Electrochemical mechanical polishing and planarization equipment for processing a conductive wafer substrate

Abstract

To provide an electrochemical mechanical polishing and flattening apparatus that increases a removing speed of a substrate material and improves polishing / flattening efficiency by introducing electrochemical reaction of a wafer substrate surface.SOLUTION: An electrochemical mechanical polishing and flattening apparatus that processes a conductive wafer substrate 5 includes: a power source 1 having a first electrode and a second electrode; a polishing table 2 which has conductivity and is connected to the first electrode; a polishing pad 3 including an action layer which has holes of an insulation material in which conductive chemical solution is housed; and a polishing head 6 which has conductivity and is connected to the second electrode, where the first electrode, the polishing table, the chemical solution, the conductive wafer substrate, the polishing head and the second electrode sequentially form an energization circuit, an electrochemical reaction layer is formed on a polished surface of the conductive wafer substrate, and the polishing head drives the conductive wafer substrate so as to move to the polishing pad in order to realize chemical mechanical polishing to the electrochemical reaction layer to process the conductive wafer substrate.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor integrated circuit chip manufacturing, and particularly relates to electrochemical mechanical polishing and planarization equipment for processing conductive wafer substrates.

Background Art

[0002] The manufacturing process of wafer substrates and semiconductor devices includes processes such as polishing and surface planarization. Usually, techniques such as mechanical polishing, chemical mechanical polishing, or planarization are used. Pressure is applied from the carrier head (polishing head) of the wafer substrate to the back side of the wafer, and parameters such as pressure, rotation speed of the polishing head, rotation speed of the polishing pad, and liquid flow rate of the polishing liquid are controlled to perform polishing or planarization processing on the front surface of the wafer substrate or the surface of the film on the polishing pad. Compared with mechanical polishing, chemical mechanical polishing and chemical mechanical polishing planarization can cause chemical reactions on the surface of the wafer substrate by adjusting the composition of the polishing liquid, realizing higher polishing or planarization processing efficiency, and at the same time realizing better polishing or planarization processing effects including higher flatness and lower defect density.

[0003] Conductive wafer substrates are divided into bulk-phase conductivity (conductive substrates) and surface conductivity (surface-layer conductive wafer substrates) according to the conduction type. The bulk conductive wafer substrate material itself has good conductive properties and can include doped 4H-SiC, etc. The surface conductive wafer substrate does not conduct electricity in the bulk phase but the surface layer can conduct electricity, for example, a metal film deposited on the surface of a silicon wafer substrate.

[0004] The polishing and planarization process of a conductive substrate or a surface layer conductive wafer substrate can use special electrochemical mechanical polishing and planarization techniques. Based on chemical mechanical polishing and planarization, electrochemical mechanical polishing and planarization further utilize the conductive properties of the wafer substrate or the surface film of the wafer substrate to form a current path, cause an electrochemical reaction on the surface of the wafer substrate or the film surface, and form an electrochemical reaction layer on the surface of the wafer substrate or the surface film of the wafer substrate through precise control of the circuit system. By further performing chemical mechanical polishing on the electrochemical reaction layer, the surface chemical reaction rate is improved, and the chemical mechanical polishing and planarization efficiency is further improved. In the electrochemical mechanical polishing and planarization equipment process, the polishing liquid that realizes the chemical mechanical polishing and planarization function is also an electrolyte that realizes the electrochemical reaction on the surface of the wafer substrate, and it is necessary to adjust the liquid chemical composition, liquid conductivity, etc. accordingly.

