Magnetron sputtering system and coating method thereof

Abstract

The invention relates to a magnetron sputtering system and a coating method thereof, the system comprises a pair of twin silicon target material and aluminum target material which are arranged in a coating chamber, the aluminum target material is located in the middle of a horizontal line where the twin silicon target material is located, the twin silicon target material is electrically connected with a medium-frequency power supply, and the aluminum target material is electrically connected with a direct-current power supply. According to the structural design, on one hand, the uniform deposition range can be expanded, the deposition difference of wide workpieces can be reduced, and the whole surface insulation consistency can be ensured, and on the other hand, the aluminum target realizes uniform doping of the aluminum element and stable control of the content, so that the toughness and binding force of the coating are improved, the influence on insulation is avoided, and the comprehensive performance of the non-conductive coating is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of magnetron sputtering technology, and in particular to a magnetron sputtering system for non-conductive coating preparation and a coating method thereof. BACKGROUND

[0002] In the preparation of non-conductive coatings (such as SiO2, N2O5) in consumer electronics and the like, the prior art mostly uses single silicon target magnetron sputtering or certain asymmetric layouts, cooperates with single power regulation, and relies on the proportion control of argon and reaction gas to control the film composition.

[0003] However, such a scheme has the following significant defects: first, the single silicon target magnetic field has a limited range of constraints, and when coating a wide component (such as a flat housing), there is a deviation in the deposition amount between the edge and the center, resulting in fluctuations in the insulation performance, which cannot meet the requirement of full-surface consistency; second, if aluminum elements are introduced to optimize the adhesion, the existing alloy target material composition is fixed, and the gas flow adjustment response is lagging, resulting in large fluctuations in the proportion of aluminum, which is easy to form a conductive channel and lose the insulation function; third, in certain asymmetric layouts, the magnetic fields interfere with each other, causing plasma to shift and overlap, excessive corrosion of the target material in the overlapping area, low deposition rate in the shifted area, and particle energy distribution disorder, which results in large porosity of the coating, insufficient adhesion, and difficulty in withstanding daily wear and tear.

[0004] In summary, the existing system cannot balance the wide uniformity, composition stability, deposition efficiency and mechanical properties, and is difficult to adapt to the stringent requirements of consumer electronics on coating insulation, wear resistance and moisture resistance. SUMMARY

[0005] To solve the above technical problems, the present application provides a magnetron sputtering system and a coating method thereof.

[0006] To achieve the above-mentioned purpose, the present application is realized by the following technical solutions: The present application provides a magnetron sputtering system, which comprises a pair of twin silicon targets and an aluminum target arranged in a coating chamber, the aluminum target is located at the center of the horizontal line where the twin silicon targets are located, the twin silicon targets are electrically connected with a medium frequency power supply, and the aluminum target is electrically connected with a direct current power supply.

[0007] As a further improvement of the present application, the horizontal distance between the centers of the twin silicon targets is 0.8m-1.2m. Preferably, the horizontal distance between the twin silicon targets is 1m.

[0008] As a further improvement of the present application, the vertical distance between the loading platform for fixing the parts to be coated in the coating chamber and the horizontal plane where the twin silicon targets and the aluminum target are located is 6cm-15cm.

[0009] As a further improvement of the application, the system further comprises a vacuum pumping device connected with the coating chamber through a vacuum pipe for pumping the coating chamber.

[0010] As a further improvement of the application, the system further comprises a vacuum gauge connected with the coating chamber for monitoring the vacuum degree of the coating chamber in real time.

[0011] As a further improvement of the application, the system further comprises an argon gas filling device connected with the coating chamber through a gas filling pipe for delivering argon gas to the coating chamber.

[0012] As a further improvement of the application, the magnetron sputtering system further comprises a film feeding chamber, a first transition chamber, a first buffer chamber and an etching chamber arranged in sequence in front of the coating chamber, and a second buffer chamber, a second transition chamber and a film discharging chamber arranged in sequence in rear of the coating chamber.

