Preparation method of etching-resistant and wear-resistant Y2O3-AlxOy composite coating

Abstract

The invention relates to a preparation method of an etching-resistant and wear-resistant Y2O3-AlxOy composite coating. The preparation method comprises the following steps: carrying out ultrasonic cleaning on a corrosion-resistant matrix; performing plasma bombardment cleaning activation on the surface of the corrosion-resistant matrix; a Y2O3 coating and an AlxOy coating are alternately deposited on a corrosion-resistant base body in a double-target magnetron sputtering mode to form the Y2O3-AlxOy composite coating, the sputtering power of a Y target is larger than that of an Al target, and the ratio of x to y in the AlxOy coating is larger than 1. According to the method, the amorphous AlxOy coating dominated by the metal state is introduced into the Y2O3 coating, growth of Y2O3 columnar crystals is continuously broken, crystal grains are refined, formation of intergranular easy-to-etch point locations is inhibited, and an yttrium aluminum oxide composite strengthening phase is formed at an interface, so that plasma etching resistance is improved; the thickness of a single-layer coating in the composite coating is very thin; under the action of growth stress, the structure of the coating presents a wave-shaped microstructure and a soft and hard alternate mechanical structure, and the soft and hard alternate mechanical structure is beneficial to inhibiting generation of transverse cracks, guiding friction crack level expansion, prolonging the friction life of the coating and reducing the wear rate.

Description

Technical Field

[0001] This invention relates to the field of material surface treatment technology, specifically to a corrosion-resistant and wear-resistant Y2O3-Al. x O y Methods for preparing composite coatings. Background Technology

[0002] In the semiconductor product manufacturing process, the components in the production equipment (such as gas nozzles, gas distribution plates, dielectric windows, electrostatic chucks, and core components such as the inner wall of the cavity) not only need to be continuously exposed to a high-density, highly active plasma environment, and endure severe chemical corrosion and ion bombardment, but also inevitably come into contact with, slide or rub against other components.

[0003] For protection in plasma environments, existing technologies widely employ ceramic coatings such as yttrium oxide (Y2O3) and alumina (Al2O3). However, these materials have the following shortcomings when dealing with the extreme conditions of the aforementioned "etching-wear" coupling: On the one hand, long-term exposure to fluorine-containing plasma environments leads to the removal of Y2O3 and Al2O3 coatings by bombardment and corrosion from high-energy reactive particles, resulting in contaminants and cavity contamination; on the other hand, low-temperature deposited Y2O3 and Al2O3 coatings have poor wear resistance, especially resistance to abrasive wear, and are prone to scratches and material peeling under friction. This not only causes dimensional inaccuracies in components due to wear, but the peeled particles also become a fatal source of contamination, leading to a decrease in wafer product yield. Summary of the Invention

[0004] Therefore, the purpose of this invention is to provide a Y2O3-Al material that is resistant to etching and wear. x O y The method for preparing the composite coating involves introducing amorphous, predominantly metallic Al atoms into the Y₂O₃ coating. x O y The coating continuously interrupts the growth of Y2O3 columnar crystals, refines the grains, and inhibits the formation of easily etchable sites between grains. At the same time, it induces the composite coating to form a wave-shaped microstructure and a mechanical structure with alternating soft and hard surfaces, achieving bidirectional synergistic optimization of etching protection and wear protection.

[0005] A type of etching-resistant and wear-resistant Y2O3-Al x O y The method for preparing a composite coating includes the following steps: Step S10: After ultrasonically cleaning the corrosion-resistant substrate, the coating process chamber is evacuated to achieve the preset vacuum level. Step S11: Argon gas is introduced into the coating process chamber through a gas ion source. After ionization of the argon gas, argon plasma is released to perform plasma bombardment cleaning and activation on the corrosion-resistant substrate surface. Step S12: Oxygen is introduced into the coating process chamber, and Y2O3 coating and Al coating are alternately deposited on the corrosion-resistant substrate using a dual-target magnetron sputtering method. x O y Coating to form Y2O3-Al x O y In the composite coating, the sputtering power of the Y target is greater than that of the Al target, and the duty cycle and frequency of the sputtering power supplies used for both the Y and Al targets are kept consistent. x O y The x:y ratio in the coating is greater than 1.

