JP2022042859A - Production of copper target for thin film coating by sputtering from hot extrusion process - Google Patents

Abstract

To provide a copper sputtering target having a crystal grain size of less than 20 microns.SOLUTION: The production of a copper sputtering target starts from the dissolution and casting process of copper having at least 99.99% of purity and copper having an oxygen content not beyond 5 ppm. Then, a hot extrusion process and a cold drawing process form a copper ingot. The hot extrusion process controls following variables so that the grain size of copper does not exceed 100 microns: 1) an extrusion ratio, 2) an ingot temperature, and 3) an extrusion rate.SELECTED DRAWING: Figure 7

Description

Related Techniques The present invention is in the field of metal science and technology in the field of copper metallurgy for thin film coating by sputtering from a hot extrusion process.

Currently, most coatings use chemical methods such as electroplating. However, this method has the disadvantage of low coating quality and also has environmental problems, so it has replaced the research and development of new coating techniques such as vacuum coating. Vacuum coating is done only in vacuum and does not use chemicals that cause environmental problems in the coating process. Vacuum coatings can also be very thin coatings known as "thin films". A "thin film" is a film having a thickness of 5 microns or less. Thin film coating in vacuum is divided into two types: thin film coating by chemical process and thin film coating by physical process.
1. 1. Chemical vapor deposition (CVD) is a chemical coating of gas, and the chemical reaction is a new coating of substrate material such as plasma CVD and laser CVD methods.
2. 2. Physical vapor deposition (PVD) is a process in which atoms in a coating are removed from the surface and these are diffused or scattered on the surface of the substrate material, such as by evaporation and sputtering.

Sputtering technology is one of the most suitable vacuum film coating techniques for research and development of some types of film products. This process uses a variety of membrane coatings such as membranes, metals, alloys, glass, ceramics and semiconductor membranes. The thickness of the membrane can be precisely controlled and the properties of the membrane can be adjusted. Industries that use sputtering technologies such as microelectronics, semiconductors, films, conductors and film resistors, hard disk drives, automotive glass, fiber optic buildings, photovoltaic TV screens, and mobile screens.

The sputtering process begins by creating an atmosphere in the coating chamber by absorbing air parcels from the coating. The pressure is controlled so that it does not exceed ^1x10-6 milligrams, then an inert gas such as argon is added until the pressure is appropriate for the coating. The coating is then initiated by forming ions of argon gas using a magnetic field. In the electric field, this causes the ions to collide with the target coating, which causes the particles of the coating on the surface of the target to scatter to the surface of the workpiece, forming a thin film if necessary.

So far, in the 1958 sputtering process, a target material has been used as an aluminum (Al) metal for the surface layer of semiconductor properties (see Liquid crystal display device of US Pat. No. 5,598,285). Aluminum resistance is not the lowest, but is used due to technical limitations.

However, in the development of IBM in the 1980s, copper (Cu) and silver (Ag) were used as target metals. This is because both of these metals have much lower resistance than aluminum and have better electromigration resistance than aluminum (Handbook of Thin Film Deposition, pp. 193-195).

The quality of the thin film depends on the operating conditions of the sputtering machine, such as the atmospheric pressure in the chamber, the number of gas ions hitting the target material, and the type of gas used. It also depends on the properties of the target material. The nature of the target material directly affects the quality during sputtering as follows.
1. 1. Purification of target material 2. Amount of dielectric content: Oxide (Al ₂ O ₃ for Al target, Cu O for Cu target).
3. 3. Porosity, void volume due to gas during sputtering 4. Crystal grain size of target material 5. Surface roughness of target material 6. The mechanical strength or hardness of the target material.

Much research has been done on material properties, manufacturing methods, and manufacturing conditions that affect the properties of the target material. The study can be summarized as follows.

