A target material leveling method

Abstract

The present invention provides a target material leveling method, the leveling method comprising the following steps: performing at least 4 leveling treatments on the target material under the condition of 15°C to 30°C; during the at least 4 leveling treatments, the leveling area of ​​the latter leveling treatment is not less than the leveling area of ​​the previous leveling treatment; during the at least 4 leveling treatments, the area range of the leveling area is 25% to 55% of the sputtering surface of the target material. The leveling method provided by the present invention is performed under the condition of 15°C to 30°C, which can avoid the risk of desoldering caused by thermal calibration. Moreover, the leveling method provided by the present invention has a simple process, and the flatness of the target material can be controlled within 1mm through at least 4 leveling treatments, which is conducive to industrial promotion and application.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor technology and relates to a method for preparing a target material, and in particular to a method for leveling a target material. Background Art

[0002] Metal sputtering target is the cathode material used in the sputtering deposition process. Under the impact of positively charged cations in the sputtering machine, the metal on the surface of the metal sputtering target is separated from the cathode in the form of molecules, atoms or ions and redeposited on the anode surface.

[0003] Since the strength of metal sputtering targets varies, in actual use it is necessary to combine a metal sputtering target that meets the performance requirements with a backing plate with a certain strength to form a target assembly, which is then installed on a sputtering machine to effectively control sputtering under the action of a magnetic field and an electric field.

[0004] However, there are differences in the thermal expansion coefficients between different metal sputtering targets and backing plates, resulting in different degrees of deformation of the target after cooling. For example, the Al target is bound to the copper backing plate, and after cooling, the entire target is "concave" with the four corners raised; while the Ti target is bound to the copper backing plate, and after cooling, the entire target is "convex" with an arch in the middle. The Mo target is bound to the copper backing plate, and after cooling, the entire target is "convex". However, poor flatness of the target will affect the sputtering coating of the target. Therefore, the deformed target needs to be leveled so that the bound target has good flatness.

[0005] CN110814096A discloses a post-welding shaping method for a metal target and a welding method, wherein a buffer pad and a cushion block are sequentially arranged above the target of a target assembly and then pressurized and shaped, wherein the hardness of the buffer pad is 30-60HA and the tensile strength is 50-100kg / cm 2 , which better relieves the instantaneous pressure on the target surface during the shaping process. It also improves the shaping efficiency of the target by heating the target before shaping and setting a gasket under the back plate of the target assembly.

[0006] CN111774437A discloses a method for pressurizing and shaping a target material after welding, the method comprising: in the process of pressurizing and shaping the target material after welding, as the temperature of the target material decreases, the pressure applied to the target material decreases step by step. The pressurization method is adopted in which the pressure gradually decreases and the cross-sectional area gradually decreases at the same time, the flatness requirement of the target material is ensured first, and then the central area where the stress is concentrated is pressurized and shaped to avoid cracks in the central area.

[0007] CN110484876A discloses a method for leveling a planar target, comprising a detection step, a leveling step, a leveling preparation sub-step, a leveling sub-step and a leveling waiting step performed in sequence: the target material and the back plate are respectively heated to 180-200°C for binding, a binding layer space is formed between the opposite surfaces of the target material and the back plate, a planar target is formed by filling the binding layer space with molten binding solder, the planar target is naturally cooled, and when cooled to 100-150°C, the planar target is leveled.

[0008] Although the prior art has a good leveling effect when leveling the target at a relatively high temperature, there is a risk of desoldering between the target and the backing plate. Therefore, it is necessary to provide a method for leveling the target at room temperature. Summary of the invention

[0009] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a target material leveling method, which can avoid the risk of desoldering caused by thermal calibration and can control the flatness of the target material within 1 mm, which is conducive to industrial promotion and application.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] The present invention provides a target material leveling method, the leveling method comprising:

[0012] Level the target at least 4 times at 15°C to 30°C;

[0013] When the leveling process is performed at least four times, the leveling area of ​​the last leveling process is not smaller than the leveling area of ​​the previous leveling process;

[0014] During the at least four leveling processes, the area of ​​the leveling region ranges from 25% to 55% of the target sputtering surface.

[0015] The leveling method provided by the present invention is not only applicable to circular planar targets, but also to long strip planar targets; the leveling method provided by the present invention is carried out under the condition of 15°C to 30°C, which can avoid the risk of desoldering caused by thermal calibration; moreover, the leveling method provided by the present invention has a simple process, and the flatness of the target can be controlled within 1 mm through at least 4 leveling treatments, which is conducive to industrial promotion and application.

