PVD pre-cleaning chamber and method for synchronous self-cleaning of special-shaped targets

Abstract

The present invention provides a PVD pre-cleaning chamber and method for synchronous self-cleaning of special-shaped targets. The PVD pre-cleaning chamber for synchronous self-cleaning of special-shaped targets includes a shielding member, an ICP generator, a self-biased wafer carrier, a special-shaped target assembly, and an electromagnet assembly. The structure of the special-shaped target assembly enables the sputtering area of ​​the aluminum particles to cover the inner wall of the shielding member without sputtering to the front of the wafer carrier, and does not affect the cleaning process of the wafer surface. The self-cleaning process of the process chamber does not need to interrupt the processing process of the wafer process, and does not require the introduction of additional sputtering material.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer processing, and in particular to a PVD pre-cleaning chamber and method for synchronous self-cleaning of special-shaped targets. Background Art

[0002] PVD (Physical Vapor Deposition) technology is widely used to deposit metal thin films in semiconductor manufacturing. Before the deposition process, a pre-clean chamber is often required to remove contaminants and residues from the wafer surface to ensure the quality of subsequent processes. This pre-clean chamber primarily uses plasma technology to achieve this cleaning purpose.

[0003] The pre-cleaning chamber typically uses an inductively coupled plasma (ICP) generator. This uses radio frequency power to ignite low-pressure process gases (such as argon, helium, and hydrogen) into a plasma. The active particles in the plasma react with contaminants (such as polymer residues and oxides) on the wafer surface, effectively removing these impurities. However, as the process continues, contaminants accumulate in the chamber, interfering with product quality.

[0004] A common method to solve this problem during the PVD process is to interrupt the process flow when it is necessary to clean the contaminants in the chamber, place a pure aluminum substrate on the wafer carrier, and bombard the aluminum surface with process gas (such as Ar⁺) to sputter out aluminum particles. The splashed aluminum particles flow in the chamber, collide with the contaminants (particles, gas impurities) and are deposited together on the chamber wall or specific collection area. At the same time, aluminum has a high chemical activity and can react with oxygen, moisture, etc. to reduce oxidation contamination, thereby absorbing the particles, contaminants or reaction by-products remaining in the chamber and reducing interference with the coating quality.

[0005] However, as the cavity is used for a longer time, more and more particles are adsorbed on the inner wall surface of the cavity, and the thickness of the pollutants becomes thicker and thicker. When the pollutants accumulate to a certain level, there is a risk of them falling off in chunks.

[0006] Patent CN118782452A provides a method for cleaning the dome of a wafer pre-cleaning chamber. When the dome maintenance cycle arrives, the carrier is first covered and then argon gas is introduced. The argon gas is ionized into argon ions using a resonator. The argon ions randomly bombard in uncertain directions, bombarding and removing loose impurities above the chamber, thereby extending the service life of the chamber.

[0007] Based on the existing method of cleaning contaminants, not only does the process flow need to be interrupted, but the chamber door must be repeatedly opened to transfer wafers in and out, and substrates in and out. The probability of contaminants in the chamber spreading to the transfer platform and contaminating the processed wafers increases. Summary of the Invention

[0008] In view of the deficiencies in the prior art, the technical solution adopted by the present invention is:

[0009] A PVD pre-cleaning chamber for synchronous self-cleaning of a special-shaped target material, comprising a process chamber body, wherein the process chamber body is provided with:

[0010] The shielding member is configured as a spherical structure with an opening facing downward, and a process space is formed inside the shielding member;

[0011] An ICP generator, ionizing the process gas in the process space into plasma;

[0012] The self-biased wafer stage moves vertically between a low position and a high position, pulling the gas ions in the plasma downward;

[0013] A special-shaped target assembly is arranged correspondingly at the opening of the shielding member, comprising an aluminum member and an insulating member. The aluminum member has an inner wall that gradually shrinks from top to bottom, so that the inner surface of the aluminum member forms a sputtering inclination angle of 0°-90° with the horizontal direction. The sputtering inclination angle causes the trajectory of the sputtered aluminum particles to cover the inner wall of the shielding member and avoid the wafer surface. The insulating member is wrapped around the lower edge of the aluminum member;

[0014] An electromagnet assembly is arranged on the periphery of the special-shaped target assembly and is used to constrain and extend the motion trajectory of electrons inside the special-shaped target assembly;

[0015] Wherein, when the self-biased wafer carrier is at the carrier high position, its carrier surface maintains a vertical distance of 0.5mm-10mm from the lower opening of the special-shaped target assembly.