[0006] Preferably, the Y2O3-Al x O y The thickness of the composite coating ranges from 1 to 5 μm, the thickness of the unit coating ranges from 6 to 20 nm, the thickness of the single-layer Y₂O₃ coating ranges from 5 to 15 nm, and the thickness of the single-layer Al coating ranges from 1 to 5 μm. x O y The coating thickness ranges from 1 to 5 nm.

[0007] Preferably, in step S10, the preset vacuum level is in the range of less than 1×10⁻⁶. -3 Pa.

[0008] Preferably, in step S11, the gas ion source is a linear anodic ion source with a voltage range of 800~1200V and a plasma bombardment time of 10~30min.

[0009] Preferably, in step S12, the vacuum degree of the coating process chamber is in the range of 0.2~1Pa, the power supply is a pulsed DC power supply, the power adjustment range is 0-500W, the duty cycle adjustment range is 10~90%, and the frequency adjustment range is 20~80kHz.

[0010] Preferably, in step S12, the Y target and the Al target are mounted on a fixed track, the corrosion-resistant substrate is fixed on a substrate holder on a translational track, and the substrate holder is provided with a pulse bias power supply that applies a negative bias voltage to the corrosion-resistant substrate and a heating device for heating the corrosion-resistant substrate.

[0011] Preferably, the translational track reciprocates between the Y target and the A1 target, with a translational period of 60~150s.

[0012] Preferably, the voltage range of the pulse bias power supply is 100~400V, and the heating temperature range of the heating device is 25~400℃.

[0013] Preferably, the Y target and Al target are at the same height from the surface to be coated, with a height range of 10~20cm.

[0014] Preferably, the material of the corrosion-resistant substrate is alumina, aluminum nitride, aluminum alloy, or stainless steel.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: First, by introducing amorphous, metallic-dominant Al into the Y2O3 coating... x O y The coating continuously interrupts the growth of Y2O3 columnar crystals, refines the grains, inhibits the formation of easily etchable sites between grains, and forms a yttrium aluminum oxide composite strengthening phase at the interface. Compared with the pure Y2O3 coating, the plasma etching resistance is improved. Second, alternating sputtering deposition of Y2O3-Al x O y Due to the very thin thickness of a single layer (<15nm), the composite coating exhibits a wavy microstructure and an alternating hard and soft mechanical structure under growth stress (Y2O3 ceramic state, high hardness; Al...). x O y The intermediate state of metal ceramics (low hardness) is conducive to increasing the mechanical friction contact area and reducing local contact stress; and the alternating soft and hard mechanical structure is conducive to suppressing the generation of transverse cracks, guiding the propagation of friction cracks, improving the friction life of the coating, reducing the wear rate, and thus reducing the particulate contaminants in the cavity. Third, Y2O3-Al x O y The composite coating achieves bidirectional synergistic optimization of etching protection and wear protection, and the preparation method is efficient and controllable, improving the stability of the production process and showing significant industrial application potential and commercial value. Attached Figure Description

[0016] Figure 1 The etching-resistant and wear-resistant Y2O3-Al in this invention x O y Flowchart of the composite coating preparation method; Figure 2 The etching-resistant and wear-resistant Y2O3-Al in this invention x O y Schematic diagram of the microstructure of the composite coating; Figure 3 This is a schematic diagram showing the installation of the Y target and Al target inside the coating process chamber in this invention; Figure 4 Y₂O₃-Al prepared under sputtering power ratios of 500 / 200W and 500W / 500W for Y and Al targets according to this invention. x O yCharacterization analysis diagram of the microstructure and composition of the composite coating; Figure 5 Y₂O₃-Al prepared under sputtering power ratios of 500 / 200W, 500W / 300W, 500W / 500W, and 0W / 500W in this invention x O y Fine XPS spectra of Al elements in the composite coating; Figure 6 Y₂O₃-Al prepared under different Y-target and Al-target sputtering power ratios in this invention x O y Etching rate diagram of composite coating in CF4 plasma environment; Figure 7 Y₂O₃-Al prepared under different Y-target and Al-target sputtering power ratios in this invention x O y Etching rate diagram of composite coating under Ar / CF4 plasma environment; Figure 8 Y₂O₃-Al prepared under different Y-target and Al-target sputtering power ratios in this invention x O y Friction curve of composite coating under vacuum environment; Figure 9 Y₂O₃-Al prepared under different Y-target and Al-target sputtering power ratios in this invention x O y Calculation chart of average friction coefficient and wear rate of composite coating in vacuum environment.