[0016] Preferably, the leveling method comprises the following steps:

[0017] (1) Measure the warpage of the target and determine the leveling area of ​​the target;

[0018] (2) performing a first leveling on a first leveling area of ​​the target material, and maintaining pressure after the first leveling, so that the target material has a first warpage;

[0019] (3) performing a second leveling on the second leveling area of ​​the target material, and maintaining pressure after the second leveling, so that the target material has a second warpage;

[0020] (4) performing a third leveling on the third leveling area of ​​the target material, and maintaining pressure after the third leveling, so that the target material has a third warpage;

[0021] (5) performing fourth leveling on the fourth leveling area of ​​the target material, wherein the warpage during the fourth leveling is the negative value of the warpage before the fourth leveling;

[0022] Repeat the fourth leveling step (5) until the warping of the target is ≤1 mm.

[0023] Preferably, the central axis of the leveling area in step (1) coincides with the central axis of the target material.

[0024] Preferably, in step (2), the area of ​​the first leveling region ranges from 25% to 35% of the target sputtering surface.

[0025] Preferably, the warpage of the first leveling in step (2) is 45% to 55% of the warpage measured in step (1).

[0026] Preferably, the pressure maintaining time in step (2) is 25 min to 35 min.

[0027] Preferably, the first warpage in step (2) is 55% to 75% of the warpage measured in step (1).

[0028] Preferably, in step (3), the area of ​​the second leveling region ranges from 35% to 45% of the target sputtering surface.

[0029] Preferably, the warpage of the second leveling in step (3) is 15% to 25% of the warpage measured in step (1).

[0030] Preferably, the pressure maintaining time in step (3) is 25 min to 35 min.

[0031] Preferably, the second warpage in step (3) is 20% to 30% of the warpage measured in step (1).

[0032] Preferably, the area range of the third leveling region in step (4) is 45% to 55% of the target sputtering surface;

[0033] Preferably, the warping degree of the third leveling in step (4) is -0.1 mm to 0.1 mm.

[0034] Preferably, the pressure maintaining time in step (4) is 55 min to 65 min.

[0035] Preferably, the third warping degree in step (4) is 0.5 mm to 1 mm.

[0036] Preferably, the area of ​​the fourth leveling region in step (5) ranges from 45% to 55% of the target sputtering surface.

[0037] Preferably, the pressure holding time during the fourth leveling in step (5) is 55 min to 65 min.

[0038] Preferably, the third leveling area in step (4) is the same as the fourth leveling area in step (5).

[0039] Preferably, the target comprises a square target or a round target.

[0040] The material of the target material of the present invention includes but is not limited to any one of a tungsten target material, a tungsten silicon target material, a chromium silicon target material, a graphite target material or an ITO target material.

[0041] Exemplarily, the length of the square target is ≥400 mm.

[0042] The width of the square target is ≥200 mm.

[0043] The thickness of the square target material is ≥10 mm.

[0044] Exemplarily, the diameter of the circular target is ≤500 mm.

[0045] Preferably, during the leveling process, a buffer pad is arranged in the leveling area.

[0046] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The leveling method provided by the present invention is not only applicable to circular planar targets, but also to long strip planar targets; the leveling method provided by the present invention is carried out under the condition of 15°C to 30°C, which can avoid the risk of desoldering caused by thermal calibration; moreover, the leveling method provided by the present invention has a simple process, and the flatness of the target can be controlled within 1 mm through at least 4 leveling treatments, which is conducive to industrial promotion and application. DETAILED DESCRIPTION

[0049] A certain embodiment of the present invention provides a target material leveling method, the leveling method comprising the following steps:

[0050] Level the target at least 4 times at 15°C to 30°C;

[0051] When the leveling process is performed at least four times, the leveling area of ​​the last leveling process is not smaller than the leveling area of ​​the previous leveling process;

[0052] During the at least four leveling processes, the area of ​​the leveling region ranges from 25% to 55% of the target sputtering surface.

[0053] The leveling method provided by the present invention is carried out under the condition of 15°C to 30°C, which can avoid the risk of desoldering caused by thermal calibration. Moreover, the leveling method provided by the present invention has a simple process, and the flatness of the target material can be controlled within 1 mm through at least 4 leveling treatments, which is conducive to industrial promotion and application.