[0013] To achieve the above object, the application further provides a film coating method based on the above-mentioned magnetron sputtering system, comprising the following steps: S1, initial parameter setting and first stage adjustment: turn on the intermediate frequency power supply, control the first input power of the twin silicon target material to be a first preset value, turn on the direct current power supply, and control the second input power of the aluminum target material to be adjusted in stages based on a first initial value according to a first preset adjustment rule; During the adjustment of the second input power, the color difference value and the resistance value of the film formed on the surface of the workpiece to be coated are monitored or detected in stages: when the color difference value and the resistance value of the film reach a preset range in a certain stage, the first input power of the twin silicon target material and the second input power of the aluminum target material corresponding to this round of iteration are recorded as the target process parameters; if only the resistance value reaches the preset range, the following steps are performed; S2, multiple rounds of iteration optimization: according to the color difference value and the resistance value detected in step S1, the first input power of the twin silicon target material is adjusted to a second preset value and kept fixed according to a second preset adjustment rule, and the second preset adjustment rule comprises: based on the deviation direction of the color difference value and the resistance value, the adjustment direction is selected and the corresponding twin silicon target material adjustment amount is matched; At the same time, a second initial value of the second input power is set, which is determined according to the color difference value and the resistance value detected in step S1, and the second input power of the aluminum target material is adjusted in stages based on the second initial value according to a third preset adjustment rule, and the third preset adjustment rule comprises: based on the deviation direction of the color difference value and the resistance value, the adjustment direction is selected; during the adjustment of the second input power, the color difference value and the resistance value of the film are continuously monitored. Repeating the operation of adjusting the first input power to the n preset value according to the second preset adjustment rule and keeping it fixed, adjusting the second input power of the aluminum target according to the aluminum target power adjustment rule in each subsequent iteration, and detecting the film performance to form a multi-iteration cycle, wherein: n >= 3, n is a positive integer; S3, optimal parameter determination: when the color difference value and the resistance value of the film in a certain iteration reach the preset range, the corresponding first input power of the twin silicon target and the second input power of the aluminum target in this iteration are recorded as the target process parameters; if the resistance value and the color difference value do not reach the preset range, the iteration is continued until the preset range is met.

[0014] As a further improvement of the present application, the following step is performed before step S1: placing the film-coated piece to be plated on the stage of the film-coating chamber, evacuating the film-coating chamber to 5.0*10 -6 mbar, and then filling the film-coating chamber with argon gas at a flow rate of 1200 SCCM.

[0015] To achieve the above-mentioned purpose, the present application also provides a non-conductive coating obtained by the above-mentioned method.

[0016] The beneficial effects of the present application are that by adopting the layout of a pair of twin silicon targets in cooperation with an aluminum target located at the middle of the horizontal line, combined with the design of electrically connecting the twin silicon target with the intermediate frequency power supply and electrically connecting the aluminum target with the direct current power supply, the comprehensive performance of the non-conductive coating can be significantly improved.

[0017] The symmetrically distributed twin silicon targets can form superimposed sputtering areas, effectively expanding the uniform deposition range, reducing the deposition difference between the edge and the center of the wide workpiece, improving the thickness and composition uniformity of the coating, and ensuring the consistent insulation performance of the entire surface of the consumer electronic product; the setting of the middle aluminum target can realize uniform doping of aluminum elements, and the precise regulation of the direct current power supply can stably control the aluminum content within a reasonable range, which not only improves the toughness and adhesion of the coating by using aluminum elements, but also avoids the formation of conductive channels affecting the insulation performance.

[0018] At the same time, the intermediate frequency power supply is adapted to the semiconductor characteristics of the silicon target, which can reduce charge accumulation and arc discharge, and the direct current power supply is adapted to the conductive characteristics of the aluminum target, which can realize rapid response power regulation, and the synergistic effect of the two can improve the stability of the plasma and the deposition efficiency, ultimately enabling the coating to meet the high insulation requirements while having excellent wear resistance and moisture resistance, which meets the harsh use requirements of consumer electronic products. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic diagram of the magnetron sputtering system of embodiment 1 of the present application.

[0020] In the figure: 1, the film feeding chamber; 2, the first transition chamber; 3, the first buffer chamber; 4, the etching chamber; 5, the film coating chamber; 6, the second buffer chamber; 7, the second transition chamber; 8, the film outlet chamber; 9, the twin silicon target; 10, the aluminum target; 11, the workpiece to be coated; 12, the carrier. DETAILED DESCRIPTION

[0021] The technical solutions of the present application will be described in detail below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0022] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the specific embodiments.

