A physical vapor deposition apparatus and a physical vapor deposition method

Abstract

The application discloses a physical vapor deposition device and a physical vapor deposition method. The physical vapor deposition device comprises a chamber, a target material arranged at the top of the chamber, a base for carrying a wafer arranged at the bottom of the chamber, an electromagnet assembly arranged at the periphery of the chamber and below the target material, the electromagnet assembly comprising a plurality of electromagnetic coils arranged at intervals along the axial direction of the chamber, the excitation parameters of each electromagnetic coil being independently adjustable, a collimator arranged in the chamber and between the electromagnet assembly and the base, a plurality of collimation holes being arranged on the collimator and penetrating through the thickness direction of the collimator, and sputtering particles sputtered from the target material entering the collimator after being modulated by the electromagnet assembly and directly shooting at the wafer on the surface of the base after being collimated by the collimator, so as to improve the incident perpendicularity of the sputtering particles.

Description

Technical Field

[0001] This application relates to the field of deposition technology, and in particular to a physical vapor deposition apparatus and a physical vapor deposition method. Background Technology

[0002] Physical vapor deposition (PVD) is a key process technology in semiconductor integrated circuit manufacturing, widely used in processes such as copper interconnects and barrier layer deposition. In copper interconnect processes, PVD-Cu deposition equipment (i.e., physical vapor deposition copper thin film deposition equipment, a type of PVD equipment specifically used for depositing thin copper films in semiconductor chip manufacturing) generates sputtered particles by sputtering a copper target, and directs these sputtered particles to deposit onto the wafer surface, completing the filling of trenches or via structures.

[0003] As semiconductor manufacturing processes continue to advance to more advanced nodes, device feature sizes continue to shrink, and the aspect ratio of trenches or vias continues to increase, the requirements for the perpendicular incidence of sputtered particles are becoming increasingly stringent. Therefore, how to improve the incident perpendicularity of sputtered particles has become a research direction in this field. Summary of the Invention

[0004] In view of the above problems, this application provides a physical vapor deposition (PVD) apparatus and a physical vapor deposition method to improve the incident perpendicularity of sputtered particles. The specific solution is as follows:

[0005] A physical vapor deposition apparatus, comprising:

[0006] A chamber, wherein a target material is disposed at the top of the chamber and a base for supporting the wafer is disposed at the bottom;

[0007] An electromagnet assembly is disposed on the outer periphery of the cavity and located below the target material. The electromagnet assembly includes a plurality of electromagnetic coils arranged at intervals along the axial direction of the cavity, and the excitation parameters of each electromagnetic coil are independently adjustable.

[0008] A collimator is disposed in the cavity and located between the electromagnet assembly and the base. The collimator has a plurality of collimation holes that penetrate along its thickness direction.

[0009] The sputtered particles ejected from the target are modulated by the electromagnet assembly and enter the collimator. After being collimated by the collimator, they are directly shot towards the wafer located on the surface of the base.

[0010] Optionally, the electromagnet assembly includes a first electromagnetic coil, a second electromagnetic coil, and a third electromagnetic coil arranged axially spaced along the chamber.

[0011] The first electromagnetic coil is used to apply a converging magnetic field to the sputtered particles, causing the sputtered particles to converge toward the central axis of the chamber; the second electromagnetic coil is used to apply a diverging magnetic field to the sputtered particles, causing the particles to diverge away from the central axis of the chamber; the third coil is used to apply an angle correction magnetic field to the sputtered particles modulated by the first and second electromagnetic coils, so as to reduce the incident angle of the sputtered particles when they enter the collimator.

[0012] Optionally, the first electromagnetic coil, the second electromagnetic coil, and the third electromagnetic coil are arranged along the direction from the top of the chamber to the bottom of the chamber;

[0013] or,

[0014] The second electromagnetic coil, the first electromagnetic coil, and the third electromagnetic coil are arranged along the direction from the top of the chamber to the bottom of the chamber.

[0015] Optionally, the space in the chamber between the target and the wafer is divided into a first space and a second space, the first space being located near the target and the second space being located near the wafer, and the collimator being located in the second space.

[0016] Optionally, it also includes an adjustment component disposed on the outer periphery of the cavity for adjusting the axial position of at least one of the first electromagnetic coil, the second electromagnetic coil, and the third electromagnetic coil in the cavity.

[0017] Optionally, the collimator has a rectangular cross-sectional view along the axial direction of the chamber.

[0018] Optionally, it further includes: a first shielding member, which is disposed around the inner periphery of the side wall of the chamber and located between the collimator and the target material.

[0019] Optionally, it further includes: a second shielding member, which is disposed around the inner periphery of the side wall of the chamber and located on the side of the collimator away from the target material;

[0020] or,

[0021] The collimator includes a collimating portion and a frame portion that is fixedly connected to the collimating portion and surrounds the collimating portion. The frame portion extends in length relative to the collimating portion toward the wafer direction and serves as a second shield.

[0022] Optionally, it further includes: a rotating assembly for controlling the collimator or the base to rotate in an axial direction perpendicular to the chamber.

[0023] A physical vapor deposition method, applied to the physical vapor deposition apparatus described in any one of the preceding claims, the method comprising:

[0024] Place the wafer on the base at the bottom of the chamber, evacuate the chamber to the predetermined vacuum level, and introduce working gas;

[0025] A sputtering power source is applied to the target material located at the top of the chamber to ionize the process gas and bombard the surface of the target material to generate sputtered particles.

