Plasma etching method and coating method based on boron target magnetron sputtering

Abstract

The invention discloses a plasma etching method and a coating method based on boron target magnetron sputtering, and belongs to the technical field of thin film material preparation. The plasma etching method comprises the following steps: in a vacuum chamber of magnetron sputtering equipment, mounting a substrate on a sample rack, and mounting a boron target on a cathode; and vacuumizing a vacuum chamber of the magnetron sputtering equipment, introducing argon, applying bipolar pulse bias to the substrate, applying radio frequency to the boron target, and further realizing plasma etching of the substrate through the magnetron sputtering equipment. The coating method comprises the following steps: directly carrying out magnetron sputtering coating in a vacuum chamber of magnetron sputtering equipment without taking out a substrate subjected to plasma etching in the vacuum chamber of the magnetron sputtering equipment. According to the invention, plasma etching can be carried out in magnetron sputtering equipment without modification of a vacuum chamber, and the scheme is high in operability and practicability.

Description

Technical Field

[0001] The invention belongs to the technical field of thin film material preparation, and in particular relates to a plasma etching method and a film coating method based on boron target material magnetron sputtering. Background Art

[0002] Magnetron sputtering is a type of physical vapor deposition that can be used to prepare a variety of materials such as metals, semiconductors, insulators, etc. It has the advantages of simple equipment, easy control, large coating area and strong adhesion, and is widely used in real production and life. Before magnetron sputtering is carried out, it is very necessary to perform surface treatment on the substrate. This is because the surface of the substrate is often contaminated with various impurities, such as oil, dust, fingerprints, etc. These impurities will affect the quality of the coating layer, making the film layer uneven or defective, and will also affect the adhesion of the film layer. Moreover, even if there are no impurities on the surface of the substrate, the oxide of the substrate will affect the adhesion of the film layer. Therefore, surface treatment of the substrate can remove impurities and oxides attached to the surface, providing the necessary guarantee for achieving high-quality thin film coating.

[0003] Substrate surface treatment mainly includes wet treatment and plasma dry treatment. The use of plasma etching to physically etch the substrate surface has the advantages of being green, environmentally friendly and having high control precision. Plasma etching generally requires customized special equipment. For example, if the plasma etching function is added to coating equipment such as magnetron sputtering, the vacuum chamber of the existing coating equipment needs to be modified (for example, a customized ion source), which is time-consuming, labor-intensive and expensive. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] To this end, a first aspect of the present invention provides a plasma etching method based on boron target magnetron sputtering, comprising:

[0006] In the vacuum chamber of the magnetron sputtering equipment, a substrate is mounted on a sample holder and a boron target is mounted on a cathode;

[0007] The vacuum chamber of the magnetron sputtering device is evacuated, and then argon gas is introduced, a bipolar pulse bias is applied to the substrate, and radio frequency is applied to the boron target material, and then plasma etching of the substrate is achieved through the magnetron sputtering device.

[0008] Furthermore, the substrate includes a copper substrate, an aluminum substrate, a molybdenum substrate, a niobium substrate, a tantalum substrate, a zirconium substrate, a tungsten substrate or a silicon substrate.

[0009] Furthermore, a bipolar pulse bias is applied to the substrate, wherein the positive pulse bias is 90V to 110V, the negative pulse bias is -500V to -800V, the frequency is 25KHz to 35KHz, and the duty cycle is 70% to 90%.

[0010] Furthermore, the radio frequency is applied to the boron target, and the radio frequency power is 80W to 120W.

[0011] Furthermore, the etching rate of the copper substrate is 2.5nm / min~2.6nm / min; the etching rate of the aluminum substrate is 0.6nm / min~0.7nm / min; the etching rate of the molybdenum substrate is 1.3nm / min~1.4nm / min; the etching rate of the niobium substrate is 1.3nm / min~1.4nm / min; the etching rate of the tantalum substrate is 1.7nm / min~1.8nm / min; the etching rate of the zirconium substrate is 1.0nm / min~1.1nm / min; the etching rate of the tungsten substrate is 0.85nm / min~0.95nm / min; the etching rate of the silicon substrate is 1.45nm / min~1.55nm / min.

[0012] Furthermore, the vacuum chamber of the magnetron sputtering device is evacuated to a vacuum degree less than 5.0×10 -4 Pa.

[0013] Furthermore, argon gas is introduced to a vacuum degree of 0.3-0.4Pa.

