Method for obtaining high-q quartz hemispherical resonator surface plated with au film based on organosilane

Abstract

The application belongs to the technical field of resonant gyro precision manufacturing, and solves the problem of low-loss Au film plating on the surface of a quartz hemispherical resonator. The application relates to a method for obtaining Au film plating on the surface of a high-Q quartz hemispherical resonator based on organic silane, which comprises the following steps: placing the hemispherical resonator on a cleaning tool, sequentially performing ultrasonic cleaning with acetone, isopropyl alcohol, alcohol and deionized water, and then drying in an oven to remove surface adsorbed water molecules; performing hydroxylation treatment on the surface of the resonator with a piranha solution to form a uniform hydroxyl on the surface of the resonator; performing aminization treatment on the surface of the resonator with organic silane to form a layer of organic silane molecules on the surface layer of the resonator; rinsing and drying the aminized resonator; placing the aminized resonator in a film plating machine to plating Au film, so that the amino group forms a covalent bond with the Au film to form a firm pure Au film on the surface of the resonator. The application improves the bonding force between the Au film and the SiO2 substrate, maintains the performance of the Au film, forms a low-loss interface and a high-purity low-loss film, and improves the Q value of the film-plated resonator.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of precision manufacturing of resonant gyroscopes, and relates to a low-loss coating technology for the surface of a quartz hemispherical resonator, in particular to a method for obtaining a high-Q quartz hemispherical resonator surface Au film based on organosilane. BACKGROUND

[0002] The hemispherical resonator is the core sensitive component of the hemispherical resonator gyroscope, and is usually made of non-conductive fused quartz glass SiO2 by ultra-precision machining. The resonator quality factor (Q value) is a core index reflecting the manufacturing performance of the resonator. The higher the resonator Q value, the smaller the vibration loss, and the higher the precision of the resonator gyroscope. The Q value of the ultra-precision machined resonator has broken through the level of 10 million. In order to realize the excitation and detection control of the hemispherical resonator, the ultra-precision machined hemispherical resonator must be coated to form a conductive thin film electrode on the surface of the resonator. Noble metal Au is an ideal electrode material with good conductivity and stable properties, and is usually deposited on the surface of the resonator by electron beam evaporation or magnetron sputtering. In the thin film deposition process, since the bonding force between Au and SiO2 is poor, an adhesion layer is usually used to improve the bonding force between them. In the process of coating the surface of the resonator, a layer of adhesion layer Cr or Ti film is usually deposited first, and then an Au film is deposited to form a Cr / Au or Ti / Au composite film. Although the Cr / Au or Ti / Au composite film improves the bonding force of the Au film, the diffusion of Cr and Ti atoms in the Au film reduces the purity and conductivity of the Au film, increases the vibration loss of the elastic wave in the Au film, and affects the long-term stability of the thin film. The Cr or Ti thin film is easy to oxidize, and the formed TiO X or Cr2O3 oxide also increases the vibration loss and reduces the Q value of the resonator. If the surface of the resonator is directly coated with an Au thin film, there is only one Au-SiO2 interface between the Au thin film and the resonator, the bonding force at the interface is poor, the vibration loss is large, and the Q value is low. After adding the adhesion layer, not only the number of interfaces increases, but also the form of the interface is more complex, which makes the Q value decrease more. As can be seen, the introduction of Cr and Ti adhesion layers for improving the bonding force has an adverse effect on the purity, conductivity, stability, oxidation resistance and vibration loss of the Au film. Therefore, it is necessary to explore a new coating method that can improve the bonding force of the film and substrate and form a low-loss thin film with the inherent properties of the Au thin film, and then obtain a high-Q coated resonator. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art, and provides a low-loss Au-organosilane-SiO2 interface that can improve the bonding force of the Au film and the SiO2 substrate, and maintain the purity, conductivity and stability of the Au thin film, thereby improving the Q value of the coated resonator.