[0026] The sputtered particles are modulated by the spatial magnetic field generated by an electromagnet assembly located below the target material. The electromagnet assembly includes multiple electromagnetic coils spaced apart along the axial direction of the chamber, and the excitation parameters of each electromagnetic coil are independently adjustable.

[0027] A collimator located below the electromagnet assembly is used to collimate the sputtered particles modulated by the magnetic field, and at least part of the sputtered particles collimated by the collimator are directly deposited on the wafer surface.

[0028] When the physical vapor deposition (PVD) equipment provided in this application is in operation, sputtered particles ejected from the target first pass through the area where the electromagnet assembly is located. Under the influence of the spatial magnetic field generated by the electromagnet assembly, they are modulated and then enter the collimator. After being collimated through the collimator's collimation aperture, they are deposited onto the wafer surface. Since the sputtered particles do not experience any magnetic field or other directional modulation after passing through the collimator and before being deposited on the wafer surface, horizontal tilting caused by subsequent magnetic field control is avoided. This allows the sputtered particles to be incident on the wafer surface in a nearly vertical direction, improving the incident perpendicularity of the sputtered particles and significantly reducing the proportion of particles blocked by the collimator. Under the same sputtering power, this increases the deposition rate and target utilization. Furthermore, with the significantly reduced proportion of particles blocked by the collimator, the amount of particles deposited on the collimator surface is greatly reduced, thereby alleviating the problem of peeling debris caused by copper layer accumulation in the collimator and extending the maintenance cycle of the PVD equipment.

[0029] In addition, in the physical vapor deposition equipment provided in this application embodiment, sputtered particles do not undergo any magnetic field modulation after passing through the collimator and are directly deposited on the wafer surface. Therefore, no horizontal tilt caused by the subsequent magnetic field will occur. When applied to wafers with deep hole structures, sputtered particles can be incident vertically to the bottom of the deep hole structure on the wafer surface, reducing the risk of overhangs at the top of the deep hole structure and the formation of internal voids, and improving the coverage of the bottom of the deep hole and the coverage of the step. Attached Figure Description

[0030] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0031] Figure 1 This is a schematic diagram of a physical vapor deposition apparatus.

[0032] Figure 2 A schematic diagram of a physical vapor deposition apparatus provided in an embodiment of this application;

[0033] Figure 3 A schematic diagram of another physical vapor deposition apparatus provided in this application embodiment;

[0034] Figure 4 A schematic diagram of another physical vapor deposition apparatus provided in this application embodiment;

[0035] Figure 5 This is a flowchart of a physical vapor deposition method provided in an embodiment of this application. Detailed Implementation

[0036] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0037] The terminology used in the embodiments section of this application is only for explaining specific embodiments of this application and is not intended to limit this application. Various modifications and variations can be made to this application without departing from its spirit or scope. Moreover, with the development of technology and the emergence of new scenarios, the technical solutions provided by the embodiments of this application are equally applicable to similar technical problems, which is obvious to those skilled in the art. Therefore, this application is intended to cover modifications and variations of this application that fall within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the embodiments provided in this application can be combined with each other without contradiction.

[0038] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] As described in the background section, improving the incident perpendicularity of sputtered particles has become a research direction in this field.

[0040] Taking PVD-Cu deposition equipment as an example, currently, the industry commonly uses a combination of a collimator (Filter Orifice, FO) and an electromagnet to control the direction of sputtered ions. The layout of this combination has undergone a gradual evolution. For example... Figure 1 As shown, the earliest PVD-Cu deposition equipment only used a collimator 01 as a single control component. However, the collimator 01, through its dense array of small holes, could only filter ions at large angles. Ions blocked by the walls of the collimator 01 holes could not participate in deposition, limiting the deposition rate and target utilization. To further improve the utilization of sputtered particles and deposition uniformity, those skilled in the art gradually added magnet components to the collimator 01 design: firstly, a set of magnets 02 was added above the collimator 01, and a set of magnets 03 was added below the collimator 01, improving the spatial distribution of the ion beam through magnetic field control; subsequently, to further improve the deposition uniformity across the entire wafer, a second set of magnets 04 was added below the collimator 01. This resulted in a layout with the collimator positioned above it, one set of magnets above the collimator, and two sets of magnets below the collimator.

[0041] In the above layout scheme, after the sputtered copper ions exit the target surface, they first pass through a magnet above the collimator. This magnet is used to initially tidy up the sputtered ions, allowing the ion beam to pass through the collimator better. Subsequently, the ions pass through the collimator located at the top of the cavity. The collimator performs preliminary collimation of the copper ions through dense small holes, filtering out ions with large angles. After passing through the collimator, the copper ions continue to move downwards and enter the two sets of electromagnet regions below the collimator. These two sets of electromagnets compensate for the horizontal deviation of the copper ions by adjusting the distribution of the electromagnetic field, thereby optimizing the deposition uniformity of the entire wafer. Finally, the copper ions are deposited on the wafer surface, completing the trench / via filling.

