阅读说明：本技术 一种镍铬合金溅射靶材及其制备方法 (Nickel-chromium alloy sputtering target material and preparation method thereof ) 是由 姚力军 潘杰 边逸军 王学泽 黄东长 于 2020-07-24 设计创作，主要内容包括：本发明涉及一种镍铬合金溅射靶材的制备方法,所述制备方法包括：先对镍铬合金铸锭进行致密化处理,再依次进行锻造、退火、轧制、终端退火、机加工,得到镍铬合金溅射靶材。所述制备方法针对熔炼铸造得到的镍铬合金铸锭的内部缺陷问题,在热塑性变形加工之前先进行致密化处理,有效避免了镍铬合金溅射靶材的内部缺陷问题,将成品率提高至90％以上；而且,制备得到的镍铬合金溅射靶材内部结构均匀,晶粒细小,晶粒≤50μm,符合半导体等高精端产业的质量要求。(The invention relates to a preparation method of a nickel-chromium alloy sputtering target material, which comprises the following steps: firstly carrying out densification treatment on a nickel-chromium alloy cast ingot, and then sequentially carrying out forging, annealing, rolling, terminal annealing and machining to obtain the nickel-chromium alloy sputtering target material. Aiming at the problem of internal defects of the nickel-chromium alloy cast ingot obtained by smelting and casting, the preparation method carries out densification treatment before thermoplastic deformation processing, effectively avoids the problem of internal defects of a nickel-chromium alloy sputtering target material, and improves the yield to more than 90%; moreover, the prepared nickel-chromium alloy sputtering target has a uniform internal structure and fine grains, the grain size is less than or equal to 50 microns, and the quality requirements of high-precision industries such as semiconductors are met.)

1. The preparation method of the nickel-chromium alloy sputtering target is characterized by comprising the following steps: firstly carrying out densification treatment on a nickel-chromium alloy cast ingot, and then sequentially carrying out forging, annealing, rolling, terminal annealing and machining to obtain the nickel-chromium alloy sputtering target material.

2. The method of manufacturing according to claim 1, wherein the densification treatment is hot isostatic pressing;

preferably, the temperature of the hot isostatic pressing is 750-1100 ℃;

preferably, the pressure of the hot isostatic pressing is 110-200 MPa;

preferably, the hot isostatic pressing time is 4-6 h.

3. The production method according to claim 1 or 2, wherein the mass ratio of chromium in the nickel-chromium alloy ingot is 18 to 22%, and the balance is nickel and inevitable impurities;

preferably, the purity of the nickel-chromium alloy ingot is 99.95-99.99%;

preferably, the nickel-chromium alloy cast ingot is obtained by smelting in any one mode of electron beam, vacuum arc remelting or vacuum induction smelting and then pouring;

preferably, the nickel-chromium alloy cast ingot is cut according to a target size, and then the densification treatment is carried out;

preferably, the cutting is performed using a horizontal sawing machine.

4. The method as claimed in any one of claims 1 to 3, further comprising a preheating treatment after the densification treatment and before the forging, wherein the preheating temperature is 900-1100 ℃;

preferably, the total deformation rate of the forging is 70 to 80%.

5. The method as claimed in any one of claims 1 to 4, wherein the annealing temperature is 1000-1150 ℃;

preferably, the heat preservation time of the annealing is 60-120 min.

6. The method for preparing the alloy steel plate according to any one of claims 1 to 5, wherein the rolling is performed for at least one round, each round is performed for 3 to 5 times, and the reduction amount of each pass is controlled to be 5 to 10 percent of the thickness of the pass before the rolling;

preferably, after one round of rolling is carried out, the nickel-chromium alloy material is returned to the furnace to be heated continuously, then the next round of rolling is carried out, and the process of rolling-heating-rolling is repeated until a nickel-chromium alloy sputtering target blank with the target diameter and the target thickness is obtained;

preferably, the heating time is 40-80 min;

preferably, the heating temperature is 1000-1150 ℃;

preferably, the total deformation of the rolling is 70-80%.