[0014] A second aspect of the present invention provides a coating method, comprising:

[0015] Plasma etching, using the above-mentioned plasma etching method to perform plasma etching on the substrate;

[0016] Magnetron sputtering coating: after the substrate is plasma etched, it does not need to be taken out from the vacuum chamber of the magnetron sputtering device, and magnetron sputtering coating is directly performed in the vacuum chamber of the magnetron sputtering device.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] The plasma etching method based on boron target magnetron sputtering provided by the present invention utilizes the existing magnetron sputtering equipment to realize plasma etching of the substrate to be etched, and there is no need to modify the vacuum chamber of the existing magnetron sputtering equipment. The scheme has strong operability and practicality. The substrate after plasma etching can directly enter the coating process under the vacuum state in the vacuum chamber of the magnetron sputtering equipment, effectively ensuring that the substrate after plasma etching is not contaminated by secondary pollution. DETAILED DESCRIPTION

[0019] In order to better understand the above-mentioned technical scheme, the technical scheme of the embodiment of the present application is described in detail through specific embodiments below. It should be understood that the embodiment of the present application and the specific features in the embodiment are detailed descriptions of the technical scheme of the embodiment of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiment of the present application and the technical features in the embodiment can be combined with each other.

[0020] According to a first aspect of an embodiment of the present invention, a plasma etching method based on boron target magnetron sputtering is provided, comprising:

[0021] In the vacuum chamber of the magnetron sputtering equipment, a substrate is mounted on a sample holder and a boron target is mounted on a cathode;

[0022] The vacuum chamber of the magnetron sputtering device is evacuated, and then argon gas is introduced, a bipolar pulse bias is applied to the substrate, and radio frequency is applied to the boron target material, and then plasma etching of the substrate is achieved through the magnetron sputtering device.

[0023] The plasma etching method based on boron target magnetron sputtering provided in the embodiment of the present invention utilizes existing magnetron sputtering equipment to realize plasma etching of a substrate without modifying the vacuum chamber of the existing magnetron sputtering equipment. The scheme has strong operability and practicality.

[0024] It can be understood that the embodiment of the present invention provides a method for adding a plasma physical etching function to a magnetron sputtering device without changing the vacuum chamber conditions of the magnetron sputtering device, thereby solving the problem in the prior art that adding a plasma etching function to an existing magnetron sputtering device requires time-consuming and labor-intensive customization of a vacuum chamber. The method only requires providing a bipolar pulse bias power supply and a boron target material. Both the bipolar pulse bias power supply and the boron target material are commercial standard products that are easy to purchase. Online plasma physical etching of a substrate can be achieved without any modification to the vacuum chamber, and the method has strong feasibility and high application value.

[0025] In some embodiments, the substrate includes a copper substrate, an aluminum substrate, a molybdenum substrate, a niobium substrate, a tantalum substrate, a zirconium substrate, a tungsten substrate, or a silicon substrate.

[0026] We used a plasma etching method based on boron target magnetron sputtering to perform plasma etching on copper substrates, aluminum substrates, molybdenum substrates, niobium substrates, tantalum substrates, zirconium substrates, tungsten substrates and silicon substrates, and found that this method can achieve plasma etching of the above-mentioned different substrate materials, but the etching rates are significantly different.

[0027] Through a large number of experiments, we summarized the etching rates of commonly used substrate materials based on applying radio frequency to boron target with a radio frequency power of 80W to 120W and applying a bipolar pulse bias to the substrate to be etched, where the positive pulse bias is 90V to 110V, the negative pulse bias is -500V to -800V, the frequency is 25KHz to 35KHz, and the duty cycle is 70% to 90%. Specifically, the etching rate of the copper substrate is 2.5~2.6nm / min; the etching rate of the aluminum substrate is 0.6~0.7nm / min; the etching rate of the molybdenum substrate is 1.3~1.4nm / min; the etching rate of the niobium substrate is 1.3~1.4nm / min; the etching rate of the tantalum substrate is 1.7~1.8nm / min; the etching rate of the zirconium substrate is 1.0~1.1nm / min; the etching rate of the tungsten substrate is 0.85~0.95nm / min; and the etching rate of the silicon substrate is 1.45~1.55nm / min.

[0028] It can be understood that the plasma etching method based on boron target magnetron sputtering of the present application can determine the etching time of different substrates according to the required etching thickness and the etching rate of different substrates.

