Method for improving utilization rate of target material in PVD (Physical Vapor Deposition) coating process

Abstract

The invention provides a method for improving the utilization rate of a target material in a PVD (Physical Vapor Deposition) coating process. The PVD coating process comprises magnetron sputtering coating; the method comprises the steps that a target material is sequentially subjected to first magnetron sputtering treatment and second magnetron sputtering treatment, and sputtering coating is completed; the power of the first magnetron sputtering treatment is 1.5-2.5 times of the power of the second magnetron sputtering treatment; the magnetic field direction in the first magnetron sputtering treatment and the second magnetron sputtering treatment is in the axial direction, and the magnetic field intensity at the two ends is higher than the magnetic field intensity in the middle. According to the method, the magnetic field design and the magnetron sputtering power are optimized in an existing magnetron sputtering device, the target material utilization rate in the PVD coating process is greatly increased, then the coating cost is reduced, the production benefit is improved, and the method is suitable for large-range application and popularization.

Description

Technical Field

[0001] The invention relates to the technical field of physical vapor deposition, and in particular to a method for improving the utilization rate of target materials in a PVD coating process. Background Art

[0002] PVD coating process refers to physical vapor deposition (PVD) technology, which is a technology that vaporizes the surface of a material into gaseous atoms or molecules through physical methods under vacuum conditions, and deposits a thin film with certain special functions on the surface of the substrate.

[0003] In the PVD coating process, the target material is a key consumable material, and its cost usually accounts for a large proportion of the total coating cost. Due to the limitations of factors such as the shape of the target material, the magnetic field distribution during the sputtering process, and the sputtering process parameters, only some areas of the target material can be effectively sputtered during use, while the target material in other areas is not fully utilized, resulting in waste of resources and increased costs. Traditional PVD coating methods often have the problem of low target material utilization.

[0004] CN105441894A discloses a focused ion beam physical vapor deposition device, wherein the process chamber is connected to the target material transmission chamber and the substrate transmission chamber, the target material transmission chamber and the substrate transmission chamber are respectively connected to the target loading chamber and the film loading chamber, the process chamber is provided with a target holder, a substrate rack, a mask plate and an ion source with a focusing module, the target material transmission chamber and the substrate transmission chamber are respectively provided with a vacuum manipulator device, and the substrate transmission chamber is also connected to the heat treatment chamber. By integrating the process chamber, the target loading chamber, the film loading chamber, the target material transmission chamber, the substrate transmission chamber and the heat treatment chamber together and forming a vacuum environment as a whole, the replacement of the target materials and the whole process of thin film material preparation can be realized under a vacuum environment. The ion beam focused by the focusing module can be concentrated to bombard only the surface of the target material to avoid cross contamination, and the size of the target material can be reduced, reducing the loss of the target material and improving the utilization rate of the target material. It can also avoid cross contamination between sputtering targets and the pollution of thin film coating caused by non-process gas pollution sources in the preparation device.

[0005] CN209243164U discloses a magnetron device and physical vapor deposition equipment. The magnetron device includes: a conveyor assembly, located above the target material, including an annular conveyor belt; the conveyor belt can be driven around an axis passing through its center and extending along its width direction; the projection of the conveyor belt in the vertical direction completely covers the target material; a magnetron assembly, fixed to the surface of the conveyor belt, including at least one magnetron structure, the magnetron structure including two soft magnets arranged along a first direction and a plurality of permanent magnets sandwiched between the two soft magnets; the soft magnet is in the shape of a long strip, and the two magnetic poles of the permanent magnet are in one-to-one contact and connection with the two soft magnets to induce a uniformly distributed magnetic field in the soft magnet. The device improves the utilization rate of the target material and reduces the cost of semiconductor manufacturing.

[0006] CN101319305A discloses a physical vapor deposition system, including a deposition reaction chamber, a magnet, a planetary gear set, a first driving device, a driving gear and a second driving device. The magnet is arranged on the deposition reaction chamber. The planetary gear set has an annular gear ring, a first gear, a second gear and a balance gear. The annular gear ring surrounds the first gear, the second gear and the balance gear, and has an inner tooth surface and an outer tooth surface. The rotation center axis of the annular gear ring coincides with the rotation center axis of the first gear. The second gear and the balance gear are meshed between the inner tooth surface and the first gear. The rotation center axis of the second gear coincides with and is connected to the rotation center axis of the magnet. The first driving device is connected to the rotation center axis of the first gear, and the driving gear is meshed with the outer tooth surface. The second driving device is connected to the driving gear. The uniformity of plasma bombardment can be improved by uniform magnetic field distribution, which can effectively improve the utilization rate of target materials.

