A method and system for target poisoning resistance based on multi-stage pulsed reactive sputtering

Abstract

The application provides a multi-stage pulse reaction sputtering based anti-target poisoning method and system, and belongs to the technical field of magnetron sputtering. The application uses air as a reaction gas and adopts a pulse direct current power source to perform reaction sputtering treatment on a metal target; the reaction sputtering treatment comprises sequentially performing a first stage, a second stage and a sputtering voltage feedback control stage. The application adjusts sputtering power and duty cycle in three stages, wherein the first stage can stabilize ignition and preliminarily clean the surface of the target, the second stage can improve the ionization rate of nitrogen in air (> 50%) and inhibit the ionization rate of oxygen (< 10%), and the sputtering voltage feedback control stage adjusts the sputtering power and the duty cycle according to the sputtering voltage drop amplitude, can efficiently sputter and peel off the insulating compound layer on the surface of the target, and effectively inhibits the poisoning state of the target. Therefore, the method of the application can effectively inhibit target poisoning, prolong the service life of the target, and does not need to use complex equipment, and has low cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of magnetron sputtering technology, and in particular to a multi-stage pulse reactive sputtering based anti-target poisoning method and system. BACKGROUND

[0002] In a conventional reactive sputtering process, the reaction of a metal target (such as an aluminum target, a titanium target) with an active gas (such as oxygen, nitrogen) tends to form an insulating compound layer on the surface of the target, i.e., target poisoning occurs, resulting in a decrease in sputtering rate and poor process stability. To solve the problem of target poisoning, current methods generally rely on medium frequency or radio frequency power sources, and closed-loop gas flow control or plasma composition detection methods can also be used, but these methods generally have the problems of complex equipment and high cost. For example, pure nitrogen or pure oxygen is used as the reaction gas, which requires a mixing and flow regulation system, and the target poisoning phenomenon is still difficult to suppress in direct current sputtering mode. SUMMARY

[0003] The present application provides a multi-stage pulse reactive sputtering based anti-target poisoning method and system, which can effectively suppress target poisoning, prolong the service life of the target, and does not require complex equipment, thus reducing costs.

[0004] To achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0005] The present application provides a multi-stage pulse reactive sputtering based anti-target poisoning method, comprising the following steps:

[0006] Air is used as the reaction gas, and a pulsed direct current power source is used to perform reactive sputtering treatment on a metal target; the metal target is a titanium target, an aluminum target, a copper target, a chromium target, a gold target, or a platinum target; the reactive sputtering treatment comprises sequentially performing a first stage, a second stage, and a sputtering voltage feedback control stage;

[0007] The conditions of the first stage include a sputtering power of 15-20% of the highest power and a duty cycle of 50-70%; the highest power is the highest power of the pulsed direct current power source;

[0008] The conditions of the second stage include a sputtering power of 40-45% of the highest power and a duty cycle of 35-45%;

[0009] The sputtering voltage feedback control stage comprises: monitoring the sputtering voltage in real time, when the sputtering voltage decreases by less than 15% of the initial sputtering voltage, keeping the sputtering power and duty cycle unchanged, when the sputtering voltage decreases by more than 15% of the initial sputtering voltage, adjusting the sputtering power to 80-100% of the highest power and the duty cycle to 10-15%, and continuing to monitor the sputtering voltage in real time, when the sputtering voltage recovers to more than 85% of the initial sputtering voltage, performing the conditions of the second stage; the initial sputtering voltage is the sputtering voltage when the first stage is started.

[0010] Preferably, the time when the sputtering voltage recovers to more than 85% of the initial sputtering voltage is less than or equal to 5 minutes.

[0011] Preferably, the maintenance time of the first stage is 1.5-2.5 minutes; the maintenance time of the second stage is 2.5-3.5 minutes.

[0012] Preferably, the highest power is 500 W.

[0013] Preferably, the initial sputtering voltage is 400-600 V.

[0014] Preferably, the pressure of air in the process of reactive sputtering treatment is 0.4-0.6 Pa.

[0015] Preferably, when the sputtering voltage cannot recover to more than 85% of the initial sputtering voltage within 5 minutes, the method further comprises the following steps: stopping the reactive sputtering treatment and starting the target surface cleaning.

[0016] Preferably, the target surface cleaning method comprises: bombarding the metal target with argon ions.

