Preparation method of copper-based yttrium oxide coating with self-repairing properties

Abstract

A method for preparing a copper-based yttrium oxide coating with self-repairing properties comprises the following steps: sputtering and depositing an yttrium oxide coating on the surface of an oxygen-free copper substrate using a pulsed DC magnetron sputtering method; transferring the oxygen-free copper substrate containing the yttrium oxide coating to a cooling chamber and allowing it to cool to form a coating substrate; placing the coating substrate into a tubular furnace, introducing an argon-hydrogen mixed protective gas into the tubular furnace, performing high-temperature annealing, and then cooling with the furnace to form a copper-based yttrium oxide coating with self-repairing properties. After cracking, the copper-based yttrium oxide coating with self-repairing properties of the present invention fills the cracks with copper oxide generated by the oxygen-free copper of the substrate and oxygen atoms in the environment, forming a "mosaic" coating structure, thereby achieving self-repair of the coating and preventing further cracking of the yttrium oxide coating. The copper oxide protective layer at the crack can effectively prevent oxygen from continuing to penetrate into the lower layer of the coating and the substrate, thereby slowing down further oxidation and damage of the coating and increasing the service life of the coating.

Description

Technical Field

[0001] The present invention relates to the technical field of material surface treatment, and in particular to a method for preparing a copper-based yttrium oxide coating with self-repairing properties. Background Art

[0002] Currently, in the semiconductor industry, etching processes often involve components within the chamber being subjected to extremely high power for a short period of time, leading to high temperatures. Consequently, copper components are often used to cool these components. During this process, the copper components within the chamber are also subject to plasma etching.

[0003] Under the high temperature and plasma environment of the etching chamber, the copper substrate is easily oxidized and etched, which will seriously affect its service life and performance. Surface coating is usually used to prepare a layer of yttrium oxide coating with high thermal shock resistance and etching resistance on the surface of copper components, which is an effective protection technology. However, due to the large difference in thermal expansion coefficient between copper and yttrium oxide (the thermal expansion coefficient of copper is 17.2×10 -6 / K, the thermal expansion coefficient of yttrium oxide is about 7.8×10 -6 / K), which causes the yttrium oxide coating to crack and peel off easily at high temperatures, thereby reducing its durability. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a method for preparing a copper-based yttrium oxide coating with self-healing properties, by spontaneously generating copper oxide under high temperature conditions to fill the gaps in the coating cracks, thereby achieving self-repair of the coating, enhancing the high temperature resistance of the coating, improving the durability and thermal shock resistance of the coating, and thus extending the service life of the coating.

[0005] A method for preparing a copper-based yttrium oxide coating with self-repairing properties comprises the following steps:

[0006] Step S11, the oxygen-free copper substrate that has been bombarded and cleaned by a gas ion source is placed into a coating process chamber, and a pulsed DC magnetron sputtering method is used to sputter and deposit an yttrium oxide coating on the surface of the oxygen-free copper substrate;

[0007] Step S12, transferring the oxygen-free copper substrate containing the yttrium oxide coating into a cooling chamber, and allowing it to cool to a preset temperature to form a coating substrate;

[0008] In step S13, the coating substrate is placed in a tube furnace, and an argon-hydrogen mixed protective gas is introduced into the tube furnace for high-temperature annealing and then cooled in the furnace to form a copper-based yttrium oxide coating with self-repairing properties.

[0009] Preferably, in step S11 , the sputtering voltage of the magnetron sputtering is in the range of 300-500 V, and the thickness of the yttrium oxide coating is in the range of 1-10 μm.

[0010] Preferably, in step S12, the preset temperature range is 25-75°C.

[0011] Preferably, in step S13, the temperature range of the high temperature annealing is 100-500° C., and the flow rate range of the introduced argon-hydrogen mixed gas is 0-10 L / s.

[0012] Preferably, in step S11, the oxygen-free copper substrate is fixed on a substrate rack, and the substrate rack is provided with a pulse bias power supply for applying a negative bias voltage to the oxygen-free copper substrate, and a heating device for heating the oxygen-free copper substrate.

