阅读说明：本技术 一种铜靶材及其制备方法 (Copper target material and preparation method thereof ) 是由 姚力军 潘杰 边逸军 王学泽 章丽娜 罗明浩 于 2021-08-13 设计创作，主要内容包括：本发明提供一种铜靶材及其制备方法,所述制备方法包括依次进行的切料、第一锻伸、第一热处理、第二锻伸、第二热处理、冷锻、第三热处理、压制、第四热处理与抛光；所述第一热处理与第二热处理的温度分别为290-310℃；所述第三热处理与第四热处理的温度分别为250-270℃。本发明提供的制备方法减少了铜靶材内部缺陷,避免了晶粒组织异常现象,提升了晶粒细化程度,进而改善了溅射薄膜的厚度分布均匀性,提升了溅射速率和镀膜质量。(The invention provides a copper target material and a preparation method thereof, wherein the preparation method comprises the steps of sequentially cutting, first forging and stretching, first heat treatment, second forging and stretching, second heat treatment, cold forging, third heat treatment, pressing, fourth heat treatment and polishing; the temperatures of the first heat treatment and the second heat treatment are 290-310 ℃ respectively; the temperatures of the third heat treatment and the fourth heat treatment are respectively 250-270 ℃. The preparation method provided by the invention reduces the internal defects of the copper target, avoids the abnormal phenomenon of the grain structure, improves the grain refinement degree, further improves the thickness distribution uniformity of the sputtered film, and improves the sputtering rate and the film coating quality.)

1. The preparation method of the copper target is characterized by comprising the steps of sequentially cutting, first forging and stretching, first heat treatment, second forging and stretching, second heat treatment, cold forging, third heat treatment, pressing, fourth heat treatment and polishing;

the temperatures of the first heat treatment and the second heat treatment are 290-310 ℃ respectively;

the temperatures of the third heat treatment and the fourth heat treatment are respectively 250-270 ℃.

2. The method of claim 1, wherein the blanking results in a first cylindrical copper target blank;

preferably, the diameter of the first cylindrical copper target blank is 170-180 mm;

preferably, the length of the first cylindrical copper target blank is 190-210 mm.

3. The production method according to claim 1 or 2, wherein the first forging comprises preheating, forging, water cooling, upsetting and drawing in this order, wherein the upsetting and drawing are alternately repeated at least 3 times;

preferably, the temperature of the preheating is 890-910 ℃;

preferably, the forging results in a square copper target blank;

preferably, the side length of the square copper target blank is 145-155 mm;

preferably, the upsetting is carried out until the length of the copper target blank is 100-120 mm;

preferably, the drawing is carried out until the length of the copper target blank is 210-230 mm;

preferably, the second forging comprises sequentially performing a second front forging and a second rear forging;

preferably, the second forward forging is in accordance with the condition of the first forging;

preferably, the second post-forging is carried out to obtain a second cylindrical copper target blank, and water cooling is carried out;

preferably, the length of the second cylindrical copper target blank is 220-230 mm.

4. The production method according to any one of claims 1 to 3, wherein the time for the first heat treatment and the second heat treatment is 25 to 35min, respectively;

preferably, the first heat treatment and the second heat treatment are respectively cooled by water cooling.

5. The production method according to any one of claims 1 to 4, wherein the cold forging includes cold forging upsetting and cold forging drawing performed in this order;

preferably, the cold forging upsetting is carried out in a ten thousand ton oil press to obtain a third cylindrical copper target blank;

preferably, the length of the third cylindrical copper target blank is 100-110 mm;

preferably, the cold forging drawing is carried out in a ten thousand ton oil press to obtain a fourth cylindrical copper target blank;

preferably, the length of the fourth cylindrical copper target blank is 220-230 mm.

6. The production method according to any one of claims 1 to 5, wherein the time for the third heat treatment and the time for the fourth heat treatment are respectively 25 to 35 min;

preferably, the third heat treatment and the fourth heat treatment are respectively cooled by water cooling.

7. The production method according to any one of claims 1 to 6, wherein the pressing comprises cutting, static pressing and rolling which are performed in this order;

preferably, the cutting is to cut off the cracked stub bars at two ends of the fourth cylindrical copper target blank to obtain a fifth cylindrical copper target blank;

preferably, the length of the fifth cylindrical copper target blank is 190-210 mm;

preferably, the static pressure is carried out in an oil press to obtain a sixth cylindrical copper target blank;

preferably, the length of the sixth cylindrical copper target blank is 110-120 mm;

preferably, the calendering is performed in a calender to obtain a seventh cylindrical copper target blank;

preferably, the seventh cylindrical copper target blank has a length of 20-22 mm.