[0016] Furthermore, the aluminum part includes:

[0017] The contraction part, whose diameter gradually decreases from top to bottom;

[0018] an upper horizontal portion connected to an upper edge of the contraction portion;

[0019] a lower horizontal portion connected to the lower edge of the contraction portion;

[0020] Wherein, the inner side surface of the contraction portion is an arc surface or a conical surface of R20-R50.

[0021] Furthermore, the insulating member includes:

[0022] a first insulating portion, attached to the outer surface of the shrinkage portion;

[0023] a second insulating portion, attached to the lower side of the upper horizontal portion;

[0024] The third insulating portion is attached to the lower side surface of the lower horizontal portion.

[0025] Furthermore, the insulating member further comprises:

[0026] The annular insulating flange is annularly connected to the inner edge of the third insulating portion, and the width of the annular insulating flange is 3mm-8mm.

[0027] Furthermore, the electromagnet assembly includes a plurality of electromagnetic units distributed along the circumferential direction.

[0028] Furthermore, the process chamber body includes:

[0029] The bottom frame of the process chamber has a wafer inlet and outlet configured on its side, and the lower position of the self-biased wafer carrier corresponds to the wafer inlet and outlet;

[0030] Process chamber top frame;

[0031] A partition is provided between the process chamber bottom frame and the process chamber top frame and is used for carrying the special-shaped target assembly.

[0032] A PVD pre-cleaning method for synchronous self-cleaning of a special-shaped target is implemented by using the PVD pre-cleaning chamber for synchronous self-cleaning of a special-shaped target:

[0033] The self-biased wafer carrier descends to the carrier low position to receive the wafer, and then rises to the carrier high position;

[0034] A stable flow of process gas is introduced into the process space. The electromagnetic field generated by the ICP generator when it is powered on transfers energy to the process gas, ionizing the gas molecules to form plasma.

[0035] The self-biased wafer stage and electromagnet assembly are powered on simultaneously until the plasma density and distribution in the process chamber stabilize and the gas ions in the plasma are drawn to the wafer surface.

[0036] Maintaining the self-biased wafer stage and electromagnet assembly in working condition for a period of time, contaminants on the wafer surface are gradually removed by gas ion bombardment and diffused within the process chamber, achieving pre-cleaning of the wafer surface.

[0037] When contaminants need to be cleaned, a DC bias is applied to the shaped target assembly to energize the shaped target assembly. Gas ions are drawn to its inner surface. Under the bombardment of the gas ions, aluminum particles are sputtered out of the surface of the shaped target assembly, adhere to the contaminants in the process chamber, and then deposited on the inner wall of the shielding member.

[0038] After the wafer surface pre-cleaning is completed, first turn off the power to the special-shaped target assembly, then turn off the electromagnet assembly, then turn off the power to the ICP generator and the self-biased wafer carrier, and finally cut off the process gas flow;

[0039] The self-biased wafer carrier is lowered to the carrier lower position to complete wafer unloading.

[0040] Furthermore, after the wafer surface is pre-cleaned and the electromagnet assembly is turned off, wait for 3s-5s and keep the ICP generator working for 3s-5s to perform secondary cleaning of residual contaminants.

[0041] Furthermore, the duration of applying the DC bias to the special-shaped target assembly accounts for 10%-50% of the total pre-cleaning time.

[0042] Furthermore, the DC bias power P and the process gas flow rate Q satisfy:

[0043] When Q<100sccm, P=500W-1500W;

[0044] When 100sccm≤Q≤200sccm, P=1500W-3000W.

[0045] Furthermore, the coverage angle θ of the sputtered aluminum particles satisfies 45°≤θ≤75°, where θ is the angle between the moving direction of the aluminum particles and the vertical direction.