[0013] Preferably, the voltage range of the pulse bias power supply is 50-200V, and the heating temperature range of the heating device is 0-300°C.

[0014] Preferably, the two sputtering cathodes in the coating process chamber are both rectangular cathode structures, and the two sputtering cathodes are symmetrically installed on the translation track and are at the same height from the surface to be coated.

[0015] Preferably, the distance between each sputtering cathode and the surface to be coated is 8 to 15 cm.

[0016] Preferably, before step S11, the preparation method further comprises:

[0017] A soft-contact electric forklift is used to transport the oxygen-free copper substrate to the positioning platform, and the robot automatically sends the oxygen-free copper substrate to the cleaning equipment for ultrasonic cleaning and drying;

[0018] The dried oxygen-free copper substrate is automatically transferred to the vacuum chamber by a robot and bombarded and cleaned using a gas ion source.

[0019] Preferably, the gas ion source is a linear anode ion source, the working gas is argon, the voltage is adjustable in the range of 800-1200 V, and the bombardment time range is 10-30 min.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] First, the present invention significantly enhances the etching resistance of the substrate by depositing an yttrium oxide coating on the surface of the copper substrate, making it suitable for long-term use in medium- and high-temperature corrosive environments;

[0022] Second, after cracking, the self-healing copper-based yttrium oxide coating of the present invention combines the oxygen-free copper of the substrate with oxygen atoms in the environment to form copper oxide, which fills the cracks and forms a "mosaic" coating structure. This achieves self-repair and prevents further cracking of the yttrium oxide coating. The copper oxide protective layer at the cracks can effectively prevent oxygen from continuing to penetrate into the lower layer of the coating and the substrate, thereby slowing down further oxidation and damage to the coating.

[0023] Third, the coating prepared by the present invention has good high-temperature crack resistance and can maintain a long service life in medium and high temperature environments, and is suitable for semiconductor manufacturing equipment and other high-temperature operating conditions.

[0024] Fourth, the present invention adopts a magnetron sputtering process to deposit the yttrium oxide coating, which has the advantages of stable process, strong controllability, and suitability for large-scale production, thereby ensuring the uniformity and consistency of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of a method for preparing a copper-based yttrium oxide coating with self-repairing properties according to the present invention;

[0026] Figure 2 Schematic diagram of the self-repairing process of the copper-based yttrium oxide coating with self-repairing properties in the present invention;

[0027] Figure 3 Schematic diagram of the production line for preparing the copper-based yttrium oxide coating with self-repairing properties in the present invention;

[0028] Figure 4 Schematic diagram of the installation of the sputtering cathode in the coating process chamber of the present invention;

[0029] Figure 5 Schematic diagram of high-temperature annealing of the yttrium oxide coating in a tube furnace in the present invention;

[0030] Figure 6 Schematic diagram of the macroscopic surface of the thermal shock test of yttrium oxide coatings grown on different substrates in the present invention;

[0031] Figure 7 These are SEM surface morphology images and EDS element analysis images of the yttrium oxide coating grown on different substrates after thermal shock tests (0 times, 20 times, and 50 times) in the present invention.

[0032] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0033] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are merely examples, and those skilled in the art may conceive of other obvious variations.

[0034] See also Figure 1 and Figure 2 In one embodiment of the present invention, a method for preparing a copper-based yttrium oxide coating with self-repairing properties is provided, comprising the following steps:

[0035] Step S11, the oxygen-free copper substrate that has been bombarded and cleaned by a gas ion source is placed into a coating process chamber, and a pulsed DC magnetron sputtering method is used to sputter and deposit an yttrium oxide coating on the surface of the oxygen-free copper substrate;

[0036] Specifically, in step S11 , the sputtering voltage of the magnetron sputtering is in the range of 300-500 V, and the thickness of the yttrium oxide coating is in the range of 1-10 μm.

[0037] It should be noted that in step S11, the oxygen-free copper substrate is fixed on a substrate rack, and the substrate rack is provided with a pulse bias power supply for applying a negative bias voltage to the oxygen-free copper substrate and a heating device for heating the oxygen-free copper substrate.