8. The method of any one of claims 1-7, further comprising leveling between the polishing and the fourth heat treatment;

preferably, the planeness of the leveled copper target material is less than or equal to 1 mm;

preferably, the roughness of the polished copper target material is less than or equal to 1.6 mu m;

preferably, the polishing further comprises cleaning, drying and packaging in sequence;

preferably, the cleaning comprises ultrasonic cleaning;

preferably, the cleaning solution adopted by the ultrasonic cleaning comprises isopropanol;

preferably, the drying comprises vacuum drying;

preferably, the vacuum degree of the vacuum drying is less than or equal to 0.01 Pa;

preferably, the packaging comprises vacuum packaging.

9. The method of any one of claims 1 to 8, comprising the steps of:

(1) cutting: preparing a first cylindrical copper target blank with the diameter of 170-180mm and the length of 190-210 mm;

(2) first forging and stretching: preheating at 890-910 ℃, forging into a cubic copper target blank with the side length of 145-155mm, upsetting after water cooling until the length of the copper target blank is 100-120mm, and then drawing until the length of the copper target blank is 210-230mm, wherein upsetting and drawing are alternately repeated for at least 3 times;

(3) first heat treatment: heat treatment is carried out for 25-35min at the temperature of 290 ℃ and 310 ℃, and then water cooling is carried out;

(4) second forward forging and stretching: preheating at 890-910 ℃, forging into a cubic copper target blank with the side length of 145-155mm, upsetting after water cooling until the length of the copper target blank is 100-120mm, and then drawing until the length of the copper target blank is 210-230mm, wherein upsetting and drawing are alternately repeated for at least 3 times;

(5) second post-forging: forging the second cylindrical copper target blank with the length of 220 and 230mm, and then carrying out water cooling;

(6) second heat treatment: heat treatment is carried out for 25-35min at the temperature of 290 ℃ and 310 ℃, and then water cooling is carried out;

(7) cold forging and upsetting: upsetting the blank into a third cylindrical copper target blank with the length of 100-110mm in a ten thousand-ton oil press;

(8) cold forging and drawing: drawing the copper target blank into a fourth cylinder copper target blank with the length of 220 and 230mm in a ten thousand-ton oil press;

(9) and (3) third heat treatment: heat treatment is carried out for 25-35min at the temperature of 250-270 ℃, and then water cooling is carried out;

(10) cutting: cutting off the cracked material heads at the two ends of the fourth cylindrical copper target blank to obtain a fifth cylindrical copper target blank with the length of 190 and 210 mm;

(11) static pressure: static pressing a sixth cylindrical copper target blank with the growth degree of 110-120mm in an oil press;

(12) rolling: pressing and rolling the copper target blank into a seventh cylindrical copper target blank with the length of 20-22mm in a rolling mill;

(13) and fourth heat treatment: heat treatment is carried out for 25-35min at the temperature of 250-270 ℃, and then water cooling is carried out;

(14) and (3) post-treatment: leveling the copper target material until the flatness is less than or equal to 1mm, and then polishing until the roughness is less than or equal to 1.6 mu m; carrying out ultrasonic cleaning on the copper target by using isopropanol, then carrying out vacuum drying, and finally carrying out vacuum packaging on the copper target, wherein the vacuum degree is less than or equal to 0.01 Pa.

10. A copper target material prepared by the preparation method according to any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field of magnetron sputtering, relates to a sputtering target material, and particularly relates to a copper target material and a preparation method thereof.

Background

Magnetron sputtering is an extremely important key technology required for manufacturing semiconductor chips, and the principle is that a physical vapor deposition technology is adopted, high-pressure accelerated gaseous ions are utilized to bombard the surface of a target material, so that atoms of the target material are sputtered out and deposited on a silicon wafer in the form of a thin film, and finally a complex wiring structure in the semiconductor chip is formed. The sputtering target has many advantages of uniformity, controllability and the like of metal coating, and is widely applied to the field of semiconductors.

Because the resistivity of the metal copper is low, the conductivity is good, and the reaction speed of the semiconductor chip can be obviously improved by adopting the copper wiring. Therefore, copper targets are widely used as sputtering targets. For the copper target material, the uniformity of the internal structure is an important guarantee for the stability of the coating quality. The microstructure and the tissue uniformity, the grain size and the orientation distribution of the copper target material have obvious influence on the performance of the copper target material. Generally, the finer the grain size, the more uniform the thickness distribution of the sputtered film and the faster the sputtering rate.

CN 1928129a discloses a method of preparing a sputter target material, said method comprising: (1) uniformly preheating the material to 130-170 ℃; (2) performing plastic processing on the material perpendicular to the axial direction, wherein the process temperature is controlled below 250 ℃; (3) carrying out heat treatment processing at the temperature of 250-500 ℃ on the material, and carrying out water cooling after heat preservation for a certain time; (4) uniformly preheating the material to 130-170 ℃; (5) and (3) performing plastic working on the material in parallel to the axial direction, wherein the process temperature is controlled below 250 ℃. The material mainly comprises aluminum and aluminum alloy, the average grain size is less than 100 mu m, and the material has certain structural orientation. The invention mainly aims at plastic deformation of aluminum and aluminum alloy at the temperature of 130-170 ℃, but has low deformation temperature, large deformation resistance and insufficient deformation for copper target materials, and is easy to cause subsequent grain structure abnormity.

