A Plasma-Enhanced Physical Vapor Deposition Method

Abstract

This invention provides a plasma-enhanced physical vapor deposition method, comprising the following steps: (1) a) sequentially forming a high-resistivity metal oxide and a metal thin film protective layer on the surface of a metal shield, and generating a negative potential; or b) depositing a metal thin film protective layer on an insulating shield by magnetron sputtering, and generating a negative potential; (2) preparing a metal film by magnetron sputtering: transferring the substrate to the stage, lifting the annular metal baffle into the shield, introducing a certain flow rate of argon gas to form a glow discharge plasma, the plasma colliding with sputtered metal atoms to generate a large number of metal ions, forming a metal film on the substrate; (3) eliminating and initializing the charge on the surface of the shield in the PVD vacuum chamber. This invention forms a high-resistivity metal oxide and a metal thin film protective layer on the surface of a metal shield or forms a metal thin film protective layer on an insulating shield, and generates a negative potential, which can enhance the plasma density during metal thin film sputtering and improve the metal thin film step coverage.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor manufacturing technology, and specifically relates to a plasma-enhanced physical vapor deposition method. Background Technology

[0002] Magnetic fields play a crucial role in plasma technology, especially high-density plasma technology. In many important technological applications, plasma generation and control are closely related to magnetic fields. Many plasma systems require specially designed magnet structures to enhance and control plasma density, distribution, and other performance and processing parameters (such as sputtering rate, etching rate, and thin film step coverage). The fundamental mechanism of the effect of magnetic fields on plasma lies in the Lorentz force. Dutch physicist Lorentz first pointed out that charged particles moving in a magnetic field are always subject to a magnetic force. The direction of the force is perpendicular to the plane formed by the magnetic field and the particle velocity, and the magnitude of the force is proportional to the particle charge (q), velocity, magnetic induction intensity, and the sine function of the angle between the latter two. The Lorentz force can be expressed as the vector product of the charged particle velocity (1) and the magnetic induction intensity (B), as shown in the following equation:

[0003] F=qv×B

[0004] The direction of the Lorentz force can be determined using the screw rule. For the same magnetic field and particle velocity direction, the Lorentz forces experienced by positively and negatively charged particles are in opposite directions. Therefore, magnetic fields can be used to separate electrons and ions in a plasma stream. The particle velocity vector can be decomposed into two components: one perpendicular to and one parallel to the magnetic field direction: v = v ⊥ + v || The perpendicular component of the magnetic field contributes to the Lorentz force. The Lorentz force causes charged particles to rotate or spiral about the direction of the magnetic field. Based on the Lorentz force and the equations of circular motion, the radius and frequency of the charged particle's rotational motion can be calculated. The rotational radius depends on the magnetic induction intensity, the particle mass (m), the charge, and the particle velocity component perpendicular to the magnetic field direction (v). ⊥ ).

[0005] r = mv ⊥ / qB

[0006] Since electrons and ions in plasma are independent and mobile, both are subject to the Lorentz force of an applied magnetic field. Electrons and positive ions have equal charges and experience Lorentz forces of opposite directions and equal magnitudes in the magnetic field. However, due to their significant mass difference, the radius of curvature of the electron's deflection in the magnetic field is significantly smaller than that of the ion. Taking argon ions and electrons in a magnetic field as an example, their velocities can be calculated from their kinetic energies. Assuming both have a kinetic energy of 100 eV and a magnetic induction intensity of 100 Gs, the radius of curvature of the electron can be estimated to be 0.3 cm, while that of the argon ion is 66 cm. This indicates that the deflection of ion motion caused by the magnetic field is very small, while the motion of electrons undergoes a significant change under the influence of the magnetic field. Although the Lorentz force does not do work on electrons and cannot increase their energy, the spiral motion it creates greatly increases the electron's path, increasing the probability of collisions with neutral atoms, and thus significantly increasing the ionization rate and plasma density. The high-density plasma causes a large number of sputtered metal atoms to ionize (M + e = M). + +2e). If an RF power supply is applied to the substrate to generate a negative bias voltage, it guides metal ions to be deposited onto the silicon wafer in a directional manner, increasing the thin film step coverage.