[0007] However, the above-mentioned methods for improving the utilization rate of target materials all use new devices and equipment, which will increase the cost of the existing coating process. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a method for improving the utilization rate of target materials in the PVD coating process. By optimizing the magnetic field design and the power of magnetron sputtering in the existing magnetron sputtering device, the utilization rate of target materials in the PVD coating process is greatly improved, thereby reducing the coating cost and improving production efficiency.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] The present invention provides a method for improving the utilization rate of target materials in a PVD coating process, wherein the PVD coating process includes magnetron sputtering coating; the method comprises:

[0011] The target material is sequentially subjected to a first magnetron sputtering treatment and a second magnetron sputtering treatment to complete sputtering coating;

[0012] The power of the first magnetron sputtering process is 1.5 to 2.5 times that of the second magnetron sputtering process; the magnetic field direction in the first magnetron sputtering process and the second magnetron sputtering process is axial, and the magnetic field strength at both ends is higher than the magnetic field strength in the middle.

[0013] The method for improving the target material utilization rate in the PVD coating process of the present invention is based on the problem that the sputtered target material is thin in the middle and thick around the edges in the prior art. Two magnetron sputterings with different powers are used, and combined with a specific magnetic field strength, the sputtering speeds of each area of ​​the target material are close to the same, thereby improving the target material utilization rate. Under the condition that the magnetic field strength at both ends is higher than the magnetic field strength in the middle, a first magnetron sputtering treatment with a higher power is performed to quickly remove impurities and oxide layers on the surface of the target material; then, a second magnetron sputtering treatment with normal sputtering power is performed under the magnetic field strength condition, so that the sputtering process is more stable and uniform, and all areas of the target material are effectively sputtered, thereby improving the target material utilization rate and reducing the coating cost.

[0014] The power of the first magnetron sputtering process of the present invention is 1.5 to 2.5 times the power of the second magnetron sputtering process, for example, it can be 1.5 times, 1.6 times, 1.8 times, 2 times, 2.2 times, 2.4 times or 2.5 times, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0015] When the power of the first magnetron sputtering treatment is less than 1.5 times the power of the second magnetron sputtering treatment, impurities and oxide layers on the surface of the target material cannot be removed well, which will lead to uneven sputtering in various areas of the subsequent target material and a significant reduction in the utilization rate of the target material; when the power of the first magnetron sputtering treatment is more than 2.5 times the power of the second magnetron sputtering treatment, it will cause the surface of the target material to overheat, affecting the stability of the coating, and will also cause the density of various defects inside the film to increase, affecting the uniformity and density of the film, and will also lead to a reduction in the utilization rate of the target material.

[0016] The present invention controls the magnetic field strength at both ends to be higher than the magnetic field strength in the middle by adjusting the magnetic field generating device. The present invention does not impose a detailed limitation on the magnetic field strength, and it can be reasonably set according to the conditions of the target material and the needs of the magnetron sputtering process.

[0017] Preferably, the target comprises a planar target or a rotating target.

[0018] Preferably, the target material comprises a metal target material or an alloy target material.

[0019] Preferably, the metal target includes any one of a copper target, a molybdenum target, a titanium target or a tantalum target.

[0020] Preferably, the rotation speed of the rotating target is 10-30 rpm, for example, it can be 10 rpm, 12 rpm, 15 rpm, 18 rpm, 20 rpm, 25 rpm or 30 rpm, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] The present invention preferably has a rotating speed of 10 to 30 rpm to ensure that the film quality of the magnetron sputtering coating is high and the target utilization rate is high. When the rotating speed of the rotating target is too low, the uniformity and density of the film will decrease, thereby affecting its corrosion resistance; when the rotating speed of the rotating target is too high, the utilization rate of the rotating target will decrease.

[0022] Preferably, the power of the first magnetron sputtering treatment is 1.5-2kW, for example, it can be 1.5kW, 1.6kW, 1.7kW, 1.8kW, 1.85kW, 1.9kW or 2kW, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] Preferably, the time of the first magnetron sputtering treatment is 2 to 5 minutes, for example, it can be 2 minutes, 2.5 minutes, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes or 5 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] The present invention does not impose any specific restrictions on the time of the second magnetron sputtering treatment, and can be reasonably adjusted according to the required coating thickness.

[0025] Preferably, a protective gas is introduced into the first magnetron sputtering process and the second magnetron sputtering process.

[0026] Preferably, the protective gas comprises nitrogen and / or argon.