CN 1409773a discloses a processing method for preparing a sputtering target material, which performs plastic processing on a metal material with a processing percentage of at least 5%/second and a processing rate of at least 100%/second, and controls temperature variation during the processing of the material, thereby achieving control of the grain size of the target material. However, high-speed plastic working at a rate of more than 100%/sec is very difficult to control in practical operation, and the speed per plastic working and the amount of deformation of the material are also difficult to calculate and determine. In the aspect of industrial scale production, the requirement on production equipment is high, and the repeatability of the production process is difficult to control.

Therefore, how to provide a preparation method of the copper target material, reduce the internal defects of the copper target material, avoid the abnormal phenomenon of the grain structure, improve the grain refinement degree, further improve the thickness distribution uniformity of the sputtered film, and improve the sputtering rate and the coating quality becomes a problem which needs to be solved urgently by technical personnel in the field at present.

Disclosure of Invention

The invention aims to provide a copper target material and a preparation method thereof, wherein the preparation method reduces the internal defects of the copper target material, avoids the abnormal phenomenon of a grain structure, improves the grain refinement degree, further improves the thickness distribution uniformity of a sputtered film, and improves the sputtering rate and the film coating quality.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a preparation method of a copper target, which comprises the steps of cutting, first forging and stretching, first heat treatment, second forging and stretching, second heat treatment, cold forging, third heat treatment, pressing, fourth heat treatment and polishing which are sequentially carried out.

The temperatures of the first heat treatment and the second heat treatment are 290 ℃ and 310 ℃, respectively, and may be, for example, 290 ℃, 292 ℃, 294 ℃, 296 ℃, 298 ℃, 300 ℃, 302 ℃, 304 ℃, 306 ℃, 308 ℃ or 310 ℃, but not limited to the values listed, and other values not listed in the range of the values are also applicable.

The temperatures of the third and fourth heat treatments are 250-270 ℃, respectively, and may be, for example, 250 ℃, 252 ℃, 254 ℃, 256 ℃, 258 ℃, 260 ℃, 262 ℃, 264 ℃, 266 ℃, 268 ℃ or 270 ℃, but are not limited to the values listed, and other values not listed in the range of the values are also applicable.

The invention processes the original copper target blank into the high-quality copper target material through a series of procedures of two times of forging and stretching, four times of heat treatment, cold forging and pressing and the like. The forging and stretching can lead the original thick dendritic crystal grains and columnar crystal grains to be crushed into fine crystal grains, and the segregation, the looseness, the air holes, the slag inclusion and the like in the copper target blank are compacted and welded, thereby leading the organization structure to be more compact; the heat treatment can eliminate the residual stress caused by extrusion in the copper target blank, properly reduce the hardness and brittleness of the obtained copper target, increase the plasticity, reduce the deformation and crack tendency of the copper target in the subsequent process and further improve the size uniformity of crystal grains.

The invention needs to strictly control the temperature range of each heat treatment, and prevents the phenomenon that the crystal grain growth is not uniform and the adverse effect is brought to the welding of a subsequent target assembly due to the over-low temperature, and the sputtering rate and the coating quality are reduced due to the over-growth of the crystal grain due to the over-high temperature. The whole set of preparation method reduces the internal defects of the copper target, avoids the abnormal phenomenon of the grain structure, improves the grain refinement degree and improves the thickness distribution uniformity of the sputtered film.

Preferably, the blanking results in a first cylindrical copper target blank.

Preferably, the first cylindrical copper target blank has a diameter of 170 and 180mm, and may be, for example, 170mm, 171mm, 172mm, 173mm, 174mm, 175mm, 176mm, 177mm, 178mm, 179mm, or 180mm, but is not limited to the recited values, and other values not recited within the range are equally applicable.

Preferably, the length of the first cylindrical copper target blank is 190-210mm, and may be 190mm, 192mm, 194mm, 196mm, 198mm, 200mm, 202mm, 204mm, 206mm, 208mm or 210mm, for example, but is not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the first forging comprises sequentially performing preheating, forging, water cooling, upsetting and drawing, wherein the upsetting and drawing are alternately repeated at least 3 times, for example, 3 times, 4 times, 5 times or 6 times, but not limited to the recited values, and other values not recited in the range of the recited values are also applicable.