Patent: US Patent Application Publication No. 2000/6139701 (Applicable Material): Copper targets with hardness greater than 45 Rockwell will have fewer splats or lower hardness than soft copper targets. High hardness copper target tests up to 75 rockwells have the same effect. As the hardness increased, the splats decreased. In order to control the hardness, the grain size (copper grain size) needs to be less than 50 microns (more preferably, the grain size is less than 25 microns). When the crystal grain size is small due to molding techniques such as forging, rolling and other processes, the hardness is high. On the other hand, a copper sputtering target material having a large crystal grain size affects an increase in surface roughness and a decrease in strength.

Patent: US Patent Application Publication No. 2004/6746553 (Honeywell International Inc): The quality of the thin film formed on the substrate by the sputtering method depends on the surface roughness. Anything that protrudes from the surface of the target causes an abnormal discharge during sputtering. This is sometimes called micro-arcing, and large particles (macro particles) are scattered from the surface of the target and adhere to the substrate. Large particles in the membrane layer can cause short circuits in semiconductor devices. Adhesion of large particles is called "particles" or "splats". This study revealed that surface roughness is related to the grain size of the target. If the grain size of the target is small and finely varied, the surface will be smoother. Therefore, reducing the grain size of the target can also prevent the problem of "particles". The quality of the thin film produced by the target with a small grain size is superior to that with a large grain size. A study of the reduction and variability of crystal grain size during the formation of target materials using the forging process in this study.

Patent: Japanese Patent Application Laid-Open No. 2010-06252 (Mitsubishi Materials Material Corp.): The copper target material must have a copper purity of at least 99.99%, and the grain size must be less than 20 microns in the multiaxial forging process. ..

Patent: JP-A11-158614: Conventional copper targets have an average grain size of less than 80 microns, resulting in less problems with coarse clusters and abnormal discharges. The resulting smaller grain size is caused by the recrystallization mechanism in the copper target manufacturing process.

Patent: US Patent Application Publication No. 2011/0139615 (Hitachi Cable Ltd): As a result of the large crystal size, the surface roughness increases, and as a result of the small crystal size, the surface roughness decreases. As the amount of molding in the cold rolling process increases, the grain size becomes smaller. The reduction in cold working is 40-70% in the cold rolling process and the grain size is 30-100 microns. The copper target is heat treated to trigger a recrystallization mechanism. The recrystallized grain size increases with the heat treatment temperature. The heat treatment temperature is (preferably) 300 to 400 ° C. When the heat treatment temperature exceeds 400 ° C., the crystal grain size becomes large. The heat treatment temperature is 300 ° C. or lower, but the recrystallized grains do not have a grain size. The manufacturing process for copper targets in this study is as follows:
Casting → Hot rolling → Cold rolling → Heat treatment → Final rolling

Patent: Japanese Patent Application Laid-Open No. 2012-046771 (Furukawa Electric Co., Ltd): A copper target is manufactured at a controlled temperature before hot working. In order to control the crystal grain size in the range of 50 to 200 microns, the rate of decrease in hot rolling and cooling rate after final rolling is controlled. The manufacturing process of the copper target in this study is as follows.
Copper slab containing Cu = 99.99% or more → hot rolling → cold working → heat treatment.

The copper slab is heated to 700-1,000 ° C. before the hot rolling process. The size of each hot-rolled pass is reduced by 5-30%. In the final pass of the final rolling, the reduction is 10-25%. Copper is cooled with cold water at least 50 ° C./sec within 60 seconds after final hot rolling.

