Magnetron sputtering device and method for improving uniformity of plasma

Abstract

The invention provides a magnetron sputtering device and method for improving the uniformity of plasmas, and the device comprises a working cavity, a back plate disposed at one side in the working cavity; the carrying table is arranged on the other side in the working cavity; at least one group of coil assemblies, wherein any group of coil assemblies comprises a first coil assembly and a second coil assembly; the second coil assembly and the first coil assembly are arranged in parallel at an interval in any direction, the projections of the second coil assembly and the first coil assembly coincide, and a magnetic field track is formed between the first coil assembly and the second coil assembly; and the back plate and / or the carrying platform are / is arranged in the magnetic field track. According to the embodiment of the invention, plasmas formed between the target material and the wafer tend to be uniformly distributed, so that the sputtering uniformity of the target material can be improved, the utilization rate of the target material can be improved, the step coverage rates of micropores or grooves near the circle center and at the edge of the wafer tend to be consistent during hole or groove filling, the production yield and reliability of the wafer are improved, and the production cost is reduced. The structure is simple and cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetron sputtering, and in particular relates to a magnetron sputtering device and a method for improving plasma uniformity. Background Art

[0002] Magnetron sputtering is one of the physical vapor deposition technologies. In existing magnetron sputtering devices, permanent magnets or electromagnets are usually placed on the back of the target material to bind secondary electrons and enhance the plasma density. However, this structure makes the magnetic field intensity distribution near the target surface uneven. On the one hand, the uneven distribution of magnetic field intensity leads to uneven distribution of plasma density. The plasma distribution shows a distribution characteristic of strong center and weak edge, which directly affects the sputtering uniformity and thus affects the target utilization rate. On the other hand, the uneven distribution of plasma density also affects the ionization rate of metal atoms, and the metal ions generated by the collision with the metal atoms of the target material are also unevenly distributed. In the process of filling holes or slots, the thickness of the metal ion film at the center and edge of the wafer is also different, which affects the step coverage of the hole or slot.

[0003] In addition, in order to improve the uniformity of the sputtering target, the existing magnetron sputtering magnetron equipment needs to be used in conjunction with a rotating mechanism. However, this structure will still cause uneven sputtering when the target is radially distributed, and produce an "etching track", i.e., annular sputtering grooves, on the target surface, resulting in low target utilization and high sputtering process costs. Summary of the invention

[0004] In order to solve at least one technical problem in the prior art, the embodiments of the present invention provide a magnetron sputtering device and method for improving plasma uniformity, which can improve the uniformity of plasma distribution. To achieve the above technical objectives, the technical solution adopted by the embodiments of the present invention is: In a first aspect, an embodiment of the present invention provides a magnetron sputtering device for improving plasma uniformity, comprising: Working chamber, A back plate, disposed at one side of the working chamber, and used for carrying the target material; A carrier, disposed at the other side of the working chamber, and used for carrying a wafer; At least one set of coil assemblies, any set of coil assemblies comprising: a first coil assembly; A second coil assembly, wherein the second coil assembly and the first coil assembly are spaced apart in any direction and arranged in parallel, the projections of the first coil assembly and the second coil assembly overlap, and a magnetic field track is formed between the first coil assembly and the second coil assembly; The back plate and / or the carrier in the working chamber are arranged in the magnetic field track.

[0005] Further, the magnetron sputtering device comprises a group of coil assemblies, wherein the first coil assembly and the second coil assembly are arranged at intervals along a first direction, wherein: The first coil assembly is disposed on a side of the back plate away from the carrier; The second coil assembly is disposed around the carrier.

[0006] Further, the first coil assembly includes a first support frame and a first coil, the first support frame extends along a first direction, and the first coil is wound on the first support frame; The second coil assembly comprises a second support frame and a second coil, the second support frame extends along the first direction, and the second coil is wound on the second support frame; The first coil and the second coil include at least one of the following features: The number of turns of the first coil is the same as the number of turns of the second coil; The winding method of the first coil is the same as the winding method of the second coil; The radius of the first coil and / or the radius of the second coil is equal to the interval between the first coil and the second coil; The input current of the first coil and / or the second coil is the same.