[0042] The inventors discovered that the above layout scheme has the following shortcomings:

[0043] Firstly, the deposition rate is low and there is a risk of particle contamination. In this layout, copper ions sputtered from the target pass directly into the collimator after passing through the magnet above the collimator. A large number of oblique ions with large exit angles are blocked by the hole walls when passing through the small holes of the collimator and deposit on the collimator surface. These blocked copper ions cannot participate in thin film deposition, reducing target utilization and deposition rate. At the same time, as the process cycle accumulates, the copper layer deposited on the collimator surface continues to thicken, which may peel off and form fragments, causing defects on the wafer.

[0044] Secondly, the ion-filling capability is insufficient. The function of the collimator is to direct ions passing through its aperture vertically downwards. However, ions still have a certain angular distribution range after passing through the collimator. When ions continue downwards into the two sets of electromagnet regions below the collimator, their trajectory is deflected by the Lorentz force of the magnetic field below, producing a horizontal tilt component. This causes the ion beam, which was originally collimated by the collimator, to be modulated by the magnetic field again before reaching the wafer surface, resulting in a directional shift. The effective incident angle deviates from the vertical direction again, weakening the collimator's collimation effect. For deep hole structures with high aspect ratios, tilted ions often collide with the upper part of the hole wall or the top opening edge, easily forming overhang structures. In subsequent electroplating processes, these overhangs will prematurely close the hole opening, leading to void defects inside the hole, directly affecting the electrical performance and reliability of the copper interconnect.

[0045] Third, with the continuous advancement of semiconductor manufacturing processes, the requirements for collimation are becoming increasingly stringent. However, when faced with the technical need to improve collimation, those skilled in the art, influenced by the existing architecture of collimator on top and electromagnet on the bottom, can only think of making improvements based on this structural layout. For example, they might add an additional collimating electric field between the electromagnet below the collimator and the wafer, increase the voltage driving power of the collimator, or adjust the collimator capacitance, in order to further reduce the deviation of the ion incident angle. Such improvements are not only costly to modify equipment (e.g., adding a collimating electric field power supply to the wafer surface, with a single power supply costing hundreds of thousands of yuan), but also fail to fundamentally solve the inherent defect that ions deviate from the vertical direction due to magnetic field modulation before reaching the wafer.

[0046] In view of this, this embodiment provides a physical vapor deposition apparatus that can be used for copper interconnect thin film deposition in semiconductor manufacturing processes. For example... Figure 2 As shown, the physical vapor deposition apparatus provided in this application embodiment includes: a chamber 100, an electromagnet assembly 200, and a collimator 300.

[0047] Specifically, in this embodiment, a target 110 is disposed on the inner side of the top of the chamber 100 for providing film-forming material during sputtering, and a base 120 is disposed at the bottom of the chamber 100 for supporting the wafer 121 to be deposited. Optionally, in some embodiments of this application, the chamber 100 can be a vacuum chamber, the target 110 can be a high-purity copper target, and the base 120 can be provided with heating elements and / or cooling channels to control the temperature of the wafer 121 during the deposition process. This application does not limit this and the specific method depends on the circumstances.

[0048] Continue as Figure 2As shown, the electromagnet assembly 200 is disposed on the outer periphery of the chamber 100 and located below the target 110. Specifically, the electromagnet assembly 200 includes multiple electromagnetic coils arranged at intervals along the axial direction of the chamber 100. The excitation parameters of each electromagnetic coil are independently adjustable. During the deposition process, a preset spatial magnetic field distribution can be formed in the space between the target 110 and the collimator 300 by independently adjusting the excitation parameters of each electromagnetic coil. This allows for directional control of the sputtered particles ejected from the target 110, enabling them to enter the collimator 300 at a smaller incident angle. Optionally, in some embodiments of this application, the excitation parameters may include the magnitude of the current, the direction of the current, and the number of turns of the electromagnetic coil winding. This application does not limit these parameters and the specific method depends on the circumstances.

[0049] Continue as Figure 2 As shown, the collimator 300 is disposed inside the chamber 100 and located between the electromagnet assembly 200 and the base 120. Optionally, the collimator 300 is a conductive metal structure with a plurality of collimation holes 310 extending along its thickness direction. The collimation holes 310 are used to allow sputtered particles to pass from the target 110 toward the wafer 121. The number, diameter, and aspect ratio of the collimation holes 310 can be designed according to process requirements. Optionally, in some embodiments of this application, the aspect ratio of the collimation holes 310 can range from 2:1 to 6:1, including the endpoint values. However, this application does not limit this and it depends on the specific circumstances.

[0050] In the physical vapor deposition apparatus provided in this application embodiment, the target 110, electromagnet assembly 200, collimator 300 and base 120 are arranged sequentially from top to bottom along the axial direction of the chamber 100. When the physical vapor deposition apparatus is in operation, the sputtered particles sputtered from the target 110 first pass through the area where the electromagnet assembly 200 is located, and are modulated under the action of the spatial magnetic field generated by the electromagnet assembly 200. Then they enter the collimator 300, are collimated through the collimation hole 310 and deposited onto the surface of the wafer 121. In this embodiment, since the sputtered particles do not undergo any magnetic field or other directional modulation after passing through the collimator 300 and before being deposited on the surface of the wafer 121, the horizontal tilt caused by subsequent magnetic field modulation is avoided. This allows the sputtered particles to be incident on the surface of the wafer 121 in a nearly vertical direction, improving the incident verticality of the sputtered particles and significantly reducing the proportion of particles blocked by the collimator 300. This allows previously wasted sputtered particles to be utilized, increasing the deposition rate by 30% to 60% at the same sputtering power, thus improving the deposition rate and target utilization. Moreover, with the significantly reduced proportion of particles blocked by the collimator 300, the amount of particles deposited on the surface of the collimator 300 is greatly reduced, thereby alleviating the problem of peeling and fragmentation caused by copper layer accumulation in the collimator 300 and extending the maintenance cycle of the physical vapor deposition equipment.

