Preparation method of ITO sputtering target material

文档序号：1960808 发布日期：2021-12-14 浏览：19次中文

阅读说明：本技术 一种ito溅射靶材的制备方法 (Preparation method of ITO sputtering target material ) 是由王永超赵泽良贾时君尤青文于 2021-10-20 设计创作，主要内容包括：本发明提供了一种ITO溅射靶材的制备方法,包括以下步骤：将纯度为99.995%的In-(2)O-(3)粉体和SnO-(2)粉体按质量比为(90～97):(10～3)进行湿法球磨混合,球磨过程加入少量分散剂和粘结剂,得到高固含量、高流动性能的ITO浆料；将所得的ITO浆料注入石膏模具中进行粉浆浇注成型,得到大尺寸ITO素坯；ITO素坯干燥脱模进行低温脱脂去除有机添加剂；将脱脂后的ITO素坯进行热等静压烧结制备ITO溅射靶材。本发明可用于大尺寸、高致密度ITO靶材的制备,且发明工艺中的热等静压烧结可以降低靶材的烧结温度和烧结时间,有效地提高生产效率,该方法适用于工业化生产。(The invention provides a preparation method of an ITO sputtering target material, which comprises the following steps: in with a purity of 99.995% 2 O 3 Powder and SnO 2 Carrying out wet ball milling mixing on the powder according to the mass ratio of (90-97) to (10-3), and adding a small amount of dispersing agent and binder in the ball milling process to obtain ITO slurry with high solid content and high flow performance; injecting the obtained ITO slurry into a gypsum mold for slip casting molding to obtain a large-size ITO biscuit; ITO biscuit drying, demoulding and low-temperature degreasing removalAn organic additive; and carrying out hot isostatic pressing sintering on the degreased ITO biscuit to prepare the ITO sputtering target. The method can be used for preparing the large-size and high-density ITO target material, the hot isostatic pressing sintering in the process can reduce the sintering temperature and the sintering time of the target material, the production efficiency is effectively improved, and the method is suitable for industrial production.)

1. The preparation method of the ITO sputtering target is characterized by comprising the following specific operation steps:

(1) in is mixed with₂O₃Powder and SnO₂Performing wet ball milling mixing on the powder to obtain ITO slurry with high solid content and high flow performance;

(2) carrying out powder slurry casting molding on the ITO slurry obtained in the step (1), and drying and demoulding to obtain an ITO biscuit;

(3) degreasing and sintering the ITO biscuit obtained in the step (2) to remove organic additives;

(4) and (4) carrying out hot isostatic pressing sintering on the ITO biscuit obtained in the step (3) to prepare the large-size high-density ITO target.

2. The production method according to claim 1, wherein In the step (1)₂O₃Powder and SnO₂The purity of the powder is 99.995%; in₂O₃The average particle diameter of the powder is 60-110 nm, and SnO₂The average particle diameter of the powder is 100-180 nm.

3. The production method according to claim 1, wherein In the step (1)₂O₃: SnO₂The mass ratio is 90:10, 93:7, 95:5 and 97: 3.

4. The production method according to claim 1, wherein In the step (1)₂O₃Powder and SnO₂The powder is subjected to wet ball milling mixing, and the process comprises the following steps:

in₂O₃Raw powder and SnO₂Deionized water and polyacrylic acid dispersing agent are added into the raw material powder, ball milling is carried out for 36-48 h, and the ball milling speed is 200-250 r/min. And (3) uniformly mixing the powder, adding a small amount of binder, and continuously performing ball milling for 30-45 min to obtain ITO slurry, vacuumizing and discharging bubbles.

5. The preparation method according to claim 1, wherein the ITO slurry obtained in the step (1) has a solid content of 70-80 wt% and a viscosity of 80-160 mPa-S (25 ℃ at a rotation speed of 3.96S)^-1）。

6. The preparation method according to claim 1, wherein in the step (2), the ITO slurry is subjected to slip casting to obtain an ITO biscuit with a diameter of 60-90 cm, a thickness of 10-15 cm and a density of 45-60%.