[0023] In the prior art, when a single silicon target is used, the magnetic field confinement range is limited by the single target magnetic field intensity distribution characteristics, and the plasma density naturally decays away from the center of the target surface, resulting in a significant difference in the number of sputtering particles received by different regions of the wide workpiece surface. This difference will directly cause the unevenness of the coating thickness, and further cause the fluctuation of the insulation performance in the edge and center regions of the workpiece, which cannot meet the basic requirement of the full-surface insulation consistency of consumer electronic products. In terms of aluminum element regulation, when an alloy target is used in the prior art, its composition is fixed and cannot be dynamically adjusted, and the response lag problem exists when relying on the flow regulation of the reaction gas to adjust the aluminum content, resulting in a large fluctuation in the proportion of aluminum element. When the aluminum content is too high, it is easy to form a conductive path in the coating to damage the insulation, and when it is too low, it is difficult to play the role of improving the toughness of the coating, resulting in the coating either losing insulation function or having insufficient mechanical properties.

[0024] To solve the above problems, the present application provides a magnetron sputtering system, comprising a pair of twin silicon targets and an aluminum target arranged in a film coating chamber, the aluminum target is located at the center of the horizontal line where the twin silicon targets are located, the twin silicon targets are electrically connected with a medium frequency power supply, and the aluminum target is electrically connected with a direct current power supply.

[0025] Based on the above technical scheme, the symmetrical layout of the twin silicon target can effectively make up for the limitation of single target magnetic field constraint by forming mutually superimposed sputtering areas, so that the plasma density distribution in a wide range is more balanced, the particle deposition difference between the edge and the center area is reduced from the root, and at the same time, the electrical connection mode of the twin silicon target and the intermediate frequency power supply can adapt to the semiconductor properties of silicon due to the alternating characteristics of the intermediate frequency power supply, so as to avoid arc discharge caused by charge accumulation on the surface of the silicon target, ensure the continuous and stable existence of the plasma, further reduce the density fluctuation in the deposition process, and finally realize the uniformity of the coating thickness and composition of the wide workpiece, and ensure the consistency of the full-surface insulation performance.

[0026] In the scheme, the aluminum target is located at the middle of the horizontal line where the twin silicon target is located. This position layout can make the particles sputtered by the aluminum target uniformly diffuse to both sides and form a complementary distribution with silicon particles, avoiding local enrichment or sparseness. At the same time, the electrical connection of the aluminum target and the direct current power supply adapts to the good conductivity of aluminum, which can realize rapid and accurate adjustment of power, so as to dynamically control the sputtering amount of aluminum element, ensure that its proportion in the coating is within a reasonable range, and both improve the wear resistance of the coating by means of the ductility of aluminum and prevent the formation of conductive channels due to high aluminum content from affecting the insulation performance.

[0027] In addition, the independent electrical connection mode of the twin silicon target and the intermediate frequency power supply, and the aluminum target and the direct current power supply can reduce the frequency coupling interference between the plasmas of different target materials due to the difference in power supply characteristics of intermediate frequency and direct current, avoid sputtering instability caused by plasma disorder, further improve the stability of the entire deposition process, and solve the problem that the prior art cannot balance the wide uniformity, composition stability and deposition reliability as a whole.

[0028] In an optional embodiment, the coating chamber is a cuboid cavity, for example, the size can be set to 2-3 m in length, 1.5-2 m in width, and 1.2-1.5 m in height, and the inner wall is made of 304 stainless steel to reduce impurity volatilization. A pair of twin silicon targets can be rectangular in shape, and the size of the target can be set to 200 mm in length, 400 mm in width, and 10 mm in height. The target surface of the target faces the loading table and is parallel to the loading table plane, and is symmetrically distributed on both sides of the coating chamber. The aluminum target is a rectangular target of the same size, which is fixed on the horizontal line between the two silicon targets by a target holder, that is, the horizontal distance between the center of the aluminum target and the center of the two silicon targets is equal. The frequency of the intermediate frequency power supply electrically connected to the twin silicon target is 10-40 kHz, and the power regulation range is 5-20 kW. The output end of the intermediate frequency power supply is connected to the silicon target through a shielding cable to reduce electromagnetic interference. The power regulation range of the direct current power supply electrically connected to the aluminum target is 3-10 kW, and the output ripple coefficient is ≤5%, which adapts to the good conductivity of the aluminum target.

[0029] In an optional embodiment, the horizontal distance between the centers of the twin silicon targets is 0.8 m to 1.2 m. The horizontal distance is the straight-line distance between the centers of the two twin silicon targets, which is adjusted by the target holder scale and is limited to a range of 0.8 m to 1.2 m. For example, when the width of the object to be coated is 0.8-1 m (such as a smartphone backboard), the horizontal distance between the twin silicon targets is preferably 1 m, at which time the sputtering areas of the two silicon targets form a uniform coverage area of 1.2 m in width above the carrier, and the difference in the amount of silicon atoms deposited at the edge and the center is ≤3%; if the width of the object to be coated is <0.8 m, it can be adjusted to 0.8 m to improve the particle density in the center area. The distance range between the twin silicon targets is matched with the size of the object to be coated (such as a wide workpiece for consumer electronics), so as to avoid the overlapping of the sputtering areas (excessive thickness in the center) caused by too small distance or the insufficient deposition at the edge caused by too large distance.