Patent: Japanese Patent No. 4974197 (Furukawa): The crystal grain size affects the sputtering characteristics. The crystal size of the present invention is 100 to 200, preferably 110 to 190 microns, more preferably 120 to 180 microns. When the crystal grains are small, the grain boundaries are large. Particles or atoms in the boundary layer are disturbed. Atoms of the coating are removed from the copper target and diffuse irregularly (non-uniformly) into the substrate material during the sputtering process. Sputtering with a large grain size requires high energy, resulting in the formation of coarse cluster atoms and the formation of a non-uniform film coating. The copper target in this study is produced by two hot working processes, a hot rolling process and a hot extrusion process. The manufacturing process is as follows.
Copper ingot (Cu = 99.99% or less) → Heat (Temperature = 700 to 1,050 ° C) → Hot rolling or hot extrusion → Water cooling (Cooling rate = 50 ° C / sec or less) → Cold rolling

For hot rolling process: Copper cake (thickness 150 x width 220 mm) → heating at a temperature of about 1,000 ° C → hot rolling (by multiple passes) → water cooling in the last pass of hot rolling (cooling rate = 50 ° C / sec or less within 60 seconds) → Copper plate (thickness 23 x width 220 mm) → Surface oxide processing (0.5 mm / side surface) → Copper plate (thickness 22 x width 220 mm) → Cold rolling → Copper plate (thickness) 20 x width 200 mm).

For hot extrusion process: Copper ingot (diameter 300 mm x length 800 mm) → heating at a temperature of about 1,000 ° C → hot extrusion → water cooling (cooling rate = 100 ° C / sec or less within 20 seconds) → copper plate (thickness) 22 x width 200 mm) → cold rolling → copper plate (thickness 20 x width 200 mm)

The results show that the grain size of both hot rolling and hot extrusion can be controlled to the desired dimensions. However, the uniformity of the copper crystal grain size in the extrusion process (head end position along the length and center-edge position along the width) is lower than in the hot rolling process.

Patent: Japanese Patent No. 4974198 (Furukawa): After the search of Japanese Patent No. 4974197, the uniformity of crystal grains is further studied. The inventors have found that dynamic recrystallization occurs during the process of hot rolling. When the copper target is cooled in the atmosphere, the problem of irregular grain size arises over the width and length of the copper target. In the present invention, the crystal grain size is controlled by water cooling at a cooling rate exceeding 50 ° C./sec. In the hot rolling process, the copper target is cooled in water within 60 seconds. In the hot extrusion process, the copper target is cooled with water within 10 seconds after being pressed through the extrusion die. The crystal grain size at thicknesses 1/2 and 1/4 is 100-200 microns (+/- 10 microns). The manufacturing process is as follows.
Casting-> hot rolling or hot extrusion-> cold rolling-> heat treatment (cold rolling and heat treatment may be repeated).

Patent: Japanese Patent Application Laid-Open No. 2013-019010 (Furukawa Electric Co., Ltd): In order to reduce abnormal discharge in the sputtering process, the sputtering target material contains at least 99.99% copper purity and has void and inclusion defects. Is not more than 30 microns, defects are not more than 10 points / mm2, the grain size is in the range of 50-200 microns and the hardness is in the range of 60-100 HV. The manufacturing process is as follows.
Copper slab (Cu = 99.99% or more) → Heated at 700 to 1,000 ° C → Hot rolling (total hot working rate% = 20% or more and hot working rate% in final hot rolling = temperature 400 (10% or more at ~ 600 ° C) → Water cooling at the last pass of hot rolling (cooling rate = 50 ° C / sec or more) → Oxide surface treatment → Cold rolling

Patent: Japanese Patent Application Laid-Open No. 2013-133491 (Hitachi Cable Ltd): The copper target shall contain a copper purity of at least 99.9% and a crystal grain size in the range of 100 to 200 microns. The manufacturing process is as follows.
Copper slab (Cu = 99.9% or more) → Hot rolling → Cold rolling (Cold working rate% = 5 to 30%)

Patent: Japanese Unexamined Patent Publication No. 2014-025129 (SH Copper Product Corp (Hitachi)): The copper target is a grade of copper having a purity of at least 99.9% and a crystal grain size of 70 to 200 microns and 100 to 150 microns. Suppose there is. The manufacturing process is as follows.
Copper slab (Cu = 99.9% or more) → Heated at 800 to 900 ° C → Hot rolling (thickness reduction rate% = 85 to 90% and temperature after hot rolling = 600 to 700 ° C)