[0007] Furthermore, the working chamber further comprises: A housing extending along a first direction; An upper cover plate is arranged on one side of the shell, and the back plate is arranged on a side of the upper cover plate close to the shell; A first cavity is provided on a side of the upper cover plate away from the housing, and the first coil assembly is provided in the first cavity; The carrier is disposed on the other side of the housing, and the second coil assembly is disposed around the carrier. The distance between the carrier and the back plate is adjustable; and / or the distance between the second coil assembly and the back plate is adjustable.

[0008] Furthermore, it also includes a lifting cylinder, which includes a cylinder body and a piston rod. The piston rod extends along a first direction, one end of the piston rod is arranged in the cylinder body, and the other end of the piston rod is fixedly connected to the second support frame.

[0009] Furthermore, a water inlet and outlet are provided on a side of the first cavity away from the shell. And / or, the second support frame is also connected to a cooling water tank.

[0010] In a second aspect, the present invention further provides a method for improving plasma uniformity in a magnetron sputtering device, which is performed in the above-mentioned magnetron sputtering device for improving plasma uniformity, and comprises the following steps: Step S1, pre-sputtering: select a target material, fix the wafer on the carrier, transfer the carrier to the working chamber, adjust the distance between the target material and the wafer, set the pre-sputtering power of the back plate to 2500-3500 W, and pre-sputter the target material for 8-12 minutes; Step S2, sputtering thin film: setting the substrate temperature to 25-300°C and the vacuum degree of the working chamber to less than 5.0×10 - 8 Torr, an inert gas with a flow rate of 40 to 60 sccm is introduced into the working chamber, the reaction pressure of the working chamber is 2 to 4 mTorr, the sputtering power of the back plate is set to 5500 to 6500 W, the input current of the coil assembly is 10 to 100 A, and a thin film is obtained after sputtering for 40 to 60 seconds.

[0011] Furthermore, the input power of the carrier is 450-650W; and / or, the frequency of the RF power supply and matching network connected to the carrier is 2 to 27.12 MHz, Furthermore, the target material has a diameter of 320 to 322 mm. And / or, the target material has a thickness of 8 to 10 mm; And / or, the distance between the target and the wafer is 50 mm to 200 mm.

[0012] Further, the target material includes a titanium target; and / or, the inert gas comprises argon; And / or, the wafer is selected from at least one of silicon, gallium arsenide, silicon carbide, quartz glass, aluminum oxide, indium phosphide, gallium nitride, gallium oxide, and aluminum nitride.

[0013] The technical solution provided by the embodiment of the present invention has the following beneficial effects: (1) In the embodiment of the present invention, a coil assembly is arranged on the outer side of the back plate and the carrier to form a uniform magnetic field, so that the plasma formed between the target material and the wafer tends to be evenly distributed, which can not only improve the uniformity of target sputtering, improve the target material utilization rate, and extend the service life of the target material, but also make the step coverage of the microholes or grooves near the center and at the edge of the wafer more consistent when filling holes or grooves, thereby improving the production yield and reliability of the wafer.

[0014] (2) The embodiment of the present invention has a simple structure. The strength of the uniform magnetic field between the coil assemblies can be adjusted by adjusting the number of turns of the first coil and the second coil, the input current, water cooling, etc., without using a rotating mechanism, thereby simplifying the existing magnetron sputtering equipment and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view of a magnetron sputtering device for improving plasma uniformity in an embodiment of the present invention.

[0016] Figure 2 3 is a distribution diagram of the square resistance of the titanium thin film in Example 1 of the present invention.

[0017] Figure 3 This is a distribution diagram of the square resistance of the titanium thin film in Comparative Example 1 of the present invention.

[0018] Figure 4 Schematic diagram of the cut-off position of the step coverage in Example 1 of the present invention and Comparative Example 1.

[0019] Figure 5 This is a SEM (scanning electron microscope) image of the titanium film in Example 1 of the present invention.