[0007] Existing magnetron sputtering techniques for increasing plasma density mostly rely on the design of the magnetron. Besides controlling plasma distribution and separating charges, the magnetic field also increases plasma density. Depending on the application requirements, different magnet structures are designed and installed, allowing for the aggregation and confinement of plasma using non-uniform magnetic fields. A non-uniform magnetic field with a weak center and strong ends can confine charged particles. This non-uniform magnetic structure is often called a "magnetic mirror," meaning that moving charged particles can be "reflected" back to the weak center by the strong magnetic fields at both ends, much like a mirror reflecting light. However, the magnetron's own magnetic field strength is very limited, averaging approximately 400 Gs on the target surface. This plasma-enhanced magnetron design results in a large difference in magnetic field strength between the center and ends, leading to poor target etching uniformity, low target utilization, and ultimately affecting film uniformity. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a plasma-enhanced physical vapor deposition (PVD) method. This invention first forms a high-resistivity metal oxide on the surface of a metal shield within the PVD equipment cavity. A metal thin film protective layer is then formed on the high-resistivity metal oxide, generating a negative potential. Alternatively, a metal thin film protective layer of a certain thickness is deposited on the insulating shield using magnetron sputtering, generating a certain negative potential. The metal thin film is then sputtered, and the film can simultaneously fill the micropores. This method enhances the plasma density during metal thin film sputtering and significantly improves the step coverage of the metal thin film.

[0009] To achieve the above technical objectives, the technical solution adopted in this embodiment of the invention is: a plasma-enhanced physical vapor deposition method, comprising the following steps:

[0010] (1) a. A high-resistivity metal oxide is formed on the surface of the shielding element inside the cavity, and a metal thin film protective layer is formed on the high-resistivity metal oxide to generate a negative potential. The shielding element is a metal shielding element; or

[0011] b. A metal thin film protective layer of a certain thickness is deposited on the shielding material by magnetron sputtering, and a certain negative potential is generated. The shielding material is an insulating shielding material.

[0012] (2) Magnetron sputtering to prepare metal film: The substrate is transferred to the stage, the annular metal baffle is lifted into the shield, and a certain flow rate of argon gas is introduced to form glow discharge plasma. The electrons accumulated on the surface of the shield in the PVD vacuum chamber will inhibit the electrons from continuing to move to the inner wall shield surface during subsequent sputtering. The electron density is enhanced, and the electrons collide with argon atoms to generate more argon positive ions and electrons. The plasma density is increased, and the plasma with increased density collides with sputtered metal atoms to generate a large number of metal ions. The stage generates a negative bias voltage due to the application of radio frequency power, which guides the metal ions to be deposited onto the substrate at an accelerated direction to form a metal film.

[0013] (3) Eliminate and initialize the charge on the surface of the shield inside the PVD vacuum chamber;

[0014] The shielding element mentioned in steps (2) and (3) is a metal shielding element or an insulating shielding element, and the shielding element mentioned in steps (2) and (3) is the same type as the shielding element in step (1).

[0015] Furthermore, case a in step (1) includes the following steps:

[0016] (1.1) Formation of high-resistivity metal oxide: The pre-sputtered substrate is transferred to the PVD vacuum chamber, and a certain flow rate and proportion of argon-oxygen mixed gas is introduced into the PVD vacuum chamber. Argon gas is ionized to form glow discharge plasma, in which argon positive ions are accelerated to bombard the target material under the action of the cathode target to generate metal atoms. The metal atoms react with oxygen to form metal oxide, and a high-resistivity metal oxide is formed on the surface of the shield in the chamber. The thickness of the high-resistivity metal oxide is >100nm and the resistivity is >1000μΩ·cm.

[0017] (1.2) Forming a metal thin film protective layer on the high-resistivity metal oxide and generating a negative potential: After forming a high-resistivity metal oxide thin film on the surface of the shield in the cavity in step (1.1), a metal thin film protective layer is formed on the high-resistivity metal oxide by magnetron sputtering. During magnetron sputtering, electrons in the plasma are accelerated away from the cathode target and migrate to the baffle and the shield in the PVD vacuum cavity, forming a negative potential on the surface of the shield, with a potential of -50~-5V.