Preferably, the temperature of the preheating is 890-910 ℃, for example 890 ℃, 892 ℃, 894 ℃, 896 ℃, 898 ℃, 900 ℃, 902 ℃, 904 ℃, 906 ℃, 908 ℃ or 910 ℃, but is not limited to the recited values, and other values not recited in this range are equally applicable.

Preferably, the forging results in a square copper target blank.

Preferably, the square copper target blank has a side length of 145-155mm, such as 145mm, 146mm, 147mm, 148mm, 149mm, 150mm, 151mm, 152mm, 153mm, 154mm or 155mm, but is not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the upset is made to a copper target blank length of 100-120mm, such as 100mm, 102mm, 104mm, 106mm, 108mm, 110mm, 112mm, 114mm, 116mm, 118mm or 120mm, but is not limited to the values recited, and other values not recited within this range are equally applicable.

Preferably, the drawing is performed until the copper target blank length is 210mm and 230mm, such as 210mm, 212mm, 214mm, 216mm, 218mm, 220mm, 222mm, 224mm, 226mm, 228mm or 230mm, but the drawing is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the second forging includes sequentially performing a second forward forging and a second backward forging.

Preferably, the second forward forging is in accordance with the condition of the first forging.

Preferably, the second post-forging is performed to obtain a second cylindrical copper target blank, and the second cylindrical copper target blank is water-cooled.

Preferably, the length of the second cylindrical copper target blank is 220-230mm, and may be, for example, 220mm, 221mm, 222mm, 223mm, 224mm, 225mm, 226mm, 227mm, 228mm, 229mm or 230mm, but is not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the time of the first heat treatment and the second heat treatment is 25-35min, such as 25min, 26min, 27min, 28min, 29min, 30min, 31min, 32min, 33min, 34min or 35min, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the first heat treatment and the second heat treatment are respectively cooled by water cooling.

Preferably, the cold forging includes cold forging upsetting and cold forging drawing performed in sequence.

Preferably, the cold forging upsetting is performed in a ten thousand ton oil press, resulting in a third cylindrical copper target blank.

Preferably, the length of the third cylindrical copper target blank is 100-110mm, and may be, for example, 100mm, 101mm, 102mm, 103mm, 104mm, 105mm, 106mm, 107mm, 108mm, 109mm or 110mm, but is not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the cold forging drawing is performed in a ten thousand ton oil press to obtain a fourth cylindrical copper target blank.

Preferably, the length of the fourth cylindrical copper target blank is 220-230mm, such as 220mm, 221mm, 222mm, 223mm, 224mm, 225mm, 226mm, 227mm, 228mm, 229mm or 230mm, but is not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the time of the third heat treatment and the fourth heat treatment is 25-35min, such as 25min, 26min, 27min, 28min, 29min, 30min, 31min, 32min, 33min, 34min or 35min, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the third heat treatment and the fourth heat treatment are respectively cooled by water cooling.

Preferably, the pressing comprises cutting, static pressing and calendering, which are performed in sequence.

Preferably, the cutting is to cut off the cracked stub bars at two ends of the fourth cylindrical copper target blank to obtain a fifth cylindrical copper target blank.

Preferably, the length of the fifth cylindrical copper target blank is 190-210mm, and may be 190mm, 192mm, 194mm, 196mm, 198mm, 200mm, 202mm, 204mm, 206mm, 208mm or 210mm, for example, but not limited to the values listed, and other values not listed in this range are also applicable.

Preferably, the static pressing is performed in an oil press to obtain a sixth cylindrical copper target blank.

Preferably, the sixth cylindrical copper target blank has a length of 110-120mm, and may be, for example, 110mm, 111mm, 112mm, 113mm, 114mm, 115mm, 116mm, 117mm, 118mm, 119mm, or 120mm, but is not limited to the values listed, and other values not listed in this range are also applicable.

Preferably, the calendering is performed in a calender resulting in a seventh cylindrical copper target blank.

Preferably, the seventh cylindrical copper target blank has a length of 20-22mm, and may be, for example, 20mm, 20.2mm, 20.4mm, 20.6mm, 20.8mm, 21mm, 21.2mm, 21.4mm, 21.6mm, 21.8mm or 22mm, but is not limited to the recited values, and other values not recited within the range of values are equally applicable.

Preferably, leveling is further included between the polishing and the fourth heat treatment.

Preferably, the flatness of the leveled copper target material is 1mm or less, and may be, for example, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm, but is not limited to the values listed, and other values not listed in the range of values are also applicable.

Preferably, the roughness of the copper target after polishing is 1.6 μm or less, and may be, for example, 0.2 μm, 0.4 μm, 0.6 μm, 0.8 μm, 1 μm, 1.2 μm, 1.4 μm or 1.6 μm, but is not limited to the values listed, and other values not listed in the numerical range are also applicable.

Preferably, the polishing is followed by washing, drying and packaging which are carried out in sequence.

Preferably, the cleaning comprises ultrasonic cleaning.