[0020] Figure 6 This is a SEM (scanning electron microscope) image of the titanium film in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] In the description of the embodiments of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0023] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] An embodiment of the present invention provides a magnetron sputtering device for improving plasma uniformity, comprising: Working chamber 1, A back plate, disposed at one side of the working chamber 1, and used for carrying the target material; A carrier 12 is provided at the other side of the working chamber 1, and the carrier 12 is used for carrying a wafer; At least one set of coil assemblies 2, any set of coil assemblies 2 comprising: A first coil assembly 21; A second coil assembly 22, wherein the second coil assembly 22 and the first coil assembly 21 are spaced apart in any direction and arranged in parallel, the projections of the first coil assembly 21 and the second coil assembly 22 overlap, and a magnetic field track is formed between the first coil assembly 21 and the second coil assembly 22; The back plate and / or the carrier 12 in the working chamber 1 are arranged in the magnetic field track.

[0026] Since the first coil assembly 21 is parallel to the second coil assembly 22 and their projections overlap, the magnetic field track is formed between the first coil assembly 21 and the second coil assembly 22 in the coil assembly 2. Compared with the magnetic field track formed by a permanent magnet or a group of coil assemblies, the magnetic field track has a more uniform magnetic field strength. Since the back plate and the carrier 12 are arranged in the magnetic field track, plasma can be formed between the target material on the back plate and the wafer on the carrier 12, and the plasma density distribution is more uniform, which is conducive to forming a more uniform thin film and can also improve the uniformity of target sputtering, thereby extending the service life of the target material.

[0027] The number and position of the coil components 2 in this application are not limited.

[0028] In a specific embodiment, three groups of coil assemblies are provided outside the working chamber 1, the first coil assembly and the second coil assembly in one group of the coil assemblies are spaced apart in the up-down direction, the first coil assembly and the second coil assembly in one group of the coil assemblies are spaced apart in the left-right direction, and the first coil assembly and the second coil assembly in one group of the coil assemblies are spaced apart in a direction perpendicular to the paper surface.

[0029] In another specific embodiment, two groups of coil assemblies are provided outside the working chamber 1, and the first coil assembly and the second coil assembly in one group of coil assemblies are spaced apart in the up-down direction, and the first coil assembly and the second coil assembly in one group of coil assemblies are spaced apart in the left-right direction.

[0030] In another specific embodiment, the magnetron sputtering device includes a group of coil assemblies 2, in which the first coil assembly 21 and the second coil assembly 22 are arranged at intervals along the first direction A, wherein: The first coil assembly 21 is disposed on a side of the back plate away from the carrier 12; The second coil assembly 22 is disposed around the carrier 12 .

[0031] like Figure 1 As shown, the first coil assembly 21 is disposed above the back plate, and the second coil assembly 22 surrounds the carrier 12 .

[0032] Further, the first coil assembly 21 includes a first support frame 211 and a first coil 212, the first support frame 211 extends along a first direction A, and the first coil 212 is wound on the first support frame 211; The second coil assembly 22 includes a second support frame 221 and a second coil 222. The second support frame 221 extends along the first direction A, and the second coil 222 is wound on the second support frame 221. The first coil 212 and the second coil 222 include at least one of the following features: The number of turns of the first coil 212 is the same as the number of turns of the second coil 222; The winding method of the first coil 212 is the same as the winding method of the second coil 222; The radius of the first coil 212 and / or the radius of the second coil 222 is equal to the interval between the first coil 212 and the second coil 222; The power input current of the first coil 212 and / or the second coil 222 is the same.

[0033] In a specific embodiment, the first coil 212 and the second coil 222 have the same number of turns and the same winding method, the radius of the first coil 212 and the radius of the second coil 222 are both equal to the interval between the first coil 212 and the second coil 222, and the driving voltage and input current of the first coil 212 and the second coil 222 are the same. Therefore, a uniform magnetic field can be formed between the first coil assembly 21 and the second coil assembly 22 in this structure, and then the target material on the back plate and the wafer on the carrier 12 can be in the uniform magnetic field.