7. The method as claimed in any one of claims 1 to 6, wherein the temperature of the terminal annealing is 450-550 ℃;

preferably, the holding time of the terminal annealing is 90-150 min;

preferably, the end annealing is followed by water cooling so that the grain stops growing, and then the machining is performed.

8. The method according to any one of claims 1 to 7, wherein the machining comprises turning to remove scale and wire cutting the outer circle in sequence;

preferably, the machining is performed using a horizontal lathe;

preferably, after the machining, sequentially carrying out detection, cleaning, drying and packaging to obtain a nickel-chromium alloy sputtering target material;

preferably, the detection comprises size detection and performance detection;

preferably, the size detection comprises diameter detection and thickness detection;

preferably, the performance test includes surface state test, grain size test and internal defect test.

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

(1) cutting a nickel-chromium alloy cast ingot with the chromium mass ratio of 18-22% and the purity of 99.95-99.99% by adopting a horizontal sawing machine according to the target size;

(2) carrying out densification treatment on the nickel-chromium alloy cast ingot obtained by cutting in the step (1) by adopting hot isostatic pressing, wherein the hot isostatic pressing temperature is controlled to be 750-;

(3) preheating the nickel-chromium alloy ingot obtained by densification in the step (2) at the temperature of 900-1100 ℃, then forging, and controlling the total deformation rate of the forging to be 70-80%;

(4) annealing the nickel-chromium alloy ingot obtained by forging in the step (3), wherein the annealing temperature is 1000-1150 ℃, and the heat preservation time is 60-120 min;

(5) rolling the nickel-chromium alloy ingot obtained by annealing in the step (4) for 3-5 times, then returning to the furnace to continue heating for 40-80min at the temperature of 1000-1150 ℃, then performing the next rolling, and repeating the rolling-heating-rolling process until obtaining a nickel-chromium alloy sputtering target blank with the target diameter and the target thickness;

wherein, the pressing amount of each pass is controlled to be 5-10% of the thickness before the rolling of the pass so as to prevent the target blank from cracking; the total deformation of the rolling is 70-80%;

(6) performing terminal annealing treatment on the nickel-chromium alloy target blank rolled in the step (5), wherein the terminal annealing temperature is 450-550 ℃, the heat preservation time is 90-150min, and water cooling is performed after the terminal annealing so as to stop the growth of crystal grains;

(7) and (4) machining the nickel-chromium alloy target blank obtained by the terminal annealing in the step (6) by adopting a horizontal lathe, wherein the machining comprises turning to remove oxide skin and linear cutting of an excircle, and then, detecting, cleaning, drying and packaging are carried out in sequence to obtain the nickel-chromium alloy sputtering target.

10. A nickel-chromium alloy sputtering target material, characterized by being prepared by the preparation method of any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of metal materials, in particular to a nickel-chromium alloy sputtering target material and a preparation method thereof.

Background

Magnetron sputtering is one of the main techniques for preparing thin film materials, ions generated by an ion source are accelerated and gathered in vacuum to form ion beam flow with high speed energy, the ion beam flow bombards the surface of a solid, kinetic energy exchange is carried out between the ions and atoms on the surface of the solid, the atoms on the surface of the solid leave the solid and are deposited on the surface of a substrate, and a thin film with the thickness of nanometer or micrometer level is formed. The bombarded solid is a raw material for preparing a magnetron sputtering deposition film, is generally called a sputtering target material, and is intensively applied to industries such as information storage, integrated circuits, displays, automobile rearview mirrors and the like.

