface of the target 21, and the target 21 and the substrate S (and the first chamber 11). And a DC power source (not shown) for applying a DC voltage therebetween. As will be described later, the target 21 is made of an indium tin oxide-based material. The sputtering cathode 20 is installed on the bottom wall portion of the first chamber 11 as a DC magnetron type sputtering cathode.

The film forming chamber 101 includes a gas introduction unit 40 for introducing a process gas (sputtering gas) for sputtering into the first chamber 11. The gas introduction unit 40 constitutes a gas introduction system together with a gas supply source, a flow rate adjustment valve, and the like (not shown). In the present embodiment, the gas introduction unit 40 introduces a mixed gas of argon (Ar) and oxygen (O ₂ ) into the first chamber 11. The partial pressure of oxygen in the mixed gas atmosphere is, for example, 2.0E-3 (2.0 × 10 ⁻³ ) Pa or more and 1.0E-2 (1.0 × 10 ⁻² ) Pa or less.

The film formation chamber 101 may have a deposition plate for preventing the film formation material from adhering to the inner wall of the first chamber 11 and other structures. By installing a deposition plate in the deposition chamber 101, contamination by the deposition material in the first chamber 11 can be suppressed, and maintenance workability of the deposition chamber 101 can be improved.

The load / unload chamber 102 includes a second chamber 12 having a sealed structure, and a vacuum pump 33 capable of evacuating the inside of the second chamber 12. The load / unload chamber 102 can be evacuated to a degree of vacuum comparable to the pressure in the film forming chamber 101, and can be maintained at that degree of vacuum. The load / unload chamber 102 has a door valve (not shown), and the substrate S can be transferred between the inside and the outside of the second chamber 12 via the door valve. When the substrate S is delivered, the load / unload chamber 102 is at atmospheric pressure.

The sputtering apparatus 100 of this embodiment further includes a carrier 50 that transports the substrate S between the film forming chamber 101 and the load / unload chamber 102 via the gate valve 103. The carrier 50 is linearly moved against a guide rail (not shown) spanned between the film forming chamber 101 and the load / unload chamber 102 by a driving source (not shown). The carrier 50 transported from the load / unload chamber 102 to the film formation chamber 101 is returned to the load / unload chamber 102 after reciprocating in the film formation chamber 101. The substrate S is held on the lower surface of the carrier 50 and is formed in the film forming chamber 101 in the process of passing immediately above the sputtering cathode 20.

Here, a glass substrate is used as the substrate S. The film formation surface of the substrate may be a glass surface that is a base material, or may be the surface of an insulating film already formed on the base material. Further, a metal wiring film such as copper may be present on the surface of the insulating film.

Here, the carrier 50 constitutes a “support portion” that supports the substrate S in the first chamber 11. Further, the sputtering cathode 20 and the gas introduction unit 40 constitute a “film formation unit”. The film forming unit forms the indium tin oxide thin film on the substrate S supported by the carrier 50 by sputtering the target 21 in the first chamber 11. Further, the magnet unit 22, the DC power source and the like constituting the sputtering cathode 20 constitute a “plasma generating mechanism”. The plasma generation mechanism generates ions for sputtering the target 21 by generating plasma of a sputtering gas (mixed gas of Ar and O ₂ ) introduced into the first chamber 11 from the gas introduction unit 40. .

[target]
Next, details of the target 21 will be described.

The target 21 is configured as a target material or a sputtering target for forming the transparent conductive film F on the substrate S by sputtering. The target 21 is a disc-like or rectangular plate-like sintered body made of an indium tin oxide (hereinafter also referred to as “ITO”) material, and the sintering density thereof is, for example, 98% or more. The

The target 21 according to the present embodiment includes a first component made of indium oxide (In ₂ O ₃ ), a second component made of tin oxide (SnO), and a third component as an additive. The third component is lanthanum (La), neodymium (Nd), dysprosium (Dy), europium (Eu), gadolinium (Gd), terbium (Tb), zirconium (Zr), aluminum (Al), silicon (Si) , At least one element selected from titanium (Ti) and boron (B) or an oxide thereof. The third component is soluble in acid, and enables amorphous ITO to be formed immediately after film formation.