[0018] Furthermore, case b in step (1) includes the following steps:

[0019] The pre-sputtered substrate is transferred to a PVD vacuum chamber, and a certain flow rate of argon gas is introduced into the PVD vacuum chamber. The argon gas is ionized to form a glow discharge plasma, in which argon positive ions are accelerated to bombard the target material under the action of the cathode target to generate metal atoms, forming a metal thin film protective layer of a certain thickness on the surface of the shield in the chamber. Electrons in the plasma are accelerated away from the cathode target and migrate to the baffle and the shield in the vacuum chamber, forming a negative potential on the surface of the shield, with a potential of -50~-5V.

[0020] Further, in step (1.1), the argon flow rate in the argon-oxygen mixed gas is 20-100 sccm, the oxygen flow rate is 10-100 sccm, the cavity reaction pressure is 1.8-20 mTorr, the target input power is 500-6000 W, and the sputtering time is 5-20 min.

[0021] Furthermore, during the pre-sputtering treatment of the substrate, the distance between the target and the substrate stage is 150-450 mm, the substrate temperature is 25-300℃, and the vacuum level of the PVD vacuum chamber is maintained at 5.0 × 10⁻⁶. -8 For sputtering power below Torr, use 1000-3000W and pre-sputter the target for 1-3 minutes.

[0022] Furthermore, the target material is one of titanium target, tantalum target, copper target, nickel target, tungsten target, titanium-tungsten alloy target and Ag target.

[0023] Furthermore, when forming the metal thin film protective layer, the argon gas flow rate is 20-60 sccm, the cavity reaction pressure is 1.2-3.6 mTorr, the target input power is 1000-10000W, and the sputtering time is 1-5 min.

[0024] Furthermore, in step (2), when preparing metal thin films by magnetron sputtering, the argon gas flow rate is 20-60 sccm, the cavity reaction pressure is 1.2-3.6 mTorr, the target sputtering power is set to 1000-10000W, the stage input RF power is set to 50-500W, the RF frequency is 2-27.12MHz, and the sputtering time is 1-5min.

[0025] Furthermore, the material, type, and purity of the annular metal baffle mentioned in step (2) are the same as those of the target material, and the lifting and lowering are controlled by a cylinder;

[0026] The annular metal baffle is used to prevent positive ions in the plasma from bombarding the insulating metal oxide film on the surface of the shield under the pull of negative potential on the surface of the shield, thereby avoiding the generation of impurities and the neutralization of the charge on the surface of the shield.

[0027] Furthermore, in step (3), during the process of the substrate stage being lowered from the process position to the initial transfer position, the charge is eliminated by the physical contact between the annular metal baffle and the spring installed at the bottom of the PVD vacuum chamber, thereby maintaining the inter-wafer stability of the step coverage.

[0028] The initial position of the annular metal baffle is when the vertical distance between the upper edge of the annular metal baffle and the baffle is 3-5mm.

[0029] When the annular metal baffle moves upward to a vertical distance of 3-5mm between its upper edge and the surface of the target material, it is at the process position of the annular metal baffle.

[0030] The beneficial effects of the technical solution provided by the embodiments of the present invention are as follows:

[0031] This invention first forms a high-resistivity metal oxide on the surface of a metal shield inside the PVD sputtering equipment cavity, and then forms a metal thin film protective layer on the high-resistivity metal oxide, generating a negative potential. Alternatively, a metal thin film protective layer of a certain thickness is deposited on the insulating shield using magnetron sputtering, generating a certain negative potential, and then the metal thin film is sputtered. The thin film can simultaneously fill the micropores. This method can enhance the plasma density during metal thin film sputtering and significantly improve the step coverage of the metal thin film. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the cavity of the PVD sputtering equipment in an embodiment of the present invention.

[0033] Figure 2 A step coverage diagram of the titanium thin film within the micropores in Embodiment 1 of the present invention.