The sputtering target material is generally obtained by a powder metallurgy sintering molding process, and the sputtering target material prepared by the process has unique chemical composition and mechanical and physical properties, so that porous, semi-compact or fully-compact materials and products can be directly prepared. As an important powder metallurgy sintering forming process, Hot Isostatic Pressing (HIP) is a process method for Pressing by utilizing various equal static pressures at high temperature, and specifically comprises the steps of filling high-temperature alloy powder into a vacuumized thin-wall forming sheath, performing Hot isostatic Pressing after welding, and removing the sheath to obtain a compact disc piece with a shape close to a required shape. The powder hot isostatic pressing material generally has a uniform fine grain structure, can avoid the macrosegregation of cast ingots, and improves the technological property and the mechanical property of the material. The method has the advantages of integration of the advantages of hot pressing and isostatic pressing, low forming temperature, compact product, excellent performance, and the defects of expensive equipment and low production rate. In addition, the sputtering target material can also be obtained by thermoplastic deformation Processing (TMP), and the process is a key technology for manufacturing the sputtering target material, wherein the ingot obtained by smelting and casting is subjected to processes such as forging, rolling, heat treatment annealing and the like, so that the structure and the performance of the metal material are improved, and the required shape and size are obtained.

Because the atomic surface energy of nickel and chromium is relatively close, the sputtering product component of the nickel-chromium alloy sputtering target material and the target material component do not have obvious deviation, which is beneficial to the selection of the target material component and the control of the film component. Therefore, the application of nichrome sputtering targets in the market is receiving more and more attention. At present, a nickel-chromium alloy sputtering target material is mainly obtained by thermoplastic deformation processing, but due to the special property of a nickel material, materials such as pure nickel, nickel alloy and the like have partial defects during smelting and casting, and finally, the inside of the target material has defects, so that the sputtering performance of a product is seriously influenced.

For example, CN102922233A discloses a method for preparing Ni-Cr magnetron sputtering target material, which comprises the procedures of vacuum melting, pouring, hot forging, rolling, annealing, machining and the like, wherein the adopted raw materials are electrolytic nickel with the purity of 99.96%, metallic chromium with the purity of 99.09%, and a small amount of rare earth, wherein the rare earth comprises 34.1 wt% of La, 65.74 wt% of Ce and a small amount of impurities, 0.05-0.4 wt% of rare earth element is added in the melting process, and the forging deformation amount and the rolling deformation amount (47.4-80.0%) are changed, so that high-quality Ni-Cr target with high density, adjustable grain size within the range of not more than 80 mu m and uniform size distribution is obtained. However, the nickel-chromium alloy sputtering target material obtained by the preparation method still has the quality problems of large crystal grains, uneven internal structure, internal defects and the like, and the yield is low.

CN102732845A discloses a high-purity high-component-uniformity nichrome target material and a preparation method thereof, wherein the preparation method is used for precisely controlling technological parameters of smelting, solidification, thermal mechanical processing and annealing heat treatment of a nickel-chromium series alloy target material based on the results of material science and process calculation simulation, so that the high uniformity of component distribution of the alloy target material is powerfully ensured; the nickel-chromium series alloy target material with high purity and high component uniformity prepared by the method has deterministic technological parameters in the preparation process, can ensure the quality stability of the target material in batch production, and can meet the requirements of the high-end market of sputtering coating. However, the key point of the preparation method is "uniform alloy target components", and a detailed plastic deformation process is not elucidated, so that the prepared nickel-chromium alloy sputtering target still has the quality problems of large grains, internal defects and the like, and the yield is low.

CN110453186A discloses a rotary nickel-chromium alloy target and a preparation method thereof, wherein the preparation method comprises the steps of preparing nickel-chromium powder, preparing a base tube, carrying out surface sand blasting treatment and bottoming treatment on the base tube in sequence, carrying out cold spraying on the nickel-chromium powder on the surface of the base tube of the target through a spray gun, and machining to obtain a finished product of the rotary nickel-chromium alloy target. Although the preparation method has the advantages of simple process, convenient operation, wide alloy component range and suitability for large-scale industrial production, the nickel-chromium alloy sputtering target material obtained by the powder metallurgy method has high gas content and cannot meet the quality requirement of high-precision industry.

In summary, there is a need to develop a novel method for preparing a nickel-chromium alloy sputtering target material, so that the prepared nickel-chromium alloy sputtering target material has a uniform internal structure and fine grains, has no defects inside the target material, and meets the quality requirements of high-precision industries such as semiconductors.

