WO2003008658A1

WO2003008658A1 - Ito sintered body sputtering target for forming high-resistance film and its manufacturing method

Info

Publication number: WO2003008658A1
Application number: PCT/JP2002/003250
Authority: WO
Inventors: Koichi Nakashima; Yoshikazu Kumahara
Original assignee: Nikko Materials Company, Limited
Priority date: 2001-07-18
Filing date: 2002-04-01
Publication date: 2003-01-30
Also published as: JP2003027223A

Abstract

An ITO sintered body sputtering target characterized by containing 20 to 50 wt% of tin oxide and its manufacturing method. The ITO sintered body sputtering target is useful to form a high-resistance transparent conductive film, especially a transparent conductive film used for determining a position on the screen of, e.g., a resistance-film touch-panel device and having a high surface resistivity of 300 to 1000 Ω/&square;.

Description

High-resistance film formation I TO sintered body sputtering target and method for producing the same

The present invention relates to a high resistance transparent conductive film, and in particular to a surface resistance as high as 300 to 1 000 Ω / well, which is used to determine the screen position of a resistive touch panel device etc.

The present invention relates to an IT sintered body sputtering sample that is useful for forming a transparent conductive film having a percentage, and a method for manufacturing the same. Field

Background art

In recent years, the demand for resistive film-type tanning panels is rapidly increasing. This resistive film type end panel uses two transparent conductive films, applies a bias to both with a certain potential difference, and is configured to specify the position where the switch is pressed by the voltage drop.

In order to pinpoint the position accurately, the voltage drop must be able to be measured accurately. For that purpose, a transparent conductive film having a high surface resistivity of about 300 to 1000 Ω / well is required.

The volume resistivity of an ITO film containing about 5 to 10 wt% of tin oxide, which is conventionally well known, is approximately 0.2 to 0.4πιΩ cm, but such a low volume In order to realize a high surface resistivity of 300 to 1000 Ω in the resistivity film, it is necessary to form an extremely thin film having a thickness of 2 to 13 nm uniformly on the substrate surface. Not very technically difficult.

In addition, in terms of function, it is also required that the properties of bendable panels, such as bending resistance, curling resistance and abrasion resistance (pen slide), are severe.

Furthermore, in order to have a uniform film thickness in the plane of the substrate, in order to obtain a high film resistivity of 200 nm or more and a high surface resistivity of 300 to 1000 Ω, The volume resistivity of the film needs to be 0.6 πιΩ · cm or more, and there is a need for a sputtering jacket for forming such a film. Disclosure of the invention

The present invention solves the above problems, and is used to determine the screen position of a high resistance transparent conductive film, particularly a resistive film type final panel device, etc. A surface resistance as high as about 300 to 1000 Ω. It is an object of the present invention to provide an IT sintered body sputtering target that is useful for forming a transparent conductive film having a ratio, and a method of manufacturing the same.

For example, the film is formed on a material such as a PET substrate, for example, in the case of a portable terminal or the like, which is used, for example, heat, humidity, alkaline corrosion, mechanical deformation such as bending or curl, pen collision Although it is necessary to withstand various environments such as abrasion, the transparent conductive film formed by the ITO sintered body sputtering target of the present invention can solve such a problem.

According to the present invention, by using a target which contains more tin oxide than the I-TO sintered body sputtering target containing about 5 to 10 wt% tin oxide which has been widely used conventionally, the above-mentioned I found that I could solve the problem.

Based on this finding, the present invention

1. Ito sintered body characterized by containing 20 to 50 wt% tin oxide. Sputtering target.

2. A sintered body as claimed in claim 1, characterized in that it contains 30 to 4 wt% tin oxide.

3. The I-TO sintered body sputtering target according to the above 1 or 2, characterized in that the sintered body density is 6.3 to 7.2 gZ cm ³ .

I will provide a. The invention further 4. Press-mold a mixed powder with zinc oxide containing 20 to 50 wt% tin oxide, and this molded body in a pure oxygen atmosphere at a temperature of 1 500 to 1650 ° C. and a pressure of 0.1 A method of producing an I-TO sintered body sputtering target characterized by pressure sintering at 5 to 1 MP a.

5. Press-form a mixed powder with indium oxide containing 30 to 40 wt% tin oxide, and compact this body in a pure oxygen atmosphere at a temperature of 1 500 to 1650C and a pressure of 0.1. A method of producing an I-TO sintered body sputtering evening get characterized by pressure sintering at 5 to 1 MP a.