[0054] The leveling treatment described in the present invention is carried out under conditions of 15°C to 30°C, for example, it can be 15°C, 18°C, 20°C, 25°C, 28°C or 30°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0055] The area range of the leveling region of the present invention is 25% to 55% of the target sputtering surface, for example, it can be 25%, 30%, 35%, 40%, 45%, 50% or 55%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0056] Exemplarily, the leveling process of the present invention is performed using a leveling machine, which can provide uniform pressure in the leveling area, thereby achieving leveling of the target material.

[0057] The target material described in the present invention refers to the target material after brazing with the back plate. Due to the difference in thermal expansion coefficient between the target material and the back plate, the target material will deform by 5mm to 30mm during the cooling process of brazing, resulting in the flatness failing to meet the use requirements of the target material. The present invention can control the flatness of the target material within 1mm by at least 4 leveling treatments, and the leveling treatment is carried out at 15℃ to 30℃, which can avoid the risk of desoldering caused by thermal calibration.

[0058] In some embodiments, the leveling method comprises the following steps:

[0059] (1) Measure the warpage of the target and determine the leveling area of ​​the target;

[0060] (2) performing a first leveling on a first leveling area of ​​the target material, and maintaining pressure after the first leveling, so that the target material has a first warpage;

[0061] (3) performing a second leveling on the second leveling area of ​​the target material, and maintaining pressure after the second leveling, so that the target material has a second warpage;

[0062] (4) performing a third leveling on the third leveling area of ​​the target material, and maintaining pressure after the third leveling, so that the target material has a third warpage;

[0063] (5) performing fourth leveling on the fourth leveling area of ​​the target material, wherein the warpage during the fourth leveling is the negative value of the warpage before the fourth leveling;

[0064] Repeat the fourth leveling step (5) until the warping of the target is ≤1 mm.

[0065] The warpage before the fourth leveling of the present invention refers to the third warpage of the target material. Exemplarily, when the third warpage of the target material is 2mm, the warpage of the target material during the fourth leveling is -2mm. Generally speaking, after the fourth leveling, the warpage of the target material is ≤1mm; if the warpage of the target material is still >1mm, repeat the fourth leveling described in step (5): that is, when performing the leveling process, make the warpage the negative value of the warpage of the target material, and maintain the pressure according to the fourth leveling holding time until the warpage of the target material is ≤1mm.

[0066] In some embodiments, the central axis of the leveling area in step (1) coincides with the central axis of the target material.

[0067] In some embodiments, the area range of the first leveling region in step (2) is 25% to 35% of the target sputtering surface, for example, it can be 25%, 28%, 30%, 32% or 35%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0068] In some embodiments, the warpage of the first leveling in step (2) is 45% to 55% of the warpage measured in step (1), for example, it can be 45%, 48%, 50%, 52% or 55%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0069] In some embodiments, the holding time of step (2) is 25 minutes to 35 minutes, for example, it can be 25 minutes, 28 minutes, 30 minutes, 32 minutes or 35 minutes, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0070] Exemplarily, using a leveling machine for leveling treatment, the pressure maintenance refers to the pressure head of the leveling machine continuously pressing on the target surface.

[0071] After the pressure maintenance in step (2) of the present invention is completed, the warpage of the target material will inevitably rebound. In some embodiments, the first warpage in step (2) is 55% to 75% of the warpage measured in step (1), for example, it can be 55%, 60%, 65%, 70% or 75%, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0072] In some embodiments, the area range of the second leveling region in step (3) is 35% to 45% of the target sputtering surface, for example, it can be 35%, 38%, 40%, 42% or 45%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0073] In some embodiments, the warpage of the second leveling in step (3) is 15% to 25% of the warpage measured in step (1), for example, it can be 15%, 18%, 20%, 22% or 25%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0074] In some embodiments, the holding time of step (3) is 25 minutes to 35 minutes, for example, it can be 25 minutes, 28 minutes, 30 minutes, 32 minutes or 35 minutes, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0075] Exemplarily, using a leveling machine for leveling treatment, the pressure maintenance refers to the pressure head of the leveling machine continuously pressing on the target surface.

