Electrochemical mechanical polishing and planarization apparatus

Abstract

Disclosed in the present invention is an electrochemical mechanical polishing and planarization apparatus, at least comprising a polishing head, wherein the polishing head comprises: a polishing head body; a hard conductive disc used for suctioning a wafer substrate; a conductive drive unit, at least part of which can be connected to a power supply, and at least part of which is in contact with and transmittingly works in conjunction with the hard conductive disc to drive the hard conductive disc to rotate circumferentially; a moving gap formed between the polishing head body and the conductive drive unit, and / or between the conductive drive unit and the hard conductive disc, and / or between the hard conductive disc and the polishing head body; and a retaining ring which is an annular component capable of being in contact with a polishing pad, wherein the hard conductive disc moves in an area defined by the retaining ring. In the present invention, by using the hard conductive disc, the circuit turn-on between the polishing head and the wafer substrate can be achieved to perform electrochemical mechanical polishing, thereby ensuring the long-term stability of electrochemical reaction; and the hard conductive disc is used for suctioning the wafer substrate at negative pressure, thereby solving the problem of a flexible film being pulled and thus broken.

Description

An electrochemical mechanical polishing and planarization device Technical Field

[0001] The present invention belongs to the technical field of semiconductor integrated circuit chip manufacturing, and in particular relates to an electrochemical mechanical polishing and planarization device. Background Art

[0002] The wafer substrate and semiconductor device manufacturing process includes processes such as polishing and surface planarization, typically using mechanical polishing, chemical mechanical polishing, or planarization techniques. A wafer carrier (polishing head) applies pressure to the wafer backside, controlling parameters such as pressure, polishing head speed, polishing disk speed, and polishing liquid flow rate to polish or planarize the wafer substrate's front surface or thin film surface on a polishing pad. Compared to mechanical polishing, chemical mechanical polishing and planarization achieve higher polishing or planarization efficiency by adjusting the polishing liquid formula to produce a chemical reaction on the wafer surface. This can also achieve better polishing or planarization results, including higher flatness and lower defectivity. Building on chemical mechanical polishing and planarization, for conductive substrates or film layers, electrochemical mechanical polishing and planarization can further utilize the conductive properties of the wafer substrate or thin film on the wafer surface to form a current path, allowing electrochemical reactions to occur on the wafer substrate or thin film surface. Through precise control of the circuit system, the surface chemical reaction rate is increased, thereby improving the efficiency of mechanical polishing and planarization.

[0003] Typically, in chemical mechanical polishing (CMP) or planarization technology, as a polishing head moves the wafer across a polishing pad, the polishing head rotates, driving a flexible membrane to rotate and polish the wafer. If a conventional flexible membrane is used in electrochemical processes to drive wafer polishing, the polishing head relies on the flexible membrane to rotate the conductive disk. The flexible membrane itself must withstand the forces of the polishing head's own rotation and the tensile forces caused by the polishing arm sweeping the polishing head across the polishing pad. Under harsh polishing conditions, the flexible membrane can be pulled so hard during polishing that it can rupture and cause safety accidents. Furthermore, existing CMP polishing processes involve pulling on the flexible membrane at the start of polishing and then returning to its original position after the polishing head stops, causing scratches between the wafer and the polishing pad, impacting the polishing process.

[0004] Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the present invention provides an electrochemical mechanical polishing and planarization device, which uses a hard conductive disk to negatively adsorb the wafer substrate and cooperates with a conductive drive unit to achieve electrical conduction. The conductive drive unit plays the functions of conduction and mechanical drive, while ensuring effective electrochemical mechanical polishing of the wafer substrate and extending the service life of the polishing head.

[0006] The technical solution adopted by the present invention to solve the technical problem is: an electrochemical mechanical polishing and planarization device, comprising at least a polishing head, the polishing head comprising:

[0007] Polishing head body;

[0008] A hard conductive disk, the lower surface of which is at least partially located in the same plane, for adsorbing the wafer substrate;

[0009] A conductive drive unit, at least part of which is connectable to a power source, and at least part of which contacts and engages with the hard conductive disk to drive the hard conductive disk to rotate circumferentially;

[0010] An active gap is formed between the polishing head body and the conductive drive unit, and / or between the conductive drive unit and the hard conductive disk, and / or between the hard conductive disk and the polishing head body;

[0011] The retaining ring is located below the polishing head body and is an annular component that can contact the polishing pad. The hard conductive disk moves within the area defined by the retaining ring.

[0012] Furthermore, the lower surface of the hard conductive disk is provided with air holes on the same plane, and the air holes are connected to the third air cavity in the hard conductive disk. When the third air cavity is under negative pressure, the hard conductive disk can absorb the wafer substrate.

[0013] Furthermore, it also includes a second air cavity with controllable pressure, which is used to drive the hard conductive disk to move up and down.

[0014] Furthermore, the hard conductive disk and the conductive drive unit are integrally connected, or the hard conductive disk and the conductive drive unit are separately provided.