[0034] During operation, plasma is formed between the target and the wafer. On the one hand, the uniform magnetic field makes the plasma density between the target and the wafer tend to be evenly distributed, which can directly improve the uniformity of target sputtering; on the other hand, metal ions will be accelerated to move to the wafer surface and form a film under the action of negative bias voltage, and before film formation, the uniform magnetic field makes the metal ions collided by the plasma tend to be evenly distributed, that is, the metal ion concentration distribution near the center and edge of the wafer is relatively uniform.

[0035] Therefore, the uniform magnetic field between the first coil assembly 21 and the second coil assembly 22 can not only improve the uniformity of film formation on the wafer surface, but also improve the distribution uniformity of metal ions with high migration directionality.

[0036] At the same time, the more uniform the distribution of metal ions, the more consistent the step coverage of the micropores or grooves near the center and edge of the wafer when filling holes or grooves, and thus the uniform magnetic field can improve the production yield and reliability of the wafer.

[0037] It should be noted that the strength of the magnetic field can be adjusted by adjusting the number of turns, input current, etc. of the first coil 212 and the second coil 222. In the present application, the number of turns and input current of the first coil 212 and / or the second coil 222 are not limited, and the number of turns, input current, etc. can be adaptively adjusted according to actual needs.

[0038] It can be understood that increasing the number of turns of the first coil 212 and / or the second coil 222, increasing the input current of the first coil 212 and / or the second coil 222, and using water cooling can significantly improve the magnetic field strength of the uniform magnetic field, thereby making the magnetic field near the target material uniform in the radial direction and the plasma density the same everywhere. This structural design can replace the rotating magnetron device on the back of the target material in the magnetron sputtering equipment in the prior art, thereby simplifying the existing magnetron sputtering device. The magnetron sputtering device in the present application has a simpler structure and lower costs, and provides a stable and uniform magnetic field in the entire magnetron sputtering space, greatly improving the utilization rate of the target material and extending the service life of the target material.

[0039] Furthermore, the working chamber 1 further comprises: The housing 13 extends along a first direction A; An upper cover plate 14 is disposed on one side of the housing 13, and a side of the upper cover plate 14 close to the housing 13 is provided with the back plate; A first cavity 15 is disposed on a side of the upper cover plate 14 away from the housing 13 , and the first coil assembly 21 is disposed in the first cavity 15 ; The carrier 12 is disposed on the other side of the housing 13 , and the second coil assembly 22 is disposed around the carrier 12 . The distance between the carrier 12 and the back plate is adjustable; and / or the distance between the second coil assembly 22 and the back plate is adjustable.

[0040] In a specific embodiment, Figure 1 As shown, the shell 13 extends from top to bottom, the upper part of the shell 13 is the upper cover plate 14, the upper part of the upper cover plate 14 is provided with the first cavity 15, and the first coil component 21 is provided in the first cavity 15, so the position of the first coil component 21 remains fixed.

[0041] The back plate is located below the upper cover plate 14, a target is provided below the back plate, the carrier 12 is provided below the shell 13 and can move up and down, a wafer is provided above the carrier 12, and the interval between the carrier 12 and the back plate is adjustable, that is, the interval between the wafer and the target is adjustable.

[0042] The second coil assembly 22 is also disposed below the housing 13 and is movable in the up-down direction, so that the interval between the first coil assembly 21 and the second coil assembly 22 can be adjusted.

[0043] Furthermore, it also includes a lifting cylinder 3, which includes a cylinder body 31 and a piston rod 32. The piston rod 32 extends along the first direction A, one end of the piston rod 32 is arranged in the cylinder body 31, and the other end of the piston rod 32 is fixedly connected to the second support frame 221.

[0044] like Figure 1 As shown, the upper end of the piston rod 32 is fixedly connected to the second support frame 221. When the piston rod 32 moves in the up and down directions, it can drive the second support frame 221 to move up and down, and then drive the second coil 222 to move up and down. This structure is conducive to adjusting the interval between the first coil assembly 21 and the second coil assembly 22, so as to facilitate the formation of a uniform magnetic field between the first coil assembly 21 and the second coil assembly 22.