[0076] After the pressure maintenance in step (3) of the present invention is completed, the warpage of the target material will inevitably rebound. In some embodiments, the second warpage in step (3) is 20% to 30% of the warpage measured in step (1), for example, it can be 20%, 22%, 25%, 28% or 30%, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0077] In some embodiments, the area range of the third leveling region in step (4) is 45% to 55% of the target sputtering surface, for example, it can be 45%, 48%, 50%, 52% or 55%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0078] In some embodiments, the warping degree of the third leveling in step (4) is -0.1mm to 0.1mm, for example, it can be -0.1mm, -0.05mm, 0mm, 0.05mm or 0.1mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0079] In some embodiments, the holding time of step (4) is 55 min to 65 min, for example, 55 min, 58 min, 60 min, 62 min or 65 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0080] Exemplarily, using a leveling machine for leveling treatment, the pressure maintenance refers to the pressure head of the leveling machine continuously pressing on the target surface.

[0081] After the pressure maintenance in step (4) of the present invention is completed, the warping of the target material will inevitably rebound.

[0082] In some embodiments, the third warping degree in step (4) is 0.5 mm to 1 mm, for example, 0.5 mm, 0.6 mm, 0.8 mm, 0.9 mm or 1 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0083] In some embodiments, the area range of the fourth leveling region in step (5) is 45% to 55% of the target sputtering surface, for example, it can be 45%, 48%, 50%, 52% or 55%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0084] In some embodiments, the holding time during the fourth leveling in step (5) is 55 min to 65 min, for example, it can be 55 min, 58 min, 60 min, 62 min or 65 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0085] In some embodiments, the third leveling area described in step (4) is the same as the fourth leveling area described in step (5).

[0086] The leveling method of the present invention is applicable to square targets or circular targets.

[0087] The material of the target includes but is not limited to any one of a tungsten target, a tungsten silicon target, a chromium silicon target, a graphite target or an ITO target.

[0088] In some embodiments, the length of the square target is ≥400 mm, for example, it can be 400 mm, 420 mm, 450 mm, 480 mm or 500 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0089] The width of the square target is ≥200 mm, for example, it can be 200 mm, 210 mm, 220 mm, 240 mm or 250 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0090] The thickness of the square target material is ≥10 mm, for example, it can be 10 mm, 11 mm, 12 mm, 14 mm or 15 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0091] In some embodiments, the diameter of the circular target is ≤500 mm, for example, it can be 50 mm, 100 mm, 200 mm, 300 mm, 400 mm or 500 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0092] In some embodiments, during the leveling process, a buffer pad is provided in the leveling area.

[0093] The buffer pad described in the present invention includes but is not limited to a silicone pad. When performing the leveling method described in the present invention, a buffer pad is placed in the leveling area of ​​the target material, and then a pad block with the same area as the leveling area is placed on the buffer pad. The pressure head of the leveling machine is evenly applied to the pad block to achieve leveling of the target material.

[0094] In some embodiments, the leveling method comprises performing at least 4 leveling treatments on the target material at a temperature of 15° C. to 30° C.; during the leveling treatment, a buffer pad is arranged in the leveling area, a pad block having the same area as the corresponding leveling area is placed on the buffer pad, and a pressure head of a leveling machine is uniformly applied to the pad block to achieve leveling of the target material. The leveling method comprises the following steps:

[0095] (1) measuring the warpage of the target material and determining a leveling area of ​​the target material; the central axis of the leveling area coincides with the central axis of the target material;

[0096] (2) performing a first leveling on a first leveling area of ​​the target material, and maintaining pressure for 25 to 35 minutes after the first leveling, wherein the target material has a first warpage; the area range of the first leveling area is 25% to 35% of the sputtering surface of the target material, and the warpage of the first leveling is 45% to 55% of the warpage measured in step (1); the first warpage is 55% to 75% of the warpage measured in step (1);

[0097] (3) performing a second leveling on the second leveling area of ​​the target material, and maintaining the pressure for 25 minutes to 35 minutes after the second leveling, the target material has a second warpage; the area range of the second leveling area is 35% to 45% of the sputtering surface of the target material, and the warpage of the second leveling is 15% to 25% of the warpage measured in step (1); the second warpage is 20% to 30% of the warpage measured in step (1);

[0098] (4) performing a third leveling on the third leveling area of ​​the target material, and maintaining the pressure for 55 minutes to 65 minutes after the third leveling, and the target material has a third warpage; the area range of the third leveling area is 45% to 55% of the sputtering surface of the target material, and the warpage of the third leveling is -0.1 mm to 0.1 mm; the third warpage is 0.5 mm to 1 mm;

[0099] (5) performing a fourth leveling on the fourth leveling area of ​​the target material, wherein the warpage during the fourth leveling is the negative value of the warpage before the fourth leveling; the area range of the fourth leveling area is 45% to 55% of the sputtering surface of the target material, and the holding time during the fourth leveling is 55 min to 65 min; the third leveling area is the same as the fourth leveling area;

[0100] Repeat the fourth leveling step (5) until the warping of the target is ≤1 mm.