[0034] Figure 3 Step coverage diagram of the titanium thin film in the micropores in Embodiment 2 of the present invention.

[0035] Figure 4 The comparative example of this invention shows the step coverage diagram of the titanium thin film within the micropores.

[0036] Explanation of reference numerals in the attached drawings: 1-shielding component; 2-ring-shaped metal baffle; 3-cylinder; 4-guide rod; 5-spring; 6-baffle; 7-track trolley. Detailed Implementation

[0037] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "inner" and "outer", "upper" and "lower", "left" and "right" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention.

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0039] like Figure 1 As shown, the shield 1 is located above the substrate inside the PVD vacuum chamber to prevent contamination of the inner wall of the chamber during physical vapor deposition. It can be replaced and cleaned when the maintenance cycle is reached.

[0040] The annular metal baffle 2 is raised and lowered by the cylinder 3. When the vertical distance between the upper edge of the annular metal baffle 2 and the baffle 6 is 3-5mm, it is the initial position of the annular metal baffle 2. When the annular metal baffle 2 moves upward to the point where the vertical distance between the upper edge and the surface of the target material is 3-5mm, it is the process position of the annular metal baffle 2.

[0041] The annular metal baffle 2 is sleeved on the guide rod 4 through a sleeve. During the process of the cylinder 3 controlling the lifting and lowering movement of the annular metal baffle 2, the guide rod 4 provides a guiding function.

[0042] The vertical distance between the left-side baffle 6 and the upper surface of the platform is 5-30mm. It is driven horizontally by the track trolley 7 to shield the substrate and prevent contamination of the substrate surface during metal oxide coating. The bottom of the spring 5 is installed at the bottom of the PVD vacuum chamber to achieve grounding. When the annular metal baffle 2 descends and contacts the spring 5, discharge can be completed, avoiding damage to the substrate.

[0043] Example 1

[0044] A plasma-enhanced physical vapor deposition method includes the following steps:

[0045] (1) Pre-sputtering: Based on the SJI-SEMI Depommerits P1 88+ Pro PVD equipment, a titanium target with a purity of 99.999% was selected. The distance between the target and the wafer stage was 250 mm. The substrate temperature was set to 300 °C, and the cavity base vacuum was maintained at 1.0 × 10⁻⁶. -8 Torr, using 1000W sputtering power, pre-sputtering target for 3 minutes;

[0046] (2) Formation of insulating metal oxide: The wafer is transferred to the PVD vacuum chamber, and an argon-oxygen mixture with an argon flow rate of 20 sccm and an oxygen flow rate of 50 sccm is introduced. The chamber reaction pressure is 3.6 mTorr, the target input power is 3000W, and the sputtering time is 10min. Argon ionization forms glow discharge plasma, in which argon positive ions are accelerated and bombard the target material under the action of the cathode target to generate metal atoms. The metal atoms react with oxygen to form metal oxide, forming a high-resistivity metal oxide on the surface of the metal shield in the chamber. The high-resistivity metal oxide is a titanium oxide thin film with a thickness of 200nm and a resistivity of 10. 4 μΩ·cm;

[0047] (3) Forming a metal thin film protective layer and generating a certain negative potential: After a high-resistivity metal oxide film is formed on the surface of the metal shield in the cavity in step (1), argon gas is continued to be introduced at a flow rate of 30 sccm, the cavity reaction pressure is 1.8 mTorr, the target input power is 10000W, and the sputtering time is 1 min. A metal thin film protective layer is formed on the surface of the metal shield in the cavity by magnetron sputtering. The metal thin film protective layer is a titanium film with a thickness of 50 nm. During magnetron sputtering, electrons in the plasma are accelerated away from the cathode target and migrate to the baffle and the shield in the PVD vacuum cavity, forming a negative potential on the surface of the shield. The potential is -10V.