[0015] Furthermore, the movable gap includes at least a radial movable gap and an axial movable gap.

[0016] Furthermore, the conductive drive unit includes a guide rod and a second drive part, the second drive part is connected to the hard conductive disk, the polishing head body forms a first drive part that is in transmission cooperation with the second drive part, the active gap is formed between the first drive part and the second drive part, and the second drive part maintains contact with the first drive part to achieve electrical conduction.

[0017] Furthermore, the conductive drive unit includes an electrically connected guide block and a wire, and the guide block is connected to the polishing head body, so that the polishing head body drives the hard conductive disk to rotate circumferentially through the guide block, and conducts current to the hard conductive disk during driving; the hard conductive disk forms a groove for the guide block to extend into, and the active gap is formed between the guide block and the groove.

[0018] Furthermore, there are multiple guide blocks, which are spaced apart along the circumference of the polishing head body, and the guide blocks maintain contact with the grooves to achieve electrical conduction.

[0019] Furthermore, the number of the wire is one or corresponds to the number of the guide blocks. When the number of the wire is one, all the guide blocks are connected as one through the ring body.

[0020] Furthermore, the conductive drive unit includes a guide rod and a second drive part, the guide rod is connected to the external power, the hard conductive disk forms a third drive part that cooperates with the second drive part in transmission, and the active gap is formed between the second drive part and the third drive part.

[0021] Furthermore, the conductive driving unit includes an elastic unit, which is connected to the polishing head body and the hard conductive disk respectively, so that the polishing head body, the elastic unit and the hard conductive disk surround and form the second air cavity.

[0022] Furthermore, the hard conductive disk has a rib which extends into the polishing head body and is sealed with the polishing head body via a seal to form the second air cavity and the movable gap, and the rib is electrically connected to the polishing head body.

[0023] Furthermore, the rotation direction of the hard conductive disk is the same as or opposite to the rotation direction of the polishing head body.

[0024] Furthermore, the lower surfaces of the hard conductive disks are located in the same plane; or, the lower surfaces of the hard conductive disks are located in the same plane to form a thickened area or a thinned area to form a height difference from nanometer level to micrometer level.

[0025] Furthermore, a flexible conductive cloth is attached to the lower surface of the hard conductive disk, and the flexible conductive cloth includes holes, and the holes match the positions of at least part of the pores of the hard conductive disk.

[0026] The beneficial effects of the present invention are as follows: 1) the hard conductive disk is used to realize the circuit conduction between the polishing head and the wafer substrate for electrochemical mechanical polishing, which can ensure the long-term stability of the electrochemical reaction and improve the process stability of electrochemical mechanical polishing; 2) the hard conductive disk is used to negatively adsorb the wafer substrate, which solves the problem that when the flexible membrane drives the wafer substrate to polish under harsh polishing conditions, the flexible membrane is pulled and causes cracking or change in elastic modulus, thereby extending the service life of the flexible parts in the polishing head; 3) the hard conductive disk is used to negatively adsorb the wafer substrate, and when the polishing head leaves the polishing pad, the return of the flexible membrane will not cause scratching between the wafer substrate and the polishing pad 4) When the flexible membrane is used as a driving component to drive the wafer substrate to polish, when it encounters grooves and other areas on the polishing pad, the force balance state fluctuates, which affects the polishing speed and the polishing efficiency. The hard drive in the hard conductive disk has higher stability, which can effectively avoid the above problems and improve the process stability. 5) The conductive drive unit not only plays the function of conductivity, but also can mechanically drive the hard conductive disk to carry the wafer substrate for polishing. The existence of the movable gap provides space for the hard conductive disk to float up and down and left and right, making the polishing more flexible. 6) The self-control function of the rotation direction of the hard conductive disk can be realized by cooperating with the retaining edge and the polishing head body. Its direction can be consistent with the rotation direction of the retaining ring and the hard conductive disk, or opposite to the rotation direction of the retaining ring and the hard conductive disk, providing more possibilities for the polishing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a schematic diagram of the three-dimensional structure of the electrochemical mechanical polishing and planarization device provided in Example 1 of the present invention.

[0028] FIG2 is a second schematic diagram of the three-dimensional structure of the electrochemical mechanical polishing and planarization device provided in the first embodiment of the present invention.

[0029] FIG3 is a schematic diagram of the three-dimensional structure of the hard conductive disk and the elastic unit provided in the first embodiment of the present invention.

[0030] FIG4 is a schematic diagram of the cross-section structure of the hard conductive disk provided in the first embodiment of the present invention.

[0031] FIG5 is a partial cross-sectional view of the hard conductive disk provided in the first embodiment of the present invention.

[0032] FIG6 is a cross-sectional view of an electrochemical mechanical polishing and planarization device provided in Example 1 of the present invention.

[0033] FIG7 is a schematic diagram of the three-dimensional structure of the hard conductive disk provided in the first embodiment of the present invention.