Preferably, the cleaning solution used for ultrasonic cleaning comprises isopropyl alcohol.

Preferably, the drying comprises vacuum drying.

Preferably, the vacuum degree of the vacuum drying is less than or equal to 0.01Pa, and may be, for example, 0.001Pa, 0.002Pa, 0.003Pa, 0.004Pa, 0.005Pa, 0.006Pa, 0.007Pa, 0.008Pa, 0.009Pa or 0.01Pa, but is not limited to the enumerated values, and other unrecited values in the numerical range are also applicable.

Preferably, the packaging comprises vacuum packaging.

As a preferred technical solution of the first aspect of the present invention, the preparation method comprises the steps of:

(1) cutting: preparing a first cylindrical copper target blank with the diameter of 170-180mm and the length of 190-210 mm;

(2) first forging and stretching: preheating at 890-910 ℃, forging into a cubic copper target blank with the side length of 145-155mm, upsetting after water cooling until the length of the copper target blank is 100-120mm, and then drawing until the length of the copper target blank is 210-230mm, wherein upsetting and drawing are alternately repeated for at least 3 times;

(3) first heat treatment: heat treatment is carried out for 25-35min at the temperature of 290 ℃ and 310 ℃, and then water cooling is carried out;

(4) second forward forging and stretching: preheating at 890-910 ℃, forging into a cubic copper target blank with the side length of 145-155mm, upsetting after water cooling until the length of the copper target blank is 100-120mm, and then drawing until the length of the copper target blank is 210-230mm, wherein upsetting and drawing are alternately repeated for at least 3 times;

(5) second post-forging: forging the second cylindrical copper target blank with the length of 220 and 230mm, and then carrying out water cooling;

(6) second heat treatment: heat treatment is carried out for 25-35min at the temperature of 290 ℃ and 310 ℃, and then water cooling is carried out;

(7) cold forging and upsetting: upsetting the blank into a third cylindrical copper target blank with the length of 100-110mm in a ten thousand-ton oil press;

(8) cold forging and drawing: drawing the copper target blank into a fourth cylinder copper target blank with the length of 220 and 230mm in a ten thousand-ton oil press;

(9) and (3) third heat treatment: heat treatment is carried out for 25-35min at the temperature of 250-270 ℃, and then water cooling is carried out;

(10) cutting: cutting off the cracked material heads at the two ends of the fourth cylindrical copper target blank to obtain a fifth cylindrical copper target blank with the length of 190 and 210 mm;

(11) static pressure: static pressing a sixth cylindrical copper target blank with the growth degree of 110-120mm in an oil press;

(12) rolling: pressing and rolling the copper target blank into a seventh cylindrical copper target blank with the length of 20-22mm in a rolling mill;

(13) and fourth heat treatment: heat treatment is carried out for 25-35min at the temperature of 250-270 ℃, and then water cooling is carried out;

(14) and (3) post-treatment: leveling the copper target material until the flatness is less than or equal to 1mm, and then polishing until the roughness is less than or equal to 1.6 mu m; carrying out ultrasonic cleaning on the copper target by using isopropanol, then carrying out vacuum drying, and finally carrying out vacuum packaging on the copper target, wherein the vacuum degree is less than or equal to 0.01 Pa.

In a second aspect, the present invention provides a copper target material prepared by the preparation method according to the first aspect.

The copper target material provided by the invention can be combined with a back plate by a diffusion welding method, so that a target material assembly is prepared. The diffusion welding method is not particularly limited as long as the target and the backing plate can be tightly bonded to each other, and for example, the diffusion welding method provided in embodiment 1 of CN 111136396a can be used.

Compared with the prior art, the invention has the following beneficial effects:

the preparation method provided by the invention processes the original copper target blank into the high-quality copper target material through a series of procedures of twice forging and stretching, four times of heat treatment, cold forging and pressing and the like. The forging and stretching can lead the original thick dendritic crystal grains and columnar crystal grains to be crushed into fine crystal grains, and the segregation, the looseness, the air holes, the slag inclusion and the like in the copper target blank are compacted and welded, thereby leading the organization structure to be more compact; the heat treatment can eliminate the residual stress caused by extrusion in the copper target blank, properly reduce the hardness and brittleness of the obtained copper target, increase the plasticity, reduce the deformation and crack tendency of the copper target in the subsequent process and further improve the size uniformity of crystal grains. The whole set of preparation method reduces the internal defects of the copper target, avoids the abnormal phenomenon of the grain structure, improves the grain refinement degree, has the density of more than 97 percent and the minimum average grain size of 15 mu m, further improves the thickness distribution uniformity of the sputtered film, and improves the sputtering rate and the film coating quality.