[0038] Specifically, the voltage range of the pulse bias power supply is 50-200 V, and the heating temperature range of the heating device is 0-300° C. The purpose is to improve the directionality of the sputtered particles of the magnetron sputtering cathode and promote the mutual diffusion between the yttrium oxide coating and the substrate.

[0039] Step S12, transferring the oxygen-free copper substrate containing the yttrium oxide coating into a cooling chamber, and allowing it to cool to a preset temperature to form a coating substrate;

[0040] Preferably, in step S12, the preset temperature range is 25-75°C, at which the coating deposition crystallization quality is good.

[0041] Step S13, placing the coating substrate into a tube furnace, introducing an argon-hydrogen mixed protective gas into the tube furnace, performing high-temperature annealing and then cooling the furnace to form a copper-based yttrium oxide coating with self-repairing properties;

[0042] Preferably, in step S13, the temperature range of high temperature annealing is 100-500°C, the flow range of the argon-hydrogen mixed gas is 0-10 L / s, and the mass fraction of hydrogen in the argon-hydrogen mixed gas is 1%, so as to suppress the oxidation reaction of the oxygen-free copper substrate.

[0043] It should be noted that, in the present invention, in order to verify the self-repairing performance of the copper-based yttrium oxide coating with self-repairing performance, the copper-based yttrium oxide coating with self-repairing performance is sent into a muffle furnace, subjected to cyclic thermal shock, kept warm for a first preset time, and cooled for a second preset time to spontaneously generate copper oxide at the cracks of the yttrium oxide coating.

[0044] Specifically, the thermal shock test was conducted in an atmospheric environment at a temperature range of 400-800°C, with 20-100 thermal cycles, a holding time of 15-50 minutes, and a cooling time of 10-20 minutes, typically using air cooling. This step demonstrates that after cracking, the yttrium oxide coating of the present invention generates copper oxide that re-bonds the yttrium oxide coating, completing the repair of the yttrium oxide coating.

[0045] It should be noted that both sputtering cathodes in the coating process chamber are rectangular cathode structures, symmetrically mounted on a translational track and at the same height from the surface to be coated. In the present invention, the magnetron sputtering cathode is configured as a rectangular cathode and mounted on a translational track. When sputtering a large substrate, the cathode reciprocates within a certain range to ensure uniform film layer thickness and avoid the sputtering gradient that can occur with fixed cathodes, which can lead to uneven film thickness.

[0046] Specifically, the distance between each sputtering cathode and the surface to be coated is 8 to 15 cm.

[0047] Furthermore, before step S11, the preparation method further includes:

[0048] A soft-contact electric forklift is used to transport the oxygen-free copper substrate to the positioning platform, and the robot automatically sends the oxygen-free copper substrate to the cleaning equipment for ultrasonic cleaning and drying;

[0049] The dried oxygen-free copper substrate is automatically transferred to the vacuum chamber by a robot and bombarded and cleaned using a gas ion source.

[0050] Specifically, the gas ion source used in this application is a linear anode ion source, the working gas is argon, the voltage is adjustable from 800 to 1200 V, and the bombardment time range is 10 to 30 minutes. The purpose is to remove the water molecule film and organic matter remaining on the substrate surface after pretreatment. Through particle bombardment, the substrate is activated and the film-substrate bonding is improved.

[0051] It should be noted that, in this application, when the vacuum degree of the cavity is 8×10 -4 ~1×10 -3 The coating process can begin within the Pa range. After the oxygen-free copper substrates with yttrium oxide coating deposited on the first set enter the cooling chamber, the next set of sample substrates stored in the ion source gas chamber will enter the coating process chamber for yttrium oxide coating deposition. Therefore, the sputtering cathode does not need to be stopped, which improves sputtering efficiency.

[0052] First, preprocessing

[0053] In a Class 1000 dust-free workshop, a soft-contact electric forklift is used to transfer the oxygen-free copper substrate to the positioning stand. After the substrate is adjusted to the appropriate position, a forklift is used to transfer the substrate to the cleaning equipment.