[0048] (4) Magnetron sputtering to prepare metal thin films: The wafer is transferred to the stage, and the annular metal shield (the metal material and purity are the same as the target material) is lifted into the metal shield. Argon gas with a flow rate of 30 sccm is introduced to form glow discharge plasma. The cavity reaction pressure is 1.8 mTorr. The target sputtering power is set to 9000W, the stage input RF power is set to 100W, the RF frequency is 13.56MHz, and the sputtering time is 1.5min. The electrons accumulated on the surface of the metal shield in the vacuum cavity will inhibit the electrons from continuing to move to the surface of the inner wall metal shield during subsequent sputtering. The electron density is enhanced. The electrons collide with argon atoms to generate more argon positive ions and electrons, which increases the plasma density. The plasma with increased density collides with sputtered metal atoms to generate a large number of metal ions. The stage generates a negative bias voltage due to the applied RF power, which will guide the metal ions to be deposited onto the silicon wafer to form a metal titanium thin film and improve the thin film step coverage.

[0049] Among them, the annular metal baffle can prevent positive ions in the plasma from bombarding the insulating metal oxide film on the surface of the metal shield under the negative potential pull of the metal shield surface, thus avoiding the generation of impurities and the neutralization of the surface charge of the metal shield.

[0050] (5) Eliminate and initialize the charge on the surface of the metal shield in the PVD vacuum chamber: During the process of the substrate stage being lowered from the process position to the initial transfer position, the charge is eliminated by the physical contact between the annular metal baffle and the spring installed at the bottom of the PVD vacuum chamber, thereby maintaining the inter-layer stability of the step coverage.

[0051] Example 2

[0052] A plasma-enhanced physical vapor deposition method includes the following steps:

[0053] (1) Pre-sputtering: Based on the SJI-SEMI Depommerits P188+ Pro PVD equipment, a titanium target with a purity of 99.999% was selected. The distance between the target and the wafer stage was 250 mm. The substrate temperature was set to 300 °C, and the cavity base vacuum was maintained at 1.0 × 10⁻⁶. -8 Torr, using 1000W sputtering power, pre-sputtering target for 3 minutes;

[0054] (2) Forming a metal thin film protective layer and generating a certain negative potential: Argon gas with a flow rate of 30 sccm is introduced into the PVD vacuum chamber to form glow discharge plasma. The chamber reaction pressure is 1.8 mTorr, the target input power is 10000W, and the sputtering time is 1 min. A metal thin film protective layer is formed on the surface of the insulating shield in the chamber by magnetron sputtering. The metal thin film protective layer is a titanium thin film with a thickness of 50 nm.

[0055] (3) Magnetron sputtering preparation of metal thin films: The wafer is transferred to the stage, and an annular metal shield (the type and purity of the metal are the same as the target material) is lifted into the insulating shield. Argon gas with a flow rate of 30 sccm is introduced to form glow discharge plasma. The cavity reaction pressure is 1.8 mTorr. The target sputtering power is set to 9000 W, the stage input RF power is set to 100 W, the RF frequency is 13.56 MHz, and the sputtering time is 1.5 min. The electrons accumulated on the surface of the insulating shield in the vacuum cavity will inhibit the electrons from continuing to move to the inner wall insulating shield surface during subsequent sputtering. Increased density leads to more argon ions and electrons colliding with argon atoms, resulting in higher plasma density. The increased plasma density then collides with sputtered metal atoms to generate a large number of metal ions. The stage, due to the application of radio frequency power, generates a negative bias voltage, which guides the metal ions to be deposited onto the silicon wafer at an accelerated and directional rate, forming a titanium thin film and improving the film step coverage. The annular metal baffle prevents the positive ions in the plasma from bombarding the insulating metal oxide film on the surface of the insulating shield under the negative potential pull of the insulating shield surface, thus avoiding impurity generation and neutralizing the charge on the surface of the insulating shield.

[0056] (4) Eliminate and initialize the charge on the surface of the insulating shield in the PVD vacuum chamber: During the process of the substrate stage being lowered from the process position to the initial transfer position, the charge is eliminated after the annular metal baffle comes into physical contact with the spring installed at the bottom of the PVD vacuum chamber, thereby maintaining the inter-layer stability of the step coverage.