6. The method for producing an I-TO sintered body sputtering target according to 4 or 5 above, wherein the sintered body density is 6. 3 to 7.2 gZ cm ³ .

To provide Embodiment of the Invention

In general, an IT sintered compact sputtering target for forming an ITO film is widely used which has a tin oxide content of 5 to 10 wt%. The reason why this composition is selected is mainly to form a low resistance film.

On the other hand, in the present invention, it is a major feature to increase the tin oxide content in the I-TO sintered body sputtering target to 20 to 5 wt%. And, by using such a target, it is possible to easily form a high resistance film with a volume resistivity of 0.6 mQ · cm or more, which is suitable for resistive film type solar panels etc., high A transparent conductive film having a surface resistivity can be obtained.

In the sputtering method, positive ions such as Ar ions physically collide with the target placed on the cathode, and the collision energy releases the material constituting the target, and the substrate on the facing anode side is mixed with the target material. This is a thin film formation method performed by laminating films of almost the same composition, and by adjusting the processing time and power supply, etc., from a thin film of several nm to a thick film of several tens of m at a stable deposition rate. It can be formed. For ITO sputtering, DC magnetron sputtering is widely used industrially because the process control during film formation is relatively easy and productivity is high.

The present invention provides a sputtering target suitable for such a film forming method.

Generally, in the sputtering of I T O, by continuing the sputtering for a long time, black protrusions called nodules are generated on the target erosion surface.

The nodules increase rapidly with the increase in the integrated sputtering power, which causes the deposition rate to decrease and the film resistivity to change. In order to compensate for these problems, it is often necessary to adjust the sputtering gas power and the sputtering gas composition.

Furthermore, since the nodule portion is inferior in electrical conductivity compared to the portion where it does not occur, it causes an abnormal discharge called a sparking in DC sputtering. When arcing occurs, particle dust may be generated concomitantly to contribute to film defects.

Because of this, if the nodules are excessively increased, it is necessary to stop the sputtering operation once to break the vacuum of the device and to remove the nodules generated on the target surface, which significantly reduces the productivity. It is causing the problem.

It is a well-known fact that it is effective to densify evening gates in order to suppress the nodules generated in the I T O target. As a result, the vacancies in the target, which become nuclei for nodule formation, are reduced, and the electrical conductivity of the target itself is also improved, making it possible to continue DC sputtering stably.

However, in the prior art, it is possible to densify a high concentration tin oxide ITO sintered body sputtering target having a tin oxide content of 20 to 50 wt% to a density of about 6.3 to 7.2 g / cm ³ . It was impossible. This is because oxygen in tin oxide is thermally dissociated or tin oxide itself is evaporated when sintering ITO because the vapor pressure of tin oxide is high. Naturally, this phenomenon becomes noticeable as the content of tin oxide increases.

In the present invention, in a pure oxygen atmosphere, the temperature is 150 ° C. to 150 ° C., and the pressure is 0.15 to 1 MP a (In addition, the temperature and pressure in this case are applicable to the present invention. The pressure sintering at a maximum temperature and a maximum pressure) can produce a high density I-TO sintered body sputtering target having a density of 6.3 to 7.2 gZ cm ³ .

This has a density much higher than that of the ITO sintered body sputtering target having a density of about 5.5 to 6.0 g / cm ³ obtained by the conventional atmospheric pressure oxygen atmosphere sintering. This has made it possible to reduce the generation of nodules generated during sputtering more than before, and to perform sputtering operation under stable conditions under stable conditions over a long period of time. Example and comparative example

Next, examples of the present invention will be described. The present embodiment is merely an example, and the present invention is not limited to this example. That is, within the technical thought of the present invention, all aspects or modifications other than the embodiment are included.

As a raw material of the ITO sputtering target, a tin oxide powder comparable to a zinc oxide powder having an average particle size of 3 m or less is used, and these powders are wet-ground uniformly under the conditions of tin oxide content described in Table 1. Mixed.

After adding a binder such as PVA to this slurry, it was dried and granulated. The mixed powder of tin oxide and tin oxide was uniformly filled in a mold, was formed by applying a pressure of 80MPa with a cold hydraulic press, and was further subjected to cold isostatic pressing at a pressure of 160MPa.