[0017] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0018] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0019] Please see Figure 1 and Figure 2 An embodiment of the present invention provides a corrosion-resistant and wear-resistant Y2O3-Al x O y The method for preparing a composite coating includes the following steps: Step S10: After ultrasonically cleaning the corrosion-resistant substrate, the coating process chamber is evacuated to achieve the preset vacuum level. Specifically, in this step, the cleaning medium for ultrasonic cleaning is anhydrous ethanol. After cleaning, the substrate is dried in inert nitrogen gas. After drying, the corrosion-resistant substrate is sent to the coating process chamber.

[0020] Preferably, the preset vacuum level is in the range of less than 1×10⁻⁶. -3 Pa.

[0021] Step S11: Argon gas is introduced into the coating process chamber through a gas ion source. After ionization of the argon gas, argon plasma is released to perform plasma bombardment cleaning and activation on the corrosion-resistant substrate surface. Specifically, in this step, the gas ion source is a linear anodic ion source with a voltage range of 800~1200V, and the plasma bombardment time is 10~30min. It should be noted that the purpose of plasma cleaning in this step is to remove impurities (mainly water molecules and organic matter) remaining on the corrosion-resistant substrate surface after ultrasonic cleaning, and to increase the activation energy to enhance the film-substrate adhesion.

[0022] Step S12: Oxygen is introduced into the coating process chamber, and Y2O3 coating and Al coating are alternately deposited on the corrosion-resistant substrate using a dual-target magnetron sputtering method. x O y Coating to form Y2O3-Al x O y In the composite coating, the sputtering power of the Y target is greater than that of the Al target, and the duty cycle and frequency of the sputtering power supplies used for both the Y and Al targets are kept consistent. x O y The x:y ratio in the coating is greater than 1.

[0023] It should be noted that the purpose of controlling the sputtering power of the Y target to be greater than that of the Al target in this step is to form Y2O3-Al with Y2O3 as the dominant component. x O y Composite coating, and the thickness of the Y2O3 coating deposited in a single cycle needs to be greater than that of Al. x O y Only by adjusting the coating thickness can we achieve synergistic optimization of corrosion resistance and tribological performance.

[0024] Preferably, the Y2O3-Al x O y The thickness of the composite coating ranges from 1 to 5 μm, the thickness of the unit coating ranges from 6 to 20 nm, the thickness of the single-layer Y₂O₃ coating ranges from 5 to 15 nm, and the thickness of the single-layer Al coating ranges from 1 to 5 μm. x O y The coating thickness ranges from 1 to 5 nm.

[0025] Specifically, in step S12, the vacuum level of the coating process chamber is in the range of 0.2~1Pa, the power supply is a pulsed DC power supply, the power adjustment range is 0-500W, the duty cycle adjustment range is 10~90%, and the frequency adjustment range is 20~80kHz.

[0026] Specifically, in step S12, the Y target and the Al target are installed on a fixed track, the corrosion-resistant substrate is fixed on a substrate holder on a translational track, and the substrate holder is provided with a pulse bias power supply that applies a negative bias voltage to the corrosion-resistant substrate and a heating device for heating the corrosion-resistant substrate.

[0027] It should be noted that the purpose of setting the negative bias voltage and heating device is to improve the directionality of sputtered particles from the magnetron sputtering cathode and to promote the Y2O3-Al... x O y The formation of a yttrium-aluminum composite reinforcing phase at the interface of the composite coating. Specifically, the voltage range of the pulse bias power supply is 100~400V, and the heating temperature range of the heating device is 25~400℃.

[0028] Preferably, the translational track reciprocates between the Y target and the A1 target, with a translational period of 60~150s.