[0101] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0102] In order to clearly illustrate the technical solution of the present invention, the target material in the specific implementation manner is a square tungsten target material with a length of 400 mm, a width of 200 mm and a thickness of 10 mm, and the warpage of the target material after brazing with the copper backing plate is 4 mm. The above-mentioned limitation of the target material is only for the purpose of clearly illustrating the technical solution and is not regarded as a further limitation of the target material.

[0103] Example 1

[0104] This embodiment provides a target material leveling method, the leveling method comprising performing four leveling treatments on the target material at 20° C.; during the leveling treatment, a buffer pad is arranged in the leveling area, a pad block having the same area as the corresponding leveling area is placed on the buffer pad, and a pressure head of a leveling machine is uniformly applied to the pad block to achieve target material leveling. The leveling method comprises the following steps:

[0105] (1) measuring the warpage of the target material and determining the leveling area of ​​the target material; the central axis of the leveling area coincides with the central axis of the target material; in this embodiment, the target material is a flat titanium target material brazed with a copper backing plate, and the warpage is 10 mm;

[0106] (2) performing a first leveling on a first leveling area of ​​the target material, and maintaining pressure for 30 minutes after the first leveling, the target material has a first warpage; the area range of the first leveling area is 30% of the sputtering surface of the target material, and the warpage of the first leveling is 50% of the warpage measured in step (1); due to the rebound after maintaining pressure, the first warpage is 64.8% of the warpage measured in step (1);

[0107] (3) performing a second leveling on the second leveling area of ​​the target material, and maintaining pressure for 30 minutes after the second leveling, the target material has a second warpage; the area range of the second leveling area is 40% of the sputtering surface of the target material, and the warpage of the second leveling is 20% of the warpage measured in step (1); due to the rebound after maintaining pressure, the second warpage is 25.6% of the warpage measured in step (1);

[0108] (4) performing a third leveling on the third leveling area of ​​the target material, and maintaining pressure for 60 minutes after the third leveling, the target material has a third warpage; the area range of the third leveling area is 50% of the sputtering surface of the target material, and the warpage of the third leveling is 0 mm; due to the rebound after maintaining pressure, the third warpage is 0.7 mm;

[0109] (5) Performing a fourth leveling on the fourth leveling area of ​​the target material, the warping degree during the fourth leveling is the negative value of the warping degree before the fourth leveling; the area range of the fourth leveling area is 50% of the sputtering surface of the target material, and the holding time during the fourth leveling is 60 minutes; the third leveling area is the same as the fourth leveling area.

[0110] Example 2

[0111] This embodiment provides a target material leveling method, the leveling method comprising performing four leveling treatments on the target material at 20° C.; during the leveling treatment, a buffer pad is arranged in the leveling area, a pad block having the same area as the corresponding leveling area is placed on the buffer pad, and a pressure head of a leveling machine is uniformly applied to the pad block to achieve target material leveling. The leveling method comprises the following steps:

[0112] (1) measuring the warpage of the target material and determining the leveling area of ​​the target material; the central axis of the leveling area coincides with the central axis of the target material; in this embodiment, the target material is a flat titanium target material brazed with a copper backing plate, and the warpage is 10 mm;

[0113] (2) performing a first leveling on a first leveling area of ​​the target material, and maintaining pressure for 25 minutes after the first leveling, the target material has a first warpage; the area range of the first leveling area is 25% of the sputtering surface of the target material, and the warpage of the first leveling is 45% of the warpage measured in step (1); due to the rebound after maintaining pressure, the first warpage is 61.2% of the warpage measured in step (1);

[0114] (3) performing a second leveling on the second leveling area of ​​the target material, and maintaining pressure for 25 minutes after the second leveling, the target material has a second warpage; the area range of the second leveling area is 35% of the sputtering surface of the target material, and the warpage of the second leveling is 15% of the warpage measured in step (1); due to the rebound after maintaining pressure, the second warpage is 20.4% of the warpage measured in step (1);