[0017] The application provides a multi-stage pulse reactive sputtering-based anti-target poisoning system, which comprises a reactive sputtering cavity, a gas supply module, a pulse direct current power supply, a monitoring module and a stage control module, the gas supply module is in communication with the reactive sputtering cavity, the pulse direct current power supply is connected with the reactive sputtering cavity, the monitoring module monitors the sputtering voltage of the reactive sputtering cavity, the stage control module is signal-connected with the gas supply module, the pulse direct current power supply and the monitoring module, and the stage control module controls and adjusts the working states of the gas supply module, the pulse direct current power supply and the monitoring module.

[0018] Beneficial effects: the anti-target poisoning method based on multi-stage pulse reactive sputtering provided by the application uses air (natural mixture of oxygen and nitrogen) as a single reaction gas instead of pure reaction gas (such as oxygen or nitrogen), which reduces the gas cost by more than 50%, and does not require gas mixing or flow control devices, which can significantly simplify the equipment structure; at the same time, the air can be directly introduced into the reactive sputtering system through a single path, which is suitable for the continuous production of oxide or nitride films of metal targets (such as aluminum targets and titanium targets), and the natural mixing ratio of nitrogen and oxygen can be realized by selective ionization through subsequent pulse sputtering parameter optimization. Specifically, the application uses a pulse direct current power supply to adjust the sputtering power and duty cycle in three stages, wherein the first stage can stabilize the ignition and preliminarily clean the target surface, the second stage can improve the nitrogen ionization rate in the air (> 50%) and inhibit the oxygen ionization rate (< 10%), and the sputtering voltage feedback control stage adjusts the sputtering power and duty cycle according to the sputtering voltage drop, which can efficiently sputter and peel off the insulating compound layer on the target surface, effectively inhibiting the poisoning state of the target. Therefore, the method of the application can effectively inhibit the poisoning of the target in the direct current sputtering mode, prolong the service life of the target, and does not require complex equipment, which is low in cost.

[0019] Further, the application only relies on a single parameter of sputtering voltage to realize closed-loop control, and the system has fast response speed and high stability; in addition, the method has good process compatibility, is suitable for modification of existing magnetron sputtering equipment, and can improve the utilization rate of metal targets by more than 30%.

[0020] The application provides an anti-target poisoning system based on multi-stage pulse reactive sputtering, which comprises a reactive sputtering chamber, a gas supply module, a pulse direct current power supply, a monitoring module and a stage control module, the gas supply module is in communication with the reactive sputtering chamber, the pulse direct current power supply is connected with the reactive sputtering chamber, the monitoring module monitors the sputtering voltage of the reactive sputtering chamber, and the stage control module is signal connected with the gas supply module, the pulse direct current power supply and the monitoring module, and controls and adjusts the working states of the gas supply module, the pulse direct current power supply and the monitoring module. The system provided by the application has simple structure, and can effectively inhibit the poisoning of the target in the direct current sputtering mode through multi-stage pulse sputtering parameter optimization, prolong the service life of the target, and is low in cost. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a logic diagram of the sputtering voltage feedback control stage in the embodiment of the application;

[0022] Figure 2 It is a structural schematic diagram of the anti-target poisoning system based on multi-stage pulse reactive sputtering in the embodiment of the application;

[0023] Figure 3XRD pattern of the target after the reactive sputtering treatment in Example 1 and Comparative Example 1;

[0024] Figure 4 Graph of the sputtering voltage during the reactive sputtering treatment in Example 1 and Comparative Example 1;

[0025] Figure 5 Graph of the sputtering voltage during the reactive sputtering treatment in Example 1 and Comparative Example 2. DETAILED DESCRIPTION

[0026] The application provides a method for preventing target poisoning based on multi-stage pulse reactive sputtering, comprising the following steps:

[0027] The reactive sputtering treatment is performed on a metal target by using air as the reaction gas and a pulse direct current power supply; the metal target is a titanium target, an aluminum target, a copper target, a chromium target, a gold target or a platinum target; the reactive sputtering treatment comprises sequentially performing a first stage, a second stage and a sputtering voltage feedback control stage;

[0028] The conditions of the first stage include that the sputtering power is 15-20% of the highest power and the duty cycle is 50-70%; the highest power is the highest power of the pulse direct current power supply;

[0029] The conditions of the second stage include that the sputtering power is 40-45% of the highest power and the duty cycle is 35-45%;

[0030] The sputtering voltage feedback control stage includes that the sputtering voltage is monitored in real time, when the sputtering voltage drop is < 15% of the initial sputtering voltage, the sputtering power and the duty cycle are kept unchanged, when the sputtering voltage drop is ≥ 15% of the initial sputtering voltage, the sputtering power is adjusted to 80-100% of the highest power and the duty cycle is adjusted to 10-15%, the sputtering voltage is continuously monitored in real time, and when the sputtering voltage is restored to > 85% of the initial sputtering voltage, the conditions of the second stage are performed; the initial sputtering voltage is the sputtering voltage when the first stage is started.