[0029] It should be noted that the period of reciprocating motion of the substrate holder on the translational track is adjusted to control the monolayer Y2O3 and Al. x O y The coating thickness is within a specified range, such as: the thickness range of a single layer of Y2O3 is 5~15nm, and the thickness of a single layer of Al is... x O y The coating thickness is 1~5nm.

[0030] Preferably, the Y target and Al target are at the same height from the surface to be coated, with a height range of 10~20cm.

[0031] It should be noted that each sputtering cathode has a rectangular structure. When sputtering a large-area substrate, the substrate holder moves back and forth between the sputtering cathodes to ensure the uniformity of the coating deposition.

[0032] Preferably, the material of the corrosion-resistant substrate is alumina, aluminum nitride, aluminum alloy, or stainless steel. The preparation method of this application will be described in detail below with reference to specific embodiments:

[0033] Please see Figure 3 A sintered polycrystalline alumina substrate with dimensions of 20×20×2 mm was ultrasonically cleaned in anhydrous ethanol, then dried with nitrogen. After treatment, it was placed in a vacuum chamber and evacuated. The vacuum level reached 8×10⁻⁶ mm. -4Ion bombardment cleaning was initiated at Pa. After cleaning, reactive gas O2 was introduced, and a composite coating was deposited by magnetron sputtering using a pulsed DC power supply. The duty cycle of the pulsed DC power supply was set to 50%, the frequency was set to 20kHz, and the power of the Y target and Al target was set to 500W / 0W, 500W / 200W, 500W / 300W, 500W / 500W, and 0W / 500W, respectively, and named Y5-Al0, Y5-Al2, Y5-Al3, Y5-Al5, and Y0-Al5. The reciprocating motion cycle of the translational track on which the substrate holder is located was set to 120s. After 2 hours of sputtering, the total thickness of the composite coating on the surface of the sintered polycrystalline alumina was approximately 1.5μm.

[0034] Please refer to Table 1 for the Y₂O₃-Al sputtering power ratios prepared under different Y and Al target sputtering power ratios in this invention. x O y In the composite coating, the Y2O3 phase and Al x O y Atomic percentage data of phase elements. The atomic percentages of elements in the composite coatings Y5-Al0, Y5-Al2, Y5-Al3, Y5-Al5, and Y0-Al5 were analyzed using energy-dispersive X-ray spectroscopy (EDS). It can be seen that the atomic percentages of Y and O elements in the Y2O3 phase are approximately 2:3 in all composite coatings, close to the standard stoichiometric ratio of Y2O3; while in the Y5-Al2 and Y5-Al3 composite coatings, the Al... x O y The atomic percentages of Al and O are both less than 1, indicating that Al x O y The Al element in the coatings was not completely oxidized, and some still existed in the metallic Al state; Al in the Y5-Al5 and Y0-Al5 coatings x O y The atomic percentages of Al and O in the two sputtering powers are close to 2:3, indicating that the Al deposited under these two sputtering powers... x O y The Al element is almost completely oxidized, forming Al2O3 with a stoichiometric ratio close to that of standard stoichiometry.

[0035] Table 1. Y₂O₃ and Al phases in the composite coating under different Y-target and Al-target sputtering power ratios. x O y Phase element atomic percentage

[0036] Please see Figure 4The microstructure and composition of the composite coatings deposited at Y:Al = 500W / 200W and 500W / 500W targets were characterized. The results showed that the Y5-Al2 composite coating deposited at Y:Al = 500W / 200W was dominated by the Y2O3 phase, with a single-layer thickness of approximately 9 nm. x O y The phase thickness is relatively thin, only about 3 nm; while when both the Y target and Al target are 500 W, the deposited composite coating Y5-Al5 is mainly composed of Al x O y The Y2O3 phase is dominant, with a single-layer thickness of about 10 nm, while the Y2O3 phase is thinner, only about 4 nm. This difference in thickness is related to the reactivity of Y and Al elements with O2 during sputtering, as well as the sputtering rates of the Y and Al targets themselves. It can be seen that in order to form a Y2O3-dominated nanolaminated composite film, the sputtering power of the Y target needs to be greater than that of the Al target.