[0051] In addition, in the physical vapor deposition apparatus provided in this application embodiment, sputtered particles do not undergo any magnetic field modulation after passing through the collimator 300 and are directly deposited onto the surface of wafer 121. Therefore, no horizontal tilt caused by the subsequent magnetic field will occur. When applied to wafers with deep hole structures, sputtered particles can be incident vertically to the bottom of the deep hole structure on the wafer surface, reducing the risk of overhangs at the top of the deep hole structure and the formation of internal voids, and improving the coverage of the bottom of the deep hole and the coverage of the step.

[0052] Optionally, in some embodiments of this application, the electromagnet assembly 200 includes a first electromagnetic coil 210, a second electromagnetic coil 220, and a third electromagnetic coil 230 arranged axially at intervals along the cavity 100, with these three sets of electromagnetic coils respectively surrounding the outer peripheral wall of the cavity 100. It should be noted that, in the embodiments of this application, each of the three sets of electromagnetic coils is connected to an independent excitation power supply, and the number of turns in each winding is independently set, so that the first electromagnetic coil 210, the second electromagnetic coil 220, and the third electromagnetic coil 230 can independently adjust the spatial magnetic field.

[0053] Based on the above embodiments, in some embodiments of this application, the first electromagnetic coil 210 is configured to apply a converging magnetic field to sputtered particles sputtered from the target 110, causing the sputtered particles to converge towards the central axis of the chamber 100, thereby reducing the probability that sputtered particles ejected at large angles cannot enter the collimation aperture 310 of the collimator 300, and improving the deposition rate and target utilization. The second electromagnetic coil 220 is configured to apply a diverging magnetic field to the sputtered particles, causing the sputtered particles to diverge away from the central axis of the chamber 100, thereby improving the uniformity of the spatial distribution of sputtered particles above the collimator 300.

[0054] For example, in some embodiments of this application, the first electromagnetic coil 210 has a stronger focusing effect on sputtered particles than the second electromagnetic coil 220 has a stronger diverging effect on sputtered particles. This is to utilize the synergistic cooperation between the first electromagnetic coil 210 and the second electromagnetic coil 220 to increase the probability of sputtered particles with large deviation angles but still usable entering the collimator 300, thereby improving the target material utilization rate. It also allows sputtered particles with excessively large deviation angles to be screened out through the combination of divergence and focusing, thereby achieving the screening and homogenization of sputtered particles. However, this application does not limit this to the specific implementation.

[0055] Optionally, in some embodiments of this application, the third electromagnetic coil 230 is configured to apply an angle-correcting magnetic field to the sputtered particles modulated by the first electromagnetic coil 210 and the second electromagnetic coil 220, so as to reduce the incident angle of the sputtered particles when they enter the collimator 300, so that the sputtered particles enter the collimator 300 as vertically as possible, improve the incident verticality of the sputtered particles, reduce the proportion of particles blocked by the collimator 300 in the sputtered particles, improve the deposition rate and target utilization, alleviate the problem of peeling fragments caused by copper layer accumulation in the collimator 300, extend the maintenance cycle of the physical vapor deposition equipment, and reduce the risk of formation of overhangs and internal voids at the top of the deep hole structure, and improve the bottom coverage and step coverage of the deep hole.

[0056] Optionally, in some embodiments of this application, the first electromagnetic coil 210 is located between the second electromagnetic coil 220 and the target 110, that is, the first electromagnetic coil 210, the second electromagnetic coil 220, and the third electromagnetic coil 230 are arranged along the direction from the top to the bottom of the chamber 100, so that sputtered particles sputtered from the target 110 first pass through the converging effect of the first electromagnetic coil 210 and then through the diverging effect of the second electromagnetic coil 220; in other embodiments of this application, the first electromagnetic coil 210 is located on the side of the second electromagnetic coil 220 away from the target 110, that is, the second electromagnetic coil 220, the first electromagnetic coil 210, and the third electromagnetic coil 230 are arranged along the direction from the top to the bottom of the chamber 100, so that sputtered particles sputtered from the target 110 first pass through the diverging effect of the second electromagnetic coil 220 and then through the converging effect of the first electromagnetic coil 210; this application does not limit this, and it can be determined according to the specific application to filter sputtered particles with different angles.

[0057] As can be seen from the above, in the embodiments of this application, the electromagnet assembly 200 includes a first electromagnetic coil 210, a second electromagnetic coil 220 and a third electromagnetic coil 230. The first electromagnetic coil 210 and the second electromagnetic coil 220 can first use magnets to filter out sputtered particles that are within a preset momentum range and whose incident direction is within a preset angle range. Then, the third electromagnetic coil 230 is used to reduce the incident angle of the sputtered particles when they enter the collimator 300, so that the sputtered particles enter the collimator 300 as vertically as possible, thereby improving the incident verticality of the sputtered particles.