[0005] Taking the polishing process of silicon carbide substrate materials as an example, due to the high hardness of silicon carbide materials, when polishing the polishing surface of the polishing pad by simple mechanical polishing, it is necessary to apply a high pressure on the back side of the wafer. The conditions are severe, the removal rate is extremely low, the production efficiency of the equipment is low, the consumption of consumables such as polishing pads is large, and the cost is high. Chemical mechanical polishing can first perform chemical modification such as oxidation on the surface of the silicon carbide substrate, reduce the surface hardness, further improve the polishing rate of the material, and improve the production efficiency of the polishing equipment. However, due to the stable chemical properties of silicon carbide materials and the slow surface oxidation rate, it is necessary to select a polishing liquid with strong oxidizing properties in the chemical mechanical polishing process, and high requirements are imposed on the corrosion resistance of the equipment hardware, which directly affects the manufacturing cost and operation reliability of the equipment. Similarly, due to the stable chemical properties of silicon carbide materials and the slow surface oxidation rate, the removal rate of chemical mechanical polishing of silicon carbide is still low and currently does not fully meet the requirements of mass production. In the case of conductive silicon carbide substrate materials, in order to break through the bottleneck of chemical mechanical polishing efficiency, an electrochemical mechanical polishing technology is used to oxidize the surface of silicon carbide by an electrochemical reaction. If a certain current density is achieved, the surface oxidation efficiency of silicon carbide can be greatly accelerated. Subsequently, combined with chemical mechanical polishing, the removal rate of silicon carbide materials can be greatly improved, the operation efficiency of the equipment can be correspondingly improved, and the operation cost of the equipment can be reduced. At the same time, the electrochemical mechanical polishing process does not need to rely on a polishing liquid / electrolyte with strong oxidizing properties, expands the selection range of equipment materials, reduces the equipment cost, extends the life of parts, improves the reliability of equipment operation, extends the continuous operation time, and can further reduce the operation cost.

[0006] The design of the circuit structure is the key to electrochemical mechanical polishing and planarization equipment. Currently, there is no electrochemical mechanical polishing and planarization equipment suitable for mass production on the market. Conventional electrochemical mechanical polishing and planarization equipment / devices can generally be divided into two types. Type 1 continues to use the basic design of conventional chemical mechanical polishing and planarization equipment: the polishing table is horizontally arranged and rotatable in the circumferential direction, the polishing pad is arranged on the upper surface of the polishing table, the lower surface of the polishing pad overlaps with the top surface of the polishing table, the liquid supply system transfers the polishing liquid to the upper surface of the polishing pad, above the polishing table / polishing pad is the carrier head (polishing head) of the wafer substrate, below the polishing head is the wafer substrate, the polishing surface (front side) is arranged downward, the polishing head presses on the back surface of the wafer substrate, and polishing or planarization treatment is performed on the front surface of the wafer substrate on the polishing pad. Based on the design of conventional chemical mechanical polishing and planarization equipment, the electrochemical mechanical polishing and planarization equipment of Type 1 realizes the circuit structure passing through the surface of the conductive wafer substrate by changing the design of the polishing table and the polishing pad: the conductive polishing table is connected to the first electrode of the power supply, the polishing pad itself attached to the polishing table is made of an insulating material, but holes penetrating in the thickness direction are designed, and when the polishing pad is immersed, the holes are filled with chemical liquid. At the same time, on the upper surface of the insulating polishing pad, a plurality of conductive contact heads generally made of a metal conductor material and rotating with the polishing pad are additionally attached. After the plurality of conductive contact heads are connected to each other, they are finally connected to the second electrode of the power supply. When the electrochemical mechanical polishing and planarization equipment of Type 1 operates, the carrier head (polishing head) of the wafer substrate presses on the back side of the wafer, the front surface of the wafer substrate overlaps with the polishing pad, the chemical liquid in the holes of the polishing pad and the conductive contact heads on the upper surface of the polishing pad are respectively in electrical contact with the front surface of the conductive wafer substrate, so that the energization circuit of the power supply's first electrode - conductive polishing table - conductive chemical liquid in the polishing pad holes - front surface of the conductive wafer substrate - conductive contact heads on the upper surface of the polishing pad - power supply's second electrode can be implemented.The design of the Type 1 electrochemical mechanical polishing and planarization equipment is applicable to the polishing of conductive wafer substrates and also to the planarization process of the surface layer conductive wafer substrates. The biggest design challenge is the design and material selection of the conductive contact head on the upper surface of the polishing pad. While the polishing table and the polishing head rotate independently, and at the same time the polishing head presses on the back side of the wafer, problems such as the chemical stability of the material surface of the conductive contact head and the certainty of electrical contact with the wafer substrate, scratches on the surface of the wafer substrate caused by the conductive contact head, particle contamination and metal contamination, wear of the conductive contact head material itself, the cost of the polishing pad, and the service life often occur.