[0030] In an optional embodiment, the vertical distance between the carrier for fixing the object to be coated in the coating chamber and the horizontal plane where the twin silicon targets and the aluminum target are located is 6 cm to 15 cm. The vertical distance refers to the vertical height of the sputtering surface of the target (the surface of the target facing the carrier) and the surface of the carrier (the plane where the object to be coated is placed), which is adjusted by the carrier lifting mechanism. When it is necessary to prioritize the uniformity of the coating (such as optical coating), it is set to 10-15 cm to reduce the difference in the direction of particle migration; when it is necessary to prioritize the deposition rate (such as mass production scenarios), it is set to 6-10 cm to shorten the particle motion path. The above technical solution facilitates the balance between particle collision probability and energy loss: when the distance is <6 cm, the particle energy is too high, resulting in excessive internal stress (the coating is prone to cracking); when the distance is >15 cm, the deposition rate decreases by >30%; within the range of 6-15 cm, the coating density is >95%, and the bonding force is >5 N / cm, meeting the wear resistance requirements of consumer electronics.

[0031] In an optional embodiment, the system further comprises a vacuum pumping device connected to the coating chamber through a vacuum pipe for pumping the coating chamber. The vacuum pumping device is composed of a mechanical pump (rough pumping) and a molecular pump (fine pumping), which are connected to the coating chamber through a Φ50 mm stainless steel vacuum pipe. The gas pumping path is provided with a valve for control: first, the mechanical pump is opened to pump the vacuum degree to below 1 Pa, and then the molecular pump is opened to pump to ≤5×10 -6 mbar (background vacuum), and the pumping time is ≤30 min. The high vacuum environment reduces the impurities (content ≤1 ppm) such as O2 and H2O in the air in the coating chamber, so as to avoid the reaction of the impurities with silicon and aluminum atoms to form impurity phases (such as Al(OH)3).

[0032] In an optional embodiment, the system further comprises a vacuum gauge connected to the coating chamber for real-time monitoring of the vacuum degree of the coating chamber. The vacuum gauge adopts an ionization vacuum gauge, which is installed on the side wall of the coating chamber (50 cm away from the target), and the measurement range is 10 -8 ~10-1 mbar, precision ±10%, real-time display and parallel operation of vacuum pumping device: when the vacuum degree > 8x10 - 6 mbar, the molecular pump is automatically started to supplement. Real-time monitoring avoids the change of plasma density caused by the fluctuation of vacuum degree, ensures the uniformity of coating composition, and solves the problem of local insulation failure caused by out-of-control vacuum in the existing system.

[0033] In an optional embodiment, the system further comprises: an argon gas charging device connected with the coating chamber through a charging pipe for delivering argon gas to the coating chamber. The argon gas charging device is composed of a high-purity argon cylinder (purity 99.999%), a mass flow controller (MFC), and a Φ10mm copper pipe. The MFC has an adjustment range of 0-2000 SCCM, and uniformly supplies gas through a gas distributor (multi-hole structure) on the side wall of the coating chamber. The working gas pressure is stabilized at 1.5x10 -3 mbar-2.5x10 -3 mbar. Stable argon flow (such as 1200 SCCM) ensures constant plasma density, reduces sputtering rate changes caused by gas fluctuations (such as fluctuations ≤2%), and improves coating thickness consistency.

[0034] In an optional embodiment, the magnetron sputtering system further comprises, in sequence from the front end of the coating chamber, an entry chamber, a first transition chamber, a first buffer chamber, an etching chamber, and, in sequence from the rear end of the coating chamber, a second buffer chamber, a second transition chamber, and an exit chamber. The etching chamber mainly uses Ar plasma to etch the surface of the workpiece to be coated, removes oil stains / oxidation layer on the surface of the workpiece, and improves the adhesion of the coating. The general parameter design is: power 500W, time 3min.