[0031] The target poisoning easily occurs in the conventional reactive sputtering process, and the target poisoning can cause the sputtering voltage to drop significantly (usually from the initial sputtering voltage to a threshold sputtering voltage below which the target poisoning begins). In the application, air is used as the reaction gas, and the output power of the pulse direct current power supply is applied in stages, the multi-stage pulse sputtering parameters are optimized, and the sputtering voltage is further controlled in real time to control the target to get rid of the poisoning state, which can effectively solve the problems of target poisoning and sputtering rate reduction of the metal target in the reactive sputtering process. The method of the application is described in detail below.

[0032] The application takes air as a reaction gas, and specifically refers to taking air as a single reaction gas, that is, only using air as a reaction gas.

[0033] The application adopts a pulse direct current power supply, specifically a pulse direct current power supply with adjustable duty cycle, and the highest power of the pulse direct current power supply is 500 W. The pulse direct current power supply is used for reaction sputtering treatment of a metal target material in cooperation with a phased and sputtering voltage feedback control modulation mode. The phased and step-by-step increasing sputtering power can reduce the negative impact on the sputtering target material, and the phased adjustment of the duty cycle can help to improve the ionization rate of the reaction gas and reduce the poisoning degree of the sputtering target material.

[0034] As an embodiment of the application, the pressure of air in the process of the reaction sputtering treatment can be 0.4-0.6 Pa, and specifically can be 0.4 Pa, 0.45 Pa, 0.5 Pa, 0.55 Pa or 0.6 Pa. The reaction sputtering treatment of the application includes sequentially performing a first stage, a second stage and a sputtering voltage feedback control stage, which will be described in detail below.

[0035] In the application, the conditions of the first stage include that the sputtering power is 15-20% of the highest power, and specifically can be 15%, 16%, 17%, 18%, 19% or 20%, and the duty cycle is 50-70%, and specifically can be 50%, 55%, 60%, 65% or 70%. As an embodiment of the application, the maintenance time of the first stage can be 1.5-2.5 min, and specifically can be 1.5 min, 1.8 min, 2 min, 2.2 min or 2.5 min. The application limits the conditions of the first stage in the above range, which can stabilize the ignition and preliminarily clean the surface of the target material.

[0036] In the application, the conditions of the second stage include that the sputtering power is 40-45% of the highest power, and specifically can be 40%, 41%, 42%, 43%, 44% or 45%, and the duty cycle is 35-45%, and specifically can be 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44% or 45%. As an embodiment of the application, the maintenance time of the second stage can be 2.5-3.5 min, and specifically can be 2.5 min, 2.8 min, 3 min, 3.2 min or 3.5 min. The application limits the conditions of the second stage in the above range, which can improve the ionization rate of nitrogen in air (>50%) and inhibit the ionization rate of oxygen (<10%).

[0037] In the present application, the sputtering voltage feedback control stage comprises: monitoring the sputtering voltage in real time, when the sputtering voltage drop amplitude < 15% of the initial sputtering voltage, keeping the sputtering power and duty cycle unchanged, when the sputtering voltage drop amplitude ≥ 15% of the initial sputtering voltage, adjusting the sputtering power to 80-100% of the highest power and the duty cycle to 10-15%; continue to monitor the sputtering voltage in real time, when the sputtering voltage recovers to > 85% of the initial sputtering voltage, the conditions of the second stage are executed; the initial sputtering voltage is the sputtering voltage when the first stage is started. As an embodiment of the present application, when the sputtering voltage drop amplitude ≥ 15% of the initial sputtering voltage, the sputtering power is adjusted to 80-100% of the highest power, specifically 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100%; and the duty cycle is adjusted to 10-15%, specifically 10%, 11%, 12%, 13%, 14% or 15%. That is, in the sputtering voltage feedback control stage of the present application, when the sputtering voltage drop amplitude ≥ 15% of the initial sputtering voltage, the sputtering power needs to be increased and the duty cycle needs to be reduced.