[0034] FIG8 is a schematic diagram of the three-dimensional structure of the polishing head body provided in the first embodiment of the present invention.

[0035] FIG9 is a schematic diagram of the three-dimensional structure of the electrochemical mechanical polishing and planarization device provided in the second embodiment of the present invention.

[0036] FIG10 is a front view of the electrochemical mechanical polishing and planarization device provided in the second embodiment of the present invention.

[0037] FIG11 is a schematic diagram of the three-dimensional structure of the hard conductive disk and the elastic unit provided in the second embodiment of the present invention.

[0038] FIG12 is a first cross-sectional view of the electrochemical mechanical polishing and planarization device provided in the second embodiment of the present invention.

[0039] FIG13 is a second cross-sectional view of the electrochemical mechanical polishing and planarization device provided in the second embodiment of the present invention.

[0040] FIG14 is a schematic diagram of the three-dimensional structure of the hard conductive disk and the elastic unit provided in the third embodiment of the present invention.

[0041] FIG15 is a cross-sectional view of an electrochemical mechanical polishing and planarization device provided in the third embodiment of the present invention.

[0042] FIG16 is a schematic diagram of the coordination structure of the hard conductive disk, the conductive driving unit, and the external power provided in the third embodiment of the present invention.

[0043] FIG17 is an enlarged view of the structure at point A in FIG16 .

[0044] FIG18 is a schematic diagram of the three-dimensional structure of the hard conductive disk provided in the third embodiment of the present invention.

[0045] FIG19 is a cross-sectional view of an electrochemical mechanical polishing and planarization device provided in a fourth embodiment of the present invention.

[0046] FIG20 is a schematic diagram of the coordination structure of the hard conductive disk and the conductive drive unit provided in the fourth embodiment of the present invention.

[0047] FIG21 is a schematic diagram of the three-dimensional structure of the polishing head body provided in the fourth embodiment of the present invention.

[0048] FIG22 is a cross-sectional view of an electrochemical mechanical polishing and planarization device provided in Example 5 of the present invention.

[0049] FIG23 is a schematic diagram of the three-dimensional structure of the hard conductive disk provided in the fifth embodiment of the present invention.

[0050] FIG24 is a cross-sectional view of an electrochemical mechanical polishing and planarization device provided in Example 6 of the present invention.

[0051] FIG25 is a schematic diagram of the coordination structure of the hard conductive disk, the conductive driving unit, and the external power provided in the sixth embodiment of the present invention.

[0052] FIG26 is a schematic diagram of the three-dimensional structure of the hard conductive disk provided in Example 6 of the present invention.

[0053] Among them, 1-polishing head body, 11-first air cavity, 12-annular groove, 2-hard conductive disk, 21-air hole, 22-third air cavity, 23-groove, 24-rib, 25-air path, 3-conductive drive unit, 31-guide rod, 311-outer gear ring, 312-external power, 32-second drive part, 33-first drive part, 34-guide block, 35-wire, 36-ring body, 37-third drive part, 4-active gap, 41-radial active gap, 42-axial active gap, 5-retaining ring, 6-second air cavity, 7-elastic unit, 8-seal. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the solutions of the present invention, the following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0055] Example 1

[0056] As shown in Figures 1 and 2, an electrochemical mechanical polishing and planarization device includes at least a polishing head, which includes a polishing head body 1, a hard conductive disk 2, a conductive driving unit 3, an active gap 4, and a retaining ring 5 located below the polishing head body 1.

[0057] A hard conductive disk 2 is a conductive disk made of a hard material, such as metal, conductive material, or other rigid conductive material. Specifically, metals may be aluminum, titanium, or stainless steel, while other conductive materials may include conductive ceramics and graphite. These materials are all conductive, allowing the hard conductive disk 2 to form a conductive circuit with the wafer substrate, polishing table, and power supply required for electrochemical mechanical polishing. Electricity is then transferred to the hard conductive disk 2 and then to the wafer substrate for surface modification, followed by mechanical polishing. In this embodiment, the lower surfaces of the hard conductive disk 2 are all located in the same plane. Of course, in other embodiments, the surface roughness of the horizontal portion of the hard conductive disk 2 can be increased or decreased in specific areas based on the thickness topography of the wafer substrate, thereby creating nanometer- to micrometer-scale height differences between different areas. In other embodiments, the side surfaces of the hard conductive disk 2 may be treated with insulation and chamfering. Insulation treatments include, but are not limited to, hard anodizing and surface coating.