[0035] For the above-mentioned magnetron sputtering system, if a single fixed power parameter is used for sputtering, due to the inherent difference in sputtering yield of silicon and aluminum targets, and the fact that coating performance (color difference value, resistance value) is extremely sensitive to composition ratio, fixed parameters cannot adapt to the subtle changes in material properties during deposition; this will cause the coating composition to deviate from the ideal range, resulting in excessive color difference value or resistance value not meeting the insulation requirements, and it is difficult to find suitable parameters through a single test; ultimately resulting in poor consistency of coating performance, which cannot meet the dual stringent standards of appearance and insulation of consumer electronic products.

[0036] To solve the above problems, the application also provides a method for coating based on the above-mentioned magnetron sputtering system, comprising the following steps: S1, initial parameter setting and first stage adjustment: turn on the intermediate frequency power supply, control the first input power of the twin silicon target material to be a first preset value, turn on the direct current power supply, and control the second input power of the aluminum target material to be adjusted in stages based on a first initial value according to a first preset adjustment rule; during the adjustment of the second input power, the color difference value and the resistance value of the film formed on the surface of the to-be-coated part are monitored or detected in stages; Specifically, the first preset adjustment rule includes a first preset period, a first preset adjustment amount, and a first adjustment direction, the first adjustment direction can be incremental or decremental, and the first preset adjustment rule and the first initial value can be set according to the experience value in the industry; For example, the first preset value can be set to 5KW, the first preset period can be set to 30min, the first preset adjustment amount can be set to 0.1KW, the first initial value is 0KW, and the first adjustment direction can be incremental, so that the second input power of the aluminum target material can be increased in stages based on the first initial value 0KW according to the first preset period 30min and the first preset adjustment amount 0.1KW; During the adjustment of the second input power, the color difference value and the resistance value of the film formed on the surface of the to-be-coated part are monitored or detected in stages: when the color difference value and the resistance value of the film reach a preset range in a certain stage, the first input power of the twin silicon target material and the second input power of the aluminum target material corresponding to this round of iteration are recorded as target process parameters; the second input power of the aluminum target material generally has the greatest influence on the resistance value, therefore, if only the resistance value reaches the preset range, the color difference value may not satisfy the preset range, and therefore the following step S2 is performed; S2, multiple rounds of iteration optimization: according to the color difference value and the resistance value detected in step S1, the first input power of the twin silicon target material is adjusted to a second preset value and kept fixed according to a second preset adjustment rule, the second preset adjustment rule includes: based on the deviation direction of the color difference value and the resistance value, a second adjustment direction is selected, the second adjustment direction includes increment or decrement, and a corresponding twin silicon target material adjustment amount is matched; At the same time, a second initial value of the second input power is set, the second initial value is determined according to the color difference value and the resistance value detected in step S1, and then the second input power of the aluminum target material is adjusted in stages based on the second initial value according to a third preset adjustment rule, the third preset adjustment rule includes: based on the deviation direction of the color difference value and the resistance value, a third adjustment direction is selected, the third adjustment direction includes increment or decrement; during the adjustment of the second input power, the color difference value and the resistance value of the film are continuously monitored; Specifically, the second preset adjustment rule includes a second preset adjustment amount and a second adjustment direction, and the second adjustment direction includes increment or decrement; the third preset adjustment rule includes a third preset period, a third preset adjustment amount and a third adjustment direction, and the third adjustment direction includes increment or decrement. The second preset value, the second initial value, the second preset adjustment rule, the second adjustment direction, the third preset adjustment rule and the third adjustment direction are set according to the color difference value and the resistance value detected in step S1. For example, the second preset adjustment amount can be 1KW, the second adjustment direction is decrement, and the first preset value can be 5KW. Then the first input power of the twin silicon target material can be gradually decreased by 1KW based on the first preset value 5KW, and the second preset value is 4KW. The third preset period can be 30min, the third preset adjustment amount can be 0.1KW, the third adjustment direction is decrement, and the second initial value is 0.7KW. Then the second input power of the aluminum target material can be gradually decreased by 0.1KW based on the second initial value 0.7KW according to the third preset period 30min. The operation of "adjusting the first input power to the nth preset value according to the second preset adjustment rule and keeping it fixed, adjusting the second input power of the aluminum target material according to the aluminum target power adjustment rule in each subsequent iteration, and detecting the film performance" is repeated to form a multi-iteration cycle, wherein n≥3, n is a positive integer. The second preset adjustment rule is a special adjustment rule for the first input power of the twin silicon target material, and the first preset adjustment rule, the third preset adjustment rule and the aluminum target power adjustment rule in each subsequent iteration are special adjustment rules for the second input power of the aluminum target material. The adjustment rules can be the same or different in adjustment period, adjustment amount or adjustment direction. S3, optimal parameter determination: when the color difference value and the resistance value of the film reach the preset range in a certain iteration, the first input power of the twin silicon target material and the second input power of the aluminum target material corresponding to this iteration are recorded as the target process parameters; if the resistance value and the color difference value do not reach the preset range, the iteration is continued until the preset range is met.