7. The preparation method according to claim 1, wherein in the step (3), the ITO green body is subjected to degreasing sintering, a small amount of organic additives added in the ball milling process are removed, and the phenomenon that the capsule bulges due to gas generated by decomposition and volatilization of organic matters in the subsequent hot isostatic pressing sintering process is avoided. The degreasing temperature is 700-800 ℃, and the degreasing time is 12-18 h.

8. The production method according to claim 1, wherein in the step (4), the degreased ITO green compact is subjected to hot isostatic pressing sintering at a sintering temperature of 1000 to 1200 ℃, a holding pressure of 150 to 180 MPa, and a holding time of 3 to 5 hours.

9. The method according to claim 1, wherein in step (4), the jacket material is low-carbon steel, the isolating material is 304 stainless steel, and the jacket is evacuated before sealing. The sheath welding adopts an argon arc welding mode.

10. The production method according to claim 1, wherein in the step (4), the capsule is peeled off by mechanical cutting after the completion of the hot isostatic pressing.

Technical Field

The invention relates to the field of advanced ceramic target preparation, in particular to a preparation method of an ITO sputtering target.

Background

The ITO film is a transparent conductive film with excellent performance, the visible light transmittance of the ITO film is higher than 95 percent, and the resistivity of the ITO film reaches 10^-4Omega cm, carrier concentration up to 10²¹ cm^-3The infrared reflectivity is up to more than 80%, and the glass has the characteristics of excellent chemical etching property, thermal stability and the like, and is widely applied to the fields of flat panel displays, solar panels, organic light emitting diodes, radiation-proof glass and the like.

The ITO sputtering target is a raw material for preparing an ITO film, and the comprehensive quality of the ITO target has an important influence on the performance of the ITO film.

At present, there are two main methods for forming an ITO biscuit: (1) and (2) performing mould pressing and cold isostatic pressing and slip casting. The former belongs to dry forming, and although the former has the characteristics of high production efficiency, easy operation and the like, the equipment is expensive, and a large-size blank cannot be prepared. The slip casting molding has low manufacturing cost and convenient operation, and can be used for preparing large-size plate blanks.

At present, the ITO target material sintering modes mainly comprise three (1) normal-pressure atmosphere sintering; (2) hot pressing and sintering; (3) and (4) hot isostatic pressing sintering. Compared with sintering in normal pressure atmosphere, the hot isostatic pressing sintering can further reduce the sintering temperature and the sintering time and shorten the production period; compared with hot-pressing sintering, the problem of uneven force application in hot pressing can be solved. The hot isostatic pressing sintering is of great significance for improving the quality, the production efficiency and the like of the ITO target material.

The patent CN 105130416A provides a method for preparing a low-resistance ITO target, in the method, a high-strength biscuit is prepared by pouring and molding powder slurry, a blank body is used for preparing the ITO target by a normal-pressure oxygen sintering method, and the process has the advantages of higher sintering temperature, longer sintering time and longer production period.

In patent CN101575203a, a method for preparing ITO sputtering target by hot pressing sintering is provided, which can cause problems of oxide decomposition, uneven stress, material pollution, etc. during hot pressing.

Patent document

Zhang Yuan Song, Yeming, bear Aichen, etc. a preparation method of ITO target material with low resistivity, CN 105130416A [ P ] 2015.

Hubai DC, Subenshuang, Liuxianning and the like, a preparation method of an ITO sputtering target material, and CN101575203A [ P ] 2009.

Disclosure of Invention

Aiming at the problems of small plate blank size, low production efficiency and the like in the prior target preparation technology. The invention provides a preparation method of an ITO sputtering target material, which comprises the following steps:

(1) in is mixed with₂O₃Powder and SnO₂Ball milling and mixing the powder by a wet method, (1) In₂O₃Powder and SnO₂Performing wet ball milling mixing on the powder to obtain ITO slurry with high solid content and high flow performance;

(2) carrying out powder slurry casting molding on the ITO slurry obtained in the step (1), and drying and demoulding to obtain an ITO biscuit;

(3) degreasing and sintering the ITO biscuit obtained in the step (2) to remove organic additives;

(4) and (4) carrying out hot isostatic pressing sintering on the ITO biscuit obtained in the step (3) to prepare the large-size high-density ITO target.