[0046] Advantages of the present invention:

[0047] The contaminant cleaning process in the process space is completed during the wafer processing process. The self-cleaning process of the process chamber does not need to interrupt the wafer processing process, does not require the introduction of additional sputtering materials, and does not require repeated opening of the chamber door, thereby reducing the probability of contamination of processed wafers.

[0048] By adding a special-shaped target assembly and guiding the plasma to bombard the target, the aluminum particles sputtered out fly upward. During the flight, they absorb pollutants (oxygen, hydrogen plasma or free radicals) free in the chamber, or bombard the pollutants above the chamber. At the same time, the potential energy carried by the sputtered aluminum particles will compact the loosely adhered particles collected on the surface of the shield above the chamber more firmly, preventing the generation of falling particles, contaminating the surface of the processed wafer, and affecting the cleaning process of the wafer surface.

[0049] The insulating parts of the special-shaped target assembly play an isolation role, especially when the corresponding self-biased wafer carrier is at the high position of the carrier, the self-biased wafer carrier will never come into contact with the aluminum parts for conduction, thereby improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a structural cross-sectional view of the present invention.

[0051] Figure 2 It is a cross-sectional view of the wafer carrier in the present invention when it is in the low position.

[0052] Figure 3 It is a cross-sectional view of the wafer carrier in the present invention when it is in the carrier high position.

[0053] Figure 4 This is a particle trajectory diagram of the present invention in working state. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present 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 only used to explain the present invention and are not intended to limit the present invention.

[0055] Please see the attached Figure 1 -Attached Figure 4 , this application proposes a PVD pre-cleaning chamber and method for synchronous self-cleaning of special-shaped targets.

[0056] The present application first proposes a PVD pre-cleaning chamber for synchronous self-cleaning of a special-shaped target, including a process chamber body 10, wherein the process chamber body 10 is provided with: a shielding member 100, which is configured as a spherical structure with an opening facing downward, and a process space is formed on its inner side; an ICP generating member 200, which ionizes the process gas in the process space into plasma; a self-biased wafer carrier 300, which rises and falls between a low position and a high position of the carrier in the vertical direction, and pulls the gas ions in the plasma downward; a special-shaped target assembly 400, which is correspondingly arranged at the opening of the shielding member 100, and includes an aluminum member 410 and an insulating member 420, wherein the aluminum member 410 has a top-down The inner wall gradually shrinks downward so that the inner surface of the aluminum part 410 forms a sputtering inclination angle of 0°-90° with the horizontal direction, and the sputtering inclination angle makes the trajectory of the sputtered aluminum particles cover the inner wall of the shielding part 100 and avoid the wafer surface. The insulating part 420 is wrapped at the lower edge of the aluminum part 410; the electromagnet assembly 500 is arranged on the periphery of the special-shaped target assembly 400, and is used to restrain and extend the movement trajectory of electrons on the inner side of the special-shaped target assembly 400; wherein, when the self-biased wafer carrier 300 is in the carrier high position, its bearing surface maintains a vertical distance of 0.5mm-10mm from the lower opening of the special-shaped target assembly 400.

[0057] In the present application, the shielding member 100, the special-shaped target assembly 400, and the self-biased wafer carrier 300 are arranged coaxially from top to bottom; the process gas enters the process space from the lower opening of the special-shaped target assembly 400; the ICP generator 200 is a commonly used ICP generating device, and its coil is wrapped around the outside of the shielding member 100. By applying a radio frequency electric field to the coil, the electromagnetic field generated by the coil transfers energy to the process gas through inductive coupling to achieve ionization of gas molecules and form a high-density plasma in the process space; the radio frequency power supply connected to the self-biased wafer carrier 300 is energized to form an electric field toward the carrier surface, thereby accelerating the gas ions to flow toward the wafer surface; after the aluminum part 410 in the special-shaped target assembly 400 is energized, its inner surface is bombarded by gas ions and sputters out aluminum particles, and the aluminum particles sputter obliquely and adhere to the contaminants in the process workpiece to achieve self-cleaning.