[0058] In this embodiment, the hard conductive disk 2 is a disc-shaped structure, as shown in Figure 5. The upper surface of the hard conductive disk 2 is impermeable, while the lower surface of the hard conductive disk 2 is at least partially coplanar. The coplanar portion of the lower surface is provided with a plurality of air holes 21. A third air cavity 22 is defined within the hard conductive disk 2, communicating with the air holes 21. This third air cavity 22 must be sealed to prevent leakage of polishing fluid and contamination of the polishing head. Other functional connections that do not affect the internal environment of the polishing head can be achieved using any other connection method, such as an air pipe connection, a screw-and-seal connection to the body, a flexible membrane cavity design, or other sealing designs. These are readily achievable in the art and will not be further described. The diameter of the air holes 21 is 0.1-3 mm, and the total area of ​​all air holes 21 accounts for 0.1-5% of the lower surface area of ​​the hard conductive disk 2. When a negative pressure is generated in the third air cavity 22, the lower surface of the hard conductive disk 2, specifically the coplanar portion of the lower surface, can directly contact and adsorb the wafer substrate.

[0059] In this embodiment, all the air holes 21 are connected. As shown in FIG4 , radially staggered and connected air channels 25 are formed inside the hard conductive disk 2. The air channels 25 are connected to the third air cavity 22. The air holes 21 are correspondingly arranged in the area where the air channels 25 are located. Therefore, the negative pressure formed by all the air holes 21 is relatively balanced.

[0060] One of the judgment logics for whether the wafer substrate is loaded on the polishing head body 1 is to perform a pressure holding test after evacuating the third air cavity 22 to detect the vacuum condition of the third air cavity 22. If the negative pressure is maintained, the wafer substrate is on the polishing head body 1; otherwise, the wafer substrate is not on the polishing head body 1.

[0061] The retaining ring 5 is an annular component that can contact the polishing pad, and the hard conductive disk 2 moves within the area defined by the retaining ring 5 .

[0062] A first air cavity 11 is formed within the polishing head body 1, which controls the vertical movement and stroke of the polishing head body 1, thereby driving the hard conductive plate 2 and wafer substrate up and down. The polishing head also includes a second air cavity 6 with controllable pressure, which is used to drive the hard conductive plate 2 up and down.

[0063] In this embodiment, the conductive drive unit 3 further includes an elastic unit 7, which is connected to the polishing head body 1 and the hard conductive disk 2, respectively. Specifically, as shown in Figure 3, the elastic unit 7 is made of an elastic material and has a generally annular structure. One side of the elastic unit 7 is connected to the outer ring of the hard conductive disk 2, and the other side is fixedly connected between the polishing head body 1 and the retaining ring 5. The elastic unit 7, the polishing head body 1, and the hard conductive disk 2 enclose a second air cavity 4. The pressure within this second air cavity 4 is controllable. By adjusting the pressure within the second air cavity 4, the elastic unit 7 can be driven to flexibly move, assisting in the floating of the hard conductive disk 2 and the wafer substrate, thereby achieving electrochemical mechanical polishing of the wafer substrate. Here, the floating of the hard conductive disk 2 and the wafer substrate refers to the use of the elastic unit 7 to improve the movement of the hard conductive disk 2 and the wafer substrate, including vertical and radial floating, while the polishing head body 1 and the hard conductive disk 2 are mechanically driven. The method for controlling the pressure within the second air cavity 4 is already implemented in the prior art and will not be further described.

[0064] Of course, on the basis of the circuit being directly connected from the power electrode to the hard conductive disk 1 during the electrochemical mechanical polishing and planarization of the wafer substrate, the circuit can also be connected from the elastic unit 7 to the hard conductive disk 2 to realize the function of the hard conductive disk 2, without specific limitation.

[0065] A portion of the conductive drive unit 3 extends from the polishing head body 1 and is connected to a power source. The conductive drive unit 3 contacts and engages with the hard conductive disk 2, thereby driving the hard conductive disk 2 in circumferential rotation. The power source is not specifically limited; any power source is sufficient.

[0066] An active gap 4 is formed between the polishing head body 1 and the conductive drive unit 3; or, the active gap 4 is formed between the conductive drive unit 3 and the hard conductive disk 2; or, the active gap 4 is formed between the hard conductive disk 2 and the polishing head body 1; or, an active gap 4 is formed between the polishing head body 1 and the conductive drive unit 3, and at the same time, an active gap 4 is also formed between the conductive drive unit 3 and the hard conductive disk 2; or, an active gap 4 is formed between the polishing head body 1 and the conductive drive unit 3, and at the same time, an active gap 4 is also formed between the hard conductive disk 2 and the polishing head body 1; or, an active gap 4 is formed between the conductive drive unit 3 and the hard conductive disk 2, and at the same time, an active gap 4 is also formed between the hard conductive disk 2 and the polishing head body 1.

[0067] The conductive drive unit 3 includes a guide rod 31 and a second drive part 32. The second drive part 32 is connected to the hard conductive disk 2. At this time, the hard conductive disk 2 is integrally connected to the second drive part 32 of the conductive drive unit 3; the guide rod 31 is connected to the hard conductive disk 2. At this time, the hard conductive disk 2 and the guide rod 31 are integrally connected. Of course, the guide rod 31 can also be connected to the second drive part 32. At this time, the hard conductive disk 2 is integrally connected to the guide rod 31 and the second drive part 32.