[0027] Preferably, the flow rate of the protective gas is 10 to 20 sccm, for example, it can be 10 sccm, 12 sccm, 15 sccm, 16 sccm, 18 sccm, 19 sccm or 20 sccm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] As a preferred technical solution of the present invention, the method comprises:

[0029] The target material is sequentially subjected to a first magnetron sputtering treatment of 2 to 5 minutes and a second magnetron sputtering treatment at a power of 1.5 to 2 kW to complete sputtering coating;

[0030] The target material includes a planar target material or a rotating target material; the target material includes a metal target material or an alloy target material; the metal target material includes any one of a copper target material, a molybdenum target material, a titanium target material or a tantalum target material; the rotation speed of the rotating target material is 10 to 30 rpm;

[0031] The power of the first magnetron sputtering treatment is 1.5 to 2.5 times the power of the second magnetron sputtering treatment; the direction of the magnetic field in the first magnetron sputtering treatment and the second magnetron sputtering treatment is axial, and the magnetic field strength at both ends is higher than the magnetic field strength in the middle; a protective gas is introduced into the first magnetron sputtering treatment and the second magnetron sputtering treatment; the protective gas includes nitrogen and / or argon; the flow rate of the protective gas is 10 to 20 sccm.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] The method for improving the target material utilization rate in the PVD coating process provided by the present invention is simple to operate. By improving the design of the magnetic field strength in the existing magnetron sputtering device and performing two magnetron sputtering processes with specific power, the target material utilization rate is significantly improved, which is of great significance for reducing coating costs and improving production efficiency. DETAILED DESCRIPTION

[0034] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0035] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0036] The following are typical but non-limiting embodiments of the present invention:

[0037] Example 1

[0038] This embodiment provides a method for improving target material utilization in a PVD coating process, the method comprising:

[0039] After the rotating target material starts to rotate at a speed of 20 rpm, a first magnetron sputtering treatment with a power of 2 kW for 3 min and a second magnetron sputtering treatment with a power of 1 kW for 20 min are sequentially performed to complete the sputtering coating;

[0040] The rotating target is a molybdenum target;

[0041] In the first magnetron sputtering process and the second magnetron sputtering process, the direction of the magnetic field is axial, and the magnetic field strength at both ends is higher than the magnetic field strength in the middle; protective gas nitrogen is introduced into the first magnetron sputtering process and the second magnetron sputtering process; the flow rate of the protective gas is 15sccm.

[0042] Example 2

[0043] This embodiment provides a method for improving target material utilization in a PVD coating process, the method comprising:

[0044] After the rotating target material starts to rotate at a speed of 30 rpm, a first magnetron sputtering treatment with a power of 1.5 kW for 5 min and a second magnetron sputtering treatment with a power of 1 kW for 15 min are sequentially performed to complete the sputtering coating;

[0045] The rotating target is a titanium target;

[0046] In the first magnetron sputtering process and the second magnetron sputtering process, the direction of the magnetic field is axial, and the magnetic field strength at both ends is higher than that in the middle; in the first magnetron sputtering process and the second magnetron sputtering process, protective gas argon is introduced; the flow rate of the protective gas is 10 sccm.

[0047] Example 3

[0048] This embodiment provides a method for improving target material utilization in a PVD coating process, the method comprising:

[0049] The planar target material is subjected to the first magnetron sputtering treatment with a power of 2 kW for 2 min and the second magnetron sputtering treatment for 30 min in sequence to complete the sputtering coating;

[0050] The planar target is a tantalum target;

[0051] The power of the first magnetron sputtering treatment is 1.5 times that of the second magnetron sputtering treatment; the direction of the magnetic field in the first magnetron sputtering treatment and the second magnetron sputtering treatment is axial, and the magnetic field strength at both ends is higher than the magnetic field strength in the middle; protective gas nitrogen is introduced into the first magnetron sputtering treatment and the second magnetron sputtering treatment; the flow rate of the protective gas is 20sccm.

[0052] Example 4

[0053] This embodiment provides a method for improving target material utilization in a PVD coating process, the method comprising:

[0054] The planar target was subjected to the first magnetron sputtering treatment with a power of 1.8 kW for 2.5 min and the second magnetron sputtering treatment for 13 min in sequence to complete the sputtering coating;

[0055] The planar target is a copper target;

[0056] The power of the first magnetron sputtering treatment is 2.5 times that of the second magnetron sputtering treatment; the direction of the magnetic field in the first magnetron sputtering treatment and the second magnetron sputtering treatment is axial, and the magnetic field strength at both ends is higher than the magnetic field strength in the middle; protective gas argon is introduced into the first magnetron sputtering treatment and the second magnetron sputtering treatment; the flow rate of the protective gas is 13sccm.

[0057] It can be seen from Examples 1 to 4 that the method for improving target utilization in a PVD coating process provided by the present invention is simple to operate, and two magnetron sputtering processes within a specific power range are performed under a specific magnetic field strength, resulting in a high target utilization rate.

[0058] Example 5

[0059] This embodiment provides a method for improving the utilization rate of the target material in the PVD coating process. The method is the same as that of Embodiment 1 except that the rotation speed of the rotating target material is 7 rpm.

