CN-122013125-A - Rotary target magnetron sputtering equipment based on dynamic magnetic field compensation and control method

CN122013125ACN 122013125 ACN122013125 ACN 122013125ACN-122013125-A

Abstract

The invention discloses a rotary target magnetron sputtering device and a method based on dynamic magnetic field compensation, and aims to improve the utilization rate of a target material and the deposition uniformity of a film. The device comprises a control system, an upper cover and a vacuum chamber, wherein the upper cover is arranged above the vacuum chamber, a rotary target assembly is arranged in the upper cover, an exciting device I and an exciting device II are circumferentially distributed on the periphery of the rotary target assembly, the rotary target assembly comprises a rotary shaft and a plurality of groups of magnetic steel fixing assemblies coaxially and circumferentially arranged on the rotary shaft, the rotary shaft extends into the vacuum chamber, a target material is detachably packaged at the bottom end of the rotary shaft, a magnetic field monitoring unit I and a magnetic field monitoring unit II are arranged at the top of the vacuum chamber on the periphery of the target material, and the sample table is positioned at the lower part of the vacuum chamber. According to the invention, the magnetic field distribution data of the target surface and the near surface are measured in real time through the magnetic field monitoring unit, and the millisecond-level cooperative regulation and control are finally realized by combining parameters such as the plasma density, the electron temperature, the target ion characteristic spectral line and the like acquired by the plasma monitoring unit and the target ion monitoring unit.

Inventors

CHANG GUIYUAN
ZHONG WEI
CHEN HAO
Meng Aofei
YAN HAN

Assignees

中步擎天新能源(湖北)有限公司

Dates

Publication Date: 20260512
Application Date: 20260210

Claims (10)