[0007] The Type 2 electrochemical mechanical polishing device is designed based on the conventional mechanical thinning and surface polishing system: the wafer substrate is arranged upward and horizontally on the polishing table, above the polishing table / wafer substrate is the polishing head, a polishing pad is adhered under the polishing head, and there is no need for a hole penetrating in the thickness direction in the polishing pad. While the polishing head / polishing pad rotates, it presses on the front side of the wafer substrate to perform thinning or surface polishing treatment of the wafer substrate. In the Type 2 electrochemical mechanical polishing device, the conductive wafer substrate is connected to the first electrode of the power supply through the conductive polishing table. At the same time, the lower parts of the polishing table, the wafer substrate, and the polishing head can all be immersed in the conductive chemical liquid and can be connected to the second electrode of the power supply through the electrode immersed in the conductive chemical liquid and energized. With such a design, an energized circuit can be formed between the first electrode of the power supply - the conductive polishing table - the conductive wafer substrate - the conductive chemical liquid - the electrode immersed in the conductive chemical liquid and energized - the second electrode of the power supply. In the Type 2 electrochemical mechanical polishing device, the wafer substrate is completely immersed in the conductive chemical liquid. The conductive chemical liquid usually requires a certain depth for arranging the energized electrode, and it is difficult to quickly and efficiently remove the by-products generated by the electrochemical polishing on the surface of the wafer substrate. The rapid attachment and detachment of the wafer substrate is also a major issue.

Summary of the Invention

[0008] In order to solve the deficiencies of the prior art, the present invention provides a design of a new electrochemical mechanical polishing and planarization apparatus that can achieve high performance, high efficiency, and low cost in the polishing and planarization of conductive wafer substrates.

[0009] The technical solution used by the present invention to solve its technical problems is as follows. An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate, a power supply having a first electrode and a second electrode, a polishing table having conductivity and connected to the first electrode, a polishing pad provided on the upper surface of the polishing table, capable of being superposed on one polishing surface of the conductive wafer substrate, and manufactured from an insulating material, and including at least an acting layer having holes penetrating in the thickness direction thereof and containing a conductive chemical liquid, a polishing head having conductivity and connected to the second electrode, and the lower surface of which can be superposed on the back surface of the polishing surface of the conductive wafer substrate, the first electrode, the polishing table, the chemical liquid, the conductive wafer substrate, the polishing head, and the second electrode sequentially form an energizing circuit to form an electrochemical reaction layer on the polishing surface of the conductive wafer substrate, the polishing head can drive the conductive wafer substrate to move relative to the polishing pad in order to achieve chemical mechanical polishing of the electrochemical reaction layer.

[0010] Furthermore, the polishing table can rotate around its own axis, the polishing head can rotate around its own axis, and can move relative to the polishing table.

[0011] Furthermore, the number of the holes is plural.

[0012] Furthermore, the total area of the holes occupies 5% to 70% of the acting layer area.

[0013] Furthermore, the total area of the holes occupies 5% to 50% of the acting layer area.

[0014] Furthermore, the polishing pad is a working layer, or the polishing pad has a two-layer or multi-layer structure in which the uppermost layer is a working layer, one or more lower layers are insulating layers, and the holes penetrate the entire thickness direction of the polishing pad.

[0015] Furthermore, the polishing pad has a two-layer or multi-layer structure in which the uppermost layer is a working layer, and one or more lower layers are conductive layers having perforations that are closed or communicate with the holes.