[0045] Furthermore, a water inlet and outlet 151 is provided on a side of the first cavity 15 away from the housing 13. And / or, the second support frame 221 is also connected to a cooling water tank 4 .

[0046] It can be understood that by injecting cooling water into the first cavity 15 through the water inlet and outlet 151, the first coil assembly 21 can be cooled, and by passing cooling water into the cooling water tank 4, the second coil assembly 22 can be cooled by heat transfer.

[0047] In a second aspect, an embodiment of the present invention further provides a method for improving plasma uniformity in a magnetron sputtering device, which is performed in the magnetron sputtering device for improving plasma uniformity, and comprises the following steps: Step S1, pre-sputtering: select a target material, fix the wafer on the carrier 12, transfer the carrier 12 to the working chamber 1, adjust the distance between the target material and the wafer, set the pre-sputtering power of the back plate to 2500-3500 W, for example, 2500 W, 2700 W, 3000 W, 3200 W, 3500 W, etc., and pre-sputter the target material for 8-12 minutes; Step S2, sputtering thin film: setting the substrate temperature to 25-300°C, for example, 25°C, 50°C, 75°C, 100°C, 150°C, 200°C, 250°C, 300°C, etc., and the vacuum degree of the working chamber 1 is less than 5.0×10 -8 Torr, for example, can be 3×10 -8 Torr, 3.5×10 -8 Torr, 4×10 -8 Torr, 4.5×10 -8 Torr 、4.8×10 -8 Torr, etc., an inert gas with a flow rate of 40 to 60 sccm is introduced into the working chamber 1, for example, it can be 40 sccm, 45 sccm, 50 sccm, 55 sccm, 60 sccm, etc., the reaction pressure of the working chamber 1 is 2 to 4 mTorr, for example, it can be 2 mTorr, 2.5 mTorr, 3 mTorr, 3.5 mTorr, 4 mTorr, etc., the sputtering power of the back plate is set to 5500 to 6500 W, for example, it can be 5500 W, 5700 W, 6000 W, 6200 W, 6500 W, etc., the input current of the coil assembly 2 is 10 to 100 A, for example, it can be 10 A, 20 A, 30 A, 40 A, 50 A, 60 A, 70 A, 80 A, 90 A, 100 A, etc., and a thin film is obtained after sputtering for 40 to 60 seconds.

[0048] Further, the input power of the carrier 12 is 450-650W, for example, 450W, 480W, 600W, 630W, 650W; And / or, the frequency of the RF power supply and the matching network connected to the carrier 12 is 2 to 27.12 MHz, for example, 12 MHz, 13 MHz, 14 MHz, 15 MHz, etc.

[0049] Furthermore, the target material has a diameter of 320 to 322 mm. And / or, the target material has a thickness of 8 to 10 mm; And / or, the distance between the target and the wafer is 50 mm to 200 mm.

[0050] Further, the target material includes a titanium target; and / or, the inert gas comprises argon; And / or, the wafer is selected from at least one of silicon, gallium arsenide, silicon carbide, quartz glass, aluminum oxide, indium phosphide, gallium nitride, gallium oxide, and aluminum nitride. Example

[0051] A method for improving plasma uniformity in a magnetron sputtering device is performed in the magnetron sputtering device for improving plasma uniformity, comprising the following steps: Step S1, pre-sputtering: select a titanium target with a diameter of 320 mm and a thickness of 9 mm, fix the silicon wafer on the carrier 12, transfer the carrier 12 to the working chamber 1, adjust the distance between the target and the wafer to 150 mm, set the sputtering power of the back plate to 3000 W, and pre-sputter the target for 10 minutes; Step S2, sputtering thin film: setting the substrate temperature to 200°C, the vacuum degree of the working chamber 1 to 4.5×10-8Torr, introducing argon gas at a flow rate of 50sccm into the working chamber 1, the reaction pressure of the working chamber 1 to 3.0×10-3Torr, setting the sputtering power of the back plate to 6000W, the input current of the coil assembly 2 to 40A, the input power of the carrier 12 to 500W, the frequency of the RF power supply and the matching network connected to the carrier 12 to 13.56MHz, and after sputtering for 50s, a titanium thin film is obtained. Example