[0068] A first driving portion 33 that is in transmission cooperation with the second driving portion 32 is formed on the polishing head body 1 , and the above-mentioned movable gap 4 is formed between the first driving portion 33 and the second driving portion 32 .

[0069] Specifically, as shown in Figures 6 to 8, the guide rod 31 is a hollow cylindrical structure, the bottom end of which is integrally connected to the upper surface of the hard conductive disk 2 (the side without the air hole 21), and the top end of which extends from the polishing head body 1; the second driving part 32 includes a plurality of fan-shaped protrusions spaced around the guide rod 31, which are fixedly connected to the outer wall of the guide rod 31. Of course, the specific shape of the protrusion is not limited and can also be square.

[0070] The first drive portion 33 is a slot structure into which the second drive portion 32 extends. When the polishing head body 1 rotates circumferentially, the first drive portion 33 and the second drive portion 32 cooperate to drive the hard conductive disk 2 to rotate circumferentially. The cross-sectional area of ​​the first drive portion 33 is larger than that of the second drive portion 32. Thus, while the second drive portion 32 engages the bottom of the slot of the first drive portion 33 to achieve electrical conduction, it can also move radially within the first drive portion 33 (radially referring to the diameter of the hard conductive disk 2). Alternatively, by connecting a power source to the first drive portion 33 to energize it, the second drive portion 32 engages the sidewalls of the slot of the first drive portion 33 to achieve electrical conduction, while also moving axially within the first drive portion 33. In other words, the second drive portion 32 engages at least the sidewall or bottom wall of the first drive portion 33 to achieve electrical conduction.

[0071] Of course, in other embodiments, the first driving portion 33 may be a convex block, and the second driving portion 32 may be a groove body, which is not specifically limited.

[0072] The radial active gap 41 and the axial active gap 42 between the above-mentioned first driving part 33 and the second driving part 32 constitute the active gap 4, that is, the active gap 4 is formed between the polishing head body 1 and the conductive driving unit 3, so that when the pressure in the second air cavity 4 is adjusted, the elastic unit 7 can be driven to perform flexible movement, assisting the hard conductive disk 2 and the wafer substrate to float, and the floating is completed in the above-mentioned active gap 4; the hard conductive disk 2 can form a conductive circuit required for electrochemical mechanical polishing with the wafer substrate, the polishing table, and the power supply, and the guide rod 31 is used to conduct electricity to the hard conductive disk 2 and then to the wafer substrate for surface modification, thereby realizing electrochemical mechanical polishing of the wafer substrate.

[0073] Example 2

[0074] As shown in Figures 9-11, in this embodiment, the conductive drive unit 3 includes an electrically connected guide block 34 and a wire 35. The guide block 34 is connected to the polishing head body 1, and the hard conductive disk 2 forms a groove 23 for the guide block 34 to extend into. In other words, the hard conductive disk 2 and the conductive drive unit 3 are separately provided. When the polishing head body 1 rotates circumferentially, the hard conductive disk 2 can be driven to rotate circumferentially by the cooperation between the guide block 34 and the groove 23. The cross-sectional area of ​​the groove 23 is larger than the cross-sectional area of ​​the guide block 34. Therefore, while the guide block 34 is in contact with the bottom of the groove 23 to achieve electrical conduction, the guide block 34 can also move radially within the groove 23 (the radial direction here refers to the diameter of the hard conductive disk 2). Alternatively, while the guide block 34 is in contact with the sidewall of the groove 23 to achieve electrical conduction, the guide block 34 can also move axially within the groove 23. In other words, the polishing head body 1 drives the hard conductive disk 2 to rotate circumferentially through the guide block 34 and conducts current to the hard conductive disk 2 during driving. The guide block 34 at least fits with the side wall or bottom wall of the groove 23 to achieve electrical conduction.

[0075] In this embodiment, there are multiple guide blocks 34 , which are spaced apart along the circumference of the polishing head body 1 . Accordingly, the number of grooves 23 is the same as the number of guide blocks 34 . There is one wire 35 or the number corresponds to the number of guide blocks 34 .

[0076] When the number of the conductive wire 35 is one, all the guide blocks 34 are connected as a whole through the ring body 36 , as shown in FIG. 12 and FIG. 13 .

[0077] The radial active gap 41 and the axial active gap 42 between the guide block 34 and the groove 23 constitute the active gap 4, that is, the active gap 4 is formed between the conductive drive unit 3 and the hard conductive disk 2. Since the guide block 34 is connected to the polishing head body 1, it can also be said that the active gap 4 is formed between the hard conductive disk 2 and the polishing head body 1. Therefore, when the pressure in the second air cavity 4 is adjusted, the elastic unit 7 can be driven to perform flexible movement, assisting the hard conductive disk 2 and the wafer substrate to float, and the floating is completed in the above-mentioned active gap 4; the hard conductive disk 2 can form a conductive circuit required for electrochemical mechanical polishing with the wafer substrate, the polishing table, and the power supply, and the electricity is conducted to the guide block 34 by the wire 35 and then to the wafer substrate for surface modification, thereby realizing the electrochemical mechanical polishing of the wafer substrate.