Patent: Japanese Patent Application Laid-Open No. 2015-017299 (SH Copper Product Corp (Hitachi)): The copper target is a grade of copper having a purity of at least 99.9% and a crystal grain size of 70 to 200 microns and 100 to 150 microns. Suppose there is. The manufacturing process is as follows.
Copper slab (Cu = 99.9% or more) → Heat at 800 to 900 ° C → Hot rolling (thickness reduction rate% = 85 to 90% and temperature after hot rolling = 600 to 650 ° C) → Cold rolling → Heat treatment (cold rolling and heat treatment may be repeated) → final cold rolling (decrease rate% = 5 to 7%).

Based on previous studies, it was found that most copper target processes are 1) forging, 2) hot rolling, and 3) hot extrusion. Usually, the forging process produces a small amount of copper target. Therefore, most copper targets can be manufactured from small to large size copper targets and are therefore manufactured from hot rolling or hot extrusion processes. However, in the current fashion, it is manufactured by a hot rolling process.

In recent years, research on copper targets by hot extrusion has been carried out (2012, Furukawa Electric). A comparison of the hot rolling process and the hot extrusion copper target manufacturing shows that the hot extrusion process produces less copper targets than the hot rolling process.
Copper target manufacturing process by hot rolling process:
1) Copper slab → 2) Heating at 1,000 ° C → 3) Hot rolling (multiple paths) → 4) Water cooling → 5) Copper plate → 6) Oxide surface treatment → 7) Copper plate → 8) Cold rolling → 9) Heat treatment → 10) Copper target (Note: steps 8 and 9 can be reproduced to the desired size).
Copper target manufacturing process by hot extrusion process:
1) Copper ingot → 2) Heating at 1,000 ° C → 3) Hot extrusion (only one pass) → 4) Water cooling → 5) Copper plate → 5) Cold rolling or cold drawing → 6) Copper target

Further, Furukawa Electric's patents (Patent Nos. 4974197 and Patent No. 4974198) study the characteristics of copper targets, especially from the viewpoint of comparing the crystal grain size between hot rolling and hot extrusion. This study revealed that the grain size of hot rolling and hot extrusion can be controlled to the desired size. However, the uniformity of the copper crystal grain size in the extrusion process (head end position along the length and center-edge position along the width) is lower than in the hot rolling process. This means that the hot extrusion process has a more uniform particle size than the hot rolling process.

In addition, various research studies have concluded that the surface roughness of the target is associated with anomalous discharges during sputtering, which causes a problem known as "particles" or "splats". Studies have shown that copper targets have a very small grain size, resulting in a smoother surface. Therefore, reducing the grain size of the copper target can also prevent the problem of "particles". Therefore, the quality of the thin film produced by the copper target material is better with a smaller grain size than with a larger grain size. However, recent research by Furukawa Electric (Patent Nos. 4974197 and 4974198) has revealed that the crystal grain size of the hot extrusion process for copper targets is 100-200 microns. Suitable for use in thin film applications, copper targets are manufactured by a hot extrusion process with a grain size of less than 100 microns. Therefore, the current study, led by Vatchakran Taechachoonhakij (Oriental Copper), has developed a copper target for hot extrusion with a small grain size in the range of 50-100 microns. Table 1 shows the summarization method for producing copper targets and the crystal grain size obtained from past and present studies.