[0037] Please see Figure 5 The bonding and valence states of Al in composite coatings prepared under different Y / Al sputtering power ratios were analyzed using photoelectron spectroscopy (XPS). The results showed that in the composite coatings deposited at Y:Al = 500W / 200W and 500W / 300W, Al was predominantly in the metallic aluminum state; while in the composite coatings deposited at Y:Al = 500W / 500W and 0W / 500W, Al was predominantly in the alumina state. This indicates that Y5-Al2 and Y5-Al3 are not only dominated by the Y2O3 phase, but also contain Al... x O y The phase is still predominantly metallic; the Y5-Al5 and Y0-Al5 coatings are predominantly Al x O y Phase is dominant, among which Al x O y The phase is predominantly in the oxidation state. A comparison shows that the XPS bonding pattern of Al corresponds to the EDS atomic percentage data.

[0038] Please see Figure 6 Plasma etching performance of coatings prepared under five different Y / Al sputtering power ratios was tested using pure CF4 gas-excited plasma, with the etching process lasting 4 hours. The results showed that the Y5-Al2 and Y5-Al3 composite coatings exhibited lower etching rates than the pure Y2O3 and pure Al2O3 coatings. The best-performing sample, Y5-Al2, showed a more than 40% improvement in etching resistance compared to the pure Y2O3 coating. With increasing Al target power in alternating Y and Al sputtering, the Al content in the composite coating... x O y With the increase of components, Y2O3-Al x Oy The increased etching rate and decreased etching resistance of the composite coating samples indicate that Y2O3-Al only exhibits good etching performance when the Y2O3 phase is dominant in the composite coating. x O y Only composite coating samples can exhibit optimized etching protection.

[0039] Please see Figure 7 Actual etching conditions typically involve mixed Ar and CF4 plasma. Using a mixed Ar and CF4 gas to excite the plasma, the plasma etching performance of coating samples prepared under five different Y / Al sputtering power ratios was tested, with the etching process lasting 4 hours. Results showed that the Y5-Al2, Y5-Al3, and Y5-Al5 composite coatings all exhibited lower etching rates than pure Y2O3 and pure Al2O3 coatings. The best-performing sample showed approximately 30% better etching resistance than the pure Y2O3 coating. Consistent with the etching behavior in a pure CF4 plasma environment, as the Al target power in alternating Y and Al sputtering increased, the Al content in the composite coating... x O y With the increase of components, Y2O3-Al x O y The etching rate of the nanocomposite coating sample increased, while its etching resistance decreased. The difference lies in the fact that the Y5-Al5 composite coating performed worse than the pure Y2O3 coating in a pure CF4 plasma etching environment, but showed better etching protection performance than the pure Y2O3 coating in an Ar and CF4 mixed plasma etching environment. This is attributed to the fact that the added Ar plasma mainly has a physical etching effect, and the Al-O bond energy is higher than the YO bond energy, making it less likely to break the bonds and be removed under physical etching.

[0040] Please see Figure 8 Tribological wear performance of coating samples prepared under five different Y / Al sputtering power ratios was tested in a vacuum environment (1 Pa) for 30 minutes. It can be seen that all samples exhibited similar friction coefficients before being worn through, but the friction lifetime of different samples showed a similar trend to that of etching performance: the friction lifetime first increased and then decreased when transitioning from pure Y2O3 coating to pure Al2O3 coating. Y5-Al2 and Y5-Al3 composite coatings showed longer friction lifetimes than pure Y2O3 and pure Al2O3 coatings, with the best-performing sample showing an approximately 60% increase in friction lifetime compared to the pure Y2O3 coating (from 750 s to 1200 s). With the increase of Al target power in alternating Y and Al sputtering, the Y2O3-Al... x O y The reduced friction life of the composite coating sample indicates that only when the Y2O3 phase is dominant in the composite coating can the Y2O3-Al... x Oy Only composite coatings can exhibit superior mechanical friction protection.