[0016] Furthermore, the step of forming an electrochemical reaction layer on the polishing surface of the conductive wafer substrate and the step of performing chemical mechanical polishing on the electrochemical reaction layer are carried out synchronously, or the step of forming an electrochemical reaction layer on the polishing surface of the conductive wafer substrate and the step of performing chemical mechanical polishing on the electrochemical reaction layer are carried out continuously.

[0017] Furthermore, the polishing head includes a first pressure medium chamber for controlling the vertical movement stroke of the conductive wafer substrate, and a second pressure medium chamber for controlling the suction assembly and realizing the suction or release of the suction assembly to the conductive wafer substrate by changing the air pressure inside the second pressure medium chamber. The suction assembly includes a deformable flexible member and a support member for supporting the flexible member, and an access point for power is provided on the suction assembly.

[0018] Furthermore, the flexible member is a conductive flexible film, and the support member is a metal member forming an access point for power.

[0019] Furthermore, the flexible member is provided with a plurality of openings for attaching the flexible film, and includes a lightweight metal plate forming an access point for power and the flexible film.

[0020] Furthermore, the flexible member includes a lightweight metal plate that forms an access point for the power supply.

[0021] Furthermore, the surface of the lightweight metal plate has a platinum plating layer.

[0022] Furthermore, the flexible member is an insulating flexible film, and inside the flexible member, a conductive coil that forms an access point for the power supply is covered.

[0023] Furthermore, the polishing table includes a polishing upper plate and a polishing lower plate that are installed concentrically and coaxially, and the polishing lower plate is connected to the rotation center axis.

[0024] Furthermore, the polishing upper plate is made of a metal material or an alloy material.

[0025] Furthermore, the polishing upper plate has a platinum plating layer.

[0026] Furthermore, the conducting wire from the power supply is connected to the polishing upper plate through the rotation center axis.

[0027] Furthermore, the polishing table has a heating or cooling function.

[0028] Furthermore, the polishing table is connected to a temperature control device.

[0029] Furthermore, it further includes a chemical liquid supply system that is used to transfer the chemical liquid to the polishing pad and can transfer the chemical liquid to the upper surface of the polishing pad.

[0030] Furthermore, it further includes a chemical liquid supply system that can transfer the chemical liquid from the polishing upper plate to the bottom of the hole.

[0031] Furthermore, the chemical liquid supply system is equipped with a flow control unit for adjusting the discharge amount of the chemical liquid, or a temperature control unit for adjusting the discharge temperature of the chemical liquid, or a concentration control unit for adjusting the discharge concentration of the chemical liquid.

[0032] Furthermore, the chemical liquid is a polishing liquid in which polishing nanoparticles are dispersed in an acidic or alkaline solution, and its pH > 8 or pH < 5.

[0033] Furthermore, when forming an electrochemical reaction layer on the polished surface of the conductive wafer substrate, the second electrode connected to the polishing head of the wafer substrate is the positive electrode, and the first electrode connected to the polishing table is the negative electrode.

[0034] Furthermore, the power supply is a constant current power supply with a current ≤ 20 A, or the power supply is a constant voltage power supply with a voltage ≤ 220 V.

[0035] Furthermore, the outer edge of the polishing pad is arranged on the polishing table, or the outer edge of the polishing pad forms ribs with a height H ≤ 3 mm relative to the upper surface of the polishing pad.

[0036] Furthermore, the diameter of the hole is 3 mm or more.

[0037] Furthermore, the holes are circular or rectangular or regular hexagonal or star-shaped, and are distributed in an array or concentrically.