[0058] The shape of the shielding member 100 and the shape of the special-shaped target assembly 400 refer to the attached Figure 2 It can be more intuitively expressed that the cross-section of the shielding member 100 is an arch. Since the aluminum member 410 does not have a horizontal inner surface, i.e., a sputtering surface, the aluminum particles are sputtered out of the special-shaped target assembly 400 in a direction that can cover the inner wall of the shielding member 100 without sputtering onto the upper surface of the self-biased wafer carrier 300, i.e., the front surface of the wafer. When it is necessary to clean the contaminants in the process space, its working principle is as shown in the attached figure. Figure 4 As shown, the sputtered aluminum particles fly upward at an angle to the horizontal. During their flight, they absorb contaminants loose in the process space and bombard them onto the arched inner wall of shield 100. Simultaneously, the potential energy carried by the aluminum particles further consolidates loosely adhered contaminants already collected on shield 100, preventing them from falling back into the process space due to gravity and contaminating the processed wafers. Once the process space is clean of contaminants, the chamber door can be opened to remove the wafers, preventing contaminants from escaping.

[0059] Therefore, the contaminant cleaning process in the process space of the present application does not require interrupting the wafer processing process, does not require additional introduction of sputtering materials, and does not require repeated opening of the chamber door, thereby reducing the probability of contamination of the processed wafers.

[0060] Since the special-shaped target assembly 400 is directly loaded into the process chamber body 10, there is no need to consider the problem that the PVD process platform requires multiple stations to be compatible with the storage of pure aluminum substrates. At the same time, the structure of the special-shaped target assembly 400 enables the sputtering area of ​​the aluminum particles to cover the inner wall of the shielding member 100 without sputtering to the front of the self-biased wafer carrier 300, and will not affect the cleaning process of the wafer surface.

[0061] It should be noted that in order to improve the sealing of the connection between the shielding member 100 and the special-shaped target assembly 400 and prevent the shielding member 100 from being charged, the connection surface between the special-shaped target assembly 400 and the shielding member 100 is insulated by adding an insulating gasket or an insulating layer.

[0062] It should be noted that the insulating member 420 meets the insulation requirements of the special-shaped target assembly 400 installed on the process chamber body 10. The insulating member 420 is specifically a ceramic member, which is fixedly connected to the aluminum member 410 by ceramic welding.

[0063] The electromagnet assembly 500 described in the present application includes a plurality of electromagnetic units distributed along the circumferential direction, which are used for secondary sputtering with electrons, thereby enhancing the plasma density near the inner side of the special-shaped target assembly 400.

[0064] In the present application, the process chamber body 10 includes: a process chamber bottom frame 10a, a side of which is provided with a wafer inlet and outlet 10b, and the lower position of the self-biased wafer carrier 300 corresponds to the wafer inlet and outlet 10b; a process chamber top frame 10c; and a partition 10d, which is arranged between the process chamber bottom frame 10a and the process chamber top frame 10c and is used to carry the special-shaped target material assembly 400.

[0065] In one embodiment, the self-biased wafer carrier 300 is located in the bottom frame 10a of the process chamber, the shielding member 100 and the ICP generator 200 are located in the top frame 10c of the process chamber, and the partition 10d separates the bottom frame 10a and the top frame 10c of the process chamber while providing a stable installation frame for the target material 400.

[0066] In this application, the aluminum member 410 includes a contraction portion 411, the diameter of which gradually decreases from top to bottom; an upper horizontal portion 412 connected to the upper edge of the contraction portion 411; and a lower horizontal portion 413 connected to the lower edge of the contraction portion 411. The lower horizontal portion 413 fills the sputtering dead angle of the contraction portion 411, increases the reliability of the sputtering area of ​​the aluminum particles covering the inner wall of the shielding member 100, and improves the quality of contaminant removal.

[0067] In one embodiment, the upper horizontal portion 412 overlaps the upper side of the partition 10 d to increase the support area for the aluminum component 410 and improve the stability of the special-shaped target assembly 400 .

[0068] In this embodiment, a chamfer is provided at the connection between the upper horizontal portion 412 and the contraction portion 411 to prevent tip discharge.

