Uniformity adjustment device and magnetron sputtering vacuum coating machine

Abstract

The present invention discloses a uniformity adjustment device and a magnetron sputtering vacuum coating machine, comprising a main body (8) and a uniformity adjustment device (6), wherein the main body (8) comprises a radio frequency power supply (1), a radio frequency matching device (2), a vacuum shield (3) and a rotating cathode cylindrical target (4); the uniformity adjustment device (6) comprises a resonant circuit, wherein the resonant circuit is composed of a multi-position adjustment inductor (12) and an adjustable capacitor (14) connected in series, wherein the multi-position adjustment inductor (12) is connected to one end of a through-wall component (7), and the other end of the through-wall component (7) is connected to a suspended end (42) of a rotating cathode cylindrical target (4); the rotating cathode cylindrical target (4) and the uniformity adjustment device (6) serve as an adjustable common load for achieving uniform adjustment of the radio frequency voltage distribution loaded on the rotating cathode cylindrical target (4). Compared with the prior art, the present invention achieves improvement of the sputtering uniformity of the vacuum coating machine without changing the original structural design.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetron sputtering and vacuum coating machines, and in particular to a columnar magnetron sputtering target uniformity adjustment device and a magnetron sputtering vacuum coating machine having the uniformity adjustment device. Background Art

[0002] In the prior art, magnetron sputtering vacuum coating machines use a rotatable cylindrical target, and the target material is selected from the material to be plated. The cylindrical target generally serves as the cathode, surrounded by a grounded anode parallel to the longitudinal axis of the cylindrical target. Multiple workpieces to be coated are hung on the grounded anode, and the workpieces and cylindrical targets are both contained within a vacuum shield. Voltage is applied to the cathode cylindrical target. After the argon gas between the cylindrical target and the grounded anode discharges and ionizes, the relatively heavy, positively charged argon ions bombard the surface of the cylindrical target under the action of the electric field, causing the atoms and molecules on the surface to exchange kinetic energy with the incident argon ions and then splash out from the target surface. The sputtered atoms have a certain amount of energy and can be redeposited and condensed on the surface of the workpiece to be coated, forming a thin film, which is sputtering coating. The built-in magnets in the cylindrical target can constrain the trajectory of electrons, increase the collision probability between electrons and argon atoms, and improve the probability of sputtering. At the same time, multiple collisions can reduce electron energy and solve the thermal effect.

[0003] Depending on the characteristics of the workpiece being coated, some require the magnetron sputtering vacuum coating machine to be driven by an intermediate frequency power supply. This involves applying the output voltage generated by the intermediate frequency power supply to the cathode cylindrical target. While this generally results in better coating uniformity, some workpieces must be driven by an RF power supply, which can result in poor coating results.

[0004] In order to increase the types of workpieces that can use magnetron sputtering vacuum coating machines, the present invention needs to solve the problem of uneven workpiece coating caused by the use of radio frequency power supply. However, vacuum coating machines are expensive, and it is more challenging to improve their sputtering uniformity while minimizing changes to the original structural design of the vacuum coating machine. This is also a technical problem that needs to be urgently solved by the present invention. Summary of the Invention

[0005] The purpose of the present invention is to propose a uniformity adjustment device and a magnetron sputtering vacuum coating machine, and to achieve uniform vacuum coating of the workpiece by sputtering by adding a uniformity adjustment device to the columnar target in the magnetron sputtering vacuum coating machine.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A uniformity adjustment device includes a metal housing 11, a front panel 17, and a resonant circuit 21; the resonant circuit is arranged in the metal housing 11, and the resonant circuit is composed of a multi-level adjustment inductor 12 and an adjustable capacitor 14 connected in series. The front panel 17 is provided with a capacitance adjustment knob 15 connected to the adjustable capacitor 14 and a level adjustment knob 18 connected to the multi-level adjustment inductor 12. A radio frequency voltage is applied to the multi-level adjustment inductor 12, the adjustable capacitor 14 is connected to the metal housing 11, and the metal housing 11 is grounded.

[0008] Furthermore, the adjustable capacitor 14 is connected to the metal housing 11 and is grounded through the metal housing 11 .

[0009] The multi-speed adjustment inductor 12 is connected to the inductor speed adjustment knob 18 via multiple speed connection lines 19 .

[0010] Furthermore, the multi-level adjustment inductor 12 is used to adjust the impedance of the resonant circuit in real time.

[0011] Furthermore, the adjustable capacitor 14 is used to balance the impedance of the resonant circuit.