[0115] (4) performing a third leveling on the third leveling area of ​​the target material, and maintaining pressure for 55 minutes after the third leveling, the target material has a third warpage; the area range of the third leveling area is 45% of the sputtering surface of the target material, and the warpage of the third leveling is 0 mm; due to the rebound after maintaining pressure, the third warpage is 0.5 mm;

[0116] (5) Performing a fourth leveling on the fourth leveling area of ​​the target material, the warping degree during the fourth leveling is the negative value of the warping degree before the fourth leveling; the area range of the fourth leveling area is 45% of the sputtering surface of the target material, and the holding time during the fourth leveling is 55 minutes; the third leveling area is the same as the fourth leveling area.

[0117] Example 3

[0118] This embodiment provides a target material leveling method, the leveling method comprising performing four leveling treatments on the target material at 20° C.; during the leveling treatment, a buffer pad is arranged in the leveling area, a pad block having the same area as the corresponding leveling area is placed on the buffer pad, and a pressure head of a leveling machine is uniformly applied to the pad block to achieve target material leveling. The leveling method comprises the following steps:

[0119] (1) measuring the warpage of the target material and determining the leveling area of ​​the target material; the central axis of the leveling area coincides with the central axis of the target material; in this embodiment, the target material is a flat titanium target material brazed with a copper backing plate, and the warpage is 10 mm;

[0120] (2) performing a first leveling on a first leveling area of ​​the target material, and maintaining pressure for 35 minutes after the first leveling, the target material has a first warpage; the area range of the first leveling area is 35% of the sputtering surface of the target material, and the warpage of the first leveling is 55% of the warpage measured in step (1); due to the rebound after maintaining pressure, the first warpage is 68.4% of the warpage measured in step (1);

[0121] (3) performing a second leveling on the second leveling area of ​​the target material, and maintaining pressure for 35 minutes after the second leveling, the target material has a second warpage; the area range of the second leveling area is 45% of the sputtering surface of the target material, and the warpage of the second leveling is 25% of the warpage measured in step (1); due to the rebound after maintaining pressure, the second warpage is 28.1% of the warpage measured in step (1);

[0122] (4) performing a third leveling on the third leveling area of ​​the target material, and maintaining pressure for 65 minutes after the third leveling, the target material has a third warpage; the area range of the third leveling area is 55% of the sputtering surface of the target material, and the warpage of the third leveling is 0.1 mm; due to the rebound after maintaining pressure, the third warpage is 1 mm;

[0123] (5) Performing a fourth leveling on the fourth leveling area of ​​the target material, the warping degree during the fourth leveling is the negative value of the warping degree before the fourth leveling; the area range of the fourth leveling area is 55% of the sputtering surface of the target material, and the holding time during the fourth leveling is 65 minutes; the third leveling area is the same as the fourth leveling area.

[0124] Example 4

[0125] This embodiment provides a target material leveling method, which is the same as that of Embodiment 1 except that the leveling process is performed at 15°C.

[0126] Example 5

[0127] This embodiment provides a target material leveling method, which is the same as that of Embodiment 1 except that the leveling process is performed at 25°C.

[0128] Example 6

[0129] This embodiment provides a target material leveling method, which is the same as that of Embodiment 1 except that the area ranges of the first leveling region, the second leveling region, the third leveling region and the fourth leveling region are all 30% of the target material sputtering surface.

[0130] Example 7

[0131] This embodiment provides a target material leveling method, which is the same as that of Embodiment 1 except that the area ranges of the first leveling region, the second leveling region, the third leveling region and the fourth leveling region are all 40% of the target material sputtering surface.

[0132] Example 8

[0133] This embodiment provides a target material leveling method, which is the same as that of Embodiment 1 except that the area ranges of the first leveling region, the second leveling region, the third leveling region and the fourth leveling region are all 50% of the target material sputtering surface.

[0134] Example 9

[0135] This embodiment provides a method for leveling a target material, which is the same as that of Embodiment 1 except that the pressure holding time in step (2) is 15 minutes.

[0136] Example 10

[0137] This embodiment provides a method for leveling a target material, which is the same as that of Embodiment 1 except that the pressure maintenance described in step (2) is not performed.

[0138] Since the pressure maintenance described in step (2) was not performed, there were obvious cracks when the warpage of the third leveling was 0 mm, and the leveling of the target material could not be achieved.