U.S. Pat. No. 5,598,285 U.S. Patent Application Publication No. 2000/6139701 U.S. Patent Application Publication No. 2004/67465553 U.S. Patent Application Publication No. 2011/0139615 Japanese Unexamined Patent Publication No. 2012-046771 Japanese Patent No. 4974197 Japanese Patent No. 4974198 Japanese Unexamined Patent Publication No. 2013-019010 Japanese Unexamined Patent Publication No. 2013-133491 Japanese Unexamined Patent Publication No. 2014-025129 JP-A-2015-017299A

Properties and Purposes of the Invention From the investigation of past studies, it can be concluded that the quality of the thin film produced by the copper target material is better with a smaller grain size than with a larger grain size. In the hot extrusion process, the uniformity of the crystal grain size of copper (head end position along the length and center edge position along the width) is higher than in the hot rolling process. Therefore, an object of the present invention is to manufacture a copper target for thin film coating by a sputtering method. The present invention is manufactured by a hot extrusion process that controls the grain size of copper to less than 100 microns so that the coating layer or thin film is of good quality. The variables in the hot extrusion process that affect the grain size and uniformity of the copper particles are:
1. 1. Extrusion ratio in hot extrusion process 2. Temperature of copper ingot before hot extrusion process 3. Extrusion speed in hot extrusion process (main ram speed)

After the copper is extruded from the extrusion die in the hot extrusion process, the copper is rapidly cooled until exposed to water (underwater extrusion). This is an important technique for preventing copper particle growth, as shown in FIG.

As shown in FIG. 6, after the hot extrusion process, the next process is a cold drawing process to obtain dimensions and hardness of 51-100 Vickers (HV).

Disclosure of the Invention Copper ingots having a copper purity of at least 99.99% and an oxygen content of no more than 5 ppm are processed by a hot extrusion process. This is the most important process for controlling the uniformity of size and grain size of copper. The variables investigated and controlled are 1) extrusion ratio, 2) ingot temperature and 3) extrusion rate.
1. 1. Extrusion ratio: In this study, the cross-sectional area or diameter of the copper ingot used in the hot extrusion extruded from the extrusion die is variable. The diameters of the copper ingots investigated are 10 inches and 12 inches.
2. 2. Ingot temperature: The temperature of the copper ingot before the hot extrusion process is 750 ° C, 800 ° C, and 850 ° C.
3. 3. Extrusion speed: The extrusion speed measured by the speed of the hydraulic cylinder used to push the copper ingot out of the extrusion die. This study will be conducted at speeds of 5, 10, 20 mm / sec.

The control variable is copper cooling. Usually, after the copper is deformed in the hot extrusion process, the grain size is reduced by a mechanism known as dynamic recrystallization. After the hot extrusion process, if the copper is cooled normally in the atmosphere, the grain size of the copper will increase.

In another study, the copper is cooled with water within 10 seconds after the heated copper is extruded from the extrusion die during the hot extrusion process. For a short period of time, the copper is sufficiently cooled so that the recrystallization process can proceed to the particle growth process, resulting in a large grain size and a non-uniform grain size.

In this study, the control of copper cooling differs from the control of other studies in which the copper is cooled immediately after it is extruded from the extrusion die in the hot extrusion process. Copper immediately moves to the water tunnel (underwater extrusion) behind the extrusion die. Since copper is cooled immediately and the grain size is small and uniform, no particle growth process is performed. The copper is then passed through a cold drawing process to ensure that the dimensions and hardness of the target material within the specifications are 50-100 Vickers (HV) prior to production in the next process.