[0078] The rest is the same as that of the first embodiment and will not be described in detail.

[0079] Example 3

[0080] As shown in Figures 14 to 18, the conductive drive unit 3 includes a guide rod 31 and a second drive part 32. The top end of the guide rod 31 is connected to the external power 312, which can be a motor. The hard conductive disk 2 forms a third drive part 37 that cooperates with the second drive part 32 in transmission. That is, at this time, the hard conductive disk 2 and the conductive drive unit 3 are separately arranged, and a movable gap 4 is formed between the second drive part 32 and the third drive part 37.

[0081] Specifically, the guide rod 31 is a cylindrical or hollow cylindrical structure, the bottom end of which is integrally connected to the second drive part 32, and the top end extends from the polishing head body 1 and has an outer ring gear 311. The motor drives the guide rod 31 to rotate circumferentially through the transmission with the outer ring gear 311, thereby driving the second drive part 32 to rotate. The second drive part 32 includes a plurality of fan-shaped protrusions arranged at intervals around the guide rod 31, which are fixedly connected to the outer wall of the guide rod 31.

[0082] The third driving portion 37 is a groove structure formed on the upper surface of the hard conductive disk 2 (the side without the air hole 21), into which the second driving portion 32 extends. When the second driving portion 32 rotates circumferentially, the cooperation between the second driving portion 32 and the third driving portion 37 can drive the hard conductive disk 2 to rotate circumferentially.

[0083] A power source is connected to the second driving portion 32 to energize it, and the cross-sectional area of ​​the third driving portion 37 is larger than that of the second driving portion 32. Thus, while the second driving portion 32 adheres to the bottom of the slot of the third driving portion 37 to achieve electrical conduction, the second driving portion 32 can also move radially within the third driving portion 37 (the radial direction here refers to the diameter of the hard conductive disk 2). Alternatively, while the second driving portion 32 adheres to the sidewall of the slot of the third driving portion 37 to achieve electrical conduction, the second driving portion 32 can also move axially within the third driving portion 37. In other words, the second driving portion 32 adheres to at least the sidewall or bottom wall of the third driving portion 37 to achieve electrical conduction.

[0084] Of course, in other embodiments, the third driving portion 37 may be a convex block, and the second driving portion 32 may be a groove body, which is not specifically limited.

[0085] The radial movable gap 41 and the axial movable gap 42 between the third driving part 37 and the second driving part 32 constitute the movable gap 4, so that when the pressure in the second air cavity 4 is adjusted, the elastic unit 7 can be driven to perform flexible movement, assisting the hard conductive disk 2 and the wafer substrate to float, and the floating is completed in the above-mentioned movable gap 4; the hard conductive disk 2 can form a conductive circuit required for electrochemical mechanical polishing with the wafer substrate, the polishing table, and the power supply, and the guide rod 31 is used to conduct electricity to the hard conductive disk 2 and then to the wafer substrate for surface modification, thereby realizing electrochemical mechanical polishing of the wafer substrate.

[0086] The rest is the same as that of the first embodiment and will not be described in detail.

[0087] Example 4

[0088] As shown in Figures 19 to 21, the difference from Example 1 is that the elastic unit 7 is not provided in this embodiment, and the hard conductive disk 2 is further provided with a rib 24 on the basis of the disc-shaped structure. The rib 24 extends from the outer ring vertically toward the polishing head body 1, and the rib 24 extends into the polishing head body 1 and is sealed with it through the seal 8, thereby forming the above-mentioned second air cavity 6 and the active gap 4. At the same time, the rib 24 can be electrically connected to the polishing head body 1, that is, the circuit in the electrochemical mechanical polishing and flattening of the wafer substrate is connected from the rib 24 to the hard conductive disk 2.

[0089] Specifically, an annular groove 12 is formed in the polishing head body 1, the radial width of which is greater than the thickness of the rib 24 on one side, thereby forming a radial movable gap 41 in the movable gap 4. The side wall of the annular groove 12 is fixed with a seal 8, and the outer wall of the rib 24 abuts against the seal 8 to achieve a sealed fit. The rib 24 can float left and right within the annular groove 12. The depth of the annular groove 12 is greater than the height of the rib 24 that can extend into the annular groove 12, thereby forming an axial movable gap 42 in the movable gap 4, that is, the rib 24 can float up and down within the annular groove 12.