[0004] The above object of the present application is achieved by the following technical scheme:

[0005] A method for obtaining high-Q quartz hemispherical resonator surface Au film based on organic silane, comprising the following steps:

[0006] Step 1: Place the hemispherical resonator on a cleaning tool, and sequentially use acetone, isopropyl alcohol, alcohol and deionized water for ultrasonic cleaning, and then dry in an oven for standby, so as to completely remove the surface adsorbed water molecules;

[0007] Step 2: Use the piranha solution to perform hydroxylation treatment on the surface of the resonator, so as to form a uniform hydroxyl on the surface of the resonator, and reduce the wetting angle of the resonator surface;

[0008] Step 3: Use organic silane to perform aminization treatment on the surface of the resonator, so as to form a layer of organic silane molecules on the surface layer of the resonator, one end of the organic silane reacts with the hydroxyl on the surface of the resonator to form a Si-O-Si covalent bond, and the other end is exposed in the form of -NH2 amino group;

[0009] Step 4: Rinse the aminized resonator clean and dry;

[0010] Step 5: Place the aminized resonator in a film plating machine to plating Au thin film, so that the amino group forms a covalent bond with the Au thin film, and a firm Au thin film is formed on the surface of the resonator; the film plating machine uses a magnetron sputtering film plating machine or an atomic layer deposition film plating equipment.

[0011] Moreover, in step 1, the ultrasonic frequency is 80-160 KHz, the oven temperature is 150-250℃, and the time is 2-6h.

[0012] Moreover, in step 2, the composition of the piranha solution is 80% H2SO4 and 20% H2O2, the volume ratio is 4:1, and the hydroxylation time is 10-20min.

[0013] Moreover, in step 3, the organic silane uses 3-aminopropyltrimethoxysilane (APTMS), γ-aminopropyltriethoxysilane (APTS) or aminopropyltrimethoxysilane (APS).

[0014] Moreover, in step 3, the components for aminization treatment are (1-5) vol% APTMS / APTS, (1-5) vol% H2O and isopropyl alcohol; the treatment time is 3-5h, and the temperature is 25℃.

[0015] Moreover, in step 3, the components for aminization treatment are 1mL APTMS and (200-300)mL H2O; the treatment time is 30-60min, and the temperature is 25℃.

[0016] And, in step 4, the rinsing uses methanol, and nitrogen is used to dry.

[0017] And, in step 5, the Au film thickness is 5-15 nm, and the deposition rate is 0.5-1 nm / s.

[0018] And, the organic silane is used to form a Si-O-Si covalent bond with the surface hydroxyl of the resonator, and the other end is in the form of -NH2 amino group to form a covalent bond with Au atoms, so that the Au film grows uniformly on the SiO2 surface with high bonding force, and a low-loss interface is formed between the Au film and the quartz substrate, and a high-Q resonator is obtained.

[0019] And, the organic silane is used to form an interface between Au and SiO2, which improves the bonding force of the Au film on the SiO2 substrate, and makes the purity of the Au film consistent with the purity of the sputtering target, which can reach 99.999wt%, and the high-purity Au film has low-loss characteristics, and a high-Q resonator can be obtained.

[0020] The present application has the advantages and positive effects that:

[0021] 1. The process method for obtaining a high-Q quartz hemispherical resonator surface Au film based on organic silane provided by the present application uses organic silane to form a layer of -NH2 amino group on the surface of the resonator, and uses the covalent bond formed by the amino group and the Au film to improve the bonding force of the Au film and form a low-loss Au-organic silane-SiO2 interface.

[0022] 2. The process of the present application is relatively simple, and the amino group treatment of the hydroxylated resonator using organic silane improves the bonding force of the Au film and the SiO2 substrate, and avoids the oxidation and diffusion problems caused by the Cr and Ti adhesion layer, maintains the purity, conductivity and stability of the Au film, obtains a low-loss film, and improves the Q value of the plated film resonator. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a flow chart of the process method of the present application.

[0024] Figure 2 It is a schematic diagram of the film growth formed by the process of the present application. DETAILED DESCRIPTION

[0025] The structure of the present application will be further described below in conjunction with the drawings and through examples. It should be noted that the present examples are descriptive and not limiting.