[0057] Comparative Example 1

[0058] A plasma physical vapor deposition method includes the following steps:

[0059] (1) Pre-sputtering: Based on the SJI-SEMI Depommerits P188+ Pro PVD equipment, a titanium target with a purity of 99.999% was selected. The distance between the target and the wafer stage was 250 mm. The substrate temperature was set to 300 °C, and the cavity base vacuum was maintained at 1.0 × 10⁻⁶. -8 Torr, using 1000W sputtering power, pre-sputtering target for 3 minutes;

[0060] (2) Preparation of metal thin film by magnetron sputtering: Argon gas with a flow rate of 30 sccm is introduced to form glow discharge plasma, the cavity reaction pressure is 1.8 mTorr, the target sputtering power is set to 9000W, the stage input RF power is set to 100W, the RF frequency is 13.56MHz, and the sputtering time is 1.5min to obtain a titanium thin film.

[0061] The thickness distribution of titanium thin films within the micropores or trenches of the substrate was observed using a scanning electron microscope. Step coverage was defined as the ratio of the film thickness at the sidewalls or bottom to the film thickness at the top plane. The average thickness of the film on both sidewalls was used to calculate the sidewall step coverage. The calculated step coverage is shown in Table 1. Figure 2 , 3 4.

[0062] Table 1 Comparison of film step coverage in Example 1 and Comparative Example 1

[0063]

[0064] Combination Figure 2 , Figure 3 , Figure 4 As shown in Table 1, observing the film step coverage under the conventional physical vapor deposition method, it can be seen that the sputtered film thickness in the middle and bottom of the sidewall of Comparative Example 1 is too thin, with a coverage rate of about 10%. However, when using the plasma-enhanced physical vapor deposition method of this application, the overall film step coverage rate is significantly higher than that of the conventional physical vapor deposition method, with relatively continuous sidewalls and a sidewall coverage rate exceeding 18% and a bottom coverage rate exceeding 30%.

[0065] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A plasma-enhanced physical vapor deposition method, characterized in that, Includes the following steps: (1) a. A high-resistivity metal oxide is formed on the surface of the shielding element inside the cavity, and a metal thin film protective layer is formed on the high-resistivity metal oxide to generate a negative potential. The shielding element is a metal shielding element; or b. A metal thin film protective layer of a certain thickness is deposited on the shielding material by magnetron sputtering, and a certain negative potential is generated. The shielding material is an insulating shielding material. (2) Magnetron sputtering to prepare metal film: The substrate is transferred to the stage, the annular metal baffle is lifted into the shield, and a certain flow rate of argon gas is introduced to form glow discharge plasma. The electrons accumulated on the surface of the shield in the PVD vacuum chamber will inhibit the electrons from continuing to move to the inner wall shield surface during subsequent sputtering. The electron density is enhanced, and the electrons collide with argon atoms to generate more argon positive ions and electrons. The plasma density is increased, and the plasma with increased density collides with sputtered metal atoms to generate a large number of metal ions. The stage generates a negative bias voltage due to the application of radio frequency power, which guides the metal ions to be deposited onto the substrate at an accelerated direction to form a metal film. (3) Eliminate and initialize the charge on the surface of the shield inside the PVD vacuum chamber; The shielding element mentioned in steps (2) and (3) is a metal shielding element or an insulating shielding element, and the shielding element mentioned in steps (2) and (3) is the same type as the shielding element in step (1).

2. The plasma-enhanced physical vapor deposition method according to claim 1, characterized in that, Case a in step (1) includes the following steps: (1.1) Formation of high-resistivity metal oxide: The pre-sputtered substrate is transferred to the PVD vacuum chamber, and a certain flow rate and proportion of argon-oxygen mixed gas is introduced into the PVD vacuum chamber. Argon gas is ionized to form glow discharge plasma, in which argon positive ions are accelerated to bombard the target material under the action of the cathode target to generate metal atoms. The metal atoms react with oxygen to form metal oxide, and a high-resistivity metal oxide is formed on the surface of the shield in the chamber. The thickness of the high-resistivity metal oxide is >100nm and the resistivity is >1000μΩ·cm. (1.2) Forming a metal thin film protective layer on the high-resistivity metal oxide and generating a negative potential: After forming a high-resistivity metal oxide thin film on the surface of the shield in the cavity in step (1.1), a metal thin film protective layer is formed on the high-resistivity metal oxide by magnetron sputtering. During magnetron sputtering, electrons in the plasma are accelerated away from the cathode target and migrate to the baffle and the shield in the PVD vacuum cavity, forming a negative potential on the surface of the shield, with a potential of -50~-5V.