[0058] Based on any of the above embodiments, in some embodiments of this application, the space in the chamber 100 between the target 110 and the wafer 121 is divided into a first space and a second space. The first space is located near the target 110, and the second space is located near the wafer 121. The collimator 300 is located in the second space. By placing the collimator in the chamber 100 near the wafer 121, the probability of sputtered particles exiting through the collimation hole 310 of the collimator 300 being deposited on the wafer surface is increased. When applied to wafers with deep hole structures, the probability of sputtered particles exiting through the collimation hole 310 of the collimator 300 reaching the bottom of the deep hole structure is increased, further reducing the risk of overhangs at the top of the deep hole structure and internal voids, and improving the coverage of the bottom of the deep hole and the coverage of the step.

[0059] Optionally, in some embodiments of this application, the ratio of the first space and the second space is 1:1, so that the collimator 300 is disposed in the lower half of the space between the target material 110 and the wafer 121, thereby reducing the distance between the collimator 300 and the surface of the wafer 121, while ensuring that the first space has sufficient space to accommodate the electromagnet assembly 200. However, this application does not limit this, and it depends on the specific circumstances.

[0060] It should be noted that in practical applications, the dimension of the collimator 300 perpendicular to the axis of the chamber 100 is typically larger than the dimension of the wafer 121 perpendicular to the axis of the chamber 100. For example, the diameter of the wafer 121 is 300 mm, and the diameter of the collimator 300 is 400 mm to 500 mm. The collimator 300 is positioned on the side of the electromagnet assembly 200 facing the wafer 121, and is relatively close to the wafer 121. Sputtered particles emitted through the collimator 300 can reach the wafer surface with a very short trajectory. Even with structural design adjustments to the collimator 300, sputtered particles emitted from the edge region of the collimator 300 are unlikely to reach the surface of the wafer 121. Therefore, in some optional embodiments of this application, such as... Figure 3 As shown, the collimator 300 has a rectangular cross-sectional view along the axial direction of the chamber 100, meaning that the bottom of the collimator 300 has no protruding structure, thereby reducing the manufacturing difficulty and cost of the collimator 300. However, this application does not limit this. In other embodiments of this application, the cross-sectional view of the collimator 300 along the axial direction of the chamber 100 may also adopt other shapes, depending on the specific circumstances.

[0061] Optionally, in some embodiments of this application, the physical vapor deposition apparatus further includes an adjustment component, which may be disposed on the outer periphery of the chamber 100, for adjusting the position of at least one of the first electromagnetic coil 210, the second electromagnetic coil 220 and the third electromagnetic coil 230 in the axial direction of the chamber 100, so as to change the relative distance between each electromagnetic coil and the target 110 and the collimator 300 by adjusting the position of the first electromagnetic coil 210, the second electromagnetic coil 220 and / or the third electromagnetic coil 230, thereby adjusting the magnetic field distribution in the chamber 100 and increasing the degree of freedom of adjustment of the magnetic field distribution in the chamber 100.

[0062] Specifically, in some embodiments of this application, the adjustment assembly includes a threaded mechanism to allow each electromagnetic coil to be detachably fixed to the outer peripheral wall of the chamber, thereby enabling the operator to disassemble and adjust the axial position of each electromagnetic coil in the chamber. In other embodiments of this application, the adjustment assembly includes a slide rail adjustment mechanism to allow the axial position of each electromagnetic coil in the chamber to be adjusted by sliding the electromagnetic coil in the adjustment assembly. However, this application does not limit this and the specific method depends on the circumstances.

[0063] It should be noted that when the adjustment component includes a slide rail adjustment mechanism, different electromagnetic coils can share the same adjustment component, or different electromagnetic coils can have their own corresponding adjustment components, depending on the specific situation.

[0064] Exemplary examples, in some embodiments of this application, the distance between the target 110 and the wafer 121 along the axial direction of the chamber 100 is approximately 600 mm. The collimator 300 is located in the area below the base 120, occupying an axial space of approximately 200 mm. The axial distance between the collimator 300 and the wafer 121 is approximately 100 mm to 200 mm. Therefore, the axial space above the collimator 300 (i.e., between the target 110 and the collimator 300) is 300 mm to 400 mm, providing sufficient space for the installation and adjustment of the electromagnet assembly 200. However, this application does not limit this, and the specific arrangement depends on the circumstances.

[0065] As can be seen from the above, during the sputtering process, some sputtered particles ejected from the target 110 will deposit onto the surface of the wafer 121, while some will not. These undeposited sputtered particles will deposit onto the collimator 300 and some onto the sidewalls of the chamber 100, causing contamination of the chamber 100. To reduce the contamination of the chamber 100 by sputtered particles, in some optional embodiments of this application, the following continues... Figure 3As shown, the physical vapor deposition apparatus further includes a first shield 400 (also known as an upper shield or upper blocking layer), which is arranged around the inner periphery of the side wall of the chamber 100 and located between the collimator 300 and the target 110, to prevent sputtered particles from depositing on the upper side wall of the chamber 100 and causing contamination to the chamber 100.

[0066] Based on any of the above embodiments, in some embodiments of this application, such as Figure 4 As shown, the physical vapor deposition apparatus also includes a second shield 500 (also known as a lower shield or lower blocking layer), located between the collimator 300 and the base 120, to prevent sputtered particles from depositing on the lower sidewall of the chamber 100 and contaminating the chamber 100.