[0029] In some embodiments, a bipolar pulse bias is applied to the substrate, wherein the positive pulse bias is 90V to 110V, the negative pulse bias is -500V to -800V, the frequency is 25KHz to 35KHz, and the duty cycle is 70% to 90%.

[0030] Specifically, we unexpectedly discovered in our experiment that by installing a boron target on the cathode of the magnetron sputtering device and applying a bipolar pulse bias to the substrate, the plasma etching function of the substrate can be realized in the vacuum chamber of the existing magnetron sputtering device. We tried to install nickel targets, gold targets, etc. on the cathode of the magnetron sputtering device, and explored the parameters of applying a bipolar pulse bias to the substrate (including positive pulse bias, negative pulse bias, frequency and duty cycle). Finally, it was concluded that by installing a boron target on the cathode of the magnetron sputtering device and applying a bipolar pulse bias to the substrate with the parameters of positive pulse bias of 90V to 110V, negative pulse bias of -500V to -800V, frequency of 25KHz to 35KHz, and duty cycle of 70% to 90%, magnetron sputtering plasma etching can be realized.

[0031] In some embodiments, radio frequency is applied to the boron target, and the radio frequency power is 80W to 120W.

[0032] It is understandable that RF power affects the coating rate, and we also found that RF power also affects the etching rate. The magnitude of RF power can be set according to the method in the prior art, and we preferably apply RF power of 80W to 120W to the boron target.

[0033] In some embodiments, the vacuum chamber of the magnetron sputtering device is evacuated to a vacuum degree of less than 5.0×10 -4 Pa.

[0034] It is understandable that the higher the vacuum degree of the vacuum chamber of the magnetron sputtering equipment, the less impurities there are in the chamber, thereby reducing the impact on etching. Experiments have found that when the vacuum degree is controlled to be less than 5.0×10 -4 Pa, which can meet our experimental requirements.

[0035] In some embodiments, argon gas is introduced to a vacuum degree of 0.3-0.4 Pa.

[0036] It is understandable that the purpose of introducing argon gas is to generate plasma ignition, and controlling the argon gas pressure at 0.3-0.4 Pa is more suitable for plasma etching of the substrate in the vacuum chamber of the magnetron sputtering equipment.

[0037] A second aspect of an embodiment of the present invention provides a film coating method, comprising:

[0038] Plasma etching, using the above-mentioned plasma etching method to perform plasma etching on the substrate;

[0039] Magnetron sputtering coating: after the substrate is plasma etched, it does not need to be taken out from the vacuum chamber of the magnetron sputtering device, and magnetron sputtering coating is directly performed in the vacuum chamber of the magnetron sputtering device.

[0040] The coating method provided in the embodiment of the present invention utilizes the existing magnetron sputtering equipment to realize plasma etching of the substrate, without the need to modify the existing magnetron sputtering equipment, and the plasma physical etching process can be performed online in a vacuum. After the substrate is plasma etched, it can enter the coating process in a vacuum state, effectively ensuring that the substrate after plasma etching is not contaminated for the second time, and has high application value in the field of coating.

[0041] Example 1 A plasma etching method based on magnetron sputtering of boron target

[0042] A plasma etching method based on boron target magnetron sputtering comprises the following steps:

[0043] 1) In the vacuum chamber of the magnetron sputtering equipment, a substrate to be plasma etched is mounted on a sample holder, a bipolar pulse bias power supply is connected to the sample holder, and a boron target is mounted on the cathode.

[0044] 2) Close the vacuum chamber door of the magnetron sputtering equipment and evacuate the chamber to a vacuum degree of less than 5.0×10 -4 Pa.

[0045] 3) Introduce argon gas into the vacuum chamber of the magnetron sputtering equipment until the vacuum degree is 0.33 Pa;

[0046] A radio frequency is applied to the boron target, the radio frequency is 13.56 MHz, and the radio power is 100 W;

[0047] A positive pulse bias of 100 V and a negative pulse bias of -500 V were applied to the sample holder with the substrate installed. The frequency was 30 KHz and the duty cycle was 89%.

[0048] 4) Open the substrate baffle and perform plasma etching on the substrate until the required etching thickness is reached.

[0049] We use the method of Example 1 to test different types of substrate materials and find that the etching rates of different substrate materials are different. The test results are shown in Table 1.

