CN111575652A - Vacuum coating equipment and vacuum coating method - Google Patents

Abstract

The invention discloses vacuum coating equipment and a vacuum coating method, wherein the vacuum coating equipment comprises a coating vacuum chamber, an evaporation source, a sample stage, a heating source, an air pumping system and a small vacuum chamber communicated with the coating vacuum chamber, and the mechanical property of a film is improved by utilizing pressure difference to improve the kinetic energy of coating molecules or atoms. The vacuum coating method comprises the steps of cleaning a substrate, placing the substrate, loading a preparation material, vacuumizing, coating and annealing. The invention provides extra directional kinetic energy for coating molecules by using the pressure difference between two connected vacuum chambers, and can also use the combination of a radio frequency power supply and a bias power supply to assist deposition when necessary. The invention provides a novel method for improving the hardness of the film by adding oriented molecular or atomic kinetic energy to optimize the mechanical property of the vacuum film, and the method is expected to provide a novel way for improving the mechanical property of the vacuum film. The preparation method is simple and convenient, easy to operate, low in cost and suitable for popularization and application.

Description

Vacuum coating equipment and vacuum coating method

technical field

The invention relates to a film preparation device and a preparation method, in particular to a device and a process for improving mechanical properties such as film hardness, which are applied to the technical field of physical vapor deposition.

Background technique

The research of thin films depends on the preparation equipment and technology of thin films. High-quality thin films are beneficial to the research of thin film physics and the development of thin film device applications. With the application of laser technology, microwave technology and ion beam technology, a variety of thin film preparation technologies and methods have been developed.

The thin film preparation technology is divided into two categories, the first category is PVD, namely physical vapor deposition, including vacuum evaporation method, magnetron sputtering method, ion plating and so on. The basic principle of vacuum evaporation is to evaporate metals, metal alloys or compounds under vacuum conditions, and then deposit them on the surface of the substrate. The evaporation methods are commonly used resistance heating, high-frequency induction heating, electron beam, laser beam, ion beam high-energy bombardment plating The material is evaporated into a gas phase and then deposited on the surface of the substrate. The basic principle of magnetron sputtering is to make argon gas glow discharge under vacuum conditions filled with argon (Ar) gas. At this time, argon (Ar) atoms are ionized into argon ions (Ar ⁺ ), and argon ions are under the action of electric field force. , to accelerate the bombardment of the cathode target made of plating material, the target material will be sputtered and deposited on the surface of the workpiece. If DC glow discharge is used, it is called direct current (Qc) sputtering, and radio frequency (RF) glow discharge is called radio frequency sputtering. Magnetron (M) glow discharge caused by magnetron sputtering. The basic principle of arc plasma coating is to use an arc ignition needle to strike the arc under vacuum conditions, so that arc discharge is carried out between the vacuum gold wall (anode) and the plating material (cathode), and multiple cathode arc spots move rapidly on the cathode surface. Quickly evaporate or even "sublime" the plating material, ionize it into an arc plasma with the plating material as the main component, and quickly deposit the plating material on the substrate. Because there are many arc spots, it is also called multi-arc evaporation ionization process. The basic principle of ion plating is to use a certain plasma ionization technology under vacuum conditions to partially ionize the atoms of the plating material into ions, and at the same time generate many high-energy neutral atoms , which are negatively biased on the substrate to be plated. In this way, under the action of a deep negative bias, ions are deposited on the surface of the substrate to form a thin film. The physical vapor deposition technology has a simple process, improved environment, no pollution, less consumables, uniform and dense film formation, and strong bonding force with the substrate. This technology is widely used in aerospace, electronics, optics, machinery, construction, light industry, metallurgy, materials and other fields. A film with properties such as conductivity.

The second type is CVD, that is, chemical vapor deposition, including metal organic compound chemical vapor deposition (MOCVD), which is to send all the reaction substances in the form of gas molecules of organic metal compounds, and use HZ gas as a carrier gas to send them to the reaction chamber. A new technology for the formation of compound semiconductors through thermal decomposition reactions. Because it uses the best method to control the gas flow, it is easy to change the composition and doping concentration of the compound, and the equipment used is relatively simple, the growth speed is fast, the cycle is short, and it is possible to carry out mass production. Beginning of application and attention in semiconductor device processing; Plasma Enhanced Chemical Vapor Deposition (PECVD), which can form solid films at lower temperatures. For example, the matrix material is placed on the cathode in a reaction chamber, the reaction gas is introduced to a lower pressure (1-600Pa), the matrix is kept at a certain temperature, and a glow discharge is generated in a certain way, the gas near the surface of the matrix is ionized, and the reaction gas is obtained. activation, and at the same time cathode sputtering occurs on the surface of the substrate, thereby improving the surface activity. There are not only the usual thermochemical reactions on the surface, but also complex plasma chemical reactions. The deposited film is formed under the combined action of these two chemical reactions. The methods of exciting glow discharge mainly include: radio frequency excitation, DC high voltage excitation, pulse excitation and microwave excitation; sol-gel process, which is to use compounds containing highly chemically active components as precursors, in liquid phase. These raw materials are uniformly mixed, and undergo hydrolysis and condensation chemical reactions to form a stable transparent sol system in the solution. The sol is slowly polymerized between the aged colloidal particles to form a gel with a three-dimensional network structure. A fluid solvent that forms a gel. The gel is dried, sintered and solidified to prepare a nanostructured material.

However, in actual production, due to the characteristics of fullerene itself, only fullerene powder or its derivatives exist in solid form, and due to the limitation of the existing technology, the ideal continuous film shape cannot be obtained, which requires a A new and economical equipment and coating process to meet this demand. For powder materials, the vacuum evaporation method is generally used to form a film. The vacuum evaporation method has wide applicability and low cost, which meets the basic conditions of production and preparation. However, the evaporation method has the following disadvantages:

(1) The molecular energy of evaporation is very low, resulting in low film quality and many surface defects;

(2) The center point of the evaporated film is thick and the surrounding area is thin;

(3) Evaporation is not suitable for large-scale production;

(4) Compared with sputtering, the required vacuum degree is higher.

Therefore, designing a new type of equipment and supporting process to solve the above shortcomings has become an urgent technical problem to be solved.

SUMMARY OF THE INVENTION

In order to solve the problems of the prior art, the object of the present invention is to overcome the deficiencies of the prior art, and to provide a vacuum coating equipment and a vacuum coating method, which utilizes the pressure difference to improve the kinetic energy of the coating molecules, and adopts the optimization of the exhaust passage in the vacuum chamber to reduce Improve the mechanical properties of the film and solve the problem of low molecular energy.

In order to achieve the above-mentioned purpose of invention and creation, the present invention adopts the following technical solutions:

A vacuum coating equipment includes a coating vacuum chamber, an evaporation source, a sample stage, a heating source, and an air extraction system. The sample stage is arranged in the coating vacuum chamber, and the heating source outputs heat to the coating vacuum chamber, thereby regulating the sample stage and setting on the sample. The temperature of the substrate on the stage; a small vacuum chamber connected with the coating vacuum chamber is also set, and the evaporation source is set in the small vacuum chamber. The pumping system includes a mechanical pump and a molecular pump. The vacuum chamber is connected to the small vacuum chamber, and the molecular pump is connected to the coating vacuum chamber and the small vacuum chamber respectively through the high valve to form a tube valve system; a small hole is opened on the wall of the small vacuum chamber, so that the small hole faces the sample stage set in the coating vacuum chamber The coating material is placed inside the small vacuum chamber as the evaporation source. First, the coating vacuum chamber and the small vacuum chamber are exhausted to high vacuum by the air extraction system; The working gas is introduced into the small vacuum chamber, and the pressure in the small vacuum chamber is changed from high vacuum to low vacuum, thus forming a pressure difference between the two vacuum chambers, providing the coating molecules to spray out from the small holes on the wall of the small vacuum chamber. Directional kinetic energy entering the coating vacuum chamber.

As a preferred technical solution of the present invention, a radio frequency coil is also arranged in the coating vacuum chamber, and the radio frequency coil is installed at the position between the small hole on the wall of the small vacuum chamber and the substrate on the sample stage set in the coating vacuum chamber, and the radio frequency power source is the radio frequency coil. Power on; the sample stage is also connected to a bias power supply; the radio frequency power supply controls the density of the plasma, and the bias power supply can control the direction of the plasma; in the cleaning stage, the radio frequency power supply is used to ionize the working gas, so that the working gas molecules become charged particles, and then The bias power supply makes the charged particles move in a directional motion, bombards the surface of the substrate, and cleans the substrate; in the evaporation coating stage, the radio frequency power supply ionizes the coating molecules to increase their energy, and the bias power supply makes the coating molecules move in a directional motion to increase their kinetic energy; thus using A combination of RF power and bias power is used to assist deposition.

As a preferred technical solution of the present invention, a pre-connecting pipeline is set between the mechanical pump and the molecular pump, and a pre-valve is set on the pre-connecting pipeline, and one end of the pre-connecting pipeline is connected to the mechanical pump and the rough valve. The other end of the pre-connecting pipeline is connected with the pipeline between the molecular pump and the high valve to form a multi-channel pumping system.

As a preferred technical solution of the present invention, a baffle is also arranged in the coating vacuum chamber, and the baffle is arranged around the working gas jet path area between the small hole on the wall of the small vacuum chamber and the sample stage.

As a preferred technical solution of the present invention, the coating vacuum chamber and the small vacuum chamber are connected in series or in a nested combination.

As a preferred technical solution of the present invention, the air pumping system draws air behind the substrate along the directional movement direction of the coating particles to maintain the pressure difference in the gas flow direction.

As a preferred technical solution of the present invention, the sample stage is formed by a combination of a large sample stage and a small sample stage. The rotational speed of the sample stage can be adjusted.

A vacuum coating method, using the vacuum coating equipment of the present invention, comprises the following steps:

a. Cleaning the substrate:

Put the pre-cleaned substrate into acetone, ethanol, and deionized water for ultrasonic cleaning for at least 10 minutes each, and then blow dry with nitrogen;

b. Place the substrate:

Place the cleaned substrate on the sample stage, and connect the sample stage to the negative bias power supply;

c. Loading preparation materials:

Put the coating material into the evaporation boat, and then put it into a small vacuum chamber together;

d. Vacuum coating:

Turn on the pumping system, pump the two vacuum chambers to high vacuum, turn on the evaporation current, and adjust the RF power, bias voltage, gas flow, temperature process parameters, and carry out vacuum coating;

In the cleaning stage, the working gas is ionized by the radio frequency power supply, so that the working gas molecules become charged particles, and then the bias power supply makes the charged particles move in a direction, bombarding the surface of the substrate, and cleaning the substrate;

In the evaporation coating stage, when the coating material starts to evaporate, the working gas is introduced into the small vacuum chamber to change the pressure in the small vacuum chamber from high vacuum to low vacuum, thereby forming a pressure difference between the large and small vacuum chambers, giving the coating film Molecules provide directional kinetic energy from the small vacuum chamber into the coating vacuum chamber, and use a combination of RF power and bias power to assist deposition to deposit the coating on the substrate;

e. Annealing:

In a high vacuum state, the coating film deposited on the substrate is cooled naturally;

f. Repeat the above-mentioned coating step d and step e at least once until the thickness of the coating film meets the requirements, thereby completing the vacuum coating process.

As a preferred technical solution of the present invention, in step d, process parameters are determined according to differences in working gas and coating molecules.

Compared with the prior art, the present invention has the following obvious outstanding substantive features and significant advantages:

1. The present invention improves the mechanical properties of the film by utilizing the pressure difference to increase the kinetic energy of the coating molecules or atoms; the present invention utilizes the pressure difference between two connected vacuum chambers to provide additional directional kinetic energy to the coating molecules, which can also be used if necessary. A combination of RF power and bias power to assist deposition;

2. The present invention provides a new method for improving the hardness of the film to optimize the mechanical properties of the vacuum film by adding directed molecular or atomic kinetic energy, and the present invention is expected to provide a new approach for improving the mechanical properties of the vacuum film;

3. The device of the present invention has compact structure, simple method, low cost, easy realization, and is suitable for popularization and application.

Description of drawings

FIG. 1 is a schematic diagram of the structural principle of a vacuum coating equipment according to an embodiment of the present invention.

Detailed ways

In order for those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be checked and fully described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some implementation cases of the present invention, but not all implementation cases. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

The above scheme will be further described below in conjunction with specific embodiments, and preferred embodiments of the present invention are described in detail as follows:

Example 1:

In this embodiment, as shown in FIG. 1 , a vacuum coating equipment includes a coating vacuum chamber 1 , an evaporation source 3 , a sample stage 5 , a heating source 6 , and an air extraction system. The sample stage 5 is arranged in the coating vacuum chamber 1 . , the heating source 6 outputs heat to the coating vacuum chamber 1, and then regulates the temperature of the sample stage 5 and the substrate arranged on the sample stage 5; also set up a small vacuum chamber 2 communicated with the coating vacuum chamber 1, the coating vacuum chamber 1 and the small vacuum chamber 2 are also provided. The vacuum chambers 2 are nested, combined and communicated, and the small vacuum chamber 2 is set inside the coating vacuum chamber 1; the evaporation source 3 is set in the small vacuum chamber 2, and the pumping system includes a mechanical pump 10 and a molecular pump 11, and the mechanical pump 10 The rough pumping valve 12 is respectively connected with the coating vacuum chamber 1 and the small vacuum chamber 2, and the molecular pump 11 is respectively connected with the coating vacuum chamber 1 and the small vacuum chamber 2 through the high valve 9 to form a tube valve system; on the wall of the small vacuum chamber 2 A small hole is opened so that the small hole faces the surface of the substrate on the sample stage 5 set in the coating vacuum chamber 1; All are exhausted to high vacuum; when the coating material begins to evaporate, the working gas is introduced into the small vacuum chamber 2 through the ventilation hole 8 of the small vacuum chamber 2, and the pressure in the small vacuum chamber 2 is changed from high vacuum to low vacuum, so that the The pressure difference is formed between the large and small vacuum chambers, which provides the directional kinetic energy for the coating molecules to be ejected from the small holes on the wall of the small vacuum chamber 2 and enter the coating vacuum chamber 1 . In this embodiment, the pressure difference is used to improve the molecular kinetic energy of the coating film, and the exhaust passage in the vacuum chamber is optimized, in order to solve the problem of low molecular energy, the mechanical properties of the film are improved. In this embodiment, two vacuum chambers, one large and one small, are nested and assembled and connected. The coating material is placed inside the small vacuum chamber 2 , and small holes are opened on the wall of the small vacuum chamber 2 . Initially, both large and small vacuum chambers are exhausted to high vacuum. When the coating material begins to evaporate, the small vacuum chamber changes from high vacuum to low vacuum, thereby forming a pressure difference between the large and small vacuum chambers, providing the coating molecules with directional kinetic energy ejected from the small holes.

In this embodiment, as shown in FIG. 1 , a radio frequency coil 4 is also arranged in the coating vacuum chamber 1 , and the radio frequency coil 4 is installed on the small hole on the wall of the small vacuum chamber 2 and the sample stage 5 set in the coating vacuum chamber 1 . At the position between the substrates, the radio frequency power supply energizes the radio frequency coil 4; the sample stage 5 is also connected to a bias power supply; the radio frequency power supply controls the density of the plasma, and the bias power supply can control the direction of the plasma; in the cleaning stage, the radio frequency power supply is used to ionize The working gas turns the working gas molecules into charged particles, and then the bias power supply makes the charged particles move in a direction, bombarding the surface of the substrate, and cleaning the substrate; in the evaporation coating stage, the radio frequency power source ionizes the coating molecules, increases their energy, and the bias voltage The power supply makes the coating molecules move directionally and increases their kinetic energy; thus, the combination of the radio frequency power supply and the bias power supply is used to assist the deposition. This embodiment utilizes a combination of RF power supply and bias power supply to assist deposition in this system. The power supplies used are RF power supply and bias power supply instead of a conventional single RF power supply. The RF power supply can control the density of the plasma, and the bias power supply The direction of the plasma can be controlled, and the two can be combined to achieve excellent results.

In this embodiment, as shown in FIG. 1 , a pre-connecting pipeline is set between the mechanical pump 10 and the molecular pump 11, and a pre-valve 13 is set on the pre-connecting pipeline. One end of the pre-connecting pipeline is connected to the The pipeline between the mechanical pump 10 and the rough pumping valve 12 is connected, and the other end of the pre-connecting pipeline is connected with the pipeline between the molecular pump 11 and the high valve 9 to form a multi-channel pumping system.

In this embodiment, as shown in FIG. 1 , a baffle 7 is also provided in the coating vacuum chamber 1 , and the baffle 7 is arranged around the working gas jet path area between the small hole on the wall of the small vacuum chamber 2 and the sample stage 5 .

In this embodiment, as shown in Figure 1, the air extraction system operates as follows:

Step 1: The mechanical pump 10 is preheated, the pre-valve is opened, and the two vacuum chambers are pumped to low vacuum;

The second step: close the pre-valve, open the high valve 9 and the molecular pump 11, and pump the two vacuum chambers to high vacuum, which can be pumped up to 1×10 ^-4 Pa.

In this embodiment, as shown in FIG. 1 , a vacuum coating method, using the vacuum coating equipment of this embodiment, includes the following steps:

a. Cleaning the substrate:

Use the pre-cleaned silicon wafer as a substrate, put it into acetone, ethanol, and deionized water for ultrasonic cleaning for 10 minutes each, and then dry it with nitrogen;

b. Place the substrate:

The cleaned substrate is placed and transferred to the coating vacuum chamber 1, and is set on the sample stage 5, and the sample stage 5 is connected to the negative bias power supply;

c. Loading preparation materials:

The fullerene powder is loaded into the evaporation boat, fixed, and then put into the small vacuum chamber 2 together;

d. Vacuum coating:

Turn on the pumping system, pump the two vacuum chambers to high vacuum, and heat them to 200°C until the vacuum in the chamber is less than 3.0×10 ^-3 Pa; turn on the evaporation current; close the high valve, and pass argon into the chamber when the vacuum reaches 2Pa Turn off the argon gas, turn on the RF power supply, the power is 50W, open the high valve and the argon gas at the same time after ignition, turn on the bias voltage to 50V, and clean for 10 minutes; after cleaning, turn off the RF bias power supply and adjust the evaporation current to 120A, The coating time is 10 minutes;

e. Annealing:

In a high vacuum state, the coating film deposited on the substrate is cooled naturally;

f. Repeat the above-mentioned coating step d and step e at least once until the thickness of the coating film meets the requirements, thereby completing the vacuum coating process.

In this embodiment, vacuum coating is performed by adjusting the process parameters of radio frequency power, bias voltage, gas flow rate, and temperature; in the cleaning stage, the working gas is ionized by the radio frequency power supply, so that the working gas molecules become charged particles, and then the power supply is biased. Let the charged particles do directional movement, bombard the surface of the substrate, and clean the substrate; in the evaporation coating stage, when the coating material begins to evaporate, the working gas is introduced into the small vacuum chamber 2 to change the pressure in the small vacuum chamber 2 from high vacuum to high vacuum. For low vacuum, a pressure difference is formed between the large and small vacuum chambers, providing directional kinetic energy for the coating molecules to enter the coating vacuum chamber 1 from the small vacuum chamber 2, and the combination of the radio frequency power supply and the bias power supply is used to assist the deposition. Coating is deposited on the substrate. The hardness of the fullerene film prepared by the differential pressure method in this example is 513HV.

Comparative example 1:

In this embodiment, a vacuum coating method includes the following steps:

a. Cleaning the substrate:

Use the pre-cleaned silicon wafer as a substrate, put it into acetone, ethanol, and deionized water for ultrasonic cleaning for 10 minutes each, and then dry it with nitrogen;

b. Place the substrate:

Transfer the cleaned substrate to a common coating vacuum chamber, set it on the sample stage, and connect the sample stage to the negative bias power supply;

c. Loading preparation materials:

Load the fullerene powder into the evaporation boat, fix it, and then put it into the ordinary coating vacuum chamber together;

d. Vacuum coating:

Turn on the pumping system, pump the vacuum chamber to a high vacuum, and heat it to 200 °C until the vacuum in the chamber is less than 3.0×10 ^-3 Pa; turn on the evaporation current, close the high valve, and pass argon into the chamber when the vacuum reaches 2Pa and close the argon gas, turn on the RF power supply, the power is 50W, open the high valve and argon gas at the same time after ignition, turn on the bias voltage to 50V, and clean for 10 minutes; after cleaning, turn off the RF bias power supply, adjust the evaporation current to 120A, and the coating time for 10 minutes;

e. Annealing:

In a high vacuum state, the coating film deposited on the substrate is cooled naturally;

f. Repeat the above-mentioned coating step d and step e at least once until the thickness of the coating film meets the requirements, thereby completing the vacuum coating process. The hardness of the fullerene film prepared by the method of this comparative example is 144.3HV.

Embodiment 2:

This embodiment is basically the same as the first embodiment, and the special features are:

In this embodiment, a vacuum coating method, using a vacuum coating device of this embodiment, includes the following steps:

a. Cleaning the substrate:

Use the pre-cleaned silicon wafer or hard alloy plate as the substrate, put it into acetone, ethanol, and deionized water for ultrasonic cleaning for 10 minutes each, and then dry it with nitrogen;

b. Place the substrate:

The cleaned substrate is placed and transferred to the coating vacuum chamber 1, and is set on the sample stage 5, and the sample stage 5 is connected to the negative bias power supply;

c. Loading preparation materials:

Transfer the cleaned sample to the small vacuum chamber 2, put the fullerene powder into the evaporation boat, fix it, and then put it into the small vacuum chamber 2 together;

d. Vacuum coating:

Turn on the pumping system, pump the two vacuum chambers to high vacuum, and heat them to 200°C until the vacuum in the chamber is less than 3.0×10 ^-3 Pa; turn on the evaporation current; close the high valve, and pass argon into the chamber when the vacuum reaches 2Pa Turn off the argon gas, turn on the RF power supply, the power is 50W, open the high valve and the argon gas at the same time after ignition, turn on the bias voltage to 50V, and clean for 10 minutes; after cleaning, adjust the RF power supply to 20W, and the bias voltage to 150V , the evaporation current is 130A, the air pressure is maintained at 5.5×10 ^-2 Pa, and the coating time is 10 minutes;

e. Annealing:

In a high vacuum state, the coating film deposited on the substrate is cooled naturally;

f. Repeat the above-mentioned coating step d and step e at least once until the thickness of the coating film meets the requirements, thereby completing the vacuum coating process. The hardness of the film prepared by the process of this embodiment is 1900HV on the silicon wafer and 2900HV on the cemented carbide.

Embodiment three:

This embodiment is basically the same as the previous embodiment, and the special features are:

In this embodiment, a vacuum coating method, using a vacuum coating device of this embodiment, includes the following steps:

a. Cleaning the substrate:

Using the pre-cleaned sapphire substrate as a substrate, put it into acetone, ethanol, and deionized water for ultrasonic cleaning for 10 minutes each, and then dry it with nitrogen;

b. Place the substrate:

The cleaned substrate is placed and transferred to the coating vacuum chamber 1, and is set on the sample stage 5, and the sample stage 5 is connected to the negative bias power supply;

c. Loading preparation materials:

Transfer the cleaned sample to the small vacuum chamber 2, put the fullerene powder into the evaporation boat, fix it, and then put it into the small vacuum chamber 2 together;

d. Vacuum coating:

Turn on the pumping system, pump the two vacuum chambers to high vacuum, and heat them to 200°C until the vacuum in the chamber is less than 3.0×10 ^-3 Pa; turn on the evaporation current; close the high valve, and pass argon into the chamber when the vacuum reaches 2Pa Turn off the argon gas, turn on the RF power supply, the power is 50W, open the high valve and the argon gas at the same time after ignition, turn on the bias voltage to 50V, and clean for 10 minutes; after cleaning, adjust the RF power supply to 30W, and the bias voltage to 120V , the evaporation current is 130A, the air pressure is maintained at 5.5×10 ^-2 Pa, and the coating time is 10 minutes;

e. Annealing:

In a high vacuum state, the coating film deposited on the substrate is cooled naturally;

f. Repeat the above-mentioned coating step d and step e at least once until the thickness of the coating film meets the requirements, thereby completing the vacuum coating process. The hardness of the thin film prepared by the process of this example on the sapphire substrate is 3800HV.

It can be seen from the comparison of Comparative Example 1 and Example 1 to Example 3 that the vacuum coating equipment of Comparative Example 1 adopts a common vacuum chamber without building a small vacuum chamber, while the vacuum coating equipment of Example 1 adopts a vacuum coating equipment that builds a small vacuum chamber. , under almost the same vacuum coating process conditions, the hardness of the fullerene film prepared by using the vacuum coating equipment of Example 1 is 2.56 times higher than that of the fullerene film prepared by using the ordinary vacuum coating equipment of Comparative Example 1. The mechanical properties of the films are remarkable. Embodiment 2 Because the auxiliary deposition is carried out under the condition of bias voltage, the hardness of the fullerene film prepared by using the vacuum coating equipment of Example 2 and the bias-assisted coating is higher than that of the fullerene film prepared by using the ordinary vacuum coating equipment of Comparative Example 1. The hardness of the film was increased by 12.17 times, and the mechanical properties of the film were significantly improved. Embodiments 2 and 3 also use cemented carbide and sapphire substrates as substrates, through double vacuum chambers, bias-assisted coating, and selection of different substrates to achieve a significant improvement in the mechanical properties of the thin films.

Embodiment 4:

This embodiment is basically the same as the previous embodiment, and the special features are:

In this embodiment, in this embodiment, a vacuum coating method, using a vacuum coating device in this embodiment, includes the following steps:

a. Cleaning the substrate:

Use the pre-cleaned silicon wafer as a substrate, put it into acetone, ethanol, and deionized water for ultrasonic cleaning for 10 minutes each, and then dry it with nitrogen;

b. Place the substrate:

The cleaned substrate is placed and transferred to the coating vacuum chamber 1, and is set on the sample stage 5, and the sample stage 5 is connected to the negative bias power supply;

c. Loading preparation materials:

Put the aluminum wire into the evaporation boat, fix it, and then put it into the small vacuum chamber 2 together;

d. Vacuum coating:

Turn on the pumping system, pump the two vacuum chambers to high vacuum, and heat them to 200°C until the vacuum in the chamber is less than 3.0×10 ^-3 Pa; turn on the evaporation current; close the high valve, and pass argon into the chamber when the vacuum reaches 2Pa Turn off the argon gas, turn on the RF power supply, the power is 50W, open the high valve and the argon gas at the same time after ignition, turn on the bias voltage to 50V, and clean for 10 minutes; after cleaning, turn off the RF bias power supply and adjust the evaporation current to 130A, The coating time is 10 minutes;

e. Annealing:

In a high vacuum state, the coating film deposited on the substrate is cooled naturally;

f. Repeat the above-mentioned coating step d and step e at least once until the thickness of the coating film meets the requirements, thereby completing the vacuum coating process. The resistivity of the aluminum thin film prepared by the process method in this embodiment is 8.481×10 ^-8 Ωm.

Comparative example two:

In this embodiment, a vacuum coating method includes the following steps:

a. Cleaning the substrate:

Use the pre-cleaned silicon wafer as a substrate, put it into acetone, ethanol, and deionized water for ultrasonic cleaning for 10 minutes each, and then dry it with nitrogen;

b. Place the substrate:

Transfer the cleaned substrate to a common coating vacuum chamber, set it on the sample stage, and connect the sample stage to the negative bias power supply;

c. Loading preparation materials:

Put the aluminum wire into the evaporation boat, fix it, and then put it into the ordinary coating vacuum chamber together;

d. Vacuum coating:

Turn on the pumping system, pump the vacuum chamber to a high vacuum, and heat it to 200 °C until the vacuum in the chamber is less than 3.0×10 ^-3 Pa; turn on the evaporation current, close the high valve, and pass argon into the chamber when the vacuum reaches 2Pa and close the argon gas, turn on the RF power supply, the power is 50W, open the high valve and argon gas at the same time after ignition, turn on the bias voltage to 50V, and clean for 10 minutes; after cleaning, turn off the RF bias power supply, adjust the evaporation current to 130A, and the coating time for 10 minutes;

e. Annealing:

In a high vacuum state, the coating film deposited on the substrate is cooled naturally;

f. Repeat the above-mentioned coating step d and step e at least once until the thickness of the coating film meets the requirements, thereby completing the vacuum coating process. The resistivity of the aluminum thin film prepared by the process method of this comparative example is 9.535×10 ^-8 Ωm.

From the comparison between Comparative Example 2 and Example 4, it can be seen that the vacuum coating equipment of Comparative Example 2 adopts an ordinary vacuum chamber without building a small vacuum chamber, while the vacuum coating equipment of Example 4 adopts a vacuum coating equipment that builds a small vacuum chamber, which is almost the same. Under the same vacuum coating process conditions, the resistivity of the aluminum thin film prepared by using the vacuum coating equipment of Example 4 is 11.05% lower than that of the aluminum thin film prepared by using the ordinary vacuum coating equipment of Comparative Example 2. At the same time, the electrical properties of the film are also improved, thereby optimizing the overall performance of the film.

Embodiment 5:

This embodiment is basically the same as the previous embodiment, and the special features are:

In this embodiment, the coating vacuum chamber 1 and the small vacuum chamber 2 are connected in series in combination. In this embodiment, two vacuum chambers are connected in series, including a first vacuum chamber and a second vacuum chamber, the first vacuum chamber is a small vacuum chamber, and the second vacuum chamber is a relatively large vacuum chamber, which is placed inside the first vacuum chamber Coating material, and a small hole is opened on the wall of the first vacuum chamber. Initially, both vacuum chambers were evacuated to high vacuum. When the coating material begins to evaporate, the first vacuum chamber is changed from a high vacuum to a low vacuum, thereby forming a pressure difference between the two vacuum chambers, providing the coating molecules with directional kinetic energy ejected from the small holes.

Embodiment 6:

This embodiment is basically the same as the previous embodiment, and the special features are:

In the present embodiment, the air pumping system draws air behind the substrate along the directional movement direction of the coating particles to maintain the pressure difference in the gas flow direction. Since the pumping speed of the molecular pump 11 is very fast, the setting of the pumping channel will affect the concentration distribution of the coating molecules in the vacuum chamber, thereby affecting the film deposition. Therefore, the exhaust passage in the vacuum chamber is optimized, specifically, the exhaust system extracts the air behind the substrate along the directional movement direction of the coating particles, and maintains the pressure difference in the gas flow direction.

Embodiment 7:

This embodiment is basically the same as the previous embodiment, and the special features are:

In this embodiment, the sample stage 5 is composed of a large sample stage and a small sample stage movably connected. The large sample stage revolves, and the small sample stage rotates along with the large sample stage. The large sample stage and the small sample stage rotate. The speed of the table can be adjusted. This and the embodiment solve the problems of large-scale production and uneven film thickness, and design a new sample stage. There is a small sample stage in the large sample stage. The large sample stage can revolve, and the small sample stage can rotate along with the revolution. , the speed can be adjusted, and the thickness of the prepared film will be more uniform.

Embodiment 8:

This embodiment is basically the same as the previous embodiment, and the special features are:

In this embodiment, in the vacuum coating method, when vacuum coating is performed in step d, the process parameters are determined according to the difference of working gas and coating molecules. In this embodiment, the pressure difference is used to increase the kinetic energy of the coating molecules or atoms, thereby improving the mechanical properties of the thin film, and the process parameters are further determined by the difference between the working gas and the coating molecules. The present invention utilizes the pressure difference between two connected vacuum chambers to provide additional directional kinetic energy to coating molecules, and can also utilize a combination of radio frequency power and bias power to assist deposition when necessary. It provides a new method to optimize the mechanical properties of vacuum thin films by adding oriented molecular or atomic kinetic energy to increase the hardness of the thin films. This invention is expected to provide a new way to improve the mechanical properties of vacuum thin films.

The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, and various changes can be made according to the purpose of the invention and creation of the present invention. Changes, modifications, substitutions, combinations or simplifications should be equivalent replacement methods, as long as they meet the purpose of the present invention, as long as they do not deviate from the technical principles and inventive concepts of the vacuum coating equipment and vacuum coating method of the present invention, all belong to the present invention. the scope of protection of the invention.

Claims (9)

1. A vacuum coating equipment, comprising a coating vacuum chamber (1), an evaporation source (3), a sample stage (5), a heating source (6), and an air extraction system, wherein the sample stage (5) is arranged in the coating vacuum chamber (1) ), the heating source (6) outputs heat to the coating vacuum chamber (1), and then regulates the temperature of the sample stage (5) and the substrate arranged on the sample stage (5); it is characterized in that: also set a vacuum chamber with the coating film (1) a small vacuum chamber (2) that is communicated, the evaporation source (3) is arranged in the small vacuum chamber (2), the air extraction system includes a mechanical pump (10) and a molecular pump (11), and the mechanical pump (10) ) are respectively connected to the coating vacuum chamber (1) and the small vacuum chamber (2) through the rough pumping valve (12), and the molecular pump (11) is respectively connected to the coating vacuum chamber (1) and the small vacuum chamber (2) through the high valve (9). ) is connected to form a tube valve system; a small hole is opened on the wall of the small vacuum chamber (2), so that the small hole faces the substrate surface on the sample stage (5) set in the coating vacuum chamber (1); The coating material is placed inside the small vacuum chamber as an evaporation source (3). First, the coating vacuum chamber (1) and the small vacuum chamber (2) are exhausted to a high vacuum by an air extraction system; when the coating material begins to evaporate, the small vacuum chamber is used. The ventilation hole (8) of (2) introduces the working gas into the small vacuum chamber (2), and changes the pressure in the small vacuum chamber (2) from high vacuum to low vacuum, thereby forming a pressure between the large and small vacuum chambers The difference provides the directional kinetic energy for the coating molecules to be ejected from the small holes on the wall of the small vacuum chamber (2) and enter the coating vacuum chamber (1). 2. The vacuum coating equipment according to claim 1 is characterized in that: a radio frequency coil (4) is also arranged in the coating vacuum chamber (1), and the radio frequency coil (4) is installed in a small hole on the wall of the small vacuum chamber (2). At the position between the substrate on the sample stage (5) provided with the coating vacuum chamber (1), the radio frequency power supply is energized for the radio frequency coil (4); the sample stage (5) is also connected to a bias power supply; the radio frequency power supply controls the plasma The density of the plasma can be controlled by the bias power supply, and the direction of the plasma can be controlled by the bias power supply; in the cleaning stage, the radio frequency power supply is used to ionize the working gas, so that the working gas molecules become charged particles, and then the bias power supply makes the charged particles move in a directional motion, bombarding the surface of the substrate. The substrate is cleaned; in the evaporation coating stage, the radio frequency power supply ionizes the coating molecules to increase their energy, and the bias power supply makes the coating molecules move in a directional motion to increase their kinetic energy; thus, the combination of the radio frequency power supply and the bias power supply is used to assist the deposition. 3. The described vacuum coating equipment according to claim 1 is characterized in that: a pre-connecting pipeline is set between the mechanical pump (10) and the molecular pump (11), and a pre-valve (13) is set on the pre-connecting pipeline ), one end of the pre-connecting pipeline is connected with the pipeline between the mechanical pump (10) and the roughing valve (12), and the other end of the pre-connecting pipeline is connected with the molecular pump (11) and the high valve (9) The pipeline connection between them forms a multi-channel pumping system. 4. The described vacuum coating equipment according to claim 1 is characterized in that: a baffle plate (7) is also provided in the coating vacuum chamber (1), and the baffle plate (7) surrounds the small hole and the sample on the wall of the small vacuum chamber (2). The working gas jet path area between the stations (5) is set. 5 . The vacuum coating equipment according to claim 1 , wherein the coating vacuum chamber ( 1 ) and the small vacuum chamber ( 2 ) are connected in series or in a nested combination. 6 . 6 . The vacuum coating equipment according to claim 1 , characterized in that: the air pumping system draws air behind the substrate along the directional movement direction of the coating particles to maintain the pressure difference in the gas flow direction. 7 . 7. The vacuum coating equipment according to claim 1, characterized in that: the sample stage (5) is formed by movably connecting a large sample stage and a small sample stage, the large sample stage revolves, and the small sample stage follows the large sample stage. The stage rotates at the same time as the revolution, and the rotation speed of the large sample stage and the small sample stage can be adjusted. 8. a vacuum coating method, adopts the described vacuum coating equipment of claim 1, is characterized in that, comprises the steps: a. Cleaning the substrate: Put the pre-cleaned substrate into acetone, ethanol, and deionized water for ultrasonic cleaning for at least 10 minutes each, and then blow dry with nitrogen; b. Place the substrate: Place the cleaned substrate on the sample stage, and connect the sample stage to the negative bias power supply; c. Loading preparation materials: Put the coating material into the evaporation boat, and then put it into a small vacuum chamber together; d. Vacuum coating: Turn on the pumping system, pump the two vacuum chambers to high vacuum, turn on the evaporation current, and adjust the RF power, bias voltage, gas flow, temperature process parameters, and carry out vacuum coating; In the cleaning stage, the working gas is ionized by the radio frequency power supply, so that the working gas molecules become charged particles, and then the bias power supply makes the charged particles move in a direction, bombarding the surface of the substrate, and cleaning the substrate; In the evaporation coating stage, when the coating material starts to evaporate, the working gas is introduced into the small vacuum chamber to change the pressure in the small vacuum chamber from high vacuum to low vacuum, thereby forming a pressure difference between the large and small vacuum chambers, giving the coating film Molecules provide directional kinetic energy from the small vacuum chamber into the coating vacuum chamber, and use a combination of RF power and bias power to assist deposition to deposit the coating on the substrate; e. Annealing: In a high vacuum state, the coating film deposited on the substrate is cooled naturally; f. Repeat the above-mentioned coating step d and step e at least once until the thickness of the coating film meets the requirements, thereby completing the vacuum coating process. 9 . The vacuum coating method according to claim 8 , wherein in the step d, the process parameters are determined according to the difference of working gas and coating molecules. 10 .

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