The compact was sintered at a maximum temperature of 160 ° C. in a pure oxygen atmosphere. At this time, the sintering maximum pressure was changed in the example and the comparative example. The surface of the sintered body thus obtained was ground using a diamond grinding wheel with a surface grinder, and the side pieces were further cut using a diamond cutter. The evening get-cut piece was metal-plated on a copper backing plate, and the evening surface was polished to obtain an I-TO sputtering evening.

Table 1 shows the tin oxide content of the target, the maximum sintering pressure and the density. table 1

As shown in Table 1 above, in Examples 1 to 4, even in the case of a high concentration tin oxide I TO sintered body sputtering target having a tin oxide content of 20 to 50 wt%, the pressure is applied at a maximum pressure of 0.5 MPa. By sintering, it was possible to densify to a density of 6.3 to 7.2 g / cm ³ .

On the other hand, in Comparative Examples 3 and 4, 0. I MP a (atmospheric pressure) did not have sufficient pressing force, and a target with a density of 6.0 gZcm ³ or more could not be obtained. In Comparative Examples 1 and 2, the tin oxide content is less than the conditions of the present invention.

The targets produced in Examples 1 to 4 and Comparative Examples 1 to 4 were sputtered under the following conditions, and the characteristics of the obtained films were measured. We also qualitatively evaluated the amount of nodules generated on the target surface at an integrated energy of 80 kWh after continuous sputtering for about 50 hours. Table 2 shows the film thickness, area resistivity, volume resistivity, and the amount of nodule generation.

Target size: 1 2 7 x 5 0 8 x 6. 3 5 mm

Spatter gas: Ar + 0 ₂

Spatter gas pressure: 0.5 P a

Spatter gas flow rate: 3 0 0 S C C M

Oxygen concentration in the sputtering gas: 1 V o 1%

Leakage flux density: 0.1 T

Input sputtering power: 1 500 W Table 2

As shown in Table 2 above, in Examples 1 to 4, a film having a thickness of about 20 nm, a surface resistivity of 400 to 1000, and a volume resistivity of 0.7 to 1. 8 mQ 'cm. was gotten. In addition, it was found that the amount of nodule generation after continuous sputtering of the targets used to form these films was all small. On the other hand, in Comparative Examples 1 and 2, a high resistance film having a surface resistivity of 300 Ω or more can not be obtained, and Comparative Examples 3 and 4 mainly generate a large amount of nodules because the density of the target is low. It became a result. Effect of the invention

As described above, according to the present invention, it is possible to achieve high resistance by using a target in which the amount of tin oxide contained in an ITO sintered body sputtering target is increased compared to that conventionally used widely. It is useful for forming a transparent conductive film, particularly a transparent conductive film having a surface resistivity as high as 300 to 100 Ζ, which is used for determining the screen position of resistive film type flat panel devices etc. It is possible to provide a composite sputtering target and a method of manufacturing the same.

Furthermore, the present invention is to perform pressure sintering in a pure oxygen atmosphere at a temperature of 15000 to 1650 ° C. and a pressure of 0.15 to 1 MP a. It has become possible to increase the density of a high concentration tin oxide ITO sintered compact sputtering target having a content of 20 to 50 wt% to a density of about 6.3 to 7.2 gZ cm ³ .

This is a high concentration tin oxide ITO sintered compact sputtering target, which has a density much higher than the density previously considered, which reduces the nodules generated on the target surface during sputtering. It has the excellent effect of being able to reduce spattering and particle dust and perform stable sputtering operations.

Claims

The scope of the claims

1. An I-TO sintered body sputtering target characterized by containing 20 to 50 wt% of tin oxide.

3. The IT 焼結体 sintered body sputtering target according to claim 1 or 2, wherein the sintered body density is 6.3 to 7.2 gZcm ³ .

4. Press-molding a mixed powder with indium oxide containing 20 to 5 wt% tin oxide, and subjecting this molded body to a temperature of 1 500 to 1650 ° C., pressure 0 in a pure oxygen atmosphere. A method of producing an I-TO sintered body sputtering target, characterized in that pressure sintering is carried out at 15 to 1 MP a.

5. A mixed powder with zinc oxide containing 30 to 40 wt% of tin oxide is press-formed, and this molded body is subjected to a temperature of 1 500 to 1650C in a pure oxygen atmosphere, a pressure of 0. A method of producing an I-TO sintered body sputtering target comprising: pressure sintering at 15 to 1 MP a.

6. The method for producing an I-TO sintered body sputtering target according to claim 4 or 5, wherein the sintered body density is 6. 3 to 7. 2 gZ cm ³ .