Drawings

Fig. 1 is a schematic flow chart of a method for preparing a copper target provided in embodiments 1 to 3.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The present embodiment provides a copper target and a method for preparing the same, as shown in fig. 1, the method includes the following steps:

(1) cutting: preparing a first cylindrical copper target blank with the diameter of 175mm and the length of 200 mm;

(2) first forging and stretching: preheating at 900 ℃, forging into a cube copper target blank with the side length of 150mm, upsetting after water cooling until the length of the copper target blank is 110mm, drawing until the length of the copper target blank is 220mm, wherein upsetting and drawing are alternately repeated for 3 times;

(3) first heat treatment: heat treatment at 300 deg.C for 30min, and water cooling;

(4) second forward forging and stretching: preheating at 900 ℃, forging into a cube copper target blank with the side length of 150mm, upsetting after water cooling until the length of the copper target blank is 110mm, drawing until the length of the copper target blank is 220mm, wherein upsetting and drawing are alternately repeated for 3 times;

(5) second post-forging: forging the blank into a second cylindrical copper target blank with the length of 225mm, and then carrying out water cooling;

(6) second heat treatment: heat treatment at 300 deg.C for 30min, and water cooling;

(7) cold forging and upsetting: upsetting the copper target blank into a third cylindrical copper target blank with the length of 105mm in a ten thousand-ton oil press;

(8) cold forging and drawing: drawing the copper target blank into a fourth cylinder copper target blank with the length of 225mm in a ten thousand ton oil press;

(9) and (3) third heat treatment: heat treatment at 260 deg.C for 30min, and water cooling;

(10) cutting: cutting off cracked material heads at two ends of the fourth cylindrical copper target blank to obtain a fifth cylindrical copper target blank with the length of 200 mm;

(11) static pressure: performing static pressing in an oil press to form a sixth cylindrical copper target blank with the length of 115 mm;

(12) rolling: pressing and rolling the copper target blank into a seventh cylindrical copper target blank with the length of 21mm in a rolling mill;

(13) and fourth heat treatment: heat treatment at 260 deg.C for 30min, and water cooling;

(14) and (3) post-treatment: leveling the copper target material to the flatness of 0.5 +/-0.1 mm, and polishing to the roughness of 1 +/-0.2 mu m; carrying out ultrasonic cleaning on the copper target by using isopropanol, then carrying out vacuum drying with the vacuum degree of 0.005Pa, and finally carrying out vacuum packaging on the copper target.

Example 2

The present embodiment provides a copper target and a method for preparing the same, as shown in fig. 1, the method includes the following steps:

(1) cutting: preparing a first cylindrical copper target blank with the diameter of 170mm and the length of 190 mm;

(2) first forging and stretching: preheating at 890 ℃, forging into a cube copper target blank with the side length of 145mm, upsetting the blank after water cooling until the length of the copper target blank is 100mm, drawing until the length of the copper target blank is 210mm, wherein upsetting and drawing are alternately repeated for 4 times;

(3) first heat treatment: heat treating at 290 deg.C for 35min, and water cooling;

(4) second forward forging and stretching: preheating at 890 ℃, forging into a cube copper target blank with the side length of 145mm, upsetting the blank after water cooling until the length of the copper target blank is 100mm, drawing until the length of the copper target blank is 210mm, wherein upsetting and drawing are alternately repeated for 4 times;

(5) second post-forging: forging the second cylindrical copper target blank into a second cylindrical copper target blank with the length of 220mm, and then performing water cooling;

(6) second heat treatment: heat treating at 290 deg.C for 35min, and water cooling;

(7) cold forging and upsetting: upsetting the blank into a third cylindrical copper target blank with the length of 100mm in a ten thousand ton oil press;

(8) cold forging and drawing: drawing the copper target blank into a fourth cylinder copper target blank with the length of 220mm in a ten thousand ton oil press;

(9) and (3) third heat treatment: heat treatment at 250 deg.C for 35min, and water cooling;

(10) cutting: cutting off cracked material heads at two ends of the fourth cylindrical copper target blank to obtain a fifth cylindrical copper target blank with the length of 190 mm;

(11) static pressure: static pressing a sixth cylindrical copper target blank with the growth degree of 110mm in an oil press;

(12) rolling: pressing and rolling the copper target blank into a seventh cylindrical copper target blank with the length of 20mm in a rolling mill;

(13) and fourth heat treatment: heat treatment at 250 deg.C for 35min, and water cooling;

(14) and (3) post-treatment: leveling the copper target material to the flatness of 0.3 +/-0.2 mm, and polishing to the roughness of 0.8 +/-0.2 mu m; carrying out ultrasonic cleaning on the copper target by using isopropanol, then carrying out vacuum drying with the vacuum degree of 0.008Pa, and finally carrying out vacuum packaging on the copper target.