[0139] Embodiment 11

[0140] This embodiment provides a method for leveling a target material, which is the same as that of Embodiment 1 except that the pressure holding time in step (3) is 15 minutes.

[0141] Example 12

[0142] This embodiment provides a method for leveling a target material, which is the same as that of Embodiment 1 except that the pressure maintenance described in step (3) is not performed.

[0143] Since the pressure maintenance described in step (2) was not performed, there were obvious cracks when the warpage of the third leveling was 0 mm, and the leveling of the target material could not be achieved.

[0144] Embodiment 13

[0145] This embodiment provides a method for leveling a target material, which is the same as that of Embodiment 1 except that the pressure holding time in step (4) is 45 minutes.

[0146] Embodiment 14

[0147] This embodiment provides a method for leveling a target material, which is the same as that of Embodiment 1 except that the pressure maintenance described in step (4) is not performed.

[0148] The flatness of the target materials after leveling treatment in Examples 1-14 was tested, and whether there were cracks on the surface of the target materials was observed. The results are shown in Table 1.

[0149] Table 1

[0150] Flatness(mm) Is there any crack? Example 1 0.53 no Example 2 0.58 no Example 3 0.56 no Example 4 0.55 no Example 5 0.53 no Example 6 0.85 There are small cracks Example 7 0.98 There are small cracks Example 8 1.10 no Example 9 0.68 no Example 10 - yes Embodiment 11 0.65 no Example 12 - yes Example 13 0.60 no Embodiment 14 0.63 no

[0151] In summary, the leveling method provided by the present invention is not only applicable to circular planar targets, but also to long strip planar targets; the leveling method provided by the present invention is carried out under the conditions of 15°C to 30°C, which can avoid the risk of desoldering caused by thermal calibration, and the leveling method provided by the present invention has a simple process, and the flatness of the target can be controlled within 1 mm through at least 4 leveling treatments, which is conducive to industrial promotion and application.

[0152] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A target material leveling method, characterized in that: The target material refers to the target material after brazing with the back plate. The leveling method is carried out at 15° C. to 30° C. and has the following steps: (1) measuring the warpage of the target material and determining a leveling area of ​​the target material, wherein the central axis of the leveling area coincides with the central axis of the target material; (2) performing a first leveling on the first leveling area of ​​the target material, wherein the warpage of the first leveling is 45% to 55% of the warpage measured in step (1), and maintaining the pressure for 25 to 35 minutes after the first leveling is completed, and the target material has a first warpage; (3) performing a second leveling on the second leveling area of ​​the target material, wherein the warpage of the second leveling is 15% to 25% of the warpage measured in step (1), and after the second leveling is completed, the pressure is maintained for 25 minutes to 35 minutes, and the target material has a second warpage; (4) performing a third leveling on the third leveling area of ​​the target material, wherein the warpage of the third leveling is -0.1 mm to 0.1 mm, and after the third leveling is completed, the pressure is maintained for 55 min to 65 min, and the target material has a third warpage; (5) Perform the fourth leveling on the fourth leveling area of ​​the target material. The warpage during the fourth leveling is the negative value of the warpage before the fourth leveling. The holding time during the fourth leveling is 55 minutes to 65 minutes. Repeat the fourth leveling step (5) until the target warpage is ≤1 mm; Step (2) The area of ​​the first leveling region is 25% to 35% of the target sputtering surface; Step (3) the area of ​​the second leveling region is 35% to 45% of the target sputtering surface; The area of ​​the third leveling region in step (4) is 45% to 55% of the target sputtering surface; The area of ​​the fourth leveling region in step (5) is 45% to 55% of the target sputtering surface; The third leveling area in step (4) is the same as the fourth leveling area in step (5); During the leveling process, the leveling area of ​​the latter leveling process is not smaller than the leveling area of ​​the former leveling process.

2. The leveling method according to claim 1, characterized in that: The first warpage in step (2) is 55% to 75% of the warpage measured in step (1).

3. The leveling method according to claim 1, characterized in that: The second warpage in step (3) is 20% to 30% of the warpage measured in step (1).

4. The leveling method according to claim 1, characterized in that: The third warping degree in step (4) is 0.5 mm to 1 mm.

5. The leveling method according to claim 1, characterized in that: The target material includes a square target material or a round target material.

6. The leveling method according to claim 1, characterized in that: During the leveling process, a buffer pad is arranged in the leveling area.