[0054] A barcode scanner is used to extract product dimensions. The automated cleaning and transfer section adaptively adjusts the position of the manipulator, lifting fixture, and transfer wheels based on the product dimensions. A forklift lifts the substrate to the robotic gripper position at the front of the cleaning machine, where it is automatically transferred to the cleaning equipment for cleaning. The cleaning process includes: ultrasonic cleaning with a chemical solution—one ultrasonic rinse—two ultrasonic rinses—scanning spray—clean air dewatering—vacuum dehydration—and cleanliness inspection.

[0055] In order to prevent the oxygen-free copper substrate from being attached by tiny particles after cleaning, this stage enters a fully automatic transfer process, including: tray splicing - tray transmission - robot grasping - substrate rack receiving substrate - substrate rack transmission to the cleaning area in the vacuum chamber.

[0056] Second, yttrium oxide coating deposition

[0057] Multiple groups of substrates enter the storage chamber - vacuum is applied - working gas argon is introduced - the first group of substrates enters the ion source chamber - gas plasma surface cleaning - the first group of substrates enters the coating process chamber, and the second group of substrates enters the ion source chamber for gas plasma cleaning - the angle and height of the sputtering cathode are adjusted to deposit yttrium oxide coating - the first group of substrates undergoes pulsed DC magnetron sputtering cathode deposition of yttrium oxide coating - after the preset time is reached, they are transported to the storage chamber for cooling, and then the second group of substrates enters the coating process chamber for yttrium oxide coating deposition, and at the same time the third group of substrates enters the ion source chamber - the above steps are repeated until all substrates complete the yttrium oxide coating deposition.

[0058] Third, high temperature annealing treatment of yttrium oxide coating

[0059] Multiple groups of deposited yttrium oxide coating samples are placed in a crucible of a high-temperature tube furnace, ensuring that the samples are stable and do not touch other objects. An appropriate atmosphere is selected (the method of the present invention uses an argon-hydrogen mixture) to fill the tube furnace. The temperature is slowly raised to a predetermined annealing temperature. The temperature is maintained at the target temperature. The temperature is slowly lowered to room temperature. The samples are removed at room temperature to obtain a copper-based yttrium oxide coating with self-healing properties.

[0060] Fourth, finished product testing

[0061] The finished products are subjected to rapid temperature rise and fall cycle tests to check the surface integrity of the yttrium oxide coating of the tested samples, whether there are cracks or wrinkles, etc., to determine whether they meet the standards. After passing the inspection, they are transferred to a nitrogen-protected storage box.

[0062] See also Figures 3 to 5In another embodiment of the present invention, a method for preparing a copper-based yttrium oxide coating with self-repairing properties is provided. The experimental contents are as follows:

[0063] An oxygen-free copper substrate measuring 20×20×2mm was pretreated and then sent to a gas ion source for ion bombardment cleaning. The substrate was then transferred to the coating chamber, where a yttrium oxide coating was grown using pulsed DC magnetron sputtering with a rectangular cathode. The voltage of the rectangular cathode yttrium target was set at 280V, resulting in a surface yttrium oxide coating approximately 2μm thick. After deposition, the substrate was cooled to 30°C, and the yttrium oxide coating was transferred to a tube furnace for high-temperature annealing at 400°C in an argon-hydrogen mixture. The finished product was then subjected to thermal shock resistance testing.

[0064] See also Figure 4 The substrate holder where the oxygen-free copper substrate is located can be loaded with a negative pulse bias voltage and is equipped with a heating device. Combined with the pulsed DC power supply used in the rectangular cathode sputtering yttrium oxide coating, it can improve the directionality of the magnetron sputtering cathode sputtering particles and promote the mutual diffusion between the oxygen-free copper substrate and the yttrium oxide coating, thereby improving the deposition quality of the yttrium oxide coating and the film-substrate bonding strength.

[0065] See also Figure 5 A tubular furnace is used for high-temperature annealing, and the gas introduced is an argon-hydrogen mixture. The introduction of protective gas can prevent the copper substrate from oxidizing at high temperatures and stabilize the high-temperature annealing process.