[0038] As an embodiment of the present application, in the sputtering voltage feedback control stage, the sputtering power is adjusted according to formula 1:

[0039] A = 0.7 + 0.6x - 0.3x 2 Formula 1;

[0040] In formula 1, A represents the percentage of the sputtering power to the highest power, and x represents the sputtering voltage drop amplitude.

[0041] According to formula 1, in the limit state, for example, when the sputtering voltage drop amplitude is 100%, the percentage of the sputtering power to the highest power also reaches 100%.

[0042] As an embodiment of the present application, in the sputtering voltage feedback control stage, the duty cycle is adjusted according to formula 2:

[0043] B = 0.09 + 0.05x Formula 2;

[0044] In formula 2, B represents the duty cycle, and x represents the sputtering voltage drop amplitude.

[0045] According to formula 2, in the limit state, for example, when the sputtering voltage drop amplitude is 100%, the corresponding duty cycle reaches 15%.

[0046] As an embodiment of the present application, the initial sputtering voltage can be 400-600V, and can be 400V, 450V, 500V, 550V or 600V.

[0047] As an embodiment of the present application, the initial sputtering voltage can be 400-600V, and can be 400V, 450V, 500V, 550V or 600V.

[0048] As an embodiment of the present application, when the sputtering voltage cannot be restored to >85% of the initial sputtering voltage within 5min, the following steps are further included: stopping the reactive sputtering treatment and starting the target surface cleaning; the target surface cleaning can include: bombarding the metal target with argon ions; the present application does not have special limitations on the specific conditions for bombarding the metal target with argon ions, and conditions well known to those skilled in the art can be used.

[0049] Figure 1 For the logic diagram of the sputtering voltage feedback control phase in the embodiments of the present application, after the second phase is completed, the sputtering voltage is monitored in real time, when the sputtering voltage decreases by <15% of the initial sputtering voltage, the sputtering power and the duty cycle are kept unchanged, when the sputtering voltage decreases by ≥15% of the initial sputtering voltage, the sputtering power is adjusted to 80-100% of the highest power and the duty cycle is adjusted to 10-15%; the sputtering voltage is continuously monitored in real time, when the sputtering voltage is restored to >85% of the initial sputtering voltage, the sputtering power is adjusted to 40-45% of the highest power and the duty cycle is adjusted to 35-45% (i.e. the conditions for executing the second phase); when the sputtering voltage cannot be restored to ≥85% of the initial sputtering voltage, the reactive sputtering treatment is stopped and the target surface cleaning is started.

[0050] The present application provides an anti-target poisoning system based on multi-stage pulsed reactive sputtering, which comprises a reactive sputtering chamber, a gas supply module, a pulsed DC power supply, a monitoring module and a stage control module. The gas supply module is in communication with the reactive sputtering chamber, the pulsed DC power supply is connected to the reactive sputtering chamber, the monitoring module monitors the sputtering voltage of the reactive sputtering chamber, and the stage control module is signal connected with the gas supply module, the pulsed DC power supply and the monitoring module. The stage control module controls and adjusts the working state of the gas supply module, the pulsed DC power supply and the monitoring module.

[0051] Figure 2 For the structural schematic diagram of the system for resisting target material poisoning based on multi-stage pulse reaction sputtering in the embodiments of the present application, the reaction sputtering chamber is used for performing reaction sputtering processing; the gas supply module is used for providing reaction gas and working gas; the pulse direct current power supply has a maximum power of 500 W; the monitoring module is used for monitoring the sputtering voltage of the reaction sputtering chamber; and the stage control module is used for dynamically regulating the duty cycle and the sputtering power in different stages during the reaction sputtering processing, wherein the stage control module dynamically regulates the duty cycle by sending a duty cycle regulation instruction to the gas supply module, and dynamically regulates the sputtering power by sending a sputtering power regulation instruction to the pulse direct current power supply.