[0038] The present invention relates to the design of a circuit structure for a novel electrochemical mechanical polishing and planarization device. Similar to a Type 1 electrochemical mechanical polishing and planarization device, an insulating polishing pad is overlapped on the upper surface of a conductive polishing table and has holes penetrating in the thickness direction. The holes are filled with a conductive chemical liquid transferred from a liquid supply arm to the polishing pad. Different from the Type 1 electrochemical mechanical polishing and planarization device, it is not necessary to design a conductive contact head on the polishing pad, but the carrier head (polishing head) of the wafer substrate is conductive. When the polishing head presses on the back side of the wafer, the front side of the wafer substrate is overlapped on the polishing pad, and an energization circuit can be established between the first electrode of the power supply - the conductive polishing table - the chemical liquid in the hole penetrating the thickness of the polishing pad - the conductive wafer substrate - the conductive polishing head - the second electrode of the power supply. The polarities of the first electrode and the second electrode of the power supply are determined by the electrochemical reaction on the surface of the wafer substrate to be designed. Taking a wafer substrate of conductive silicon carbide as an example, when a conductive chemical liquid is accommodated in the holes of the polishing pad and in the electrochemical reaction, the upper plate of the polishing table is the cathode and the surface (polishing head) of the wafer substrate is the anode, the surface of the wafer substrate of conductive silicon carbide can be oxidized.

[0039] In the electrochemical mechanical polishing / planarization process of a conductive wafer substrate, the polishing table and the polishing pad attached to the upper surface of the polishing table rotate around the axis of the polishing table, the substrate of the polishing head rotates around the axis of the polishing head, and can move relative to the polishing table. The wafer substrate overlaps on the polishing pad as the polishing head rotates, but moves relative to the polishing pad. An electrochemical reaction occurs on the surface of the conductive wafer substrate when passing through the hole region of the polishing pad, and chemical mechanical polishing / planarization is performed when passing through the non-hole region of the polishing pad. When the wafer substrate moves relative to the polishing table as the polishing head rotates, the electrochemical reaction and chemical mechanical polishing / planarization on the surface of the conductive wafer substrate can be continuously repeated, thereby realizing the electrochemical mechanical polishing / planarization of the surface of the conductive wafer substrate.

[0040] The beneficial effects of the present invention include the following. 1) Electrochemical mechanical polishing of the conductive wafer substrate introduces an electrochemical reaction on the surface of the wafer substrate compared with mechanical polishing or conventional chemical mechanical polishing / planarization, significantly improving the removal rate of the substrate material and the efficiency of polishing / planarization, and greatly reducing the equipment operation cost. 2) Compared with the conventional type 1 electrochemical mechanical polishing equipment, the circuit design is simpler. Without the conductive contact head on the upper surface of the polishing pad, the defect rate of the polished surface of the wafer substrate can be significantly reduced, the surface smoothness can be improved, surface metal contamination and particle contamination can be reduced, and at the same time, the life of the polishing pad can be extended and the cost of consumables can be reduced. 3) Compared with the conventional type 2 electrochemical mechanical polishing device, in the electrochemical mechanical polishing process, the electrochemical reaction and the chemical mechanical polishing rate can be independently controlled and adjusted, the electrochemical mechanical polishing rate of the surface of the wafer substrate can be adjusted for each region, and the wafer substrate can be detached and attached simply and quickly.

Brief Description of the Drawings

[0041]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

[0042] Here, 1 - power supply, 11 - access point, 12 - conducting wire, 2 - polishing table, 21 - upper polishing plate, 22 - lower polishing plate, 23 - rotation center axis, 3 - polishing pad, 31 - working layer, 311 - hole, 32 - insulating layer, 33 - conductive layer, 34 - rib, 4 - chemical liquid, 41 - chemical liquid supply system, 5 - conductive wafer substrate, 51 - polishing surface of the conductive wafer substrate, 6 - polishing head, 71 - first pressure medium chamber, 72 - second pressure medium chamber, 73 - adsorption assembly.

Embodiments for Carrying Out the Invention

[0043] For those skilled in the art to better understand the method of the present invention, hereinafter, in combination with the drawings in the embodiments of the present invention, the technical solutions in the embodiments of the invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative efforts should belong to the scope of the claims of the present invention.