[0067] For example, both the first shielding member 400 and the second shielding member 500 are annular structures, arranged around the inner periphery of the side wall of the chamber 100. However, this application does not limit this, and it depends on the specific circumstances.

[0068] In other embodiments of this application, the physical vapor deposition apparatus may also omit the second shield 500, instead using the frame of the collimator 300 as a lower shield to prevent sputtered particles from depositing on the lower sidewall of the chamber 100 and contaminating the chamber 100. Specifically, in this embodiment, continuing as... Figure 3 As shown, the collimator 300 includes a collimation portion 320 and a frame portion 330 that is fixedly connected to the collimation portion 320 and surrounds the collimation portion 320. The frame portion 330 extends a certain length relative to the collimation portion 320 in the direction toward the wafer 121 and serves as a second shielding element.

[0069] It should be noted that in practical applications, the first shield 400, the second shield 500, and the collimator 300 need to be replaced periodically because sputtered particles will be deposited on their surfaces. In this embodiment, the frame portion of the collimator 300 is used to achieve the function of the second shield, which can reduce the cost of physical vapor deposition equipment.

[0070] Optionally, in some embodiments of this application, the collimator 300 can be mounted on the inner periphery of the side wall of the chamber 100 via a support ring. Specifically, a support ring is provided on the inner periphery of the side wall of the chamber 100, and the collimator 300 is detachably supported on the support ring for periodic replacement or cleaning. However, this application does not limit this, and it depends on the specific circumstances.

[0071] Optionally, in some embodiments of this application, the collimator 300 is connected to an external circuit via a conductive connector. Specifically, the collimator 300 is connected to a bias power supply, which is used to apply a bias voltage to the collimator 300. During the deposition process, the potential difference between the collimator 300 and the surrounding plasma can be changed by adjusting the magnitude and polarity of the bias voltage applied to the collimator 300, thereby adjusting the energy and trajectory of sputtered particles passing through the collimation aperture 310, and thus optimizing the particle energy distribution and deposition uniformity deposited on the surface of wafer 121.

[0072] Optionally, in some embodiments of this application, the collimator 300 is further connected to a capacitor adjustment device. This device is used to adjust the capacitance to ground of the collimator 300, thereby changing the impedance matching characteristics of the collimator 300 in a radio frequency environment, affecting the coupling efficiency of the plasma within the chamber 100, and thus assisting in adjusting the transmission efficiency of sputtered particles. Exemplarily, this capacitor adjustment device can be a variable capacitor module, and its connection method with the collimator 300 is a conventional technique in the art and will not be described further here.

[0073] Optionally, in the embodiments of this application, the capacitance to ground of the collimator 300 and the bias voltage applied to the collimator 300 can be adjusted independently to increase the degree of adjustment freedom of the collimator 300.

[0074] It should be noted that, due to the close distance between the collimator 300 and the wafer 121 (e.g., 100mm to 200mm), the collimation of the sputtered particles emitted from the collimator 300 is relatively good. Therefore, the amount of sputtered particles emitted from the collimation hole 310 of the collimator 300 deposited on the surface of the wafer 121 is likely to differ between the amount of sputtered particles deposited in the first region corresponding to the collimation hole region on the surface of the wafer 121 and the amount of sputtered particles deposited in the second region corresponding to the non-collimation hole region in the collimator 300 on the surface of the wafer 121. Therefore, in some embodiments of this application, the physical vapor deposition apparatus further includes a rotating component for controlling the collimator 300 or the base 120 to rotate in a direction perpendicular to the axial direction of the chamber 100, so that during the deposition process, the collimator 300 and the base 120 rotate relative to each other, thereby reducing the difference in the amount of sputtered particles deposited in the first region corresponding to the collimation hole region on the wafer surface and the amount of sputtered particles deposited in the second region corresponding to the non-collimation hole region in the collimator on the wafer surface, and improving the uniformity of sputtered particle deposition on the wafer surface.

[0075] Optionally, in some embodiments of this application, the following continues... Figure 3 and Figure 4As shown, the physical vapor deposition apparatus also includes a magnetron 600, which is disposed on the side of the target 110 away from the electromagnet assembly 200 and can be disposed on the top of the chamber 100. It is used to generate a confinement magnetic field near the target surface. The confinement magnetic field generated by the magnetron is combined with the electric field between the target and the chamber wall to make the secondary electrons generated during sputtering move along a spiral path, prolonging the movement path and residence time of the electrons near the target surface, thereby increasing the probability of collision ionization of electrons with working gas atoms, forming a high-density plasma near the target 110 surface, and enhancing sputtering efficiency.

[0076] Optionally, in some embodiments of this application, the physical vapor deposition apparatus may also include standard components of physical vapor deposition apparatus such as sputtering power supply, vacuum system, and air intake system. This application does not limit these components and may specify them depending on the circumstances.

[0077] Accordingly, embodiments of this application also provide a physical vapor deposition method, applied to any of the physical vapor deposition apparatuses described above, such as... Figure 5 As shown, the method includes:

[0078] Step S1: Place the wafer on the base at the bottom of the chamber, evacuate the chamber to a predetermined vacuum level, and introduce a working gas. Optionally, during the deposition process, a vacuum system can be used to evacuate the chamber to a predetermined vacuum level, and argon (Ar) gas can be introduced into the chamber as the working gas through an inlet system. However, this application does not limit this to the specific method used.