[0052] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the embodiments in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0053] Embodiment 1

[0054] In this embodiment, an aluminum oxide film is prepared by a reaction sputtering method, an aluminum target is used as the target material, air is used as the reaction gas, the air is directly introduced into a reaction sputtering system (reaction sputtering chamber) through a single path, a pulse direct current power supply (with a maximum power of 500 W) is used as the power supply, and the output power of the power supply is applied in stages. The preparation method of the aluminum oxide film comprises the following steps:

[0055] An aluminum target is installed in the reaction sputtering chamber, air is introduced into the reaction sputtering chamber, the air pressure in the reaction sputtering chamber is set to 0.5 Pa without active flow control, a pulse direct current power supply is turned on, and reaction sputtering processing is performed. During the reaction sputtering processing, the initial sputtering voltage is set to 600 V, and the threshold sputtering voltage is set to 510 V (decreased by 15% compared with the initial sputtering voltage). The reaction sputtering processing comprises sequentially performing a first stage, a second stage, and a sputtering voltage feedback control stage.

[0056] The conditions of the first stage include that the sputtering power is 15% of the maximum power (75 W) and the duty cycle is 60%, and the duration is 2 min.

[0057] The conditions of the second stage include that the sputtering power is 40% of the maximum power (200 W) and the duty cycle is 40%, and the duration is 3 min.

[0058] The sputtering voltage feedback control stage comprises: maintaining the conditions of the second stage to continue sputtering and monitoring the sputtering voltage in real time; when the sputtering voltage drops to 510 V (i.e. 15% lower than the initial sputtering voltage), the current sputtering power is adjusted to 80% of the highest power (400 W) and the duty cycle is adjusted to 10%, the sputtering voltage is continuously monitored in real time, if the sputtering voltage recovers to 510 V (i.e. recovers to 85% of the initial sputtering voltage) within 5 min, the sputtering power is reduced to 40% of the highest power (200 W) and the duty cycle is adjusted to 40%, i.e. the conditions of the second stage are executed; if the sputtering voltage does not recover to 510 V within 5 min, the sputtering is suspended and the target surface cleaning (specifically, the surface is cleaned by bombarding the metal target with argon ions) is started.

[0059] After the reaction sputtering treatment is completed, cleaning and sampling are performed to obtain the aluminum oxide film.

[0060] Comparative Example 1

[0061] Referring to the method operation of Example 1, the difference is that in this comparative example, the reaction gas used is pure oxygen, the duty cycle is set to 30%, the sputtering power is 500 W, the pressure in the reaction sputtering chamber during sputtering is 0.6 Pa, and the sputtering duration is 10 min.

[0062] Comparative Example 2

[0063] Referring to the method operation of Example 1, the difference is that in this comparative example, the sputtering voltage feedback control stage is not performed, and the duration of the second stage is 8 min.

[0064] Test Example 1

[0065] The target materials after reaction sputtering treatment in Example 1 and Comparative Example 1 are analyzed by XRD detection method. According to the spectral line intensity marked for elemental aluminum and aluminum oxide components, the composition of the aluminum oxide film sample can be semi-quantitatively analyzed to some extent. The sampling time is 10 min after the start of sputtering (to ensure that the sputtering process enters a steady state under the method of the present application). When target poisoning occurs during sputtering, some of the elemental aluminum in the target will be converted to aluminum oxide, thereby reducing the intensity ratio of the spectral lines corresponding to elemental aluminum and aluminum oxide in the XRD analysis results of the target, i.e. the content of elemental aluminum decreases, and the content of aluminum oxide relatively increases. Figure 3The XRD pattern of the target after the reactive sputtering treatment in Example 1 and Comparative Example 1 is shown. The results show that the ratio of the intensity of the elemental aluminum and aluminum oxide spectrum lines of the target after the reactive sputtering treatment in Example 1 of the application (about 13 / 4) is greater than the ratio of the intensity of the elemental aluminum and aluminum oxide spectrum lines of the target after the reactive sputtering treatment in Comparative Example 1 using pure oxygen (about 9 / 5). According to the preliminary calculation of the XRD data, the generation rate of the insulating compound layer on the surface of the target in Example 1 of the application is reduced by 45% compared with the pure oxygen sputtering in Comparative Example 1. It shows that the poisoning of the target is deeper in Comparative Example 1 using pure oxygen reactive sputtering, and there is more elemental aluminum converted into aluminum oxide, while the content of aluminum oxide generated on the surface of the target in Example 1 of the application is lower, and the elemental aluminum is retained to a greater extent, proving that the method of the application can effectively inhibit the poisoning of the target.