[0012] A magnetron sputtering vacuum coating machine, comprising:

[0013] The main body 8 includes an RF power supply 1, an RF matching device 2, a vacuum shield 3, and a rotating cathode cylindrical target 4; the RF power supply 1 is connected to the RF matching device 2, the RF matching device 2 is connected to the anode 41 of the rotating cathode cylindrical target 4, the RF matching device 2 is grounded, the rotating cathode cylindrical target 4 is disposed in the vacuum shield 3, and the suspended end 42 of the rotating cathode cylindrical target 4 outputs an RF voltage;

[0014] A uniformity adjustment device 6, wherein the multi-speed adjustment inductor 12 in the uniformity adjustment device 6 is connected to one end of the through-wall component 7, the through-wall component 7 is fixed on the vacuum shielding cover 3, and the other end of the through-wall component 7 is connected to the suspended end 42 of the rotating cathode cylindrical target 4, the through-wall component 7 is fixed on the vacuum shielding cover 3, the rotating cathode cylindrical target 4 and the uniformity adjustment device 6 serve as an adjustable common load, and are used to achieve uniform adjustment of the RF voltage distribution loaded on the rotating cathode cylindrical target 4.

[0015] Furthermore, the wall penetration member 7 is fixed on the vacuum shielding cover 3 .

[0016] Furthermore, the multi-level adjustable inductor 12 is used to adjust the impedance of the common load in real time.

[0017] Furthermore, the adjustable capacitor 14 is used to balance the impedance of the common load.

[0018] Compared with the prior art, the present invention can achieve the following beneficial technical effects:

[0019] 1) Improve the sputtering uniformity of the vacuum coating machine without changing its original structural design;

[0020] 2) After installing the adjustment device, the glow discharge becomes uniform and the brightness of the magnetron sputtering target is consistent from top to bottom, so the thickness of the film plated on the workpiece to be coated is consistent from top to bottom. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of a vacuum coating machine in the prior art;

[0022] Figure 2 It is a schematic diagram of the effect of the non-uniformity of the glow discharge of a cylindrical target;

[0023] Figure 3 It is a structural diagram of the magnetron sputtering vacuum coating machine of the present invention;

[0024] Figure 4 and Figure 5 It is a structural diagram of the uniformity adjustment device and the wall penetration member of the present invention;

[0025] Figure 6 is a schematic diagram of a resonant circuit in the uniformity adjustment device of the present invention;

[0026] Figure 7 This is a schematic diagram showing the effect of the uniformity of the glow discharge of a cylindrical target;

[0027] Reference numerals:

[0028] 1. RF power supply, 2. RF matching device, 3. Vacuum shield, 4. Rotating cathode cylindrical target, 5. Workpiece, 6. Uniformity adjustment device, 7. Wall-penetrating member, 41. Anode, 42. Suspended end (cathode), 8. Main body, 9. Projection of the coated workpiece, 10. Copper wire, 11. Metal casing, 12. Multi-position adjustable inductor, 13. Connecting wire, 14. Adjustable capacitor, 15. Capacitor adjustment knob, 16. Wall-penetrating bushing, 17. Front panel, 18. Inductor position adjustment knob, 19. Position connecting wire, 20. Mounting bracket, 21. Resonant circuit.

[0029] The technical solution will be described in detail below with reference to the accompanying drawings and embodiments.

[0030] like Figure 1As shown, the structure of a vacuum coating machine in the prior art that uses an RF power supply to apply RF voltage to a cathode cylindrical target includes an RF power supply 1, an RF matching device 2, a vacuum shield 3, a rotating cathode cylindrical target 4, and a workpiece 5. The anode 81 of the rotating cathode cylindrical target 4, the RF power supply 1, and the outer shell of the RF matching device 2 are all grounded. The suspended end 42 (cathode) of the rotating cathode cylindrical target 4, the rotating cathode cylindrical target 4, and the workpiece 5 are located within the interior space of the vacuum shield 3. The workpiece 5 to be coated is suspended around the rotating cathode cylindrical target 4, and the workpiece 5 is suspended on the same rotating cathode cylindrical target with a grounded anode. The RF signal output by the RF power supply 1 passes through the RF matching device 2 to ensure maximum efficiency. The RF signal is applied to the anode 81 of the rotating cathode cylindrical target, which serves as the input end of the cylindrical target and is driven by applying the RF voltage. Since the cylindrical target is relatively long, usually longer than 1 meter, the voltage distribution on it is uneven, causing uneven electric field distribution, resulting in strong discharge at the RF input end and weak discharge at the other end of the cylindrical target. That is, at the same moment, the voltage distribution of the rotating cathode cylindrical target 4 from the upper layer to the lower layer is uneven, so that the electric field distribution of the rotating cathode cylindrical target 4 and the workpieces 5 to be coated suspended around it is also uneven, which ultimately leads to thick coating on the workpieces suspended on the upper layer and thin coating on the workpieces suspended on the lower layer, causing uneven sputtering.