Disclosure of Invention

In view of the problems in the prior art, the invention provides a preparation method of a nickel-chromium alloy sputtering target, aiming at the problem of internal defects of a nickel-chromium alloy cast ingot obtained by smelting and casting, densification treatment is carried out before thermoplastic deformation processing, so that the problem of internal defects of the nickel-chromium alloy sputtering target is effectively avoided, and the yield is improved to more than 90%; moreover, the prepared nickel-chromium alloy sputtering target has a uniform internal structure and fine grains, the grain size is less than or equal to 50 microns, and the quality requirements of high-precision industries such as semiconductors are met.

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

one of the purposes of the invention is to provide a preparation method of a nickel-chromium alloy sputtering target material, which comprises the following steps: firstly carrying out densification treatment on a nickel-chromium alloy cast ingot, and then sequentially carrying out forging, annealing, rolling, terminal annealing and machining to obtain the nickel-chromium alloy sputtering target material.

Aiming at the problem of internal defects of the nickel-chromium alloy cast ingot obtained by smelting and casting, the preparation method firstly densifies the nickel-chromium alloy cast ingot by 100 percent through densification treatment, eliminates the casting problems of shrinkage porosity, macro segregation, tissue defects and the like in the cast ingot, and improves the overall mechanical property and plastic deformation capability of the cast ingot; and then forging, annealing, rolling, terminal annealing and machining are sequentially carried out, so that on one hand, casting defects such as loose structure and the like in the cast ingot can be further eliminated, on the other hand, crystal grains are refined, and finally the nickel-chromium alloy sputtering target material with uniform internal structure, crystal grains less than or equal to 50 mu m and no defect in the interior is obtained, the yield is more than 90 percent, and the quality requirements of high-precision industries such as semiconductors and the like are met.

In a preferred embodiment of the present invention, the densification process is hot isostatic pressing.

Preferably, the hot isostatic pressing temperature is 750-.

Preferably, the hot isostatic pressing pressure is 110-.

Preferably, the hot isostatic pressing is carried out for a period of 4-6 hours, such as 4 hours, 4.2 hours, 4.5 hours, 4.7 hours, 5 hours, 5.3 hours, 5.5 hours, 5.6 hours, 5.8 hours, or 6 hours, but not limited to the recited values, and other values not recited in the range of values are equally applicable.

The densification treatment of the invention adopts hot isostatic pressing, and further controls the temperature, pressure and time of the hot isostatic pressing, and the nickel-chromium alloy cast ingot obtained by smelting and casting can be pressed through various equal static pressures at high temperature and high pressure, so that the nickel-chromium alloy cast ingot achieves 100% densification, thereby effectively eliminating the casting problems of shrinkage porosity and shrinkage cavity, macrosegregation, tissue defect and the like in the cast ingot, and improving the overall mechanical property and plastic deformation capability of the cast ingot.

According to a preferable technical scheme of the invention, the mass ratio of chromium in the nickel-chromium alloy ingot is 18-22%, and the balance is nickel and inevitable impurities.

The mass ratio of chromium in the nickel-chromium alloy ingot of the present invention is 18 to 22%, for example, 18%, 18.5%, 19%, 19.5%, 20%, 20.5%, 21%, 21.5%, or 22%, but is not limited to the values listed, and other values not listed in the numerical range are also applicable.

Preferably, the purity of the nickel-chromium alloy ingot is 99.95-99.99%, such as 99.95%, 99.96%, 99.97%, 99.98%, or 99.99%, etc., but is not limited to the recited values, and other values not recited within the range of values are equally applicable.

The purity of the nickel-chromium alloy ingot refers to the sum of the mass ratio of chromium to nickel.

Preferably, the nickel-chromium alloy ingot is obtained by smelting in any one of an electron beam mode, a vacuum arc remelting mode and a vacuum induction smelting mode and then pouring.

Preferably, the nickel-chromium alloy ingot is cut according to a target size, and then the densification treatment is performed.

Preferably, the cutting is performed using a horizontal sawing machine.