[0079] Step S2: A sputtering power supply is applied to the target material positioned at the top of the chamber, ionizing the process gas and bombarding the target surface to generate sputtered particles. Optionally, the sputtering power supply can be a DC power supply or a HIPIMS power supply or a combination thereof; this application does not limit this, and the specific method is determined according to the process requirements.

[0080] Step S3: The sputtered particles are modulated by the spatial magnetic field generated by the electromagnet assembly positioned below the target. The electromagnet assembly includes a first electromagnetic coil, a second electromagnetic coil, and a third electromagnetic coil arranged at intervals along the axial direction of the chamber, and the excitation parameters of each electromagnetic coil are independently adjustable.

[0081] Optionally, in some embodiments of this application, modulating the sputtered particles using the spatial magnetic field generated by an electromagnet assembly disposed below the target includes:

[0082] A first current is applied to the first electromagnetic coil, causing the first electromagnetic coil to apply a converging magnetic field to the sputtered particles, causing the sputtered particles to converge toward the central axis of the chamber;

[0083] A second current is applied to the second electromagnetic coil, causing the second electromagnetic coil to apply a diverging magnetic field to the sputtered particles, causing the sputtered particles to diverge in a direction away from the central axis of the chamber;

[0084] A third current is applied to the third electromagnetic coil, which then applies an angle-correcting magnetic field to the sputtered particles modulated by the first and second electromagnetic coils. This reduces the incident angle of the sputtered particles as they enter the collimator, allowing them to enter the collimator as vertically as possible. This reduces the proportion of sputtered particles blocked by the collimator, improves the deposition rate and target utilization, alleviates the problem of spalling debris caused by copper layer accumulation in the collimator, extends the maintenance cycle of the physical vapor deposition equipment, reduces the risk of overhangs and internal voids at the top of the deep hole structure, and improves the bottom coverage and step coverage of the deep hole.

[0085] Based on the above embodiments, in some embodiments of this application, a converging magnetic field can be applied to the sputtered particles using a first electromagnetic coil to cause the sputtered particles to converge toward the central axis of the chamber, and then a diverging magnetic field can be applied to the sputtered particles using a second electromagnetic coil to cause the sputtered particles to diverge away from the central axis of the chamber; alternatively, a diverging magnetic field can be applied to the sputtered particles using a second electromagnetic coil to cause the sputtered particles to diverge away from the central axis of the chamber, and then a converging magnetic field can be applied to the sputtered particles using a first electromagnetic coil to cause the sputtered particles to converge toward the central axis of the chamber. This application does not limit this approach and the specific method depends on the circumstances.

[0086] For example, in some embodiments of this application, the first electromagnetic coil has a stronger focusing effect on sputtered particles than the second electromagnetic coil has a stronger diverging effect on sputtered particles. This is to utilize the synergistic cooperation between the first and second electromagnetic coils to increase the probability of sputtered particles with large deviation angles but still usable entering the collimator, thereby improving the target material utilization rate. Furthermore, sputtered particles with excessively large deviation angles are screened out through the combination of divergence and focusing, thus achieving the screening and homogenization of sputtered particles. However, this application does not limit this to the specific implementation, but rather depends on the circumstances.

[0087] Step S4: A collimator located below the electromagnet assembly is used to collimate the sputtered particles modulated by the magnetic field. At least a portion of the collimated sputtered particles are directly deposited on the wafer surface. It should be noted that in this embodiment, the sputtered particles, after being collimated by the collimator, do not undergo any further modulation by a magnetic field or other directions before deposition on the wafer surface. Therefore, no horizontal tilt caused by subsequent magnetic fields occurs, improving deposition efficiency and target utilization. Furthermore, the sputtered particles are directed as vertically as possible towards the wafer surface. When applied to wafers with deep-hole structures, this increases the probability that sputtered particles exiting the collimator's aperture can reach the bottom of the deep-hole structure, further reducing the risk of overhangs at the top and internal voids in the deep-hole structure, and improving the coverage of the bottom and steps of the deep-hole.

[0088] It should be noted that, due to the close distance between the collimator and the wafer (e.g., 100mm to 200mm), the collimation of the sputtered particles emitted from the collimator is relatively good. Therefore, the sputtered particles emitted through the collimator's collimation aperture are easily deposited on the wafer surface, resulting in a difference in the amount of sputtered particles deposited in the first region corresponding to the collimation aperture on the wafer surface and the amount of sputtered particles deposited in the second region corresponding to the non-collimation aperture region of the collimator on the wafer surface. Therefore, in some embodiments of this application, the method further includes: during the deposition process, rotating at least one of the wafer or the collimator, so that the collimator and the substrate undergo relative rotational motion during the deposition process, reducing the difference in the amount of sputtered particles deposited in the first region corresponding to the collimation aperture on the wafer surface and the amount of sputtered particles deposited in the second region corresponding to the non-collimation aperture region of the collimator on the wafer surface, thereby improving the uniformity of sputtered particle deposition on the wafer surface.