The target 21 having the above structure is sputtered in the film forming chamber 101 to form the ITO film F containing the first, second, and third components on the substrate S. Therefore, the composition of the target 21 is appropriately adjusted according to the composition of the ITO film F to be formed. The oxygen concentration of the ITO film F may be adjusted by the oxygen partial pressure in the film formation chamber 101 during film formation.

A typical weight ratio of indium oxide (first component) to tin oxide (second component) is 9: 1, but is adjusted in the range of 97.5: 2.5 to 85:15, for example. . Moreover, the addition amount of the additive (third component) is represented by the following formula (1), where α is the additive element.
0.1 ≦ {α / (In + Sn + α)} ≦ 10 [atomic%] (1)
When the additive element is an oxide, when the oxide is αOx, the addition amount is expressed by the following equation (2).
0.06 ≦ {αOx / (In ₂ O ₃ + SnO) + αOx} ≦ 6 [atomic%] (2)

When the amount of the third component added is less than 0.1 atomic%, it is difficult to stably form an amorphous ITO film. In other words, an ITO film in which crystalline and amorphous are mixed may be formed. On the other hand, when the added amount of the third component exceeds 10 atomic%, it becomes difficult to obtain desired characteristics with respect to the conductive characteristics and light transmittance of the obtained ITO film. The addition amount of the third component varies depending on the type of element used, but is selected within the above range.

By using the target 21 configured as described above, an amorphous indium tin oxide thin film (ITO film) F can be formed on the substrate S. Since the ITO film F immediately after film formation is in an amorphous state, a weak acidic etching solution such as oxalic acid or acetic acid can be used when patterning the ITO film F. In addition, after patterning, the ITO film F is crystallized by annealing (heat treatment), whereby an ITO film F having a low specific resistance and excellent conductive characteristics can be obtained.

[Method for producing transparent conductive film]
Next, the manufacturing method of the transparent conductive film which concerns on this embodiment is demonstrated. FIG. 2 shows the process flow. The method for producing a transparent conductive film of the present embodiment includes an ITO film F film forming process (step ST1), an ITO film F patterning process (step ST2), and an ITO film F annealing process (step ST3). .

(Film formation process)
In the film forming process (step ST1) of the ITO film F, the sputtering apparatus 100 shown in FIG. 1 is used. With reference to FIG. 1, the substrate S carried into the load / unload chamber 102 is held on the lower surface of the carrier 50. Thereafter, the vacuum pump 33 is driven to evacuate the load / unload chamber 102. When the pressure in the load / unload chamber 102 becomes approximately the same as the pressure in the film formation chamber 101 (for example, 0.67 Pa), the gate valve 103 is opened and the carrier 50 is transferred into the film formation chamber 101. After the carrier 50 is transferred from the load / unload chamber 102 to the film formation chamber 101, the gate valve 103 is closed. The carrier 50 transported to the film forming chamber 101 is moved linearly in the film forming chamber 101. The substrate S is formed by the sputtering cathode 20 while being moved together with the carrier 50.

A sputtering gas (Ar + O ₂ ) is introduced into the film formation chamber 101 from the gas introduction unit 40 at a predetermined flow rate. The introduced sputtering gas is excited by a DC electric field applied between the target 21 and the carrier 50 and a fixed magnetic field formed on the surface of the target 21 by the magnet unit 22, thereby generating a sputtering gas plasma. To do. Ions (particularly Ar ions) in the plasma are attracted to the sputtering cathode 20 under the action of an electric field, and the surface of the target 21 is sputtered. The ITO particles that have been sputtered from the surface of the target 21 due to the sputtering effect of ions adhere to and deposit on the surface of the substrate S facing the target 21, thereby forming an ITO film F on the surface of the substrate S. Moreover, oxygen contained in the sputtering gas generates highly active oxygen radicals, and the generated oxygen radicals react with ITO particles knocked out from the surface of the target 21. Therefore, the oxygen concentration of the ITO film F formed on the substrate S is controlled by the amount of oxygen in the sputtering gas.