[0037] Based on the above-mentioned film coating method, the problem of difficult precise control of coating performance by the existing fixed parameter sputtering method is effectively solved through the logical design of phased parameter adjustment and multi-iteration optimization. Specifically as follows: In the method, step S1 can establish a direct correlation between the content of aluminum element and the performance of the coating by fixing the twin silicon target power, adjusting the aluminum target power in stages according to a preset period and a preset adjustment amount, and synchronously monitoring the chromatic aberration value and the resistance value, thereby avoiding the randomness of blind adjustment; the mode of "single-variable adjustment + real-time monitoring" can accurately capture the influence law of the change of the content of aluminum on the performance, thereby providing basic data for subsequent optimization.

[0038] The multi-round iteration optimization of step S2 upgrades the single-factor adjustment to multi-parameter collaborative optimization through the cyclic logic of "adjusting the twin silicon target power → readjusting the aluminum target power → detecting the performance": the fixing and adjustment of the twin silicon target power can control the basic deposition amount of the silicon element, and the reverse or progressive adjustment of the aluminum target power can compensate the influence of the change of the content of silicon on the performance, and the two form a dynamic balance; the iteration mechanism can gradually narrow the parameter range, avoid the deviation caused by not considering the interaction between silicon and aluminum in single adjustment, and significantly improve the parameter matching accuracy.

[0039] Step S3 ensures the consistency of the performance of the coating in batch production by determining the target parameters corresponding to the ideal performance, thereby fundamentally solving the problem of large performance fluctuation of the existing method.

[0040] Overall, the coating method of the application realizes the accurate regulation of the chromatic aberration value and the resistance value of the coating through the logical chain of "initial exploration → iterative approximation → accurate locking", and solves the technical problem that the fixed parameter method cannot balance the consistency and accuracy of the performance.

[0041] In an optional embodiment, the following step is performed before step S1: placing the workpiece to be coated on a loading table in a coating chamber, evacuating the coating chamber to 5.0x10 -6 The vacuum evacuation and argon filling operation in the present scheme provide a stable vacuum environment and plasma basis for subsequent parameter adjustment: the high vacuum state reduces the interference of impurity gas on silicon and aluminum atoms, and the stable argon atmosphere ensures the uniformity of plasma density, thereby avoiding the influence of environmental fluctuations on the correlation between parameters and performance, making the monitoring data more reliable, and further improving the efficiency and accuracy of iterative optimization.

[0042] In order to facilitate the understanding of the technical scheme of the application, specific embodiments are also provided, which are as follows: Embodiment 1 The present embodiment provides a magnetron sputtering system, which is a continuous line cavity coating device, such as Figure 1As shown, in turn includes the film room 1, the first transition chamber 2, the first buffer chamber 3, etching chamber 4, coating chamber 5, the second buffer chamber 6, the second transition chamber 7, the film room 8, wherein: coating chamber 5 is provided with a pair of twin silicon target 9 and aluminum target 10, the horizontal distance between the twin silicon target 9 is 1 m, aluminum target 10 is located in the horizontal line of twin silicon target 9 in the middle, the twin silicon target 9 and the intermediate frequency power supply is electrically connected, the aluminum target 10 and the direct current power supply is electrically connected, coating chamber 5 is also provided with a load 12 for fixing the target coating 11, the load 12 and the vertical distance of twin silicon target 9 or aluminum target 10 is 10 cm.

[0043] The magnetron sputtering system further comprises: vacuum pumping device, argon gas charging device, wherein: The vacuum pumping device is connected with the first transition chamber 2, the first buffer chamber 3, the etching chamber 4, the coating chamber 5, the second buffer chamber 6, the second transition chamber 7 through the vacuum pipe respectively, for pumping each chamber, and a vacuum gauge is further arranged on each chamber respectively, the vacuum gauge is used for monitoring the vacuum degree of the first transition chamber 2, the first buffer chamber 3, the etching chamber 4, the coating chamber 5, the second buffer chamber 6, the second transition chamber 7 in real time. The argon gas charging device is connected with the coating chamber 5 through the gas charging pipe, for delivering argon to the coating chamber 5.