1. A rotary target magnetron sputtering device based on dynamic magnetic field compensation comprises a control system (301), an upper cover (010), a vacuum chamber (001) and a sample stage (002), and is characterized in that the upper cover (010) is arranged above the vacuum chamber (001), a rotary target assembly (101) is arranged in the upper cover (010), exciting devices I (203) and II (204) are circumferentially distributed on the periphery of the rotary target assembly (101), the rotary target assembly (101) comprises a rotary shaft (102) and a plurality of groups of magnetic steel fixing assemblies coaxially and circumferentially arranged on the rotary shaft (102), the rotary shaft (102) extends into the vacuum chamber (001), a target (106) is detachably packaged at the bottom end of the rotary shaft (102), a magnetic field monitoring unit I (201) and a magnetic field monitoring unit II (202) are arranged at the top of the vacuum chamber (001) on the periphery of the target (106), the sample stage (002) is arranged at the lower part of the vacuum chamber (001), a substrate (003) is arranged on the sample stage (002), the axial core of the vacuum chamber is connected with a rotating component (004), a plasma monitoring unit (007) is arranged in the vacuum chamber (001) near the position of the sample stage (002), and a plasma generating unit (005) and a target ion monitoring unit (008) which are aligned with a space region between the target (106) and the substrate (003) are arranged on the side wall of the vacuum chamber (001).
2. The rotating target magnetron sputtering device based on dynamic magnetic field compensation as claimed in claim 1, wherein a spectrum window is arranged on the side wall of the vacuum chamber (001), the detection end of the target ion monitoring unit (008) is positioned in the spectrum window, and the output end of the target ion monitoring unit is connected with the optical fiber spectrometer.
3. The rotating target magnetron sputtering device based on dynamic magnetic field compensation as claimed in claim 1, wherein a first magnetic steel fixing component (103), a second magnetic steel fixing component (104) and a third magnetic steel fixing component (105) are circumferentially fixed on the rotating shaft (102).
4. The rotating target magnetron sputtering device based on dynamic magnetic field compensation as set forth in claim 1, wherein the first magnetic field monitoring unit (201) and the second magnetic field monitoring unit (202) are both composed of high-temperature Hall effect sensors, each sensor is circumferentially mounted on the top of the vacuum chamber (001) along the periphery of the target (106), and circumferential included angles of adjacent sensors are equal.
5. The rotating target magnetron sputtering device based on dynamic magnetic field compensation as set forth in claim 1, wherein the first excitation device (203) and the second excitation device (204) both comprise an electromagnetic coil group and a soft magnetic material framework, wherein the electromagnetic coil group comprises radial coils and axial coils, each coil is wound on the soft magnetic material framework, and the radial coils and the axial coils are orthogonally arranged to form a two-dimensional magnetic field adjusting capability.
6. The rotating target magnetron sputtering device based on dynamic magnetic field compensation as recited in claim 1, wherein the plasma monitoring unit (007) mainly comprises a langmuir probe, a vacuum feed-through, the langmuir probe being introduced into the vacuum chamber through the vacuum feed-through and being exposed to a near-surface plasma region of the target (106).
7. The apparatus of claim 1, wherein the control system (301) is electrically connected to the first magnetic field monitoring unit (201), the second magnetic field monitoring unit (202), the first exciting device (203), the second exciting device (204), the plasma monitoring unit (007), the plasma generating unit (005), and the driving mechanism of the rotary target assembly (101), respectively, for receiving the signals and outputting the control command.
8. A sputtering method of an apparatus according to claim 1 to 7, comprising the steps of: S1, initializing equipment, namely setting target magnetic field distribution B 0 (r, theta, z) on the surface of a target material and a plasma density threshold n 0 in an initialization stage, starting vacuumizing to below 10 -4 Pa, introducing working gas, and maintaining the air pressure at 0.1-1 Pa; S2, real-time monitoring, wherein a magnetic field monitoring unit collects actual magnetic field distribution B a (r, theta, z, T) of the near-surface of the target in real time at a sampling frequency of 100Hz to 1kHz, and meanwhile, a plasma monitoring unit measures plasma density n (r, theta, z, T) and electron temperature T e (T), and a target ion monitoring unit measures target ion characteristic spectral line intensity I (T); s3, calculating deviation, namely defining magnetic field space deviation by the control system according to the following steps: ΔB(r,θ,z,t)=B a (r,θ,z,t)-B 0 (r,θ,z), Wherein r is the radial distance, θ is the circumferential angle, z is the axial height, and t is the time variable; s4, dynamic compensation, wherein the control system is based on a plasma coupling model: n(r,θ,z,t)=k 1 ·B a (r,θ,z,t)+k 2 ·T e (t)+k 3 ·I(t), calculating plasma density deviation: Δn(r,θ,z,t)=n(r,θ,z,t)-n 0 , And calculates the compensation magnetic field by using the following PID algorithm: , converting the compensation magnetic field into a drive current: , The electromagnetic coil group is controlled to generate a compensation magnetic field according to the driving current, and the compensation magnetic field is overlapped on the original magnetic field to realize dynamic regulation and control; Wherein k 1 、k 2 、k 3 is a fitting coefficient, N is a coil turn number, mu 0 is vacuum magnetic permeability, L is a coil equivalent length, and T e (T) is electron temperature due to the fact that the rotating target has axisymmetry and adopts more natural cylindrical coordinates; S5, repeatedly executing the steps of real-time monitoring, deviation calculation and dynamic compensation, performing closed loop iteration until the absolute value delta B (r, θ, z, t) |is less than or equal to 5% ·|b 0 (r, θ, z) | and |Δn (r, θ, z, t) | is less than or equal to 10% ·n 0 .
9. The method of claim 8, wherein in the step S4, when I (t) deviates from the preset threshold I 0 by + -15%, the sputtering power P (t) needs to be adjusted synchronously as follows: P(t)=P 0 ·[1+λ·(I 0 -I(t))/I 0 ], Where P 0 is the initial power and λ is the power adjustment coefficient.
10. The method according to claim 8, wherein in S4, the scaling factor K p in the PID algorithm is modified to K p '=K p ·P（t）/P 0 , and the modified K p ' is used to replace K p to participate in the calculation of the compensation magnetic field B c .