[0066] Figure 4 The sputtering voltage change graph during the reactive sputtering treatment in Example 1 and Comparative Example 1 is shown. The results show that in Comparative Example 1, the target enters a poisoning state after 4-5 min of sputtering, and a large decrease in sputtering voltage occurs. While in Example 1, the method suppresses the generation of aluminum oxide, and after 5 min of sputtering, it enters a relatively stable state, and the stability of the sputtering voltage is more than 1.5 times that of the pure oxygen reactive sputtering mode at the same time. And through testing, the reactive sputtering deposition rate can be stabilized at 10 nm / min ± 0.5 nm / min in the stable interval of 5-10 min using the method of Example 1, which shows that the stability of the sputtering rate in Example 1 is more than 1.5 times that of the pure oxygen reactive sputtering mode in Comparative Example 1. In addition, the aluminum oxide film prepared by the method of Example 1 of the application has good uniformity, and the thickness deviation is ≤5%.

[0067] Test Example 2

[0068] Figure 5 The sputtering voltage change graph during the reactive sputtering treatment in Example 1 and Comparative Example 2 is shown. By comparing the time when the sputtering voltage in Example 1 and Comparative Example 2 drops to the same interval, the results show that the sputtering voltage feedback control stage in Example 1 of the application can extend the poisoning time of the target by more than 1.5 times, which can effectively reduce the process interruption rate in actual industrial production, thereby reducing production costs and improving production efficiency.

[0069] The above only describes the preferred embodiments of the application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the application, and these improvements and refinements should also be considered within the scope of protection of the application.

Claims

1. A method for resisting target poisoning based on multi-stage pulse reactive sputtering, characterized in that, Includes the following steps: Air is used as the reactant gas, and a pulsed DC power supply is used to perform reactive sputtering on a metal target; the metal target is a titanium target, aluminum target, copper target, chromium target, gold target, or platinum target; the reactive sputtering process includes a first stage, a second stage, and a sputtering voltage feedback control stage in sequence. The conditions for the first stage include: the sputtering power is 15-20% of the maximum power and the duty cycle is 50-70%; the maximum power is the maximum power of the pulsed DC power supply; The conditions for the second stage include: the sputtering power is 40-45% of the highest power and the duty cycle is 35-45%; The sputtering voltage feedback control stage includes: real-time monitoring of the sputtering voltage; when the sputtering voltage drop is less than 15% of the initial sputtering voltage, maintaining the sputtering power and duty cycle unchanged; when the sputtering voltage drop is greater than or equal to 15% of the initial sputtering voltage, adjusting the sputtering power to 80-100% of the maximum power and the duty cycle to 10-15%; continuing to monitor the sputtering voltage in real time; when the sputtering voltage recovers to more than 85% of the initial sputtering voltage, executing the conditions of the second stage; the initial sputtering voltage is the sputtering voltage at the start of the first stage.

2. The method for preventing target poisoning according to claim 1, characterized in that, The time required for the sputtering voltage to recover to >85% of the initial sputtering voltage is ≤5 minutes.

3. The method for preventing target poisoning according to claim 1, characterized in that, The duration of the first stage is 1.5 to 2.5 minutes; the duration of the second stage is 2.5 to 3.5 minutes.

4. The method for preventing target poisoning according to claim 1, characterized in that, The maximum power is 500W.

5. The method for preventing target poisoning according to claim 1, characterized in that, The initial sputtering voltage is 400~600V.

6. The method for preventing target poisoning according to claim 1, characterized in that, The air pressure during the reactive sputtering process is 0.4~0.6 Pa.

7. The method for preventing target poisoning according to any one of claims 2 to 6, characterized in that, When the sputtering voltage cannot be restored to >85% of the initial sputtering voltage within 5 minutes, the following steps are also included: stopping the reactive sputtering process and initiating target surface cleaning.

8. The method for preventing target poisoning according to claim 7, characterized in that, The target surface cleaning method includes: bombarding the metal target with argon ions.

9. A system used in the anti-target poisoning method based on multi-stage pulse reactive sputtering as described in any one of claims 1 to 8, characterized in that, The device includes a reactive sputtering chamber, a gas supply module, a pulsed DC power supply, a monitoring module, and a staged control module. The gas supply module is connected to the reactive sputtering chamber, the pulsed DC power supply is connected to the reactive sputtering chamber, the monitoring module monitors the sputtering voltage of the reactive sputtering chamber, and the staged control module is signal-connected to the gas supply module, the pulsed DC power supply, and the monitoring module. The staged control module controls and adjusts the operating status of the gas supply module, the pulsed DC power supply, and the monitoring module.

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