[0044] An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate, comprising a power supply 1, a polishing table 2 connected to the first electrode of the power supply 1 and having conductivity, a polishing pad 3 installed on the upper surface of the polishing table 2, and a polishing head 6 connected to the second electrode of the power supply 1 and having conductivity.

[0045] In this embodiment, the first electrode is the negative electrode and the second electrode is the positive electrode. In other embodiments, the first electrode may be the positive electrode and the second electrode may be the negative electrode.

[0046] The polishing table 2 can rotate around the axis of the polishing table, the polishing head 6 can rotate around the axis of the polishing head, and can move relative to the polishing table 2.

[0047] The power supply 1 supplies a stable constant current or constant voltage to the electrochemical circuit. The power supply 1 may be a constant current power supply with a current ≤ 20 A, or the power supply 1 is a constant voltage power supply with a voltage ≤ 220 V.

[0048] The polishing pad 3 can be superposed on the polishing surface 51 of the conductive wafer substrate 5, and at least includes an active layer 31 made of an insulating material and having holes 311 penetrating in the thickness direction and accommodating a conductive chemical liquid 4. On the surface of the wafer substrate, an electrochemical reaction occurs in the hole region of the active layer 31, and chemical mechanical polishing is performed in the region of the active layer 31 that is not a hole.

[0049] Regarding the step of generating an electrochemical reaction in the hole region of the active layer 31 on the polishing surface of the conductive wafer substrate 5 to form an electrochemical reaction layer and the step of performing chemical mechanical polishing in the region of the active layer 31 that is not a hole in the formed electrochemical reaction layer, the electrochemical reaction in the hole region occurs at the same time, the formation layer of the electrochemical reaction is formed, and the two steps may be implemented synchronously so that chemical mechanical polishing of the electrochemical reaction layer is performed in other regions that are not holes. Or, first, an electrochemical reaction occurs in the hole region of the active layer 31 on the polishing surface of the conductive wafer substrate 5 to form an electrochemical reaction layer, and then chemical mechanical polishing of the electrochemical reaction layer is performed in the region of the active layer 31 that is not a hole, and the two steps may be implemented asynchronously by repeating the above steps.

[0050] The lower surface of the polishing head 6 can be overlapped with the back surface of the polishing surface 51 of the conductive wafer substrate 5, and the conductive wafer substrate 5 is driven to move relative to the polishing pad 3. The conductive wafer substrate 5 is mounted on the conductive polishing head 6, moves to the polishing pad 3, and a large amount of conductive chemical liquid 4 in the pores 311 is uniformly distributed on the polishing surface 51 of the conductive wafer substrate 5 and the polishing pad 3 for performing an electrochemical reaction. By applying a downward pressure to the back surface of the conductive wafer substrate 5, the power supply 1, the polishing table 2, the chemical liquid 4, the conductive wafer substrate 5, the polishing head 6, and the power supply 1 sequentially form a conduction circuit to form an electrochemical reaction layer on the polishing surface 51 of the conductive wafer substrate 5. When the polishing head 6 is driven so that the conductive wafer substrate 5 moves relative to the polishing pad 3, the non-pore regions of the electrochemical reaction layer and the working layer 31 act on each other to realize chemical mechanical polishing of the electrochemical reaction layer.

[0051] As shown in FIG. 2, the number of the pores 311 is plural, and its diameter is 3 mm or more, that is, in FIG. 2, R ≧ 3 mm. The pores 311 are circular and are distributed in an array or concentrically. The pores 311 may have any other shape and may be arbitrarily distributed. The total area of the pores 311 occupies 5% to 70% of the area of the working layer 31. In a preferred method, the total area of the pores 311 occupies 5% to 50% of the area of the working layer 31. The setting of the above area can optimize the electrochemical reaction rate and at the same time realize the coincidence of the formation rate of the electrochemical reaction layer and the polished rate of chemical mechanical polishing.

[0052] The shape of the pores 311 is not limited and may be rectangular, regular hexagonal or star-shaped.