3. The plasma-enhanced physical vapor deposition method according to claim 1, characterized in that, Case b in step (1) includes the following steps: The pre-sputtered substrate is transferred to a PVD vacuum chamber, and a certain flow rate of argon gas is introduced into the PVD vacuum chamber. The argon gas is ionized to form a glow discharge plasma, in which argon positive ions are accelerated to bombard the target material under the action of the cathode target to generate metal atoms, forming a metal thin film protective layer of a certain thickness on the surface of the shield in the chamber. Electrons in the plasma are accelerated away from the cathode target and migrate to the baffle and the shield in the vacuum chamber, forming a negative potential on the surface of the shield, with a potential of -50~-5V.

4. The plasma-enhanced physical vapor deposition method according to claim 2, characterized in that, In step (1.1), the argon flow rate in the argon-oxygen mixed gas is 20-100 sccm, the oxygen flow rate is 10-100 sccm, the cavity reaction pressure is 1.8-20 mTorr, the target input power is 500-6000 W, and the sputtering time is 5-20 min.

5. The plasma-enhanced physical vapor deposition method according to claim 2 or 3, characterized in that, During pre-sputtering of the substrate, the distance between the target and the substrate stage is 150-450 mm, the substrate temperature is 25-300℃, and the vacuum level of the PVD vacuum chamber is maintained at 5.0 × 10⁻⁶ mm. -8 For sputtering power below Torr, use 1000-3000W and pre-sputter the target for 1-3 minutes.

6. The plasma-enhanced physical vapor deposition method according to claim 2 or 3, characterized in that, The target material is one of the following: titanium target, tantalum target, copper target, nickel target, tungsten target, titanium-tungsten alloy target, and Ag target.

7. The plasma-enhanced physical vapor deposition method according to claim 2 or 3, characterized in that, When forming the metal thin film protective layer, the argon gas flow rate is 20-60 sccm, the cavity reaction pressure is 1.2-3.6 mTorr, the target input power is 1000-10000W, and the sputtering time is 1-5 min.

8. The plasma-enhanced physical vapor deposition method according to claim 1, characterized in that, In step (2), when preparing metal thin films by magnetron sputtering, the argon gas flow rate is 20-60 sccm, the cavity reaction pressure is 1.2-3.6 mTorr, the target sputtering power is set to 1000-10000W, the stage input RF power is set to 50-500W, the RF frequency is 2-27.12MHz, and the sputtering time is 1-5min.

9. The plasma-enhanced physical vapor deposition method according to claim 1, characterized in that, The material, type and purity of the annular metal baffle mentioned in step (2) are the same as those of the target material, and the lifting and lowering are controlled by a cylinder; The annular metal baffle is used to prevent positive ions in the plasma from bombarding the insulating metal oxide film on the surface of the shield under the negative potential pull of the shield surface, thereby avoiding the generation of impurities and the neutralization of the charge on the surface of the shield.

10. The plasma-enhanced physical vapor deposition method according to claim 1, characterized in that, In step (3), during the process of the substrate stage being lowered from the process position to the initial transfer position, the charge is eliminated by the physical contact between the annular metal baffle and the spring installed at the bottom of the PVD vacuum chamber, thereby maintaining the inter-wafer stability of the step coverage. The initial position of the annular metal baffle is when the vertical distance between the upper edge of the annular metal baffle and the baffle is 3-5mm. When the annular metal baffle moves upward to a vertical distance of 3-5mm between its upper edge and the surface of the target material, it is at the process position of the annular metal baffle.

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