[0069] In some specific embodiments, the inner surface of the contraction portion 411 is an arc surface or a conical surface with an angle of R20-R50. When the inner surface of the contraction portion 411 is an arc surface, the angle between the section of the contraction portion 411 at different points and the horizontal plane varies, causing the trajectory of the sputtered aluminum particles to move upward in a scattered manner, improving the utilization rate of the target surface and effectively covering the space where contaminants exist. When the inner surface of the contraction portion 411 is a conical surface, the angle between the section of the contraction portion 411 at different points and the horizontal plane remains constant, causing the trajectory of the sputtered aluminum particles to move upward at a specific angle. Although the requirement of covering the space where contaminants exist is achieved, the movement path of the aluminum particles is partially repeated, and the utilization rate of the target surface is reduced.

[0070] To accommodate the shape of aluminum component 410, in this application, insulating component 420 includes a first insulating portion 421, which is attached to the outer surface of contracted portion 411; a second insulating portion 422, which is attached to the underside of upper horizontal portion 412; and a third insulating portion 423, which is attached to the underside of lower horizontal portion 413. First insulating portion 421, second insulating portion 422, and third insulating portion 423 are integrally constructed and have equal thickness, providing stable shielding for aluminum component 410.

[0071] Furthermore, the insulating member 420 further includes an annular insulating flange 424 , which is annularly connected to the inner edge of the third insulating portion 423 . The width of the annular insulating flange 424 is 3 mm to 8 mm.

[0072] The addition of an annular insulating flange 424 completely isolates the self-biased wafer stage 300 from the aluminum component 410, improving the safety of the shaped target assembly 400. The inner diameter of the annular insulating flange 424 corresponds to the size of the lower opening of the shaped target assembly 400. When the self-biased wafer stage 300 is raised to its upper position, its support surface maintains a vertical distance of 0.5 mm to 10 mm from the lower opening of the shaped target assembly 400, allowing process gases to enter the process space through the gap between the two.

[0073] The present application also proposes a PVD pre-cleaning method for synchronous self-cleaning of a special-shaped target, which is implemented by using a PVD pre-cleaning chamber for synchronous self-cleaning of a special-shaped target, and is characterized by:

[0074] The self-biased wafer carrier 300 is lowered to the carrier low position to receive the wafer, and then raised to the carrier high position;

[0075] A stable flow of process gas is introduced into the process space, and the electromagnetic field generated by the ICP generator 200 when powered on transfers energy to the process gas, ionizing the gas molecules to form plasma.

[0076] The self-biased wafer stage 300 and the electromagnet assembly 500 are powered on simultaneously until the plasma density and distribution in the process chamber are stable and the gas ions in the plasma are drawn to the wafer surface.

[0077] The self-biased wafer stage 300 and the electromagnet assembly 500 are maintained in the working state for a period of time, and the contaminants on the wafer surface are gradually removed by the gas ion bombardment and diffused in the process chamber, thereby achieving pre-cleaning of the wafer surface;

[0078] When contaminants need to be cleaned, a DC bias is applied to the shaped target assembly 400 to power the shaped target assembly 400. Gas ions are drawn to the inner surface of the shaped target assembly 400. Under the bombardment of the gas ions, aluminum particles are sputtered out of the surface of the shaped target assembly 400, adhere to the contaminants in the process chamber, and then deposited on the inner wall of the shielding member 100.

[0079] After the wafer surface pre-cleaning is completed, the shaped target assembly 400 is first powered off, then the electromagnet assembly 500 is turned off, then the ICP generator 200 and the self-biased wafer stage 300 are powered off, and finally the process gas flow is cut off;

[0080] The self-biased wafer carrier 300 is lowered to the carrier lower position to complete wafer unloading.

[0081] Typically, argon is used as the process gas.

[0082] For easy understanding, please refer to the attached Figure 1 , a number of PIN needles 10e are arranged in the vertical direction in the process chamber body 10, and the PIN needles pass through the self-biased wafer carrier 300; before the process gas is introduced, the self-biased wafer carrier 300 is in the carrier low position, corresponding to the wafer inlet and outlet 10b, and the wafer enters the process chamber body 10 from the wafer inlet and outlet 10b and sits on the PIN needles 10e, and then the self-biased wafer carrier 300 rises to the carrier high position, and the wafer gradually separates from the PIN needles and sits on the upper surface, i.e., the front surface, of the self-biased wafer carrier 300; after the process gas flow is cut off, the self-biased wafer carrier 300 is lowered from the carrier high position to the carrier low position, and the wafer is lifted up by the PIN needles 10e again, and the wafer is moved out of the process chamber body 10 from the wafer inlet and outlet 10b, and a wafer processing cycle is completed.