[0052] A method for improving plasma uniformity in a magnetron sputtering device is performed in the magnetron sputtering device for improving plasma uniformity, comprising the following steps: Step S1, pre-sputtering: select a titanium target with a diameter of 320 mm and a thickness of 9 mm, fix the silicon wafer on the carrier 12, transfer the carrier 12 to the working chamber 1, adjust the distance between the target and the wafer to 150 mm, set the pre-sputtering power of the back plate to 3000 W, and pre-sputter the target for 10 minutes; Step S2, sputtering thin film: setting the substrate temperature to 200°C, the vacuum degree of the working chamber 1 to 4.5×10-8Torr, introducing argon gas at a flow rate of 50 sccm into the working chamber 1, the reaction pressure of the working chamber 1 to 3.0×10-3Torr, setting the input power of the back plate to 6000W, the input current of the coil assembly 2 to 40A, the input power of the carrier 12 to 500W, the frequency of the RF power supply and the matching network connected to the carrier 12 to 13.56MHz, and the target material continuously runs for 50s; The steps S1 and S2 are cycled, and after 1000 wafers are continuously sputtered and deposited using the magnetron sputtering device for improving plasma uniformity, the target material is taken out, and the thickness of the thinnest part of the target material is measured.

[0053] A magnetron sputtering method for titanium thin film is carried out in an existing common magnetron sputtering device, wherein a permanent magnet is used in the existing magnetron sputtering device, and the average magnetic field strength of the permanent magnet corresponding to the target surface is generally 400 to 600 G, and comprises the following steps: Step S1, pre-sputtering: select a titanium target with a diameter of 320 mm and a thickness of 9 mm, fix the silicon wafer on the carrier 12, transfer the carrier 12 to the working chamber 1, adjust the distance between the target and the wafer to 150 mm, set the sputtering power of the back plate to 3000 W, and pre-sputter the target for 10 minutes; Step S2, sputtering thin film: setting the substrate temperature to 200°C, the vacuum degree of the working chamber 1 to 4.5×10-8Torr, introducing argon gas at a flow rate of 50sccm into the working chamber 1, the reaction pressure of the working chamber 1 to 3.0×10-3Torr, setting the sputtering power of the back plate to 6000W, the input current of the coil assembly 2 to 40A, the input power of the carrier 12 to 500W, the frequency of the RF power supply and the matching network connected to the carrier 12 to 13.56MHz, and after sputtering for 50s, a titanium thin film is obtained.

[0054] A magnetron sputtering method for titanium thin film is carried out in an existing common magnetron sputtering device, wherein a permanent magnet is used in the existing magnetron sputtering device, and the average magnetic field strength of the permanent magnet corresponding to the target surface is generally 400 to 600 G, and comprises the following steps: Step S1, pre-sputtering: select a titanium target with a diameter of 320 mm and a thickness of 9 mm, fix the silicon wafer on the carrier 12, transfer the carrier 12 to the working chamber 1, adjust the distance between the target and the wafer to 150 mm, set the pre-sputtering power of the back plate to 3000 W, and pre-sputter the target for 10 minutes; Step S2, sputtering thin film: setting the substrate temperature to 200°C, the vacuum degree of the working chamber 1 to 4.5×10-8Torr, introducing argon gas at a flow rate of 50 sccm into the working chamber 1, the reaction pressure of the working chamber 1 to 3.0×10-3Torr, setting the input power of the back plate to 6000W, the input current of the coil assembly 2 to 40A, the input power of the carrier 12 to 500W, the frequency of the RF power supply and the matching network connected to the carrier 12 to 13.56MHz, and the target material continuously runs for 50s; Step S1 and step S2 are cycled, and after 1000 wafers are continuously sputtered and deposited using an existing magnetron sputtering device, the target material is taken out and the thickness of the thinnest part of the target material is measured. Example

[0055] The titanium thin films provided in the application examples 1-2 and the comparative examples 1-2 were tested. Specifically, the titanium thin films prepared in the embodiment 1 and the comparative example 1 of the same area were selected as the first group of samples, and the sheet resistance, uniformity and step coverage of the first group of samples were tested; the target materials used in the embodiment 2 and the comparative example 2 were selected as the second group of samples, and the thickness of the thinnest part of the remaining target materials was measured respectively. Among them, the sheet resistance and uniformity of the thin film are shown in Table 1, and the step coverage is shown in Table 2.