[0044] Embodiment 2 The embodiment also provides a coating method based on the magnetron sputtering system of embodiment 1, comprising the following steps: A1, the target coating is placed on the load of the film room, the vacuum pumping device is used for pumping the first transition chamber, the first buffer chamber, the etching chamber, the coating chamber, the second buffer chamber, the second transition chamber, the vacuum degree of the first transition chamber is maintained at 2.0*10 -6 mbar, the vacuum degree of the first buffer chamber is maintained at 4.0*10 -6 mbar, the vacuum degree of the coating chamber is maintained at 5.0*10 - 6 mbar, the vacuum degree of the second buffer chamber is maintained at 4.0*10 -6 mbar, the vacuum degree of the second transition chamber is maintained at 2.0*10 - 6 mbar, after pumping, the argon is filled into the coating chamber, the argon flow is 1200 SCCM, after filling argon, the pressure of the coating chamber is maintained at 1.5*10 -3 mbar~2.5*10 -3 mbar.

[0045] A2, the target coating is sequentially passed through the first transition chamber, the first buffer chamber, the etching chamber and then enters the coating chamber.

[0046] A3. Initial parameter setting and first stage adjustment: Turn on the medium frequency power supply, control the first input power of the twin silicon target to the first preset value, the first preset value is 5KW, turn on the DC power supply, control the first initial value of the second input power of the aluminum target to 0KW, and then make staged adjustments based on the first initial value according to the first preset period and the first preset adjustment amount. The first preset period is 30 minutes, and the first preset adjustment amount is 0.1KW, and the power is increased in stages. During the second input power adjustment process, the color difference value and resistance value of the thin film formed on the surface of the workpiece to be coated are monitored in real time or detected in stages. For example, the color difference value and resistance value of the thin film corresponding to some different parameters during this experimental period are shown in Table 1: Table 1

[0047] A4, multiple rounds of iterative optimization: According to the color difference value and resistance value results detected in step A3, the first input power of the twin silicon target is adjusted to a second preset value according to the second preset adjustment rule and kept fixed. The second preset adjustment rule includes a second adjustment amount and a second adjustment direction. The second adjustment amount is 1KW, and the second adjustment direction is decreasing. The first preset value in step A3 is 5KW. Therefore, the second preset value is 4KW. Then, the second input power of the aluminum target is controlled to be adjusted in stages based on the second initial value according to the third preset period and the third preset adjustment amount. The second initial value is 0.7KW, the third preset period is 30min, and the third preset adjustment amount is 0.1KW, which is gradually decreased. During the second input power adjustment process, the color difference value and resistance value of the film continue to be monitored; Repeat the steps of "adjusting the first input power to the nth preset value according to the second preset adjustment rule and keeping it fixed, adjusting the second input power of the aluminum target according to the aluminum target power adjustment rule in each subsequent iteration, and testing the film performance" to form multiple iterations, where n ≥ 3, and n is a positive integer. For example, the color difference and resistance values ​​of the film corresponding to some different parameters during this experiment are shown in Table 2: Table 2

[0048] A5. Determining Optimal Parameters: When the color difference and resistance values ​​of the film reach the preset ranges during a certain iteration, the first input power of the twin silicon target and the second input power of the aluminum target corresponding to that iteration are recorded as the target process parameters. If neither the resistance nor the color difference values ​​reach the preset ranges, the iteration continues until they meet the preset ranges. For example, after adjustments in A3 and A4, when the first input power of the twin silicon target is 4 kW and the second input power of the aluminum target is 0.4 kW, the color difference and resistance values ​​of the film formed on the coated part meet the process requirements.

[0049] The test standard of the color difference value is reference to GB / T 7921-2008 "Uniform color space and color difference formula", and the test standard of the resistance value is reference to GB / T 1410-2006 "Test method of volume resistivity and surface resistivity of solid insulating materials".

[0050] In addition, the application also carries out the bonding force test on the thin film formed on the film plating piece when the first input power of the twin silicon target material is 4KW and the second input power of the aluminum target material is 0.4KW, and the bonding force level is HF2 level (using a diamond cone indenter with a cone angle of 120 degrees and a top ball radius of 0.2mm, the indenter is vertically pressed into the thin film surface of the film plating piece under the force of 150Kg, and then the bonding force level is evaluated according to the damage state of the coating around the indentation according to the VDI3198 standard), which shows excellent bonding force performance.