[0026] A method for obtaining a high-Q quartz hemispherical resonator surface Au film based on organic silane, please refer to Figure 1 , comprising the following steps:

[0027] Step 1: Put the hemisphere resonator on a cleaning tool, and sequentially clean it with acetone, isopropyl alcohol, alcohol and deionized water by ultrasonic cleaning, and then dry it in an oven for use, so as to completely remove the surface adsorbed water molecules. The ultrasonic frequency is 80-160 KHz, the oven temperature is 150-250 °C, and the time is 2-6 h.

[0028] Step 2: The surface of the resonator is treated with piranha solution to form a uniform hydroxyl group on the surface of the resonator, so that the wetting angle of the resonator surface is reduced. The composition of the piranha solution is 80% H2SO4 and 20% H2O2, the volume ratio is 4:1, and the hydroxylation time is 10-20 min.

[0029] Step 3: The surface of the resonator is treated with organosilane to form a layer of organosilane molecules on the surface of the resonator. The organosilane has the characteristics that one end can react with the hydroxyl group on the surface of the resonator to form a Si-O-Si covalent bond, and the other end is exposed in the form of -NH2 amino group. The organosilane is 3-aminopropyltrimethoxysilane (APTMS), γ-aminopropyltriethoxysilane (APTS) or aminopropyltrimethoxysilane (APS), etc. For example:

[0030] APTMS / APTS: (1-5) vol% APTMS / APTS, (1-5) vol% H2O and isopropyl alcohol, treatment time 3-5 h, temperature 25 °C.

[0031] APS: 1 mL APS and (200-300) mL H2O, treatment time 30-60 min, temperature 25 °C;

[0032] Step 4: Rinse the aminated resonator and blow dry. The rinse is preferably methanol, and the nitrogen is blown dry, which can maximize the protection of the organosilane molecular layer formed on the surface of the resonator, and ensure the continuity, uniformity and integrity of the organosilane molecular layer.

[0033] Step 5: Put the aminated resonator in a plating machine to plate Au thin film. The plating machine can be a magnetron sputtering plating machine or an atomic layer deposition plating equipment, so that the amino group forms a covalent bond with the Au thin film, improves the bonding force of the Au thin film, and the thickness of the Au film is 5-15 nm, and the deposition rate is 0.5-1 nm / s.

[0034] Example 1.

[0035] Step 1: Put the hemisphere resonator on a cleaning tool, and sequentially clean it with acetone, isopropyl alcohol, alcohol and deionized water by ultrasonic cleaning, and then dry it in an oven for use, so as to completely remove the surface adsorbed water molecules. The ultrasonic frequency is 80-160 KHz, the oven temperature is 150-250 °C, and the time is 2-6 h.

[0036] Step 2: The surface of the harmonic oscillator was hydroxylated using a piranha solution. The piranha solution consisted of 80% H2SO4 and 20% H2O2 in a volume ratio of 4:1, and the hydroxylation time was 15 min.

[0037] Step 3: The surface of the harmonic oscillator is amination treated with 1 mLAPS and 300 mL H2O for 30–60 min at 25 °C to form a layer of organosilanes on the surface of the harmonic oscillator.

[0038] Step 4: Rinse the amination harmonic oscillator with methanol and dry it with nitrogen.

[0039] Step 5: Place the aminated harmonic oscillator in a magnetron sputtering coating machine or atomic layer deposition coating equipment to form covalent bonds between the amino group and the Au film. The Au film thickness is 10 nm, and the deposition rate is 0.5 nm / s.

[0040] After testing and analysis, it was found that when Au was directly deposited on the surface of the harmonic oscillator, the thin film grew in an island-like pattern, such as... Figure 2 As shown, the interface of this type of thin film is not continuous, resulting in poor adhesion, poor conductivity, and high vibration loss, making it difficult to pass the adhesive test. However, when using organosilane + Au thin films, the film grows in a layered manner, resulting in continuous film, low vibration loss, and good adhesion, thus passing the adhesive test. Compared to Cr / Au or Ti / Au films, organosilane + Au films do not contain Cr or Ti, nor do they exhibit Cr or Ti diffusion or oxidation behavior. Therefore, the Au film has high purity. If sputtering deposition is used, the film purity can be consistent with the target material, reaching 99.999 wt%, and there is no oxidation problem. Therefore, its stability and conductivity are consistent with pure Au films. Table 1 shows the comparison of Q values ​​of hemispherical resonators before and after different film deposition. After depositing organosilane + Au films, the Q value of the resonator increases by 20-35% compared to Cr / Au films, demonstrating that the above process can obtain high-Q-value deposited resonators.