Example 3

The present embodiment provides a copper target and a method for preparing the same, as shown in fig. 1, the method includes the following steps:

(1) cutting: preparing a first cylindrical copper target blank with the diameter of 180mm and the length of 210 mm;

(2) first forging and stretching: preheating at 910 ℃, forging into a cube copper target blank with the side length of 155mm, upsetting after water cooling until the length of the copper target blank is 120mm, drawing until the length of the copper target blank is 230mm, wherein upsetting and drawing are alternately repeated for 5 times;

(3) first heat treatment: heat treatment at 310 deg.C for 25min, and water cooling;

(4) second forward forging and stretching: preheating at 910 ℃, forging into a cube copper target blank with the side length of 155mm, upsetting after water cooling until the length of the copper target blank is 120mm, drawing until the length of the copper target blank is 230mm, wherein upsetting and drawing are alternately repeated for 5 times;

(5) second post-forging: forging the second cylindrical copper target blank into a second cylindrical copper target blank with the length of 230mm, and then performing water cooling;

(6) second heat treatment: heat treatment at 310 deg.C for 25min, and water cooling;

(7) cold forging and upsetting: upsetting the copper target blank into a third cylindrical copper target blank with the length of 110mm in a ten thousand-ton oil press;

(8) cold forging and drawing: drawing the copper target blank into a fourth cylinder copper target blank with the length of 230mm in a ten thousand ton oil press;

(9) and (3) third heat treatment: heat treatment at 270 deg.C for 25min, and water cooling;

(10) cutting: cutting off cracked material heads at two ends of the fourth cylindrical copper target blank to obtain a fifth cylindrical copper target blank with the length of 210 mm;

(11) static pressure: performing static pressing in an oil press to obtain a sixth cylindrical copper target blank with the length of 120 mm;

(12) rolling: rolling the copper target blank into a seventh cylindrical copper target blank with the length of 22mm in a rolling machine;

(13) and fourth heat treatment: heat treatment at 270 deg.C for 25min, and water cooling;

(14) and (3) post-treatment: leveling the copper target material to the flatness of 0.8 +/-0.2 mm, and polishing to the roughness of 1.4 +/-0.2 mu m; carrying out ultrasonic cleaning on the copper target by using isopropanol, then carrying out vacuum drying with the vacuum degree of 0.01Pa, and finally carrying out vacuum packaging on the copper target.

Example 4

This embodiment provides a copper target and a method for manufacturing the same, wherein the preparation method is the same as embodiment 1 except that the time for the first heat treatment and the time for the second heat treatment are respectively changed to 20min, and therefore, the detailed description thereof is omitted.

Example 5

This embodiment provides a copper target and a method for manufacturing the same, wherein the preparation method is the same as embodiment 1 except that the time for the first heat treatment and the time for the second heat treatment are respectively changed to 40min, and therefore, the detailed description thereof is omitted.

Comparative example 1

This comparative example provides a copper target and a method for preparing the same, wherein the conditions are the same as those in example 1 except that the temperature of the first heat treatment is reduced to 280 ℃, and thus the details are not repeated herein.

Comparative example 2

This comparative example provides a copper target and a method for preparing the same, wherein the conditions are the same as those in example 1 except that the temperature of the first heat treatment is increased to 320 ℃, and thus the details are not repeated herein.

Comparative example 3

This comparative example provides a copper target and a method for preparing the same, wherein the conditions are the same as those in example 1 except that the temperature of the second heat treatment is reduced to 280 ℃, and thus the details are not repeated herein.

Comparative example 4

This comparative example provides a copper target and a method for preparing the same, wherein the conditions are the same as those in example 1 except that the temperature of the second heat treatment is increased to 320 ℃, and thus the details are not repeated herein.

Comparative example 5

This comparative example provides a copper target and a method for preparing the same, wherein the conditions are the same as those in example 1 except that the temperature of the third heat treatment is reduced to 240 ℃, and thus the details are not repeated herein.

Comparative example 6

This comparative example provides a copper target and a method for preparing the same, wherein the conditions are the same as those in example 1 except that the temperature of the third heat treatment is increased to 280 ℃, and thus the details are not repeated herein.

Comparative example 7

This comparative example provides a copper target and a method for preparing the same, wherein the remaining conditions are the same as those in example 1 except that the temperature of the fourth heat treatment is reduced to 240 ℃, and thus, the details are not repeated herein.

Comparative example 8

This comparative example provides a copper target and a method for preparing the same, wherein the conditions are the same as those in example 1 except that the temperature of the fourth heat treatment is increased to 280 ℃, and thus the details are not repeated herein.

The results of the performance tests of the copper targets obtained in examples 1 to 5 and comparative examples 1 to 8 are shown in Table 1.