[0051] Although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be combined appropriately to form other embodiments that those skilled in the art can understand.

[0052] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present application, and they are not used to limit the protection scope of the present application, and any equivalent embodiments or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.

Claims

1. A magnetron sputtering system, characterized in that: It includes a pair of twin silicon targets and aluminum targets arranged in a coating chamber, wherein the aluminum target is located in the middle of a horizontal line where the twin silicon targets are located, the twin silicon targets are electrically connected to a medium frequency power supply, and the aluminum target is electrically connected to a direct current power supply.

2. The magnetron sputtering system according to claim 1, characterized in that The horizontal distance between the centers of the twin silicon targets is 0.8m to 1.2m.

3. The magnetron sputtering system according to claim 1, characterized in that The vertical distance between the carrier for fixing the workpiece to be coated in the coating chamber and the horizontal plane where the twin silicon target and the aluminum target are located is 6 cm to 15 cm.

4. The magnetron sputtering system according to any one of claims 1 to 3, characterized in that: The system further comprises a vacuum pumping device, which is connected to the coating chamber via a vacuum tube and is used for vacuuming the coating chamber.

5. The magnetron sputtering system according to claim 4, characterized in that The system further comprises a vacuum gauge connected to the coating chamber for monitoring the vacuum degree of the coating chamber in real time.

6. The magnetron sputtering system according to any one of claims 1 to 3, characterized in that: The system further comprises an argon gas filling device, which is connected to the coating chamber via a gas filling pipe and is used for conveying argon gas to the coating chamber.

7. The magnetron sputtering system according to any one of claims 1 to 3, characterized in that: The magnetron sputtering system also includes a film feeding chamber, a first transition chamber, a first buffer chamber, and an etching chamber, which are sequentially arranged at the front end of the coating chamber, and a second buffer chamber, a second transition chamber, and a film discharging chamber, which are sequentially arranged at the rear end of the coating chamber.

8. A method for coating a film using a magnetron sputtering system according to any one of claims 1 to 7, characterized in that: The steps include: S1. Initial parameter setting and first stage adjustment: Turn on the intermediate frequency power supply, control the first input power of the twin silicon target to a first preset value, turn on the DC power supply, and control the second input power of the aluminum target to be adjusted in stages based on the first initial value according to the first preset adjustment rule; During the second input power adjustment process, the color difference value and the resistance value of the thin film formed on the surface of the to-be-coated article are monitored in real time or detected in stages: when the color difference value and the resistance value of the thin film reach a preset range in a certain stage, the first input power of the twin silicon target and the second input power of the aluminum target corresponding to this iteration are recorded as target process parameters; if only the resistance value reaches the preset range, the following steps are executed; S2, multiple rounds of iterative optimization: Based on the color difference value and resistance value results detected in step S1, the first input power of the twin silicon target is adjusted to a second preset value according to a second preset adjustment rule and kept fixed, wherein the second preset adjustment rule includes: selecting an adjustment direction based on the deviation direction of the color difference value and the resistance value, and matching the corresponding twin silicon target adjustment amount; At the same time, a second initial value of the second input power is set, the second initial value is determined based on the color difference value and resistance value results detected in step S1, and then the second input power of the aluminum target is controlled to be staged adjusted based on the second initial value according to a third preset adjustment rule, the third preset adjustment rule including: selecting an adjustment direction based on the deviation direction of the color difference value and the resistance value; during the second input power adjustment process, continuing to monitor the color difference value and resistance value of the film; Repeating the operations of "adjusting the first input power to an nth preset value according to the second preset adjustment rule and keeping it fixed, adjusting the second input power of the aluminum target according to the aluminum target power adjustment rule in each subsequent iteration, and detecting the film performance" to form multiple iterative cycles, where: n ≥ 3, n is a positive integer; S3. Determination of optimal parameters: When the color difference value and resistance value of the film reach the preset range in a certain round of iteration, the first input power of the twin silicon target and the second input power of the aluminum target corresponding to this round of iteration are recorded as the target process parameters; if the resistance value and the color difference value do not reach the preset range, continue to iterate until the preset range is met.

9. The method according to claim 8, characterized in that Before step S1, the following steps are performed: the workpiece to be coated is placed on the carrier of the coating chamber, and the coating chamber is evacuated to 5.0×10 -6 mbar, and then argon gas was filled into the coating chamber with a flow rate of 1200 SCCM.

10. A non-conductive coating, characterized in that: The non-conductive coating is obtained by the method according to claim 8 or 9.

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