[0041] Please see Figure 9 The average friction coefficient and wear rate of coating samples prepared under five different Y / Al sputtering power ratios were statistically analyzed after tribological testing. The results show that the average friction coefficient and wear rate of the samples transitioning from pure Y₂O₃ coatings to pure Al₂O₃ coatings exhibit a similar pattern to the etching protection performance: initially improving and then deteriorating. x O y Among the composite coatings, the Y5-Al2 and Y5-Al3 composite coatings dominated by the Y2O3 phase exhibit optimized average friction coefficient and wear rate.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A corrosion-resistant and wear-resistant Y2O3-Al x O y A method for preparing a composite coating, characterized in that, Includes the following steps: Step S10: After ultrasonically cleaning the corrosion-resistant substrate, the coating process chamber is evacuated to achieve the preset vacuum level. Step S11: Argon gas is introduced into the coating process chamber through a gas ion source. After ionization of the argon gas, argon plasma is released to perform plasma bombardment cleaning and activation on the corrosion-resistant substrate surface. Step S12: Oxygen is introduced into the coating process chamber, and Y2O3 coating and Al coating are alternately deposited on the corrosion-resistant substrate using a dual-target magnetron sputtering method. x O y Coating to form Y2O3-Al x O y In the composite coating, the sputtering power of the Y target is greater than that of the Al target, and the duty cycle and frequency of the sputtering power supplies used for both the Y and Al targets are kept consistent. x O y The x:y ratio in the coating is greater than 1.

2. The etching-resistant and wear-resistant Y2O3-Al according to claim 1 x O y A method for preparing a composite coating, characterized in that, The Y2O3-Al x O y The thickness of the composite coating ranges from 1 to 5 μm, the thickness of the unit coating ranges from 6 to 20 nm, the thickness of the single-layer Y₂O₃ coating ranges from 5 to 15 nm, and the thickness of the single-layer Al coating ranges from 1 to 5 μm. x O y The coating thickness ranges from 1 to 5 nm.

3. The etching-resistant and wear-resistant Y2O3-Al according to claim 1 x O y A method for preparing a composite coating, characterized in that, In step S10, the preset vacuum level is in the range of less than 1×10⁻⁶. -3 Pa.

4. The etching-resistant and wear-resistant Y2O3-Al according to claim 1 x O y A method for preparing a composite coating, characterized in that, In step S11, the gas ion source is a linear anodic ion source with a voltage range of 800~1200V and a plasma bombardment time of 10~30min.

5. The etching-resistant and wear-resistant Y2O3-Al according to claim 1 x O y A method for preparing a composite coating, characterized in that, In step S12, the vacuum level of the coating process chamber is in the range of 0.2~1Pa, the power supply is a pulsed DC power supply, the power adjustment range is 0-500W, the duty cycle adjustment range is 10~90%, and the frequency adjustment range is 20~80kHz.

6. The etching-resistant and wear-resistant Y2O3-Al according to claim 1 x O y A method for preparing a composite coating, characterized in that, In step S12, the Y target and the Al target are mounted on a fixed track, and the corrosion-resistant substrate is fixed on a substrate holder on a translational track. The substrate holder is provided with a pulse bias power supply that applies a negative bias voltage to the corrosion-resistant substrate and a heating device for heating the corrosion-resistant substrate.

7. The etching-resistant and wear-resistant Y2O3-Al according to claim 6 x O y A method for preparing a composite coating, characterized in that, The translational orbit reciprocates between the Y target and the A1 target, with a translational period of 60~150s.

8. The etching-resistant and wear-resistant Y2O3-Al according to claim 6 x O y A method for preparing a composite coating, characterized in that, The voltage range of the pulse bias power supply is 100~400V, and the heating temperature range of the heating device is 25~400℃.

9. The etching-resistant and wear-resistant Y2O3-Al according to claim 6 x O y A method for preparing a composite coating, characterized in that, The Y-target and Al-target are at the same height from the surface to be coated, with a height range of 10~20cm.

10. The etching-resistant and wear-resistant Y2O3-Al according to any one of claims 1 to 9 x O y A method for preparing a composite coating, characterized in that, The corrosion-resistant substrate is made of alumina, aluminum nitride, aluminum alloy, or stainless steel.

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