[0031] like Figure 2 The following is a schematic diagram of the effect of the columnar target non-uniformity example. Figure 1 The following shows the observation effect of the vacuum coating machine in the prior art during use. The projection 9 of the coated workpiece clearly shows the uneven glow discharge state: the upper layer is brighter, corresponding to the thicker film formed on the coated workpiece, while the lower layer is darker, corresponding to the thinner film formed on the coated workpiece.

[0032] In order to adjust the voltage distribution on the columnar target and make the voltage distribution on the columnar target uniform, the present invention provides the following technical solution: a uniformity adjustment device is connected outside the coating machine, one end of the copper wire is connected to the original suspended end of the columnar target, and the other end is connected to the uniformity adjustment device after passing through a wall-penetrating piece.

[0033] Example

[0034] like Figure 3As shown, in the magnetron sputtering vacuum coating machine of the present invention, in the main body 8, the RF power supply 1 is connected to the RF matcher 2, the RF matcher 2 is connected to the anode 41 of the rotating cathode cylindrical target 4, and the RF matcher 2 is grounded. The above connections are all connected using copper wire 10. The suspended end 42 of the rotating cathode cylindrical target is connected to the uniformity adjustment device 6 through the through-wall part 7. It is fixed on the vacuum shielding cover 3 by the through-wall part 7. The through-wall part 7 is made of copper tape. The through-wall part 7 is set on the vacuum shielding cover 3, and the other end of the through-wall part 7 is connected to the suspended end 42 of the rotating cathode cylindrical target 4.

[0035] The RF power supply 1 outputs a RF signal, which is passed through the RF matcher 2 to load the RF voltage onto the anode 81 of the rotating cathode cylindrical target, thereby driving the rotating cathode cylindrical target 4. The rotating cathode cylindrical target 4 and the workpiece 5 are located in the internal space of the vacuum shield 3. The workpiece 5 to be coated is suspended around the rotating cathode cylindrical target 4, and the workpieces 5 are respectively workpieces suspended on the same rotating cathode cylindrical target. Among them, after the RF signal output by the RF power supply 1 passes through the RF matcher 2, the RF signal is loaded onto one end of the anode of the rotating cathode cylindrical target 4 with maximum efficiency, and this end serves as the input end of the cylindrical target. The rotating cathode cylindrical target 4 and the uniformity adjustment device 6 are an adjustable common load for the RF signal, that is, the impedance of the common load is jointly determined by the cylindrical magnetron sputtering target and the uniformity adjustment device. According to actual needs, multiple rotating cathode cylindrical targets 4 can be set. The suspended end 42 of the rotating cathode cylindrical target 4 is connected to the uniformity adjustment device 6. The rotating cathode cylindrical target 4 and the uniformity adjustment device 6 serve as an adjustable common load, and the voltage value loaded on the cylindrical target is affected by adjusting the impedance, thereby achieving uniform adjustment of the voltage value distribution loaded on the cylindrical target by adjusting the impedance of the common load.

[0036] like Figure 4 and Figure 5 As shown, the uniformity adjustment device of the present invention includes a resonant circuit composed of a multi-speed adjustable inductor 12 and an adjustable capacitor 14 connected in series with each other, arranged in the metal shell 11. One end of the adjustable capacitor 14 is connected to one end of the multi-speed adjustable inductor 12 via a connecting wire. The adjustable capacitor 14 is connected to the metal shell 11, and the entire metal shell 11 is grounded. The multi-speed adjustable inductor 12 is used to adjust the impedance of the resonant circuit in real time. The adjustable capacitor 14 is used to balance the impedance of the resonant circuit. A capacitance adjustment knob 15 connected to the adjustable capacitor 14 and a speed adjustment knob 18 connected to the multi-speed adjustable inductor 12 via multiple speed connection wires 19 are provided on the front panel 17. One end of the adjustable capacitor 14 is connected to one end of the multi-speed adjustable inductor 12 via a connecting wire 13. A wall bushing 16 is set on a mounting bracket 20, and the mounting bracket 20 is fixed to the outer wall of the vacuum shield 3. The wall bushing 7 is installed through the wall bushing 16.

[0037] The radio frequency voltage is transmitted to the multi-level adjustment inductor 12 through the wall penetration member 7 .

[0038] The inductance adjustment knob 18 is used for inductance adjustment. For example, both an air-core inductor coil and a magnetic-core inductor coil can be adjusted by changing the number of coil turns using the inductance adjustment knob 18 .

[0039] In the uniformity adjustment device of the present invention,

[0040] like Figure 6 FIG. 1 is a schematic diagram of a resonant circuit in a uniformity adjustment device according to the present invention. The control circuit of the uniformity adjustment device is a series circuit consisting of an inductor and a capacitor.