It is a figure which shows the sputtering coating system. A = anode, T = target, S = workpiece, P = plasma It is a figure which shows the physical sputtering process. It is a figure which shows the sputtering machine. It is a figure which shows the plasma formation in a thin film coating. It is a figure which shows the water of the hot extrusion process. It is a figure which shows the cold drawing process. It is a figure which shows the position of a sample with respect to the measured crystal particle size according to the length of a copper rod. It is a figure which shows the position of a sample with respect to the measured crystal particle size according to the width of a copper rod. It is a figure which shows the crystal grain size (ingot diameter 10 inches, temperature 750 ° C., speed 5 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 750 ° C., speed 5 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 10 inches, temperature 750 ° C., speed 5 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 750 ° C., speed 10 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 10 inches, temperature 750 ° C., speed 10 mm / sec) at the position of a central part. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 750 ° C., speed 10 mm / sec) at a tail position. It is a figure which shows the crystal grain size (ingot diameter 10 inches, temperature 750 ° C., speed 20 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 750 ° C., speed 20 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 10 inches, temperature 750 ° C., speed 20 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 5 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 10 inches, temperature 800 degreeC, speed 5 mm / sec) at the central part position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 5 mm / sec) at the tail position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 10 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 10 mm / sec) at the position of a central part. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 10 mm / sec) at the tail position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 20 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 10 inches, temperature 800 degreeC, speed 20 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 10 inches, temperature 800 degreeC, speed 20 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 850 ° C., speed 5 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 850 ° C., speed 5 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 10 inches, temperature 850 ° C., speed 5 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 850 ° C., speed 10 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 10 inches, temperature 850 ° C., speed 10 mm / sec) at the position of a central part. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 850 ° C., speed 10 mm / sec) at a tail position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 850 ° C., speed 20 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 850 ° C., speed 20 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 10 inches, temperature 850 ° C., speed 20 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 750 ° C., speed 5 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 750 ° C., speed 5 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 750 ° C., speed 5 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 750 ° C., speed 10 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 750 ° C., speed 10 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 750 ° C., speed 10 mm / sec). It is a figure which shows the crystal grain size (ingot diameter 12 inches, temperature 750 ° C., speed 20 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 750 ° C., speed 20 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 750 ° C., speed 20 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 800 degreeC, speed 5 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 800 degreeC, speed 5 mm / sec) at the central part position. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 800 degreeC, speed 5 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 800 degreeC, speed 10 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 800 degreeC, speed 10 mm / sec) at the central part position. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 800 degreeC, speed 10 mm / sec). It is a figure which shows the crystal grain size (ingot diameter 12 inches, temperature 800 degreeC, speed 20 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 800 degreeC, speed 20 mm / sec) at the central part position. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 800 degreeC, speed 20 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 850 ° C., speed 5 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 12 inches, temperature 850 ° C., speed 5 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 850 ° C., speed 5 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 850 ° C., speed 10 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 12 inches, temperature 850 ° C., speed 10 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 850 ° C., speed 10 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 850 ° C., speed 20 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 12 inches, temperature 850 ° C., speed 20 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 850 ° C., speed 20 mm / sec).

Prior to the hot extrusion process, a copper ingot (10 inches in diameter, 643 mm in length, 12 inches in diameter, 471 mm in length) heated at 750 ° C., 800 ° C., 850 ° C. is prepared. The heated copper ingot is immediately extruded from the extrusion die into the water tunnel (underwater extrusion). As shown in Table 2, the extrusion speeds are 5 mm / sec, 10 mm / sec, and 20 mm / sec. The dimensions of copper after pressing from an extrusion die are 188 mm wide, 24 mm thick and 6,000 mm long. The copper is then drawn through a drawing die in a cold drawing process. The reduction rate of the cold drawing process is 14% (does not exceed 30%). The dimensions of the copper after being drawn through the drawing die are 185 mm in width, 21 mm in thickness, and 7,000 mm in length. As shown in FIG. 7, the sample of the microstructure test is cut from the positions of the head, the center, and the tail according to the length of the copper rod.

As shown in FIG. 8, all samples (head, center, and tail) are confirmed for microstructure at edge width and center of width at the surface, 1/4 of thickness and 1/2 of thickness. ..

The results of the 10-inch diameter microstructure at each position of the copper ingot are shown in FIGS. 9-35 and Table 3. And the results of the 12 inch diameter microstructure at each position of the copper ingot are shown in FIGS. 36-62 and Table 4.

Best Mode Already clarified in the disclosure of the invention.