In the present embodiment, a so-called passing film formation method is employed in which film formation is performed while passing the substrate S above the target 21. In the present embodiment, the substrate S is formed on the forward path of the carrier 50 that reciprocates in the film forming chamber 101, but is not limited thereto, and may be formed on the return path of the carrier 50, or the forward path and the return path. Both may be formed into a film. In addition, the substrate S is transported through the film formation chamber 101 without heating (room temperature). However, if necessary, a heating source may be incorporated in the sputtering apparatus 100 to heat the substrate to a predetermined temperature during film formation.

The substrate S on which the ITO film F is formed is transferred to the load / unload chamber 102 through the gate valve 103 together with the carrier 50. Thereafter, the gate valve 103 is closed, the load / unload chamber 102 is opened to the atmosphere, and the film-formed substrate S is taken out through a door valve (not shown). As described above, the amorphous ITO film F is formed on the surface of the substrate S.

(Patterning process)
In the patterning step (step ST2), the ITO film F is patterned into a predetermined shape by a wet etching method. Prior to this, a resist mask is formed on the ITO film F. In the etching step, the ITO film F exposed from the opening of the resist mask is dissolved by applying an etching solution on the surface of the substrate S from above the resist mask. Then, the patterning process of the ITO film | membrane F is completed through the washing | cleaning and drying process of the board | substrate S. FIG.

According to this embodiment, since the ITO film F manufactured by the sputtering apparatus 100 is in an amorphous state, in the patterning process of the ITO film F, an etching solution containing weakly acidic oxalic acid (for example, oxalic acid or The ITO film F can be etched using a chemical solution (ITO-05N, ITO-06N, ITO-07N) (trade name) manufactured by Kanto Chemical. As a result, it becomes easy to ensure a high etching selection ratio between the underlayer of the ITO film F, the metal wiring layer, and the like, so that good etching characteristics can be obtained. Further, it has been confirmed that the generation of etching residues during patterning of the ITO film F can be suppressed.

The patterning shape of the ITO film F differs depending on the type of device to be manufactured. For example, when an ITO film is used as a pixel electrode for a liquid crystal display, the ITO film F is patterned on a pixel basis. When the ITO film is used for a solar power generation module, the ITO film F is patterned in units of individual power generation cells.

(Annealing process)
In the annealing process (step ST3), the ITO film F is crystallized by annealing (heat treatment) the patterned ITO film F. The purpose of crystallization of the ITO film F is to reduce the specific resistance of the ITO film F and improve the conductive characteristics.

In the annealing process of the ITO film F, a heat treatment furnace is typically used. The annealing conditions can be set as appropriate, and can be set to 200 ° C. or higher in the atmosphere, for example. When the annealing temperature is less than 200 ° C., the ITO film F may be mixed with crystals and amorphous. The upper limit of the annealing temperature is not particularly limited, and is appropriately determined depending on the heat resistance of the substrate S, ITO film F, or other functional thin film (insulating film, metal film) other than the ITO film F formed on the substrate S. Is set. The annealing atmosphere is not limited to air, and may be a nitrogen atmosphere, for example. The annealing time is set according to the annealing temperature. Typically, the annealing time is set shorter as the annealing temperature becomes higher.

As described above, the transparent conductive film (ITO film F) according to this embodiment is manufactured. The transparent conductive film of this embodiment includes a first component made of indium oxide, a second component made of tin oxide, La, Nd, Dy, Eu, Gd, Tb, Zr, Al, Si, Ti, and B. And a third component comprising at least one element selected from the group consisting of oxides thereof.

According to the method for producing a transparent conductive film of the present embodiment, the amorphous ITO film F can be formed as it is. In particular, according to this embodiment, an amorphous ITO film can be manufactured without adding water vapor to the sputtering gas. Therefore, adverse effects associated with the addition of water vapor to the sputtering gas, for example, generation of particles due to easy peeling of the ITO film attached to the deposition preventing plate, and the stable exhausting action of the film forming chamber 101 are hindered. It is possible to prevent variations in sputtering pressure due to the above.

Further, according to the present embodiment, it is possible to use a weakly acidic etching solution such as oxalic acid when patterning the formed ITO film F by etching. As a result, it becomes easy to ensure a high etching selection ratio between the base film and other wiring layers, so that good etching characteristics can be obtained.

Furthermore, according to this embodiment, since the ITO film F is crystallized by heat treatment (annealing), the ITO film F having good conductive characteristics can be manufactured. Since the ITO film F manufactured in this way has good transmittance characteristics in the visible light region, it can be suitably used as a transparent conductive film for flat panel displays, solar power generation modules and the like.

Example 1
A sputtering target (hereinafter also referred to as “Dy-added ITO target”) in which 1.5 atomic% of dysprosium oxide was added to indium tin oxide was produced. Using this Dy-added ITO target, an ITO film having a thickness of 1000 mm (hereinafter also referred to as “Dy-added ITO film”) was formed on the substrate by the sputtering apparatus shown in FIG. The film forming conditions are as follows: DC power 600 W (1.16 W / cm ² ), distance between target and substrate (T / S distance) 100 mm, magnetic unit magnetic field size 300 G, film forming rate (dynamic rate) 70 mm. · M / min. As a sputtering gas, a mixed gas of argon and oxygen was used, and a plurality of ITO film samples were formed with different oxygen partial pressures. Here, the partial pressure of argon is 0.67 Pa (200 sccm), the partial pressure of oxygen is 0 Pa, 1.33 × 10 ⁻³ Pa, 2.66 × 10 ⁻³ Pa, 5.32 × 10 ⁻³ Pa, 7.98. × 10 ⁻³ Pa and 1.06 × 10 ⁻² Pa were set.

The X-ray diffraction intensity of the ITO film sample produced at an oxygen partial pressure of 5.32 × 10 ⁻³ Pa was measured. As a measuring device, “Rinto (trade name)” manufactured by Rigaku Corporation was used. Next, the etching rate of each produced ITO film sample was measured. As the etching solution, a chemical solution containing oxalic acid (“ITO-06N” (trade name) manufactured by Kanto Chemical Co., Inc.) was used. Subsequently, each ITO film sample was annealed in the atmosphere at 230 ° C. for 1 hour. The X-ray diffraction intensity, specific resistance, and visible light (wavelength: 400 nm to 800 nm) transmittance of each ITO film sample after annealing were measured. For the measurement of specific resistance, “Loresta MCP-T350 (trade name)” manufactured by Mitsubishi Chemical Corporation was used. For the measurement of the X-ray diffraction intensity and the visible light transmittance, ITO film samples prepared at an oxygen partial pressure of 5.32 × 10 ⁻³ Pa were used. For measurement of visible light transmittance, “U-4100” manufactured by Hitachi, Ltd. was used.

(Example 2)
A sputtering target obtained by adding 1 atomic% of boron oxide to indium tin oxide (hereinafter also referred to as “B-added ITO target”) was produced. Using this B-added ITO target, an ITO film (hereinafter also referred to as “B-added ITO film”) was formed under the same conditions as in Example 1. With respect to the formed B-added ITO film, the etching rate, specific resistance, light transmittance, and X-ray diffraction intensity before and after annealing were measured under the same conditions as in Example 1.

(Comparative Example 1)
A sputtering target in which 5 atomic% of cerium oxide was added to indium tin oxide (hereinafter referred to as “Ce-added ITO target”) was produced. An ITO film (hereinafter also referred to as “Ce-added ITO film”) was formed under the same conditions as in Example 1 using this Ce-added ITO target. With respect to the formed Ce-added ITO film, the etching rate, specific resistance, light transmittance, and X-ray diffraction intensity before and after annealing were measured under the same conditions as in Example 1.

(Comparative Example 2)
An ITO target containing indium oxide and tin oxide is sputtered in a sputtering gas containing argon, oxygen and water vapor to form an ITO film (hereinafter also referred to as “H ₂ O-added ITO film”) on the substrate. A film was formed. The film formation conditions were the same as in Example 1, and the sputtering pressure was formed by changing the oxygen partial pressure to form a plurality of ITO films. Here, the argon partial pressure is 0.67 Pa, the water vapor partial pressure is 2.66 × 10 ⁻³ Pa, the oxygen partial pressure is 0 Pa, 1.33 × 10 ⁻³ Pa, 2.66 × 10 ⁻³ Pa, 5 .32 × 10 ⁻³ Pa. With respect to the formed H ₂ O-added ITO film, the etching rate, specific resistance, light transmittance, and X-ray diffraction intensity before and after annealing were measured under the same conditions as in Example 1. For the measurement of the visible light transmittance, an ITO film sample produced at an oxygen partial pressure of 1.33 × 10 ⁻³ Pa was used.

The X-ray diffraction intensities before annealing of the Dy-added ITO film, B-added ITO film, Ce-added ITO film and H ₂ O-added ITO film are shown in FIG. 3A, and the X-ray diffraction intensities after annealing are shown in FIG. B) respectively. As shown in FIG. 3A, a halo pattern indicating an amorphous state was recognized in the X-ray diffraction pattern of the ITO film before annealing, that is, the ITO film immediately after the film formation. In addition, as shown in FIG. 3B, an intensity peak was observed at the diffraction angle inherent to the ITO crystal, and this confirmed that the annealed ITO film was in a crystalline state.

Next, FIGS. 4A and 4B are experimental results showing the specific resistance of each ITO film sample before and after annealing. FIG. 4A shows the state before annealing, and FIG. Each after annealing is shown. Regarding each plot in the figure, “♦” indicates an H ₂ O-added ITO film, “■” indicates a Ce-added ITO film, “▲” indicates a Dy-added ITO film, and “●” indicates a B-added ITO film. (The same applies to FIG. 5).

For any of the Dy-added ITO film, the B-added ITO film, and the Ce-added ITO film, it was confirmed that the specific resistance after annealing can be lower than that before annealing. This is because the specific resistance is lower in the crystalline state than in the amorphous state. The specific resistance after annealing is the minimum for any ITO film sample when the oxygen partial pressure is 5.32 × 10 ⁻³ Pa. About Dy-added ITO film and Ce-added ITO film are about 300 μΩcm, and B is added. The ITO film was about 400 μΩcm.

On the other hand, regarding the H ₂ O-added ITO film, it was confirmed that the minimum value of specific resistance (about 300 μΩcm) can be obtained by the annealing process when the oxygen partial pressure is 1.33 × 10 ⁻³ Pa. That is, it was confirmed that the specific resistances of the Dy-added ITO film and the Ce-added ITO film have values comparable to the specific resistance of the H ₂ O-added ITO film.

Next, FIG. 5 is an experimental result showing the etching rate of each amorphous ITO film sample. It was confirmed that the Dy-added ITO film has an etching rate equivalent to that of the H ₂ O-added ITO film. It was confirmed that the etching rate of the B-added ITO film was higher than the etching rate of the H ₂ O-added ITO film. On the other hand, the Ce-added ITO film was confirmed to have a lower etching rate than the H ₂ O-added ITO film. This is presumably because Ce oxide is less soluble in weak acids than Dy oxide and B oxide.

And FIG. 6 is an experimental result which shows the visible light transmittance | permeability of each ITO film | membrane after annealing. It was confirmed that the Dy-added ITO film and the B-added ITO film had a visible light transmittance (90% or more) equivalent to that of the H ₂ O-added ITO film. On the other hand, regarding the Ce-added ITO film, it was confirmed that the decrease in the transmittance in the range of 500 nm to 600 nm was remarkable as compared with other ITO films.

As described above, according to the Dy-added ITO film and the B-added ITO film according to this example, an etching rate, specific resistance, and visible light transmittance equivalent to those of the H ₂ O-added ITO film can be obtained. Further, by using the Dy-added sputtering target or the B-added sputtering target, an ITO film having excellent patterning characteristics, conductive characteristics, and light transmission characteristics can be stably formed.

As mentioned above, although embodiment of this invention was described, of course, this invention is not limited to this, A various deformation | transformation is possible based on the technical idea of this invention.

For example, in the above-described embodiment, the addition amount of Dy in the Dy-added sputtering target is 1.5 atomic% and the addition amount of B in the B-added sputtering target is 1 atomic%, but is not limited thereto. Since the etching rate, specific resistance, visible light transmittance, etc. of the obtained ITO film change depending on the amount of addition of these third components, the amount of addition can be appropriately adjusted according to the required characteristics. is there.