[0053] As shown in FIG. 3, the polishing pad 3 may be an insulating polishing pad having a single-layer structure. At this time, the entire polishing pad 3 is the working layer 31.

[0054] As shown in FIG. 4, the polishing pad 3 may have a two-layer or multi-layer structure. Whether it is a two-layer structure or a multi-layer structure, the uppermost layer is the working layer 31, and the one or more lower layers are the insulating layer 32. Moreover, the holes 311 penetrate through the entire thickness direction of the polishing pad 3, that is, the holes 311 extend from the working layer 31 to the lower insulating layer 32.

[0055] The polishing pad 3 may have a two-layer or multi-layer structure. Whether it is a two-layer structure or a multi-layer structure, the uppermost layer is the working layer 31, and the one or more lower layers are a conductive layer 33 having a completely closed structure as shown in FIG. 5 or having a perforation communicating with the holes 311. Here, the communication may be a complete face-to-face communication or a partial face-to-face communication.

[0056] The outer edge of the polishing pad 3 is arranged on the polishing table 2, or the outer edge of the polishing pad 3 protrudes upward from the upper surface of the polishing pad 3 to form a rib 34 with a height H≦3 mm with respect to the upper surface of the polishing pad, that is, about 3 mm higher than the upper surface of the polishing pad 3. As shown in FIG. 6, the rib may have a structure with the same material as the polishing pad 3 and an increased height at the edge. As shown in FIG. 7, the rib may be a height-increasing layer coated with a heterogeneous material on the outer ring of the polishing pad 3. The heterogeneous material for increasing the height of the rib 34 may be a hard corrosion-resistant material such as plastic or a flexible material such as rubber.

[0057] As shown in FIG. 8, the polishing head 6 includes a first pressure medium chamber 71 for controlling the vertical movement stroke of the conductive wafer substrate 5 and at least one second pressure medium chamber 72 for controlling the suction assembly 73. By changing the air pressure inside the second pressure medium chamber 72, that is, by pressurizing or evacuating the second pressure medium chamber 72, the form or stroke of the suction assembly 73 is changed, so that the suction or release of the suction assembly 73 to the conductive wafer substrate 5 can be realized. The realization of specific functions is a prior art, and the description thereof is omitted here.

[0058] As shown in FIG. 11, the polishing table 2 includes a polishing upper plate 21 and a polishing lower plate 22 that are both installed concentrically and coaxially, and are also installed concentrically and coaxially with the rotation center axis 23. The polishing lower plate 22 is connected to the rotation center axis 23. Driven by the transmission device, the polishing upper plate 21 and the polishing lower plate 22 rotate coaxially, and the rotation speed can be controlled.

[0059] The polishing pad 3 is adhered to the upper surface of the polishing upper plate 21 and is in direct contact with the polishing surface 51 of the conductive wafer substrate 5. The holes 311 and the chemical liquid 4 on the polishing pad 3 provide channels for electrochemical reactions. The non-hole regions of the polishing pad 3 provide a supporting surface for the chemical mechanical polishing of the electrochemical reaction layer.

[0060] The polishing upper plate 21 is made of a metal material or an alloy material, and the conducting wire 12 from the power supply 1 is connected to the polishing upper plate 21 through the rotation center axis 23. Specifically, the polishing upper plate 21 may be an aluminum alloy or a titanium alloy, and a platinum layer may be plated on the surface of the aluminum alloy or titanium alloy.

[0061] The polishing upper plate 21 is connected to a temperature control device, and the value is fed back by the temperature sensor of the polishing pad. The device control system sends a temperature adjustment command, and the temperature control device realizes temperature control including heating and cooling of the polishing pad. Heating or cooling can be realized by adjusting the water temperature of the circulation water channel on the back surface of the polishing upper plate.

[0062] The circulation water channel system of the polishing plate includes one or more water inlets and one or more water outlets. The circulation water channel may be an independent annular chamber or an interconnected chamber.