[0056] Step coverage: Observe the film thickness of the cross section of the micropore on the wafer surface under a scanning electron microscope, and measure the film thickness at the top plane, side wall, and bottom of the micropore. Figure 4 As shown, the ratio of the film thickness at the side wall to the top plane and the ratio of the film thickness at the bottom to the top plane are calculated respectively, which is the step coverage, wherein the film thickness at the side wall is the average value of the film thickness on both sides of the side wall.

[0057] Table 1 Sheet resistance and uniformity of titanium thin films prepared in Example 1 and Comparative Example 1 Thin film square resistance Rs (Ω / £) Uniformity (%) Example 1 4.87 1.605 Comparative Example 1 5.33 2.748 Table 2 Step coverage at the edge of the titanium film prepared in Example 1 and Comparative Example 1 Micropore location Step coverage of titanium film in Example 1 (%) Step coverage x ratio of titanium film in comparative example 1 (%) Side wall upper film thickness / top film thickness 31.49% 28.47% Side wall middle film thickness / top film thickness 19.08% 16.99% Side wall bottom film thickness / top film thickness 19.98% 17.54% Bottom film thickness / top film thickness 40.37% 34.48% Depend on Figure 2 , Figure 3As can be seen from Table 1, compared with the titanium thin film produced by the magnetron sputtering device in the prior art in Comparative Example 1, the titanium thin film produced by the magnetron sputtering device for improving plasma uniformity in Example 1 has lower film square resistance at any part, showing more excellent performance.

[0058] Depend on Figure 5 , Figure 6 As can be seen from Table 2, compared with the titanium thin film produced by the magnetron sputtering device in the prior art in Comparative Example 1, the titanium thin film produced by the magnetron sputtering device for improving plasma uniformity in Example 1 has a more uniform plasma density distribution between the target material and the wafer during the sputtering process, and the step coverage at the edge of the wafer is significantly higher, resulting in better wafer quality.

[0059] In Example 2 of the present invention and Comparative Example 2, it can be obtained after measurement that the thinnest thickness of the target material used in the magnetron sputtering device in the prior art in Comparative Example 2 is only 4.95 mm, and a relatively obvious annular etching groove is produced on the target surface, while the thinnest thickness of the target material used in the magnetron sputtering device for improving plasma uniformity in Example 2 can reach 7.76 mm, and the thickness of the target surface is relatively uniform. Under the same conditions, the target material in Example 2 has a higher utilization rate and a longer service life.

[0060] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A magnetron sputtering device for improving plasma uniformity, characterized in that: include: Working chamber (1), A back plate, arranged at one side of the working chamber (1), the back plate being used to carry the target material; A carrier (12) is arranged at the other side of the working chamber (1), and the carrier (12) is used to carry a wafer; At least one group of coil assemblies (2), any group of coil assemblies (2) comprising: A first coil assembly (21); a second coil component (22), the second coil component (22) and the first coil component (21) being spaced apart and arranged in parallel along any direction, the first coil component (21) and the second coil component (22) having overlapping projections, and forming a magnetic field track between the first coil component (21) and the second coil component (22); The back plate and / or the carrier (12) in the working chamber (1) are arranged in the magnetic field track.

2. The magnetron sputtering device for improving plasma uniformity according to claim 1, characterized in that: The magnetron sputtering device comprises a group of coil assemblies (2), wherein the first coil assembly (21) and the second coil assembly (22) are arranged at intervals along a first direction (A), wherein: The first coil assembly (21) is arranged on a side of the back plate facing away from the carrier (12); The second coil component (22) is arranged around the carrier (12).