DESCRIPTION OF SYMBOLS 11 ... 1st chamber 12 ... 2nd chamber 20 ... Sputtering cathode 21 ... Sputtering target 22 ... Magnet unit 30 ... Vacuum exhaust system 40 ... Gas introduction part 50 ... Carrier 100 ... Sputtering apparatus 101 ... Film-forming chamber 102 ... Load / Unload chamber 103 ... Gate valve

Claims

A first component made of indium oxide, a second component made of tin oxide, and at least one selected from lanthanum, neodymium, dysprosium, europium, gadolinium, terbium, zirconium, aluminum, silicon, titanium, and boron Placing a substrate in a chamber having a target material comprising a third component comprising an element or oxide thereof;
A method for producing a transparent conductive film, comprising forming an indium tin oxide thin film on a substrate by sputtering the target material.
It is a manufacturing method of the transparent conductive film according to claim 1, and further,
Patterning the indium tin oxide thin film with an etchant;
A method for producing a transparent conductive film, wherein the indium tin oxide thin film is crystallized by heat treatment.
It is a manufacturing method of the transparent conductive film according to claim 2,
The third component is dysprosium or an oxide thereof.
It is a manufacturing method of the transparent conductive film according to claim 2,
The method for producing a transparent conductive film, wherein the third component is boron or an oxide thereof.
It is a manufacturing method of the transparent conductive film according to claim 3 or 4,
The target material is sputtered in a mixed gas atmosphere of argon and oxygen.
It is a manufacturing method of the transparent conductive film according to claim 5,
The method for producing a transparent conductive film, wherein the partial pressure of oxygen in the mixed gas atmosphere is 2.0E-3 Pa or more and 1.0E-2 Pa or less.
It is a manufacturing method of the transparent conductive film according to claim 3 or 4,
The method for producing a transparent conductive film, wherein the heat treatment temperature of the indium tin oxide thin film is 200 ° C. or higher.
It is a manufacturing method of the transparent conductive film according to claim 2,
The said etching liquid is the aqueous solution containing oxalic acid. The manufacturing method of a transparent conductive film.
A chamber capable of maintaining a vacuum state;
A support for supporting the substrate in the chamber;
A first component made of indium oxide, a second component made of tin oxide, and at least one selected from lanthanum, neodymium, dysprosium, europium, gadolinium, terbium, zirconium, aluminum, silicon, titanium, and boron An indium tin oxide thin film is formed on the substrate supported by the support portion by sputtering the target material in the chamber, the target material including a third component made of an element or an oxide thereof. An apparatus for producing a transparent conductive film, comprising: a film forming unit.
It is a manufacturing apparatus of the transparent conductive film according to claim 9,
The film forming unit includes:
A gas introduction system for introducing a process gas containing an oxidizing gas into the chamber;
An apparatus for producing a transparent conductive film, further comprising: a plasma generation mechanism for generating ions for sputtering the target material by generating plasma of the process gas.
A sputtering target for forming a transparent conductive film on a substrate by a sputtering method,
A first component comprising indium oxide;
A second component comprising tin oxide;
A sputtering target comprising a third component comprising at least one element selected from lanthanum, neodymium, dysprosium, europium, gadolinium, terbium, zirconium, aluminum, silicon, titanium, and boron, or an oxide thereof.
The sputtering target according to claim 11,
The third component is at least one element selected from lanthanum, neodymium, dysprosium, europium, gadolinium, terbium, zirconium, aluminum, silicon, titanium, and boron, and the added amount of the third component ( α) is
0.1 ≦ {α / (In + Sn + α)} ≦ 10 [atomic%]
Sputtering target represented by
The sputtering target according to claim 11,
The third component is at least one oxide selected from lanthanum, neodymium, dysprosium, europium, gadolinium, terbium, zirconium, aluminum, silicon, titanium, and boron, and the added amount of the third component (ΑOx) is
0.06 ≦ {αOx / (In 2 O 3 + SnO) + αOx} ≦ 6 [atomic%]
Sputtering target represented by
A transparent conductive film formed on a substrate by a sputtering method,
A first component comprising indium oxide;
A second component comprising tin oxide;
A transparent conductive film comprising a third component comprising at least one element selected from lanthanum, neodymium, dysprosium, europium, gadolinium, terbium, zirconium, aluminum, silicon, titanium, and boron, or an oxide thereof.