[0050] Table 1 Etching rates of different substrate materials in Example 1

[0051]

[0052] Comparative Example 1 A plasma etching method based on magnetron sputtering of boron target

[0053] Comparative Example 1 is different from Example 1 in that no bipolar pulse bias is applied in step 3). We used the method of Comparative Example 1 to perform plasma etching on substrates of different materials in Table 1. It was found that the method of Comparative Example 1 could not achieve plasma etching on the substrate, but instead a layer of boron film was plated on the substrate.

[0054] Comparative Example 2 A plasma etching method based on magnetron sputtering of boron target

[0055] Comparative Example 2 is different from Example 1 in that in step 3), the positive pulse bias voltage applied is 500V, the negative pulse bias voltage is -100V, the frequency is 30KHz, and the duty cycle is 89%. We use the method of Comparative Example 2 to perform plasma etching on substrates of different materials in Table 1. It is found that the method of Comparative Example 2 cannot achieve plasma etching on the substrate, but instead a layer of boron film is plated on the substrate.

[0056] Comparative Example 3 A plasma etching method based on gold target magnetron sputtering

[0057] Comparative Example 3 is different from Example 1 in that an Au target is installed on the cathode of the magnetron sputtering device. We use the method of Comparative Example 3 to perform plasma etching on substrates of different materials in Table 1. It is found that the method of Comparative Example 3 cannot achieve plasma etching on the substrate, but instead a layer of Au film is plated on the substrate.

[0058] Comparative Example 4: A plasma etching method based on nickel target magnetron sputtering

[0059] Comparative Example 4 is different from Example 1 in that a Ni target is installed on the cathode of the magnetron sputtering device. We use the method of Comparative Example 4 to perform plasma etching on substrates of different materials in Table 1. It is found that the method of Comparative Example 4 cannot etch the substrate, but instead a layer of Ni film is plated on the substrate.

[0060] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed. The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application. The above are only preferred implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A plasma etching method based on boron target magnetron sputtering, characterized in that: include: In the vacuum chamber of the magnetron sputtering equipment, a substrate is mounted on a sample holder and a boron target is mounted on a cathode; The vacuum chamber of the magnetron sputtering device is evacuated, and then argon gas is introduced, a bipolar pulse bias is applied to the substrate, and radio frequency is applied to the boron target material, and then plasma etching of the substrate is achieved through the magnetron sputtering device.

2. The plasma etching method based on boron target magnetron sputtering according to claim 1, characterized in that: The substrate includes a copper substrate, an aluminum substrate, a molybdenum substrate, a niobium substrate, a tantalum substrate, a zirconium substrate, a tungsten substrate or a silicon substrate.

3. The plasma etching method based on boron target magnetron sputtering according to claim 2, characterized in that: The substrate is applied with a bipolar pulse bias, wherein the positive pulse bias is 90V to 110V, the negative pulse bias is -500V to -800V, the frequency is 25KHz to 35KHz, and the duty cycle is 70% to 90%.

4. The plasma etching method based on boron target magnetron sputtering according to claim 3, characterized in that: The radio frequency is applied to the boron target, and the radio frequency power is 80W to 120W.

5. The plasma etching method based on boron target magnetron sputtering according to claim 4, characterized in that: The etching rate of the copper substrate is 2.5nm / min~2.6nm / min; the etching rate of the aluminum substrate is 0.6nm / min~0.7nm / min; the etching rate of the molybdenum substrate is 1.3nm / min~1.4nm / min; the etching rate of the niobium substrate is 1.3nm / min~1.4nm / min; the etching rate of the tantalum substrate is 1.7nm / min~1.8nm / min; the etching rate of the zirconium substrate is 1.0nm / min~1.1nm / min; the etching rate of the tungsten substrate is 0.85nm / min~0.95nm / min; the etching rate of the silicon substrate is 1.45nm / min~1.55nm / min.

6. The plasma etching method based on boron target magnetron sputtering according to claim 1, characterized in that: The vacuum chamber of the magnetron sputtering equipment is evacuated to a vacuum degree less than 5.0×10 -4 Pa.

7. The plasma etching method based on boron target magnetron sputtering according to claim 6, characterized in that: Argon gas is introduced to a vacuum degree of 0.3-0.4 Pa.

8. A coating method, characterized in that: include: Plasma etching, using the plasma etching method according to any one of claims 1 to 7 to perform plasma etching on the substrate; Magnetron sputtering coating: after the substrate is plasma etched, it does not need to be taken out from the vacuum chamber of the magnetron sputtering device, and magnetron sputtering coating is directly performed in the vacuum chamber of the magnetron sputtering device.

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