[0041] Table 1 Comparison of Q values ​​of hemispherical harmonic oscillators before and after coating with different thin films.

[0042] Sample No. Q value after plating Cr / Au (10 nm) film (10,000) Q value after organic silane + Au (10 nm) film (10,000) No. 1 1060 1380 No. 2 950 1200 No. 3 1000 1350 No. 4 870 1270 No. 5 900 1240

[0043] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A method for obtaining a high Q-value quartz hemispherical resonator surface Au film based on organosilane, characterized by comprising the following steps: It comprises the following steps: ​ Step 1: Put the hemispherical resonator on a cleaning tool, and sequentially clean it by ultrasonic cleaning with acetone, isopropyl alcohol, alcohol and deionized water, and then dry it in an oven for use, so as to completely remove the surface adsorbed water molecules; Step 2: Hydroxylate the surface of the resonator by using the piranha solution, so as to form a uniform hydroxyl on the surface of the resonator, and reduce the wetting angle of the surface of the resonator; Step 3: Aminoate the surface of the resonator by using the organosilane, so as to form a layer of organosilane molecules on the surface layer of the resonator, one end of the organosilane reacts with the hydroxyl on the surface of the resonator to form a Si-O-Si covalent bond, and the other end is exposed in the form of -NH2 amino group; Step 4: Rinse the aminoated resonator clean and dry it; Step 5: Put the aminoated resonator in a plating machine to plate Au film, so that the amino group forms a covalent bond with the Au film, and a firm pure Au film is formed on the surface of the resonator; the plating machine uses a magnetron sputtering plating machine; The Au film plating method utilizes the one end of the organosilane to react with the hydroxyl on the surface of the resonator to form a Si-O-Si covalent bond, and the other end to form a covalent bond with the Au atom in the form of -NH2 amino group, so that the Au film grows uniformly on the surface of the resonator with high bonding force, and then a low-loss interface is formed between the Au film and the resonator substrate, and a high-Q resonator is obtained; The Au film plating method utilizes the organosilane to form an interface between Au and the resonator, improves the bonding force of the Au film on the resonator substrate, and at the same time makes the purity of the Au film consistent with the purity of the sputtering target material, reaching 99.999wt%, and such high-purity Au film has low-loss characteristics, and then a high-Q resonator is obtained.

2. The method for obtaining a high Q-value quartz hemispherical resonator surface Au film formation based on an organic silane according to claim 1, characterized by: In step 1, the ultrasonic frequency is 80-160KHz, the oven temperature is 150-250℃, and the time is 2-6h.

3. The method for obtaining a high Q-value quartz hemispherical resonator surface Au film based on organosilane according to claim 1, characterized in that: In step 2, the composition of the piranha solution is 80% H2SO4 and 20% H2O2, the volume ratio is 4:1, and the hydroxylation time is 10-20min.

4. The method for obtaining a high Q-value quartz hemispherical resonator surface Au film based on organosilane according to claim 1, characterized in that: In step 3, the organosilane is 3-aminopropyltrimethoxysilane APTMS and γ-aminopropyltriethoxysilane APTS.

5. The method for obtaining a high-Q quartz hemispherical resonator surface Au film based on organosilane according to claim 4, characterized in that: In step 3, the components for aminoating treatment are: 1-5vol% APTMS / APTS, 1-5vol% H2O and isopropyl alcohol; the treatment time is 3-5h, and the temperature is 25℃.

6. The method for obtaining a high-Q quartz hemispherical resonator surface Au film based on organosilane according to claim 1, characterized in that: In step 4, the rinsing uses methanol, and nitrogen is used for drying.

7. The method for obtaining a high-Q quartz hemispherical resonator surface Au film based on organosilane according to claim 1, characterized in that: In step 5, the thickness of the Au film is 5-15nm, and the deposition rate is 0.5-1nm / s.

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