[0060] Example 6

[0061] This embodiment provides a method for improving the utilization rate of the target material in the PVD coating process. The method is the same as that of Embodiment 1 except that the rotation speed of the rotating target material is 35 rpm.

[0062] Combining Example 1 with Examples 5 to 6, it can be seen that the rotation speed of the rotating target in Example 5 is too low, which will lead to a decrease in the uniformity and density of the film, thereby affecting its corrosion resistance, and the target utilization rate is also reduced; the rotation speed of the rotating target in Example 6 is too high, which will lead to a significant reduction in the utilization rate of the rotating target.

[0063] Comparative Example 1

[0064] This comparative example provides a method for improving target material utilization in a PVD coating process, which is the same as Example 1 except that the power of the first magnetron sputtering process is 1.2 times the power of the second magnetron sputtering process.

[0065] Comparative Example 2

[0066] This comparative example provides a method for improving target material utilization in a PVD coating process, which is the same as Example 1 except that the power of the first magnetron sputtering process is three times the power of the second magnetron sputtering process.

[0067] It can be seen from the combined effect of Example 1 and Comparative Examples 1 to 2 that the power of the first magnetron sputtering treatment in Comparative Example 1 is relatively low, and the impurities and oxide layer on the target surface cannot be removed well, which will lead to uneven sputtering of various regions of the subsequent target material and reduced target material utilization; the power of the first magnetron sputtering treatment in Comparative Example 2 is relatively high, which will cause overheating of the target surface, affect the stability of the coating and the uniformity and density of the thin film, and at the same time reduce the utilization rate of the target material.

[0068] Comparative Example 3

[0069] This comparative example provides a method for improving target material utilization in a PVD coating process, which is the same as Example 1 except that the magnetic field strength at both ends of the first magnetron sputtering process and the magnetic field strength in the middle of the second magnetron sputtering process is the same.

[0070] It can be seen from Example 1 and Comparative Example 3 that the magnetic field strength at both ends of the first magnetron sputtering treatment and the second magnetron sputtering treatment in Comparative Example 3 is the same as the magnetic field strength in the middle, which will cause the sputtered target material to be thin in the middle and thick around the edges, thereby reducing the utilization rate of the target material.

[0071] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for improving target material utilization in a PVD coating process, characterized in that: The PVD coating process includes magnetron sputtering coating; the method includes: The target material is sequentially subjected to a first magnetron sputtering treatment and a second magnetron sputtering treatment to complete sputtering coating; The power of the first magnetron sputtering process is 1.5 to 2.5 times that of the second magnetron sputtering process; the magnetic field direction in the first magnetron sputtering process and the second magnetron sputtering process is axial, and the magnetic field strength at both ends is higher than the magnetic field strength in the middle.

2. The method according to claim 1, characterized in that The target includes a planar target or a rotating target.

3. The method according to claim 1 or 2, characterized in that: The target material includes a metal target material or an alloy target material; Preferably, the metal target includes any one of a copper target, a molybdenum target, a titanium target or a tantalum target.

4. The method according to claim 2, characterized in that: The rotation speed of the rotating target is 10-30 rpm.

5. The method according to any one of claims 1 to 4, characterized in that: The power of the first magnetron sputtering process is 1.5-2 kW.

6. The method according to any one of claims 1 to 5, characterized in that: The first magnetron sputtering treatment lasts for 2 to 5 minutes.

7. The method according to any one of claims 1 to 6, characterized in that: A protective gas is introduced into the first magnetron sputtering process and the second magnetron sputtering process.

8. The method according to claim 7, characterized in that The protective gas includes nitrogen and / or argon.

9. The method according to claim 7, characterized in that: The flow rate of the protective gas is 10-20 sccm.

10. The method according to any one of claims 1 to 9, characterized in that: The method comprises: The target material is sequentially subjected to a first magnetron sputtering treatment of 2 to 5 minutes and a second magnetron sputtering treatment at a power of 1.5 to 2 kW to complete sputtering coating; The target material includes a planar target material or a rotating target material; the target material includes a metal target material or an alloy target material; the metal target material includes any one of a copper target material, a molybdenum target material, a titanium target material or a tantalum target material; the rotation speed of the rotating target material is 10 to 30 rpm; The power of the first magnetron sputtering treatment is 1.5 to 2.5 times the power of the second magnetron sputtering treatment; the direction of the magnetic field in the first magnetron sputtering treatment and the second magnetron sputtering treatment is axial, and the magnetic field strength at both ends is higher than the magnetic field strength in the middle; a protective gas is introduced into the first magnetron sputtering treatment and the second magnetron sputtering treatment; the protective gas includes nitrogen and / or argon; the flow rate of the protective gas is 10 to 20 sccm.