Further, In the step (1), In₂O₃Powder and SnO₂The purity of the powder is 99.995%; in₂O₃The average particle diameter of the powder is 60-110 nm, and SnO₂The average particle diameter of the powder is 100-180 nm.

Further, In the step (1), In₂O₃: SnO₂The mass ratio is 90:10, 93:7, 95:5 and 97: 3.

Further, In the step (1), In₂O₃Powder and SnO₂The powder is subjected to wet ball milling mixing, and the process comprises the following steps:

in₂O₃Raw powder and SnO₂Deionized water and polyacrylic acid are added into the raw material powderAnd ball-milling and mixing the powder for 36-48 h at a ball-milling speed of 200-250 r/min. And (3) uniformly mixing the powder, adding a small amount of binder, and continuously performing ball milling for 30-45 min to obtain ITO slurry, vacuumizing and discharging bubbles.

Further, the ITO slurry obtained in the step (1) has a solid content of 70-80 wt% and a viscosity of 80-160 mPa & S (25 ℃, rotation speed of 3.96S)^-1）。

Further, in the step (2), the ITO slurry is subjected to powder slurry casting molding to obtain an ITO biscuit with the diameter of 60-90 cm, the thickness of 10-15 cm and the density of 45-60%.

Further, in the step (3), the ITO biscuit is subjected to degreasing sintering, a small amount of organic additives added in the ball milling process are removed, and the phenomenon that a sheath bulges due to gas generated by decomposition and volatilization of organic matters in the subsequent hot isostatic pressing sintering process is avoided. The degreasing temperature is 700-800 ℃, and the degreasing time is 12-18 h.

Further, in the step (4), the degreased ITO biscuit is subjected to hot isostatic pressing sintering, wherein the sintering temperature is 1000-1200 ℃, the pressure maintaining pressure is 150-180 MPa, and the pressure maintaining time is 3-5 h.

Further, in the step (4), in the hot isostatic pressing treatment process, the jacket material is low-carbon steel, the isolation material is 304 stainless steel, and vacuumizing and exhausting are performed before jacket sealing.

Further, in the step (4), the sheath welding adopts an argon arc welding mode.

Further, in the step (4), the capsule is stripped by a mechanical cutting method after the hot isostatic pressing is finished.

Further, the prepared ITO target material has the diameter of 50-80 cm, the thickness of 8-12 cm, the density of over 99 percent and the resistivity of 1.6-2.0 multiplied by 10^-4 mΩ·cm。

Compared with the prior art, the invention has the following advantages:

by the powder slurry casting molding process, the ITO biscuit with large size and high strength is prepared, the shrinkage of the sheath in the HIP link in the hot pressing process can be reduced, and cracking caused by too large deformation of the sheath is prevented.

By a Hot Isostatic Pressing (HIP) sintering process, the ITO biscuit is uniformly stressed in the sintering process, and compared with hot-pressing sintering, the problems of uneven target material density, cracking deformation and the like are avoided; compared with the traditional normal-pressure oxygen sintering, the method further reduces the temperature and time required by sintering and shortens the preparation period of the target material. The invention is suitable for industrial production.

Drawings

FIG. 1 is a process flow diagram of the ITO target preparation method of the present invention.

Detailed Description

The invention will be further illustrated with reference to specific examples, but is not limited to the examples given.

Example 1

Weighing In₂O₃: SnO₂Adding pure water, polyacrylic acid dispersing agent and binder into raw material powder with a mass ratio of 90:10 according to requirements, and performing ball milling and mixing to prepare ITO slurry with a solid content of 75%;

injecting the ITO slurry into a gypsum mold to obtain an ITO green compact with the diameter of 80cm, the thickness of 15cm and the density of 58%;