[0066] See also Figure 6 The figure shows the surface macromorphology of yttrium oxide coatings grown on different substrates (single crystal silicon substrate and oxygen-free copper substrate) after thermal shock at 600°C (0, 20, and 50 times). The figure shows that yttrium oxide coatings grown on oxygen-free copper substrates have excellent high-temperature resistance.

[0067] See also Figure 7 The figure shows the SEM surface morphology and EDS elemental distribution spectra of yttrium oxide coatings grown on different substrates (single crystal silicon and oxygen-free copper) after 10, 20, and 50 thermal shock cycles at 600°C. The figure shows that the yttrium oxide coating grown on single crystal silicon delaminated after 10 thermal shock cycles, exposing the substrate; whereas the yttrium oxide coating grown on oxygen-free copper exhibited self-healing, with no substrate exposure.

[0068] The above shows and describes 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 above embodiments and descriptions merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a copper-based yttrium oxide coating with self-repairing properties, characterized in that: The following steps are involved: Step S11, the oxygen-free copper substrate that has been bombarded and cleaned by a gas ion source is placed into a coating process chamber, and a pulsed DC magnetron sputtering method is used to sputter and deposit an yttrium oxide coating on the surface of the oxygen-free copper substrate; Step S12, transferring the oxygen-free copper substrate containing the yttrium oxide coating into a cooling chamber, and allowing it to cool to a preset temperature to form a coating substrate; In step S13, the coating substrate is placed in a tube furnace, and an argon-hydrogen mixed protective gas is introduced into the tube furnace for high-temperature annealing and then cooled in the furnace to form a copper-based yttrium oxide coating with self-repairing properties, wherein the temperature range of the high-temperature annealing is 100-500°C.

2. The method for preparing a copper-based yttrium oxide coating with self-repairing properties according to claim 1, characterized in that: In step S11 , the sputtering voltage of the magnetron sputtering is in the range of 300-500 V, and the thickness of the yttrium oxide coating is in the range of 1-10 μm.

3. The method for preparing a copper-based yttrium oxide coating with self-repairing properties according to claim 1, characterized in that: In step S12, the preset temperature range is 25-75°C.

4. The method for preparing a copper-based yttrium oxide coating with self-repairing properties according to claim 1, characterized in that: In step S11, the oxygen-free copper substrate is fixed on a substrate frame, and the substrate frame is provided with a pulse bias power supply for applying a negative bias voltage to the oxygen-free copper substrate and a heating device for heating the oxygen-free copper substrate.

5. The method for preparing a copper-based yttrium oxide coating with self-repairing properties according to claim 4, characterized in that: The voltage range of the pulse bias power supply is 50-200V, and the heating temperature range of the heating device is 0-300°C.

6. The method for preparing a copper-based yttrium oxide coating with self-repairing properties according to claim 1, characterized in that: The two sputtering cathodes in the coating process chamber are both rectangular cathode structures. The two sputtering cathodes are symmetrically installed on the translation track and are at the same height from the surface to be coated.

7. The method for preparing a copper-based yttrium oxide coating with self-repairing properties according to claim 6, characterized in that: The distance between each sputtering cathode and the surface to be coated is 8~15cm.

8. The method for preparing a copper-based yttrium oxide coating with self-repairing properties according to claim 1, characterized in that: Before step S11, the preparation method further includes: A soft-contact electric forklift is used to transport the oxygen-free copper substrate to the positioning platform, and the robot automatically sends the oxygen-free copper substrate to the cleaning equipment for ultrasonic cleaning and drying; The dried oxygen-free copper substrate is automatically transferred to the vacuum chamber by a robot and bombarded and cleaned using a gas ion source.

9. The method for preparing a copper-based yttrium oxide coating with self-repairing properties according to claim 8, characterized in that: The gas ion source is a linear anode ion source, the working gas is argon, the voltage is adjustable in the range of 800~1200V, and the bombardment time range is 10~30min.

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