3. The magnetron sputtering device for improving plasma uniformity according to claim 1, characterized in that: The first coil assembly (21) comprises a first support frame (211) and a first coil (212); the first support frame (211) extends along a first direction (A); and the first coil (212) is wound on the first support frame (211); The second coil assembly (22) comprises a second support frame (221) and a second coil (222); the second support frame (221) extends along a first direction (A); and the second coil (222) is wound on the second support frame (221); The first coil (212) and the second coil (222) include at least one of the following features: The number of turns of the first coil (212) is the same as the number of turns of the second coil (222); The winding method of the first coil (212) is the same as the winding method of the second coil (222); The radius of the first coil (212) and / or the radius of the second coil (222) is equal to the interval between the first coil (212) and the second coil (222); The input current of the first coil (212) and / or the second coil (222) is the same.

4. The magnetron sputtering device for improving plasma uniformity according to claim 3, characterized in that: The working chamber (1) further comprises: A housing (13) extending along a first direction (A); An upper cover plate (14) is provided on one side of the shell (13), and the back plate is provided on a side of the upper cover plate (14) close to the shell (13); A first cavity (15) is arranged on a side of the upper cover plate (14) facing away from the housing (13), and the first coil assembly (21) is arranged in the first cavity (15); The carrier (12) is arranged on the other side of the housing (13), and the second coil assembly (22) is arranged around the carrier (12). The spacing between the carrier (12) and the back plate is adjustable; and / or the spacing between the second coil assembly (22) and the back plate is adjustable.

5. The magnetron sputtering device for improving plasma uniformity according to claim 4, characterized in that: It also comprises a lifting cylinder (3), the lifting cylinder (3) comprising a cylinder body (31) and a piston rod (32), the piston rod (32) extending along a first direction (A), one end of the piston rod (32) being arranged in the cylinder body (31), and the other end of the piston rod (32) being fixedly connected to the second support frame (221).

6. The magnetron sputtering device for improving plasma uniformity according to claim 4, characterized in that: A water inlet and outlet (151) is provided on a side of the first cavity (15) facing away from the shell (13). And / or, the second support frame (221) is also connected to a cooling water tank (4).

7. A method for improving plasma uniformity in a magnetron sputtering device, characterized in that: The method is carried out in a magnetron sputtering device for improving plasma uniformity as claimed in any one of claims 1 to 6, comprising the following steps: Step S1, pre-sputtering: selecting a target material, fixing a wafer on the carrier (12), transferring the carrier (12) to the working chamber (1), adjusting the distance between the target material and the wafer, setting the pre-sputtering power of the back plate to 2500-3500 W, and pre-sputtering the target material for 8-12 minutes; Step S2, sputtering thin film: setting the substrate temperature to 25-300°C, and the vacuum degree of the working chamber (1) to less than 5.0×10 - 8 Torr, an inert gas with a flow rate of 40 to 60 sccm is introduced into the working chamber (1), the reaction pressure of the working chamber (1) is 2 to 4 mTorr, the sputtering power of the back plate is set to 5500 to 6500 W, the input current of the coil assembly (2) is 10 to 100 A, and a thin film is obtained after sputtering for 40 to 60 seconds.

8. The method for improving plasma uniformity in a magnetron sputtering device according to claim 7, characterized in that: The input power of the carrier (12) is 450-650W; And / or, the frequency of the radio frequency power supply and the matching network connected to the carrier (12) is 2 to 27.12 MHz.

9. The method for improving plasma uniformity in a magnetron sputtering device according to claim 7, characterized in that: The target material has a diameter of 320 to 322 mm. And / or, the target material has a thickness of 8 to 10 mm; And / or, the distance between the target and the wafer is 50 mm to 200 mm.

10. The method for improving plasma uniformity in a magnetron sputtering device according to claim 7, characterized in that: The target material comprises a titanium target; and / or, the inert gas comprises argon; And / or, the wafer is selected from at least one of silicon, gallium arsenide, silicon carbide, quartz glass, aluminum oxide, indium phosphide, gallium nitride, gallium oxide, and aluminum nitride.

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