[0083] It should be noted that the process in which aluminum particles are sputtered out of the surface of the special-shaped target assembly 400, adhere to the contaminants in the process chamber, and then deposited on the inner wall of the shielding member 100 is the self-cleaning process of the process chamber; the self-cleaning frequency is controlled by the power-on time of the aluminum part 410 in the special-shaped target assembly 400, wherein the duration of the DC bias applied to the special-shaped target assembly 400 accounts for 10%-50% of the total pre-cleaning time, and the power-on time is set according to the amount of contaminants on the surface of the processed wafer. The more contaminants on the wafer surface, the longer the target material is powered on.

[0084] In one embodiment, after the wafer surface is pre-cleaned and the electromagnet assembly 500 is turned off, a 3-5 second wait is performed, with the ICP generator 200 remaining in operation for another 3-5 seconds to perform a secondary cleanup of any remaining contaminants. During this wait, even if contaminants land on the wafer surface again, they will be bombarded a second time, ensuring the pre-cleaning effect of the wafer surface. The ICP generator 200 and self-biased wafer stage 300 are then powered off to complete the self-cleaning operation.

[0085] In one embodiment, the DC bias power P and process gas flow rate Q satisfy the following conditions: when Q < 100 sccm, P = 500W-1500W; when 100 sccm ≤ Q ≤ 200 sccm, P = 1500W-3000W. Dynamic matching of process gas flow rate and sputtering power can address the over- or under-sputtering issues caused by fixed parameters in traditional methods. When the argon flow rate increases, appropriately increasing the power can maintain a stable sputtering output.

[0086] In one embodiment, the coverage angle θ of the sputtered aluminum particles satisfies 45°≤θ≤75°, where θ is the angle between the movement direction of the aluminum particles and the vertical direction. θ can be controlled by adjusting the curvature radius R of the contraction portion 411 or the taper of the conical surface.

[0087] By adopting the above-mentioned self-cleaning method, the wafer processing process in the process space includes a contaminant cleaning process, without interrupting the wafer processing and without repeatedly opening the chamber door to perform operations such as wafer out, substrate in, and substrate out, thereby reducing the probability of contamination of the processed wafer.

[0088] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A PVD pre-cleaning chamber for synchronous self-cleaning of a special-shaped target, comprising a process chamber body (10), characterized in that: The process chamber body (10) is provided with: The shielding member (100) is configured as a spherical structure with an opening facing downward, and a process space is formed inside the shielding member; An ICP generating element (200) ionizes the process gas in the process space into plasma; A self-biased wafer carrier (300) is raised and lowered between a carrier low position and a carrier high position in a vertical direction to pull gas ions in the plasma downward; A special-shaped target assembly (400) is arranged correspondingly at the opening of the shielding member (100), comprising an aluminum member (410) and an insulating member (420); the aluminum member (410) has an inner wall that gradually shrinks from top to bottom, so that the inner surface of the aluminum member (410) forms a sputtering inclination angle of 0°-90° with the horizontal direction, and the sputtering inclination angle causes the trajectory of the sputtered aluminum particles to cover the inner wall of the shielding member (100) and avoid the wafer surface; the insulating member (420) is wrapped at the lower edge of the aluminum member (410); An electromagnet assembly (500) is arranged on the periphery of the special-shaped target assembly (400) and is used to constrain and extend the motion trajectory of electrons inside the special-shaped target assembly (400); When the self-biased wafer carrier (300) is at a carrier high position, a vertical distance of 0.5 mm to 10 mm is maintained between its carrier surface and the lower opening of the special-shaped target assembly (400); The aluminum part (410) includes: a contraction portion (411), the diameter of which gradually decreases from top to bottom; An upper horizontal portion (412) is connected to the upper edge of the contraction portion (411); A lower horizontal portion (413) connected to the lower edge of the contraction portion (411); The inner side surface of the contraction portion (411) is an arc surface or a conical surface with an angle of R20-R50.