Description

Rotary target magnetron sputtering equipment based on dynamic magnetic field compensation and control method Technical Field The invention belongs to the technical field of magnetron sputtering coating, and particularly relates to a rotary target magnetron sputtering device based on dynamic magnetic field compensation and a control method. Background As a high-efficiency physical vapor deposition method, the magnetron sputtering technology is widely applied to the preparation of functional films such as semiconductors, optical films, decorative coatings and the like. The rotary target magnetron sputtering device effectively improves the utilization rate of the target material by continuously rotating the cylindrical target material, reduces the local erosion and nodulation phenomena of the surface of the target material, and shows obvious advantages in large-scale industrial production. However, the conventional rotary target magnetron sputtering apparatus has an inherent disadvantage in that a static magnetic field generated by a magnetic steel assembly fixedly installed inside the rotary target and a relative motion between the rotating target surface are generated, resulting in periodic fluctuation of the magnetic field distribution of the target surface. The non-uniformity of the magnetic field can directly cause non-uniform plasma density distribution, thereby causing the problems of non-uniform film thickness, non-uniform microstructure and the like. In the prior art, in order to solve the problem of non-uniformity of magnetic field, some improvements have been presented. The solution to this problem at home and abroad is mainly focused on optimizing the static arrangement mode of permanent magnets, such as adopting Halbach array (structural design and magnetic field analysis of rotating cathode magnetic field device for magnetron sputtering, motor and control application 2024,51 (03)) or optimizing the magnetic pole shape. Although the methods can improve the initial magnetic field distribution to a certain extent, the methods cannot respond to the real-time dynamic change of the magnetic field in the rotation process of the target. Dynamic magnetic field rectangular planar magnetic control targets developed by Beijing northern Hua Chuan vacuum technology Co., ltd.) expand etching areas by horizontal and vertical movement of magnet assemblies on planar targets (dynamic magnetic field rectangular planar magnetic control targets developed, vacuum 2023,60 (05)). However, this technique is directed to a planar target, and the problem of circumferential magnetic field fluctuation peculiar to a rotating target cannot be solved by adopting a mechanical scanning method. In the patent (publication No. CN 119800314A) of 'on-line swinging type adjustable magnetic rod for magnetron sputtering' applied by Rui vacuum equipment (Jiaxing) limited company, a plurality of independently controlled adjusting components drive a magnetic yoke to locally change the distance between the magnetic yoke and the surface of a sputtering target, so that the adjustment of the local magnetic field intensity is realized. Although the method realizes on-line adjustment, the method is still mechanical in nature, and has limitations on response speed and structural complexity applied inside the rotary target. In addition, the patent (publication number CN119243101 a) of "magnetron sputtering device and method for improving plasma uniformity" applied by the semiconductor technology limited company, improves plasma uniformity by arranging a coil assembly between the target and the wafer to form a magnetic field track, which is a compensation mode of an external magnetic field, and does not directly aim at and compensate dynamic magnetic field fluctuation of the surface of the rotating target itself. In recent years, some research institutions have begun to explore more advanced magnetic field control techniques. The variable magnetic field magnetron sputtering coating device developed by the institute of electrical engineering of China academy of sciences regulates and controls the magnetic field distribution by regulating the current and the direction of the inner electromagnetic coil and the outer electromagnetic coil in the cathode magnet, but the technology is mainly applied to a planar cathode system. In addition, although a method for online adjusting magnetic field strength according to the shape of the target is proposed in the prior art such as a sputtering method and sputtering apparatus (application number CN 202210506190.9) for improving the utilization rate of the rotating target, the adjustment basis is the shape of the target rather than real-time magnetic field distribution, and dynamic compensation of the circumferential magnetic field of the rotating target is not involved. Therefore, development of a magnetron sputtering device and a magnetron sputtering method capable of non-mechanically monitoring and actively compen