TABLE 1

The density detection method comprises the following steps: measuring the density by an Archimedes drainage method, and taking the ratio of the obtained density to the density of a standard copper metal as the density of a sample; measuring the grain size of the average grain size according to the microstructure image of the surface of the copper target and calculating the average value; the C-Scan flaw detection method comprises the following steps: and C-Scan flaw detection is carried out by adopting a PDS-34000 ultrasonic flaw detector.

As can be seen from Table 1: the density of the copper target material obtained in the embodiments 1 to 5 can reach more than 97 percent, and the copper target material has fine grains, uniform size distribution, minimum average grain size of 15 mu m and no defect in the interior of the structure; in contrast, in comparative examples 1 to 8, the density of the obtained copper target material was reduced and even internal defects occurred due to the unreasonable selection of the temperature range for the heat treatment.

Application example 1

In this application example, the copper target provided in embodiment 1 is applied, and a copper target assembly is prepared by combining a diffusion welding method with a back plate, where the diffusion welding method is the method provided in embodiment 1 in CN 111136396a, and includes the following steps:

(1) preparing a copper target material, a C18000 back plate with a groove and a stainless steel cushion block, wherein the areas of the copper target material and the stainless steel cushion block are equal to the bottom area of the groove of the back plate; turning and smoothing the welding surface of the copper target by adopting a diamond blade, and turning a thread on the welding surface of the back plate, wherein the bulge of the thread is called a thread, the distance between adjacent threads in the thread is 0.45mm, and the height of the thread is 0.15 mm;

(2) cleaning and drying the copper target material obtained in the step (1) and the C18000 back plate with the groove, wherein IPA cleaning liquid is adopted for ultrasonic cleaning for 10min, then vacuum drying is carried out for 50min under the condition that the vacuum degree is 0.005Pa, then the copper target material, the stainless steel sheet with the thickness of 0.15mm and the stainless steel cushion block are sequentially placed into the groove of the C18000 back plate, wherein the assembly gap between the copper target material and the C18000 back plate is 0.2mm, and the whole body is placed into an aluminum sheath after the assembly treatment is finished;

(3) sealing the aluminum sheath obtained in the step (2) by adopting argon arc welding, and degassing after helium leakage inspection reaches the standard; wherein the degassing treatment temperature is 200 ℃, the vacuum degree is 0.005Pa, and the time is 4 h;

(4) placing the degassed aluminum sheath obtained in the step (3) into a hot isostatic pressing machine for hot isostatic pressing welding, wherein the hot isostatic pressing welding temperature is 250 ℃, the pressure is 100MPa, and the time is 5 hours, and removing the aluminum sheath, the stainless steel sheet and the stainless steel cushion block after the hot isostatic pressing welding is completed to obtain a diffusion-welded assembly;

(5) and (4) cleaning and drying the diffusion-welded assembly obtained in the step (4), wherein IPA cleaning solution is adopted for ultrasonic cleaning for 20min, then vacuum drying is carried out for 60min under the condition that the vacuum degree is 0.008Pa, after the macroscopic corrosion detection reaches the standard, the boundary line of the copper target and the C18000 backboard is found, an electron beam welding line is machined, and then electron beam welding is carried out for 4 times, so that the copper target assembly is obtained.

The copper target component obtained by the application example is used for magnetron sputtering coating, the thickness of the obtained sputtering film is uniform, the coating quality is excellent, and the sputtering rate is obviously improved because the crystal grains of the selected copper target are fine.

Comparative application example 1

The copper target material provided in comparative example 1 is applied to the comparative application example, and the copper target material assembly is prepared by combining the diffusion welding method and the back plate, and the specific steps of the diffusion welding method are the same as those of application example 1, so that the detailed description is omitted here.

Compared with the application example 1, the copper target material assembly obtained by the comparative application example is used for magnetron sputtering coating, the thickness uniformity of the sputtered film obtained by the comparative application example is obviously reduced, and the sputtering rate and the coating quality are both inferior to those of the application example 1.

Therefore, the preparation method provided by the invention processes the original copper target blank into the high-quality copper target material through a series of procedures such as twice forging and stretching, four times of heat treatment, cold forging and pressing and the like. The forging and stretching can lead the original thick dendritic crystal grains and columnar crystal grains to be crushed into fine crystal grains, and the segregation, the looseness, the air holes, the slag inclusion and the like in the copper target blank are compacted and welded, thereby leading the organization structure to be more compact; the heat treatment can eliminate the residual stress caused by extrusion in the copper target blank, properly reduce the hardness and brittleness of the obtained copper target, increase the plasticity, reduce the deformation and crack tendency of the copper target in the subsequent process and further improve the size uniformity of crystal grains. The whole set of preparation method reduces the internal defects of the copper target, avoids the abnormal phenomenon of the grain structure, improves the grain refinement degree, has the density of more than 97 percent and the minimum average grain size of 15 mu m, further improves the thickness distribution uniformity of the sputtered film, and improves the sputtering rate and the film coating quality.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.