[0089] In summary, in the physical vapor deposition method provided in this application, sputtered particles ejected from the target first pass through the area where the electromagnet assembly is located, where they are modulated by the spatial magnetic field generated by the electromagnet assembly. They then enter the collimator, are vertically collimated through the collimation aperture, and are deposited onto the wafer surface. Since the sputtered particles do not experience any magnetic field or other directional modulation after passing through the collimator and before deposition on the wafer surface, horizontal tilting caused by subsequent magnetic field control is avoided. This allows the sputtered particles to be incident on the wafer surface in a nearly vertical direction, significantly reducing the proportion of particles blocked by the collimator. Under the same sputtering power, this improves the deposition rate and target utilization. Furthermore, with the significantly reduced proportion of particles blocked by the collimator, the amount of particles deposited on the collimator surface is greatly reduced, thereby alleviating the problem of peeling debris caused by copper layer accumulation in the collimator and extending the maintenance cycle of the physical vapor deposition equipment.

[0090] In addition, in the physical vapor deposition method provided in this application embodiment, sputtered particles do not undergo any magnetic field modulation after passing through the collimator and are directly deposited on the wafer surface. Therefore, no horizontal tilt caused by the subsequent magnetic field will occur. When applied to wafers with deep hole structures, sputtered particles can be incident vertically to the bottom of the deep hole structure on the wafer surface, reducing the risk of overhangs at the top of the deep hole structure and the formation of internal voids, and improving the coverage of the bottom of the deep hole and the coverage of the step.

[0091] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on its differences from other embodiments, and similar or identical parts between embodiments can be referred to interchangeably. Regarding the methods disclosed in the embodiments, since they correspond to the apparatus disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to in the decorative section.

[0092] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

Claims

1. A physical vapor deposition apparatus, characterized in that, include: A chamber, wherein a target material is disposed at the top of the chamber and a base for supporting the wafer is disposed at the bottom; An electromagnet assembly is disposed on the outer periphery of the cavity and located below the target material. The electromagnet assembly includes a plurality of electromagnetic coils arranged at intervals along the axial direction of the cavity, and the excitation parameters of each electromagnetic coil are independently adjustable. A collimator is disposed in the cavity and located between the electromagnet assembly and the base. The collimator has a plurality of collimation holes that penetrate along its thickness direction. The sputtered particles ejected from the target are modulated by the electromagnet assembly and enter the collimator. After being collimated by the collimator, they are directly shot towards the wafer located on the surface of the base.

2. The physical vapor deposition apparatus according to claim 1, characterized in that, The electromagnet assembly includes a first electromagnetic coil, a second electromagnetic coil, and a third electromagnetic coil arranged at intervals along the axial direction of the chamber. The first electromagnetic coil is used to apply a converging magnetic field to the sputtered particles, causing the sputtered particles to converge toward the central axis of the chamber; the second electromagnetic coil is used to apply a diverging magnetic field to the sputtered particles, causing the particles to diverge away from the central axis of the chamber; the third coil is used to apply an angle correction magnetic field to the sputtered particles modulated by the first and second electromagnetic coils, so as to reduce the incident angle of the sputtered particles when they enter the collimator.

3. The physical vapor deposition apparatus according to claim 2, characterized in that, The first electromagnetic coil, the second electromagnetic coil, and the third electromagnetic coil are arranged along the direction from the top of the chamber to the bottom of the chamber; or, The second electromagnetic coil, the first electromagnetic coil, and the third electromagnetic coil are arranged along the direction from the top of the chamber to the bottom of the chamber.

4. The physical vapor deposition apparatus according to claim 2, characterized in that, The space between the target and the wafer in the chamber is divided into a first space and a second space. The first space is located on the side closer to the target, and the second space is located on the side closer to the wafer. The collimator is located in the second space.

5. The physical vapor deposition apparatus according to claim 4, characterized in that, It also includes an adjustment component disposed on the outer periphery of the cavity, for adjusting the axial position of at least one of the first electromagnetic coil, the second electromagnetic coil and the third electromagnetic coil in the cavity.

6. The physical vapor deposition apparatus according to claim 1, characterized in that, The collimator has a rectangular cross-sectional view along the axial direction of the chamber.

7. The physical vapor deposition apparatus according to claim 1, characterized in that, Also includes: The first shielding element is arranged around the inner circumference of the side wall of the chamber, located between the collimator and the target material.

8. The physical vapor deposition apparatus according to claim 1, characterized in that, Also includes: The second shielding element is arranged around the inner circumference of the side wall of the chamber and is located on the side of the collimator away from the target material; or, The collimator includes a collimating portion and a frame portion that is fixedly connected to the collimating portion and surrounds the collimating portion. The frame portion extends in length relative to the collimating portion toward the wafer direction and serves as a second shield.

9. The physical vapor deposition apparatus according to claim 1, characterized in that, Also includes: A rotating assembly for controlling the collimator or the base to rotate in an axial direction perpendicular to the chamber.

10. A physical vapor deposition method, characterized in that, Applied to the physical vapor deposition apparatus according to any one of claims 1-9, the method comprises: Place the wafer on the base at the bottom of the chamber, evacuate the chamber to the predetermined vacuum level, and introduce working gas; A sputtering power source is applied to the target material located at the top of the chamber to ionize the process gas and bombard the surface of the target material to generate sputtered particles. The sputtered particles are modulated by the spatial magnetic field generated by an electromagnet assembly located below the target material. The electromagnet assembly includes multiple electromagnetic coils spaced apart along the axial direction of the chamber, and the excitation parameters of each electromagnetic coil are independently adjustable. A collimator located below the electromagnet assembly is used to collimate the sputtered particles modulated by the magnetic field, and at least part of the sputtered particles collimated by the collimator are directly deposited on the wafer surface.

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