[0041] After the inductor and capacitor of the resonant circuit are connected in series, the relationship between the total impedance Rz, the inductance L and the capacitance C is:

[0042] Rz=j(2πfL)+1 / j(2πfC)=j[2πfL-1 / (2πfC)]

[0043] Among them, L represents the inductance index, C represents the capacitance value, j represents the imaginary unit, and the value is , f represents the frequency of alternating current, f=13.56MHz.

[0044] Referring to the above formula, in actual use, appropriate impedance is obtained by configuring a fixed inductor or adjusting the inductor in real time, and appropriate impedance balancing is performed by configuring a fixed capacitor or adjusting the capacitor in real time.

[0045] The working principle of the resonant circuit is described in conjunction with the present invention: by introducing the series connection of the inductor coil and the capacitor, it is connected to the suspended end of the rotating cathode cylindrical target. The RF signal output by the RF power supply is applied to the anode of the rotating cathode cylindrical target via the RF matcher to drive the rotating cathode cylindrical target. The RF voltage is output through the suspended end and transmitted to the inductor through the wall-penetrating component. Since the cylindrical magnetron sputtering target and the cylindrical uniformity adjustment device are the common loads of the RF signal, the impedance is jointly determined by the cylindrical magnetron sputtering target and the uniformity adjustment device. Therefore, the impedance of the common load is actually adjusted by the uniformity adjustment device. That is, the value of the series inductor coil and capacitor is adjusted to change the impedance of the RF load, thereby changing the voltage distribution of the magnetron target, and achieving the result of changing the plasma distribution of the magnetron target.

[0046] The modified vacuum coating machine with uniformity adjustment device changes the impedance of the RF load by adjusting the inductor coil and capacitor in series to change the voltage distribution on the magnetron target, thereby changing the distribution of the magnetron target plasma. The final implementation effect of the modified solution is as follows: Figure 7As shown, through the observation window, it can be observed that the glow discharge around the cylindrical target is uniform from top to bottom. It can be clearly seen that the brightness is consistent from top to bottom. After the uniformity problem is solved, the film thickness of the workpiece is consistent from top to bottom without obvious difference.

[0047] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection claimed by the present invention. For those skilled in the art, any modification, equivalent substitution, or variation made without departing from the spirit and principles of the present invention through various changes and variations shall fall within the technical content and protection scope disclosed by the present invention.

Claims

1. A magnetron sputtering vacuum coating machine, characterized in that: include: A main body (8) and a uniformity adjustment device (6), wherein the main body (8) comprises a radio frequency power supply (1), a radio frequency matching device (2), a vacuum shield (3), and a rotating cathode cylindrical target (4), wherein a suspended end (42) of the rotating cathode cylindrical target (4) is connected to the uniformity adjustment device (6), and the rotating cathode cylindrical target (4) and the uniformity adjustment device (6) serve as an adjustable common load for achieving uniform adjustment of the radio frequency voltage distribution loaded on the rotating cathode cylindrical target (4); The radio frequency power supply (1) is connected to the radio frequency matching device (2), the radio frequency matching device (2) is connected to the anode (41) of the rotating cathode cylindrical target (4), the radio frequency matching device (2) is grounded, the rotating cathode cylindrical target (4) is arranged in a vacuum shield (3), and the suspended end (42) of the rotating cathode cylindrical target (4) outputs a radio frequency voltage; the multi-speed adjustment inductor (12) in the uniformity adjustment device (6) is connected to one end of the through-wall component (7), the other end of the through-wall component (7) is connected to the suspended end (42) of the rotating cathode cylindrical target (4), and the through-wall component (7) is fixed on the vacuum shield (3). The uniformity adjustment device comprises a metal shell (11), a front panel (17) and a resonant circuit (21); the resonant circuit is arranged in the metal shell (11), and the resonant circuit is composed of a multi-speed adjustment inductor (12) and an adjustable capacitor (14) connected in series; a capacitance adjustment knob (15) connected to the multi-speed adjustment inductor (12) and a speed adjustment knob (18) connected to the multi-speed adjustment inductor (12) are arranged on the front panel (17); a radio frequency voltage is loaded on the multi-speed adjustment inductor (12); the adjustable capacitor (14) is connected to the metal shell (11), and the metal shell (11) is grounded.

2. The magnetron sputtering vacuum coating machine according to claim 1, characterized in that: The multi-speed regulating inductor (12) is used to adjust the impedance of the common load in real time.

3. The magnetron sputtering vacuum coating machine according to claim 1, characterized in that: The adjustable capacitor (14) is used to balance the impedance of the common load.

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