[0090] Similar to the first embodiment, the conductive drive unit 3 includes a guide rod 31 and a second drive portion 32. The second drive portion 32 is connected to the hard conductive disk 2. The polishing head body 1 is formed with a first drive portion 33 that engages with the second drive portion 32 in a transmission manner. The aforementioned movable gap 4 is formed between the first drive portion 33 and the second drive portion 32. In other words, while the movable gap 4 is formed between the conductive drive unit 3 and the hard conductive disk 2, the movable gap 4 is also formed between the hard conductive disk 2 and the polishing head body 1.

[0091] In this embodiment, the rib 24 can rotate at any angle in the annular groove 12 because it is not restricted by the elastic unit 7 . That is, the rotation direction of the hard conductive disk 2 and the polishing head body 1 can be the same or opposite.

[0092] For example, to reduce wear on the retaining ring 5, the retaining ring 5 and the hard conductive disk 2 rotate in the same direction. That is, the hard conductive disk 2 and the polishing head body 1 rotate in the same direction. The hard conductive disk 2 rotates in opposite directions to the retaining ring 5 and the polishing head body 1, thereby increasing the surface removal rate of the wafer substrate. Specifically, while the polishing table rotates counterclockwise, the hard conductive disk 2 drives the wafer substrate to rotate clockwise, significantly improving the polishing removal rate. Other aspects are the same as in Example 1 and are not further described.

[0093] Example 5

[0094] As shown in FIG. 22 and FIG. 23 , the elastic unit 7 is not provided in this embodiment. The hard conductive disk 2 is further provided with a rib 24 on the basis of the disc-shaped structure. The specific matching structure is the same as that of the fourth embodiment and will not be repeated here.

[0095] Similar to the second embodiment, the conductive drive unit 3 includes an electrically connected guide block 34 and a wire 35. The guide block 34 is connected to the polishing head body 1. The hard conductive disk 2 forms a groove 23 for the guide block 34 to extend into. When the polishing head body 1 rotates circumferentially, the hard conductive disk 2 can be driven to rotate circumferentially through the cooperation between the guide block 34 and the groove 23. The radial active gap 41 and the axial active gap 42 between the guide block 34 and the groove 23 constitute the active gap 4.

[0096] Of course, the positions of the guide block 34 and the groove 23 can also be interchanged. The guide block 34 is connected to the hard conductive disk 2, and a groove 23 for the guide block 34 to extend into is formed in the polishing head body 1, thereby forming a movable gap 4 between the polishing head body 1 and the conductive driving unit 3. Then, while the movable gap 4 is formed between the polishing head body 1 and the conductive driving unit 3, an movable gap 4 is also formed between the hard conductive disk 2 and the polishing head body 1.

[0097] The rest is the same as that of the first embodiment and will not be described in detail.

[0098] Example 6

[0099] As shown in FIG. 24 to FIG. 26 , the elastic unit 7 is not provided in this embodiment. The hard conductive disk 2 is further provided with a rib 24 on the basis of the disc-shaped structure. The specific matching structure is the same as that of the fourth embodiment and will not be repeated here.

[0100] Similar to the third embodiment, the conductive drive unit 3 includes a guide rod 31 and a second drive portion 32. The top end of the guide rod 31 is connected to an external power source 312. The hard conductive disk 2 forms a third drive portion 37 that cooperates with the second drive portion 32. A movable gap 4 is formed between the second drive portion 32 and the third drive portion 37. Thus, while the movable gap 4 is formed between the conductive drive unit 3 and the hard conductive disk 2, a movable gap 4 is also formed between the hard conductive disk 2 and the polishing head body 1.

[0101] Of course, the positions of the second driving part 32 and the third driving part 37 can also be interchanged, with the structure of the second driving part 32 being set on the hard conductive disk 2 and the structure of the third driving part 37 being set on the conductive driving unit 3 .

[0102] The rest is the same as that of the first embodiment and will not be described in detail.

[0103] Example 7

[0104] On the basis of Example 1 and Example 3, radial gaps and axial gaps are further provided between the outer wall of the guide rod 31 and the polishing head body 1, thereby forming a movable gap 4 between the polishing head body 1 and the conductive drive unit 3. At the same time, a movable gap 4 is also formed between the conductive drive unit 3 and the hard conductive disk 2.

[0105] Example 8

[0106] In this embodiment, the lower surface of the hard conductive plate 2 is attached with a flexible conductive cloth, whose resistivity is less than 10 -3 The flexible conductive cloth includes pores that match the positions of at least some of the pores 21 of the hard conductive plate 2, so that the air path is smoother when the air cavity 3 is pressurized or vacuumed, which is beneficial for better adsorption of the wafer substrate during vacuum processing of the air cavity 3.

[0107] The other structures are the same as those in any of the embodiments 1 to 7 and will not be described in detail.