2. The PVD pre-cleaning chamber for synchronous self-cleaning of special-shaped targets according to claim 1, characterized in that: The insulating member (420) comprises: A first insulating portion (421) is attached to the outer surface of the contraction portion (411); a second insulating portion (422) attached to the lower side of the upper horizontal portion (412); The third insulating portion (423) is attached to the lower side surface of the lower horizontal portion (413).

3. The PVD pre-cleaning chamber with synchronous self-cleaning for special-shaped targets according to claim 2, characterized in that: The insulating member (420) further includes: The annular insulating flange (424) is annularly connected to the inner edge of the third insulating portion (423), and the width of the annular insulating flange (424) is 3 mm to 8 mm.

4. The PVD pre-cleaning chamber for synchronous self-cleaning of a special-shaped target according to any one of claims 1 to 3, characterized in that: The process chamber body (10) comprises: A process chamber bottom frame (10a) is provided with a wafer inlet and outlet (10b) on its side, and the lower position of the self-biased wafer carrier (300) corresponds to the wafer inlet and outlet (10b); Process chamber top frame (10c); A partition (10d) is provided between the process chamber bottom frame (10a) and the process chamber top frame (10c), and is used to carry the special-shaped target assembly (400).

5. A PVD pre-cleaning method for synchronous self-cleaning of a special-shaped target, implemented using the PVD pre-cleaning chamber for synchronous self-cleaning of a special-shaped target as claimed in claim 1, characterized in that: The self-biased wafer carrier (300) is lowered to a carrier low position to receive the wafer, and then raised to a carrier high position; A process gas with a stable flow rate is introduced into the process space, and the electromagnetic field generated by the ICP generating element (200) when it is powered on transfers energy to the process gas, ionizing the gas molecules to form plasma; The self-biased wafer carrier (300) and the electromagnet assembly (500) are simultaneously powered on and operated until the plasma density and distribution in the process chamber are stabilized and the gas ions in the plasma are drawn to the wafer surface; Maintaining the working state of the self-biased wafer carrier (300) and the electromagnet assembly (500) for a period of time, the pollutants on the wafer surface are gradually removed by gas ion bombardment and diffused in the process chamber, thereby achieving pre-cleaning of the wafer surface; When it is necessary to clean the contaminants, a DC bias is applied to the special-shaped target assembly (400) so that the special-shaped target assembly (400) is powered on and works, gas ions are drawn to the inner surface thereof, and under the bombardment of the gas ions, aluminum particles are sputtered out of the surface of the special-shaped target assembly (400), adhere to the contaminants in the process chamber, and are deposited on the inner wall of the shielding member (100); After the wafer surface pre-cleaning is completed, the special-shaped target assembly (400) is first powered off, and then the electromagnet assembly (500) is turned off. Then, the ICP generating element (200) and the self-biased wafer carrier (300) are powered off, and finally, the process gas flow is cut off. The self-biased wafer carrier (300) is lowered to the carrier lower position to complete wafer unloading.

6. The PVD pre-cleaning method for synchronous self-cleaning of a special-shaped target according to claim 5, characterized in that: After the wafer surface is pre-cleaned and the electromagnet assembly (500) is turned off, wait for 3s-5s and keep the ICP generating element (200) working for 3s-5s to perform secondary cleaning of residual contaminants.

7. The PVD pre-cleaning method for synchronous self-cleaning of a special-shaped target according to claim 5, characterized in that: The duration of the DC bias applied to the special-shaped target assembly (400) accounts for 10%-50% of the total pre-cleaning duration.

8. The PVD pre-cleaning method for synchronous self-cleaning of a special-shaped target according to claim 7, characterized in that: The DC bias power P and the process gas flow rate Q satisfy: When Q<100sccm, P=500W-1500W; When 100sccm≤Q≤200sccm, P=1500W-3000W.

9. The PVD pre-cleaning method for synchronous self-cleaning of a special-shaped target according to claim 5, characterized in that: The coverage angle θ of the sputtered aluminum particles satisfies 45°≤θ≤75°, where θ is the angle between the moving direction of the aluminum particles and the vertical direction.

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