In a preferred embodiment of the present invention, the densification process and the forging process further include a preheating process, wherein the preheating process is performed at a temperature of 900-.

The preheating treatment before forging can effectively prevent the cracking problem of the cast ingot in the forging process.

Preferably, the forging has a total deformation of 70-80%, such as 70%, 72%, 74%, 75%, 78%, or 80%, but not limited to the recited values, and other values not recited within this range are equally applicable.

The forging treatment of the invention can further eliminate casting defects such as loose structure and the like in the cast ingot, optimize the microstructure in the cast ingot and crush the columnar crystal of the cast ingot into fine crystal grains, thereby playing a role in grain refinement.

In a preferred embodiment of the present invention, the annealing temperature is 1000-1150 ℃, such as 1000 ℃, 1020 ℃, 1050 ℃, 1070 ℃, 1100 ℃, 1130 ℃, or 1150 ℃, but the annealing temperature is not limited to the values listed, and other values not listed in the range of the values are also applicable.

Preferably, the annealing is carried out for a holding time of 60-120min, such as 60min, 70min, 80min, 90min, 100min, 110min or 120min, but not limited to the recited values, and other values not recited in the range of values are also applicable.

The annealing treatment of the invention can not only eliminate the residual stress and the internal structure defect in the forged nickel-chromium alloy cast ingot, but also is beneficial to the smooth proceeding of the subsequent rolling.

As a preferable technical scheme of the invention, the rolling is carried out for at least one round, each round is carried out for 3-5 times, and the reduction amount of each pass is controlled to be 5-10% of the thickness before the rolling of the pass so as to prevent the target blank from cracking.

The rolling of the invention is carried out for 3-5 times, such as 3 times, 4 times or 5 times, and the skilled person can reasonably select the rolling according to the actual situation.

The amount of reduction per pass controlled according to the invention is in the range of 5 to 10%, for example 5%, 6%, 7%, 8%, 9% or 10% of the thickness before rolling in that pass, but is not limited to the values listed, and other values not listed within this range are equally applicable.

Preferably, after one round of rolling is carried out, the nickel-chromium alloy material is returned to the furnace to be heated continuously, then the next round of rolling is carried out, and the process of rolling-heating-rolling is repeated until the nickel-chromium alloy sputtering target blank with the target diameter and the target thickness is obtained.

Preferably, the heating time is 40-80min, such as 40min, 50min, 60min, 70min or 80min, but not limited to the recited values, and other values not recited in the range of values are equally applicable.

Preferably, the heating temperature is 1000-.

Preferably, the total rolling deformation is 70-80%, for example 70%, 72%, 75%, 77%, 79% or 80%, etc., but is not limited to the recited values, and other values not recited within this range are equally applicable.

The rolling of the invention not only can further refine grains and homogenize the structure, but also can shape the nickel-chromium alloy sputtering target blank to obtain the target blank with target diameter and target thickness; the purpose of the remelting and heating is to ensure the temperature of the cast ingot and improve the plastic deformation capacity of the nickel-chromium alloy cast ingot; the rolling temperature and the rolling reduction of each pass are further controlled to ensure that the nickel-chromium alloy sputtering target blank does not crack, and when the temperature is too low and the reduction is too large, the nickel-chromium alloy sputtering target blank cracks.

In a preferred embodiment of the present invention, the temperature of the terminal annealing is 450-.

Preferably, the holding time for the terminal annealing is 90-150min, such as 90min, 100min, 110min, 120min, 130min, 140min or 150min, but not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the end annealing is followed by water cooling so that the grain stops growing, and then the machining is performed.

As a preferred technical scheme of the invention, the machining comprises the steps of turning to remove oxide scales and wire-electrode cutting to form an excircle in sequence.

Preferably, the machining is performed using a horizontal lathe.

Preferably, after the machining, the nickel-chromium alloy sputtering target material is obtained by sequentially carrying out detection, cleaning, drying and packaging.

Preferably, the detection comprises a size detection and a performance detection.