It is a figure which shows the sputtering coating system. A = anode, T = target, S = workpiece, P = plasma It is a figure which shows the physical sputtering process. It is a figure which shows the sputtering machine. It is a figure which shows the plasma formation in a thin film coating. It is a figure which shows the water of the hot extrusion process. It is a figure which shows the cold drawing process. It is a figure which shows the position of a sample with respect to the measured crystal particle size according to the length of a copper rod. It is a figure which shows the position of a sample with respect to the measured crystal particle size according to the width of a copper rod. It is a figure which shows the crystal grain size (ingot diameter 10 inches, temperature 750 ° C., speed 5 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 750 ° C., speed 5 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 10 inches, temperature 750 ° C., speed 5 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 750 ° C., speed 10 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 10 inches, temperature 750 ° C., speed 10 mm / sec) at the position of a central part. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 750 ° C., speed 10 mm / sec) at a tail position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 750 ° C., speed 20 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 750 ° C., speed 20 mm / sec) at the position of a central part. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 750 ° C., speed 20 mm / sec) at a tail position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 5 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 5 mm / sec) at the position of a central part. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 5 mm / sec) at the tail position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 10 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 10 mm / sec) at the position of a central part. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 10 mm / sec) at the tail position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 800 degreeC, speed 20 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 10 inches, temperature 800 degreeC, speed 20 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 10 inches, temperature 800 degreeC, speed 20 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 850 ° C., speed 5 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 850 ° C., speed 5 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 10 inches, temperature 850 ° C., speed 5 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 850 ° C., speed 10 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 10 inches, temperature 850 ° C., speed 10 mm / sec) at the position of a central part. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 850 ° C., speed 10 mm / sec) at a tail position. It is a figure which shows the crystal particle size (ingot diameter 10 inches, temperature 850 ° C., speed 20 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 10 inches, temperature 850 ° C., speed 20 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 10 inches, temperature 850 ° C., speed 20 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 750 ° C., speed 5 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 750 ° C., speed 5 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 750 ° C., speed 5 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 750 ° C., speed 10 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 750 ° C., speed 10 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 750 ° C., speed 10 mm / sec). It is a figure which shows the crystal grain size (ingot diameter 12 inches, temperature 750 ° C., speed 20 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 750 ° C., speed 20 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 750 ° C., speed 20 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 800 degreeC, speed 5 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 800 degreeC, speed 5 mm / sec) at the central part position. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 800 degreeC, speed 5 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 800 degreeC, speed 10 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 800 degreeC, speed 10 mm / sec) at the central part position. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 800 degreeC, speed 10 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 800 degreeC, speed 20 mm / sec) at the head position. It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 800 degreeC, speed 20 mm / sec) at the central part position. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 800 degreeC, speed 20 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 850 ° C., speed 5 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 12 inches, temperature 850 ° C., speed 5 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 850 ° C., speed 5 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 850 ° C., speed 10 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 12 inches, temperature 850 ° C., speed 10 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 850 ° C., speed 10 mm / sec). It is a figure which shows the crystal particle size (ingot diameter 12 inches, temperature 850 ° C., speed 20 mm / sec) at the head position. It is a figure which shows the crystal grain size (ingot diameter 12 inches, temperature 850 ° C., speed 20 mm / sec) at the position of a central part. It is a figure which shows the crystal grain size at the tail position (ingot diameter 12 inches, temperature 850 ° C., speed 20 mm / sec).

Claims (10)

A copper target containing at least 99.99% pure copper. A copper target that does not contain more than 5 ppm oxygen. A copper target containing other elements not exceeding 100 ppm. Next process:
4.1) Hot extrusion in water,
4.2) Cold withdrawal,
4.3) The copper target according to any one of claims 1 to 3, which comprises stretching. A copper ingot that is heated to 750-850 ° C. prior to hot extrusion. A copper ingot that is extruded from an extrusion die and quenched in water at a temperature not exceeding 40 ° C without contact with air. Copper ingots with extrusion speeds of 5 mm / sec, 10 mm / sec, and 20 mm / sec (measured by main ram). Copper ingot with a reduction in cold drawing not exceeding 35%. Copper target A copper target in which the grain size of copper does not exceed 100 microns. A copper target whose hardness does not exceed 100 Vickers.

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