[0108] The above specific embodiments are used to illustrate the present invention rather than to limit the present invention. Any modifications and changes made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. An electrochemical mechanical polishing and planarization device, characterized in that, At least including a polishing head, the polishing head includes: A polishing head body (1); A hard conductive disk (2), at least part of its lower surface is in the same plane, used for adsorbing a wafer substrate; A conductive driving unit (3), at least part of which can be connected to a power source, at least part of which is in contact with and in driving cooperation with the hard conductive disk (2) to drive the hard conductive disk (2) to rotate circumferentially; An active gap (4) is formed between the polishing head body (1) and the conductive driving unit (3), and / or between the conductive driving unit (3) and the hard conductive disk (2), and / or between the hard conductive disk (2) and the polishing head body (1); A retaining ring (5), located below the polishing head body (1), is an annular component that can contact a polishing pad, and the hard conductive disk (2) moves within the area defined by the retaining ring (5).

2. The electrochemical mechanical polishing and planarization device according to claim 1, wherein: Air holes (21) are formed in the part of the lower surface of the hard conductive disk (2) that is in the same plane, and the air holes (21) are communicated with a third air cavity (22) inside the hard conductive disk (2). When the third air cavity (22) is in a negative pressure state, the hard conductive disk (2) can adsorb the wafer substrate.

3. The electrochemical mechanical polishing and planarization device according to claim 1, wherein: It also includes a second air cavity (6) with controllable pressure, which is used to drive the hard conductive disk (2) to move up and down.

4. The electrochemical mechanical polishing and planarization device according to claim 3, wherein: The hard conductive disk (2) and the conductive driving unit (3) are integrally connected, or the hard conductive disk (2) and the conductive driving unit (3) are separately arranged.

5. The electrochemical mechanical polishing and planarization device according to claim 3, characterized in that: The active gap (4) at least includes a radial active gap (41) and an axial active gap (42).

6. The electrochemical mechanical polishing and planarization device according to claim 3, wherein: The conductive driving unit (3) includes a guide rod (31) and a second driving part (32), the second driving part (32) is connected to the hard conductive disk (2), the polishing head body (1) forms a first driving part (33) that is in driving cooperation with the second driving part (32), an active gap (4) is formed between the first driving part (33) and the second driving part (32), and the second driving part (32) remains in contact with the first driving part (33) to achieve electrical conduction.

7. The electrochemical mechanical polishing and planarization device according to claim 3, characterized in that: The conductive driving unit (3) includes an electrically connected conductive block (34) and a wire (35), the conductive block (34) is connected to the polishing head body (1), so that the polishing head body (1) drives the hard conductive disk (2) to rotate circumferentially through the conductive block (34) and conducts current to the hard conductive disk (2) during driving; a groove (23) for the conductive block (34) to extend into is formed in the hard conductive disk (2), and an active gap (4) is formed between the conductive block (34) and the groove (23).

8. The electrochemical mechanical polishing and planarization device according to claim 7, wherein: The number of the conductive blocks (34) is multiple, which are arranged at intervals along the circumference of the polishing head body (1), and the conductive blocks (34) remain in contact with the groove (23) to achieve electrical conduction.

9. The electrochemical mechanical polishing and planarization device according to claim 7, wherein: The number of the wires (35) is one or corresponding to the number of the conductive blocks (34). When the number of the wires (35) is one, all the conductive blocks (34) are connected into a whole through a ring body (36).

10. The electrochemical mechanical polishing and planarization device according to claim 3, wherein: The conductive driving unit (3) includes a guide rod (31) and a second driving part (32). The guide rod (31) is connected to an external power source. The hard conductive disk (2) forms a third driving part (37) that is in transmission cooperation with the second driving part (32), and the moving gap (4) is formed between the second driving part (32) and the third driving part (37).

11. The electrochemical mechanical polishing and planarization device according to claim 6 or 7 or 10, characterized in that: The conductive driving unit (3) includes an elastic unit (7) that is respectively connected to the polishing head body (1) and the hard conductive disk (2), so that the polishing head body (1), the elastic unit (7), and the hard conductive disk (2) enclose to form the second air cavity (6).

12. The electrochemical mechanical polishing and planarization device according to claim 6 or 7 or 10, characterized in that: The hard conductive disk (2) has a flange (24). The flange (24) extends into the polishing head body (1) and is in sealed cooperation with it through a seal (8) to form the second air cavity (6) and the moving gap (4), and the flange (24) is electrically connected to the polishing head body (1).

13. The electrochemical mechanical polishing and planarization device according to claim 12, wherein: The rotation direction of the hard conductive disk (2) is the same as or opposite to the rotation direction of the polishing head body (1).

14. The electrochemical mechanical polishing and planarization device according to claim 1 or 2, characterized in that: The lower surfaces of the hard conductive disks (2) are located in the same plane; alternatively, the parts of the lower surfaces of the hard conductive disks (2) that are located in the same plane form a thickened area or a thinned area to form a height difference from nanometers to micrometers.

15. The electrochemical mechanical polishing and planarization device according to claim 2, characterized in that: A flexible conductive cloth is attached to the lower surface of the hard conductive disk (2). The flexible conductive cloth contains holes, and the positions of the holes match the positions of at least some of the air holes (21) of the hard conductive disk (2).

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