Preferably, the size detection comprises diameter detection and thickness detection.

Preferably, the performance test includes surface state test, grain size test and internal defect test.

The surface state detection is used for judging whether the surface of the prepared nickel-chromium alloy sputtering target material has wrinkles and cracks.

The internal defect detection of the invention uses ultrasonic C scanning technology, C-SCAN detection for short, the technology integrates ultrasonic detection and data acquisition, storage, processing and image display under the control of a microcomputer, and the internal defect can be displayed according to different colors by displaying the outline of a workpiece through images.

As a preferred technical scheme of the invention, the preparation method comprises the following steps:

(1) cutting a nickel-chromium alloy cast ingot with the chromium mass ratio of 18-22% and the purity of 99.95-99.99% by adopting a horizontal sawing machine according to the target size;

(2) carrying out densification treatment on the nickel-chromium alloy cast ingot obtained by cutting in the step (1) by adopting hot isostatic pressing, wherein the hot isostatic pressing temperature is controlled to be 750-;

(3) preheating the nickel-chromium alloy ingot obtained by densification in the step (2) at the temperature of 900-1100 ℃, then forging, and controlling the total deformation rate of the forging to be 70-80%;

(4) annealing the nickel-chromium alloy ingot obtained by forging in the step (3), wherein the annealing temperature is 1000-1150 ℃, and the heat preservation time is 60-120 min;

(5) rolling the nickel-chromium alloy ingot obtained by annealing in the step (4) for 3-5 times, then returning to the furnace to continue heating for 40-80min at the temperature of 1000-1150 ℃, then performing the next rolling, and repeating the rolling-heating-rolling process until obtaining a nickel-chromium alloy sputtering target blank with the target diameter and the target thickness;

wherein, the pressing amount of each pass is controlled to be 5-10% of the thickness before the rolling of the pass so as to prevent the target blank from cracking; the total deformation of the rolling is 70-80%;

(6) performing terminal annealing treatment on the nickel-chromium alloy target blank rolled in the step (5), wherein the terminal annealing temperature is 450-550 ℃, the heat preservation time is 90-150min, and water cooling is performed after the terminal annealing so as to stop the growth of crystal grains;

(7) and (4) machining the nickel-chromium alloy target blank obtained by the terminal annealing in the step (6) by adopting a horizontal lathe, wherein the machining comprises turning to remove oxide skin and linear cutting of an excircle, and then, detecting, cleaning, drying and packaging are carried out in sequence to obtain the nickel-chromium alloy sputtering target.

The second purpose of the invention is to provide a nickel-chromium alloy sputtering target material which is prepared by the preparation method of the first purpose.

The nickel-chromium alloy sputtering target material can be combined with a copper back plate or an aluminum back plate through brazing or diffusion welding, and finally, precision machining is carried out according to the target size specified in a drawing, so that the nickel-chromium alloy sputtering target material component for magnetron sputtering is finally obtained.

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

(1) aiming at the problem of internal defects of the nickel-chromium alloy cast ingot obtained by smelting and casting, the preparation method carries out densification treatment before thermoplastic deformation processing, effectively avoids the problem of internal defects of a nickel-chromium alloy sputtering target material, and improves the yield to more than 90%;

(2) the nickel-chromium alloy sputtering target prepared by the preparation method has a uniform internal structure and fine grains, the grain size is less than or equal to 50 microns, the grain size can be generally controlled within the range of 20-30 microns, and the quality requirements of high-precision industries such as semiconductors are met.

Drawings

FIG. 1 is a metallographic picture (magnified 40 times) of a nickel-chromium alloy sputtering target material prepared in example 1 of the present invention;

FIG. 2 is a scanned image of a nickel-chromium alloy sputtering target prepared in example 1 of the present invention;

FIG. 3 is a scanned image of a NiCr alloy sputtering target prepared in example 4 of the present invention;

fig. 4 is a scanned image of a nichrome sputtering target prepared in comparative example 1 of the present invention.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings. 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.

To facilitate understanding of the invention, the following examples are set forth: