CN110468381B

CN110468381B - High-frequency oscillation pulse magnetron sputtering method

Info

Publication number: CN110468381B
Application number: CN201910811921.9A
Authority: CN
Inventors: 杨超; 蒋百铃; 曹政; 王戎; 郝娟
Original assignee: Xian University of Technology
Current assignee: Xian University of Technology
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2021-08-10
Anticipated expiration: 2039-08-30
Also published as: CN110468381A

Abstract

A high-frequency oscillating pulse magnetron sputtering method, comprising the following steps: 1) soaking a sample to be coated in acetone and an alcohol solution for ultrasonic cleaning, blowing dry, placing it on a sample workpiece rack in a vacuum chamber, and evacuating, Pour argon gas; 2) turn on the high-frequency oscillation pulsed target power supply and pulse negative bias substrate power supply to clean the sample surface by ion bombardment, the ion cleaning time is 20-40min, 3) Pour reactive gas, the vacuum degree in the vacuum chamber When it reaches 0.4~1.2Pa, turn on the adjustable inductance to pulse the target voltage, and the film deposition time is 20~180min; 4) After the film deposition is completed, turn off the high-frequency oscillating pulse power supply, pulse negative bias substrate power supply, reactive gas valve and workpiece holder Rotating mechanism, the coating sample is taken out after the temperature in the vacuum chamber drops to room temperature; it has the characteristics of high ionization rate, dense film structure and good performance.

Description

High-frequency oscillation pulse magnetron sputtering method

Technical Field

The invention belongs to the technical field of material manufacturing, and particularly relates to a high-frequency oscillation pulse magnetron sputtering method.

Background

The traditional direct current magnetron sputtering technology is one of the mainstream Physical Vapor Deposition (PVD) technologies at present, and is widely applied to the industrial field due to the advantages of low deposition temperature, compact structure of a prepared film layer, smooth surface and the like. However, due to the impact miss and glow discharge, most of the deposited particles are neutral atoms with lower kinetic energy and are not restricted by an electromagnetic field, which not only causes poor plating-around property of the deposited particles during film formation and is difficult to obtain a film with uniform thickness on the surface of a large-size or complex-shaped workpiece, but also causes defects such as lattice mismatch and the like of the deposited particles with lower kinetic energy during film formation, which causes the internal stress of the film to be gradually accumulated along with the increase of the thickness, so that the sample has unfavorable phenomena such as film cracking or peeling when being subjected to load.

Aiming at the defects caused by low ionization rate of deposited particles in the traditional direct current magnetron sputtering technology, researchers develop a high-power pulse magnetron sputtering technology, and apply target voltage of over kilovolt to induce high-power plasma discharge in a pulse period with the pulse width of only dozens or hundreds of microseconds so as to greatly improve the ionization rate of Ar atoms between a cathode and an anode, and through Ar, the ionization rate of Ar atoms between the cathode and the anode is improved⁺To the yinThe high-density bombardment of the target surface realizes the improvement of the off-target quantity and the ionization rate of the deposited particles. However, to avoid melting the target surface due to high power discharge, it is usually necessary to use a very low duty cycle. Finally, although the technology achieves the purpose of improving the plating winding performance and the film-substrate binding force of deposited particles in practical application, the technology is not sufficient for accelerating the aging speed of a system insulating part by kilovolt high voltage, greatly reduces the deposition rate of a film by extremely low duty ratio, and limits the successful popularization of the high-power pulse magnetron sputtering technology in the industrial field.

Although the high-power pulse magnetron sputtering technology has the technical defects, the design concept of improving the ionization rate of the deposited particles by utilizing high-power discharge has obvious effect on improving the plating property of the deposited particles, the film substrate binding force and the like.

Disclosure of Invention

Aiming at the defects of the traditional high-power pulse magnetron sputtering technology, the invention aims to provide a high-frequency oscillation pulse magnetron sputtering method, namely a double-frequency pulse magnetron sputtering technology, can improve the technical problems of extremely low deposition rate of the high-power pulse magnetron sputtering technology and high voltage between electrodes during high-power discharge, and has the advantages of high ionization rate of deposited particles, good plating property and strong film-substrate binding force of a prepared film layer.

In order to achieve the purpose, the invention adopts the technical scheme that:

a high-frequency oscillation pulse magnetron sputtering method, namely a dual-frequency pulse magnetron sputtering technology, comprises the following steps:

step 1, respectively soaking a sample to be coated in acetone and alcohol solution, ultrasonically cleaning for 10-20 min, taking out and using pure N₂Air drying, placing on a sample workpiece rack in a vacuum chamber with a target base distance of 130-200 mm, and pumping the air pressure in the vacuum chamber to 1 × 10 by a vacuum pump^-3Introducing argon below Pa, and keeping the vacuum degree between 0.1Pa and 1.0 Pa;

and 2, starting a high-frequency oscillation pulse type target power supply and a pulse negative bias substrate power supply to carry out plasma bombardment cleaning on the surface of the sample, wherein the control parameters are as follows: the target voltage is-300 to-400V, the target voltage oscillation frequency is 10 to 100kHz, the voltage oscillation amplitude is 50V, the pulse duty ratio is 2.5 to 100 percent, and the pulse discharge on-off frequency is 10 to 100 Hz; negative bias of a matrix pulse power supply is-400 to-600V, duty ratio is 60 to 80 percent, frequency is 10 to 150Hz, ion cleaning time is 20 to 40min, and rotating speed of a sample workpiece rack is 1 to 5 r/min;

step 3, introducing reactive gas, enabling the vacuum degree in the vacuum cavity to reach 0.4-1.2 Pa, switching on an adjustable inductor to adjust the high-frequency oscillation pulse target voltage to-400-800V, adjusting the target voltage oscillation frequency to 10-100 kHz, adjusting the pulse discharge on-off frequency to 10-100 Hz, adjusting the pulse duty ratio to 2.5-80% and adjusting the pulse peak value target current to 10-150A; the negative bias voltage of the matrix pulse power supply is adjusted to-50 to-120V, the duty ratio is 60 to 80 percent, the frequency is 40 to 100Hz, and the film deposition time is 20 to 180 min;

and 4, after the film deposition is finished, closing the high-frequency oscillation pulse power supply, the pulse negative bias matrix power supply, the reaction gas valve and the workpiece frame rotating mechanism, and taking out the film coating sample after the temperature in the vacuum cavity is reduced to room temperature.

The high-frequency oscillation pulse power supply is characterized in that the output characteristic of the power supply is achieved by utilizing a main circuit topological structure of three-phase full-wave rectification, an ultra-fast IGBT module and high-frequency transformer boosting: the maximum output power of the pulse stage is 8kW, the peak value of the output voltage is-1200V, the load is 0-1000V, the average current of the pulse output is 0.1-8.0A, the maximum pulse peak current can reach 200A, the target voltage oscillation frequency is 10-100 kHz, the voltage oscillation amplitude is 50V, the pulse discharge cut-off frequency is 10-100 Hz, the pulse duty ratio is 2.5-100%, and the power supply voltage and current precision is less than or equal to 1%, the cathode end of the constructed high-frequency oscillation pulse type power supply is loaded on a circular cathode target material with the diameter phi of 170mm, the anode end is loaded on a cylindrical vacuum cavity with the size phi of 450mm multiplied by H400mm, four cathode target materials are mounted on a circular 304 stainless steel frame body with the size of phi 225mm on the side surface of the vacuum cavity, the frame bodies are 5mm away from the outer edge of the cathode target and are uniformly distributed at an angle of 90 degrees with each other, and the surface roughness is less than 0.8 mu m.

And 3, preferentially depositing a pure metal bottom layer with the thickness of 100-300 nm as a transition layer before depositing the compound film according to the requirement so as to improve the bonding force between the film and the substrate. For example: when the hard CrN film is deposited on the iron-based sample, a layer of pure Cr metal priming layer can be preferentially deposited after the surface of the sample is subjected to plasma cleaning, and then the CrN film is deposited, so that the film-based bonding force between the CrN film and the sample can be obviously improved.

And 3, introducing the reactive gas mainly comprising Ar in the step 3.

The reactive gas introduced in the step 3 also comprises N₂、O₂、CH₄Or C₂H₂。

The cooling and taking out in the step 4 can be realized by any one of the following modes: cooling the sample subjected to film coating in a vacuum chamber to below 50 ℃, taking out, and then cooling to room temperature in an atmospheric environment; or the sample after completing the film coating is directly cooled to room temperature in the vacuum cavity and then taken out.

The invention has the beneficial effects that:

in the magnetron sputtering environment, in order to improve the ionization rate of Ar gas and deposited particles, the high-power pulse magnetron sputtering technology can be used for realizing high-voltage ionization and a high-frequency oscillation way under a lower voltage (hundreds of volts). The electron work function of the bonding metal target surface crystal boundary and other defect micro-regions is about 30 percent less than that of the inside of the crystal, namely the bonding metal target is subjected to Ar with the same density⁺The electron escape flux of the defect micro-region is about 30% higher than the physical principle of the interior of the crystal during bombardment. If the high-frequency oscillation technology of voltage is adopted, the Ar gas ionization rate can be improved at lower voltage, and Ar can be enhanced⁺The bombardment density of the target surface increases the total amount of electrons escaping from the target surface (namely, the target current). At this time, the electron emission flux of the defect micro-region is about 30% higher than that of the crystal, which causes rapid temperature rise (influenced by joule heat and ion bombardment energy) of the defect micro-region. The increase of the temperature further increases the electron escape flux of the defective micro-area, thereby inducing a self-enhancement mechanism of electron escape of the defective micro-area. The duration of the mechanism is controlled in millisecond order, the defect micro-area can generate the heat accumulation effect of high-flux electron escape, the temperature and energy requirements for triggering the thermal emission of target surface deposition particles are met, and the target surface deposition particle thermal emission control method is characterized in thatThe plating material particles in the micro-area of the induced target surface defect are off-targeted by a non-melting heat emission mechanism. Namely, through reasonably regulating and controlling the high-frequency oscillation voltage, the current peak value and the oscillation period among the electrodes, the plating material particles in the defect micro-area are off-targeted by a non-melting thermal emission mechanism. The characteristics of high yield and high kinetic energy of the deposited particles are given by a non-melting thermal emission off-target mechanism, so that the ionization rate and the plating winding performance of the plating particles are improved, and the deposition rate of a plating layer is increased.

Briefly, the object of the present invention can be achieved by the following key steps: firstly, a main circuit topological structure of three-phase full-wave rectification, an ultra-fast IGBT module and a high-frequency transformer is utilized to enable the output characteristic of a power supply to reach: the maximum output power of the pulse stage is 8kW, the output voltage no-load is greater than-1200V (peak value), the on-load is 0-1000V, the pulse output average current is 0.1-8.0A, the maximum pulse peak current can reach 200A, the target voltage oscillation frequency is 10-100 kHz, the voltage oscillation amplitude is 50V, the pulse discharge on-off frequency is 10-100 Hz, the pulse duty ratio is 2.5-100%, and the power supply voltage and current precision is less than or equal to 1%; loading the cathode end of the constructed novel high-frequency oscillation pulse electric field on a round cathode target material with the diameter phi of 170mm, loading the anode end on a cylindrical vacuum cavity with the size phi of 450mm multiplied by H400mm, installing four cathode target materials on a round 304 stainless steel frame with the size phi of 225mm on the side surface of the vacuum cavity, wherein the frame bodies are 5mm away from the outer edge of the cathode target and are uniformly distributed at an angle of 90 degrees with each other, and the surface roughness is less than 0.8 mu m; the vacuum cavity is also provided with a heating device, and the temperature in the vacuum cavity can be adjusted through a temperature control system so as to regulate and control the growth mode and the tissue state of the film.

The invention mainly constructs a high-frequency oscillation pulse electric field environment between a cathode target material and an anode vacuum cavity, and achieves the purposes of high ionization rate of deposited particles, compact prepared film tissue and good performance by allocating electric field parameters such as oscillation voltage with microsecond-order frequency, pulse discharge time with millisecond order, voltage/current and the like; the method can integrate the advantages of compact film structure, smooth surface and good film-substrate combination in the traditional pulse magnetron sputtering preparation, and can improve the process defects of extremely low deposition rate, extremely high interelectrode voltage and the like in the traditional pulse magnetron sputtering (avoid the defects of extremely high voltage and the like between the cathode and the anode, and avoid the defects of extremely high voltage and the like between the cathode and the anode); the preparation method is simple, convenient and stable, has less working procedures and high yield, and can meet the requirements of industrial production.

The high-frequency oscillation pulse magnetron sputtering method is applied to various samples to be coated in the coating field, the selection of the materials is very wide, the materials comprise iron base, high-speed steel, lightweight alloy, metal, non-metal materials and the like, coating components are selected according to the service conditions of the use environment of the samples, and the corresponding regulation and control are carried out on the film tissue structure, wherein the coating components comprise a coating metal base functional film, a nitride hard film, a carbon-doped chemical low-friction coefficient film, a carbon-based anti-wear film, a corrosion-resistant film, an optical film and the like.

Drawings

FIG. 1a is a schematic diagram of the waveforms of voltage and current of a high frequency oscillating pulse power supply.

Fig. 1b is a waveform diagram when the voltage high-frequency oscillation region is enlarged.

Detailed Description

The invention is explained in further detail below with reference to the figures and the specific embodiments.

step 1, respectively soaking a sample to be coated in acetone and alcohol solution, ultrasonically cleaning for 10-20 min, taking out and using pure N₂Air drying, placing on a sample workpiece rack in a vacuum chamber with a target base distance of 130-200 mm, and pumping the air pressure in the vacuum chamber to 9 x 10 by a vacuum pump^-4Pa or 1X 10^-3Introducing argon below Pa, and keeping the vacuum degree between 0.1Pa and 1.0 Pa;

The reactive gases introduced in the step 3 are mainly Ar and N₂、O₂、CH₄、C₂H₂The selection of the gas is determined according to the preparation process of the film layer; for example: the preparation of the pure metal film only uses Ar gas as reaction gas; preparation of nitride or oxide thin films Using Ar and N₂/O₂The mixed gas of Ar gas as main reaction gas and N₂Or O₂The gas is doping gas with flow ratio N₂The flow rate of/Ar is 1/2-1/10; preparation of pure carbon or carbide films using Ar and CH₄/C₂H₂The mixed gas of the gases is used as a reaction gas, wherein Ar gas is the main reaction gas, CH₄Or C₂H₂Gas is doping gas with flow ratio CH₄The flow rate of Ar gas is 1-1/10. The introduced reaction gas has the main function of preparing a compound film and can be used as an additional reaction source to increase the deposition rate of the film.

Example 1

Preparing a hard CrN film on the surface of an M2 high-speed steel polished sample by a high-frequency oscillation pulse magnetron sputtering method, and implementing the following steps:

step one, cleaning M2 high-speed steel polishing samples with the size of phi 50mm by acetone and alcohol solution ultrasonic wave for 10min respectively, and then using pure N₂Air drying, placing on a rotary workpiece holder in a vacuum chamber, setting the rotation speed at 1r/min, setting the distance between the target and the sample at 130mm, and pumping the vacuum degree in the vacuum chamber to be less than 9 × 10^-4When Pa, introducing Ar gas, wherein the flow rate of the Ar gas is 15mL/min, and the vacuum degree is 0.1 Pa;

step two, starting a high-frequency oscillation pulse type target power supply and a matrix pulse power supply to carry out plasma bombardment cleaning on the sample, wherein the control parameters are as follows: the Cr target voltage is-300V, the target voltage oscillation frequency is 10kHz, the voltage oscillation amplitude is 50V, the pulse duty ratio is 2.5 percent, and the pulse discharge cut-off frequency is 10 Hz; negative bias voltage of the matrix pulse power supply is-400V, frequency is 10Hz, duty ratio is 60%, and ion cleaning time is 20 min;

step three, preparing a pure Cr transition layer with the thickness of 100nm on the surface of the matrix, and introducing N₂And maintaining the vacuum degree at 0.4Pa, and starting to deposit a CrN film, wherein the control parameters are as follows: the high-frequency oscillation pulse Cr target voltage is-400V, the target voltage oscillation frequency is 10kHz, the pulse discharge cut-off frequency is adjusted to 10Hz, the pulse duty ratio is 2.5 percent, and the pulse peak value target current is 10A; adjusting the negative bias voltage of the matrix pulse power supply to-50V, the frequency of 40Hz, the duty ratio of 60 percent and the deposition duration of 20 min;

and step four, after the film deposition is finished, closing the high-frequency oscillation pulse power supply, the pulse negative bias matrix power supply and the reaction gas valve, and taking out the sample after the sample is cooled to room temperature.

Determining the tissue morphology and physical properties of the deposited CrN film, wherein the surface morphology and the cross-sectional morphology of the film are observed by a Scanning Electron Microscope (SEM), and the thickness of the film is directly measured by a cross-sectional SEM picture; roughness was measured at 5X 5 μm using an Atomic Force Microscope (AFM)²Measuring within a range; the crystal structure of the film is detected by an X-ray diffractometer (XRD), the size of crystal grains of the film growing along each crystal face is calculated by using the Scherrer formula and the half-height width value by utilizing the diffraction peak intensity in the XRD pattern of the pure Ti film, and the average value is taken as the average crystal grain size of the film. The hardness was measured using a nanoindenter equipped with a diamond indenter that was perpendicularly pressed into the sample surface to a depth of 1/10 mm of the film thickness, and calculated using the Oliver-Pharr formula, with a Poisson's ratio of 0.3.

The test results were as follows:

the CrN film has a compact columnar crystal structure, the thickness of the CrN film is 0.5 mu m, the deposition rate is 25nm/min, the surface roughness Ra is 8nm, the hardness is 30.7GPa, and the elastic modulus is 325.4 GPa.

Example 2

A CrCN thin film with a low friction coefficient is deposited on the surface of a GCr15 bearing steel sample with a mirror polished surface by a high-frequency oscillation pulse magnetron sputtering method, and the method is implemented according to the following steps:

firstly, grinding the surface of a GCr15 bearing steel sample by No. 400, 600, 800, 1000, 1200 and 1500 water sandpaper respectively, then carrying out mirror polishing, then soaking the sample into acetone and alcohol solution respectively, carrying out ultrasonic cleaning for 20min, and after cleaning, using pure N₂Air-drying, placing on a rotatable work rest in a vacuum chamber, setting the rotation speed at 5r/min, setting the distance between the target and the sample at 200mm, and pumping the vacuum degree in the vacuum chamber to less than 1 × 10^-3Introducing Ar gas when Pa is needed, wherein the flow rate of the Ar gas is 80mL/min, and the vacuum degree is maintained at 1.0 Pa;

and step two, starting a high-frequency oscillation pulse type Cr target power supply and a matrix pulse power supply to carry out plasma bombardment cleaning on the surface of the sample, wherein the control parameters are as follows: the Cr target voltage is-400V, the target voltage oscillation frequency is 100kHz, the voltage oscillation amplitude is 50V, the pulse duty ratio is 100%, and the pulse discharge cut-off frequency is 100 Hz; negative bias of the matrix pulse power supply is set to-600V, the frequency is 150Hz, the duty ratio is 80%, and the cleaning time is 40 min;

step three, preparing a pure Cr transition layer with the thickness of 300nm on the surface of the substrate, and introducing reaction gas N₂And CH₄Gas, enabling the vacuum degree in the vacuum cavity to reach 1.2Pa, starting a high-frequency oscillation pulse Cr target power supply and two high-frequency oscillation pulse C target power supplies to deposit a CrCN working layer; the control parameters are as follows: adjusting the high-frequency oscillation pulse Cr target voltage to-800V, adjusting the oscillation frequency of the target voltage to 100kHz, adjusting the pulse discharge cut-off frequency to 100Hz, adjusting the pulse vacuum ratio to 80% and adjusting the pulse peak value target current to 150A; adjusting the voltage of a high-frequency oscillation pulse C target to-800V, the oscillation frequency of the target voltage to 100kHz, the on-off frequency of pulse discharge to 100Hz, the pulse vacuum ratio to 80 percent and the pulse peak target current to 50A (note that two targets Cr target and C target are respectively provided, and parameters need to be introduced respectively); adjusting the negative bias voltage of the matrix pulse power supply to-120V, the frequency of 100Hz, the duty ratio of 80 percent, and the deposition duration of 180 min;

and step four, cooling the plated film sample to below 50 ℃ in the vacuum chamber, taking out the sample, and then cooling the sample to room temperature in the atmospheric environment.

Determining the tissue structure and physical properties of the deposited CrCN thin film, wherein the surface appearance and the cross-section appearance of the thin film are observed by a Scanning Electron Microscope (SEM), and the thickness of the thin film is directly measured by a cross-section SEM picture; roughness was measured at 5X 5 μm using an Atomic Force Microscope (AFM)²Measuring within a range; measuring the hardness by using a nanometer indentation hardness meter provided with a diamond pressure head, wherein the vertical indentation depth of the pressure head is 1/10 of the thickness of the film, the calculation is carried out by using an Oliver-Pharr formula, and the Poisson ratio is 0.25; a ball-disk type micro-friction experiment instrument is adopted to measure the friction coefficient and the pressure of 5N in an atmospheric environment (the temperature is 25 +/-1 ℃, and the relative humidity of air is 20 +/-1 RH%), and laser confocal is utilized to measure the abrasion volume of a film and calculate the abrasion rate (the WC-Co hard alloy grinding ball slides on the surface of a sample at the linear speed of 25mm/s for 150 m).

The test results were as follows:

the CrCN film shows a compact tissue structure, the thickness is 12.3 mu m, the deposition rate is 68nm/min, the surface roughness Ra is 11nm, the hardness is 23.5GPa, the friction coefficient is 0.05, and the wear rate is 2.5 multiplied by 10^-17m³/N·m。

Example 3

Depositing a pure Cr conductive corrosion-resistant film on the surface of a monocrystalline silicon piece or 304 stainless steel sample by a high-frequency oscillation pulse magnetron sputtering method, and implementing the following steps:

step one, after a monocrystalline silicon wafer with the size of 20mm multiplied by 20mm or a polished M2 high-speed steel sample with the diameter of 50mm is subjected to ultrasonic cleaning for 15min respectively by acetone and alcohol solution, pure N is used₂Air drying, placing into a vacuum chamber at a position opposite to the workpiece holder of the target surface, rotating at 3r/min, setting the distance between the target and the sample at 170mm, and vacuumizing to 9 × 10^-4Introducing Ar gas when Pa is needed, wherein the flow rate of the Ar gas is 40mL/min, and the vacuum degree is maintained at 0.5 Pa;

turning on a high-frequency oscillation pulse type Cr target power supply and a pulse negative bias substrate power supply to carry out plasma bombardment cleaning on the surface of the sample, wherein the control parameters are as follows: the target voltage is-350V, the target voltage oscillation frequency is 50kHz, the voltage oscillation amplitude is 50V, the pulse duty ratio is 50%, and the pulse discharge cut-off frequency is 50 kHz; the negative bias voltage of the matrix pulse power supply is set to-500V, the frequency is 80Hz, and the duty ratio is 70%. The cleaning time is 30 min;

step three, the flow of the introduced Ar gas is unchanged, a pure Cr film layer is deposited, and the control parameters are as follows: the high-frequency oscillation pulse Cr target voltage is-600V, the target voltage oscillation frequency is 50kHz, the pulse discharge cut-off frequency is 50Hz, the pulse duty ratio is 40%, and the pulse peak value target current is 70A; the negative bias of the matrix pulse power supply is gradually adjusted from-500V to-85V, the frequency is 70Hz, the duty ratio is 70%, and the film deposition time is 80 min;

and step four, after the film coating is finished, cooling the sample to room temperature in the vacuum cavity and taking out the sample.

The morphology and physical properties of the prepared pure Cr film are determined, wherein the surface morphology and the cross-sectional morphology of the film are observed by a Scanning Electron Microscope (SEM), and the thickness of the film is directly measured by a cross-sectional SEM picture; roughness was measured at 5X 5 μm using an Atomic Force Microscope (AFM)²Measuring within a range; the crystal structure of the film was examined by X-ray diffractometry (XRD). The intrinsic hardness of the sample was calculated using a widmannstatten indenter equipped with a diamond indenter loaded 20 g. And (3) detecting the corrosion resistance of the sample by adopting an electrochemical workstation and a smoke test box, wherein the corrosive agent is 3.5% of NaCl aqueous solution.

The test results were as follows:

the film thickness is 11.03 μm, the surface roughness Ra is 11nm, the average grain size is less than 10nm, the grains have no obvious preferred orientation, the intrinsic hardness is 1226HV, the corrosion potential is-0.4V, and the corrosion current is 2.7 multiplied by 10^-7A, the salt spray test showed corrosion after 24h and was completely corroded after 180 h.

Referring to fig. 1 a-1 b, the target voltage exhibits a high-low voltage oscillation shape with a microsecond period, while the target current can be stably maintained at a set value within a discharge time on the order of milliseconds.

The foregoing is a preferred embodiment of the present invention, and it will be apparent to those skilled in the art that variations, modifications, substitutions and alterations can be made in the embodiment without departing from the principles and spirit of the invention.

Claims

1. a high frequency oscillation pulse magnetron sputtering method, i.e. dual frequency pulse magnetron sputtering technology, is characterized in that, comprises the following steps:

Step 1, soak the samples waiting to be coated in acetone and alcohol solutions for ultrasonic cleaning for 10-20 minutes, take them out and dry them with pure N ₂ gas, and place them on the sample workpiece rack in the vacuum chamber. Pump to below 1×10 ^- ³ Pa, pass in argon and keep the vacuum between 0.1~1.0Pa;

Step 2, turn on the high-frequency oscillation pulsed target power supply and the pulsed negative bias voltage substrate power supply to carry out ion bombardment cleaning on the surface of the sample. The control parameters are: the target voltage is -300~-400V, the target voltage oscillation frequency is 10~100kHz, and the voltage oscillation amplitude 50V, pulse duty ratio 2.5～100%, pulse discharge breaking frequency 10～100Hz; negative bias voltage of matrix pulse power supply is -400～-600V, duty ratio 60～80%, frequency 10～150Hz, ion cleaning time 20～40min, sample workpiece rack speed 1～5r/min;

Step 3, feed reactive gas, the vacuum degree in the vacuum chamber reaches 0.4-1.2Pa, turn on the adjustable inductor to adjust the pulse target voltage to -400--800V, the target voltage oscillation frequency is 10-100kHz, and the pulse discharge breaking frequency Adjust to 10～100Hz, pulse duty ratio 2.5～80%, pulse peak target current is 10～150A; negative bias voltage of matrix pulse power supply is adjusted to -50～-120V, duty ratio 60～80%, frequency 40～ 100Hz, film deposition time 20-180min;

Step 4, after the film deposition is completed, turn off the high-frequency oscillating pulse power supply, the pulse negative bias substrate power supply, the reaction gas valve and the workpiece holder rotating mechanism, and take out the coating sample after the temperature in the vacuum chamber drops to room temperature; the cooling and Take out any of the following methods: the coated samples are taken out after being cooled to below 50°C in the vacuum chamber, and then cooled to room temperature in the atmospheric environment; or the coated samples are taken out after being directly cooled to room temperature in the vacuum chamber;

The high-frequency oscillating pulse power supply, wherein the main circuit topology structure using three-phase full-wave rectification, ultra-fast IGBT module and high-frequency transformer boosting enables the output characteristics of the power supply to reach: the maximum output power in the pulse stage is 8kW, and the output voltage is 8kW. Peak -1200V, load 0~-1000V, average pulse output current 0.1~8.0A, maximum pulse peak current up to 200A, power supply voltage and current accuracy ≤1%, load the cathode end of the constructed high-frequency oscillation pulsed power supply On a circular cathode target with a diameter of Φ170mm, the anode end is loaded on a cylindrical vacuum chamber with a size of Φ450mm×H400mm, and four cathode targets are installed on the side surface of the vacuum chamber with a size of Φ225mm. Round 304 stainless steel The frame body is 5 mm away from the outer edge of the cathode target, and is evenly distributed at 90° to each other, and the surface roughness is less than 0.8 μm.

2. A high-frequency oscillation pulse magnetron sputtering method as claimed in claim 1, characterized in that, in the vacuum chamber described in step 3, the temperature in the vacuum chamber is adjusted by a temperature control system as required to control the temperature in the vacuum chamber. The deposition temperature of the film on the surface of the substrate is convenient to control the growth mode, structure and residual stress of the film.

3. A high-frequency oscillation pulse magnetron sputtering method according to claim 1, characterized in that, in the step 3, a layer of pure metal with a thickness of 100-300 nm can be preferentially deposited before the compound film is deposited as required The bottom layer is used as a transition layer to improve the bonding force between the film and the substrate.

4 . The high-frequency oscillation pulse magnetron sputtering method according to claim 1 , wherein the reactive gas introduced in step 3 is mainly Ar. 5 .

5 . The high-frequency oscillation pulsed magnetron sputtering method according to claim 1 , wherein the reactive gas introduced in step 3 further comprises N ₂ , O ₂ , CH ₄ or C ₂ H ₂ . 6 .