[0063] To provide the chemical liquid required for the electrochemical mechanical polishing and planarization equipment, a chemical liquid supply system is further included, which is used to transfer the chemical liquid 4 to the polishing pad 3 and can transfer the chemical liquid 4 to the upper surface of the polishing pad 3. During the process, due to the rotation of the polishing table 2, the chemical liquid supply system evenly distributes the chemical liquid 4 into the through holes 311 of the electrochemical polishing pad 3. The chemical liquid supply system can also transfer the chemical liquid 4 from the upper polishing plate 21 to the bottom of the hole 311, and the upper polishing plate 21 needs to be provided with a liquid supply channel.

[0064] The chemical liquid supply system 41 can control the flow rate of the chemical liquid and may be equipped with a flow rate control unit for adjusting the discharge amount of the chemical liquid 4, or can control the temperature of the chemical liquid and may be equipped with a temperature control unit for adjusting the discharge temperature of the chemical liquid 4, or can control the concentration of the chemical liquid and may be equipped with a concentration control unit for adjusting the discharge concentration of the chemical liquid 4.

[0065] The chemical liquid 4 may specifically be a polishing liquid formed by dispersing polishing nanoparticles in an acidic or alkaline solution, with its pH > 8 or pH < 5. The chemical liquid 4 may also be a mixed solution of a polishing liquid and an electrolytic solution, and the electrolytic solution provides the anions and cations necessary for conduction to the polishing liquid. A solvent with strong oxidizing properties such as potassium permanganate or hydrogen peroxide can be added to the chemical liquid 4.

[0066] The implementation method using the above electrochemical mechanical polishing and planarization equipment includes the following steps.

[0067] (a) By controlling the pressure in the second pressure medium chamber in the polishing head, the conductive polishing head places the conductive wafer substrate on the placement table and transfers it directly above the electrochemical polishing pad.

[0068] (b) The chemical liquid supply system transfers the chemical liquid onto the polishing pad, and fills the grooves and holes of the polishing pad with the chemical liquid by the coaxial rotation of the polishing pad and the polishing table.

[0069] (c) The air bags in the first and second pressure medium chambers of the polishing head are pressurized, the conductive wafer substrate is pushed down by the flexible member of the polishing head, and the polishing surface contacts the upper surface of the polishing pad. The back surface of the conductive wafer substrate contacts the flexible member of the polishing head and is connected to the second electrode of the power supply by the central axis of rotation of the polishing head via a lead wire. At the same time, the polishing surface of the conductive wafer substrate contacts the chemical liquid in the polishing pad hole, the chemical liquid contacts the polishing upper plate, and the polishing upper plate is connected to the first electrode of the power supply by the central axis of rotation of the polishing lower plate and the polishing table via a lead wire, forming an electric current conduction circuit for electrochemical mechanical polishing and planarization. In the case of a surface conductive wafer substrate, by controlling the alternating current of the conductive coil in the flexible member of the polishing head, an eddy current can be formed in the surface conductive wafer substrate, and an electric current circuit can be established between this eddy current and the polishing table.

[0070] (d) By the rotation of the polishing head, the swing, and the rotation of the polishing pad, sufficient contact between the polishing surface of the conductive wafer substrate and the chemical liquid in the hole is realized.

[0071] (e) Under the action of the chemical liquid and the electric current circuit, the conductive wafer substrate causes an electrochemical reaction on the polishing surface to form an electrochemical reaction layer.

[0072] (f) The polishing head rotates, the polishing pad and the polishing table rotate together, the polishing head moves relatively on the polishing table, and the polishing surface of the conductive wafer substrate alternates between the electrochemical reaction contact point and the chemical mechanical polishing point. An electrochemical reaction is caused in the hole area of the polishing pad to form an electrochemical reaction layer. Chemical mechanical polishing is performed in the area where the electrochemical reaction layer is not in the hole. After polishing with the reaction layer, it is transferred to the hole area to cause an electrochemical reaction to form an electrochemical reaction layer. Chemical mechanical polishing is performed in the area where the electrochemical reaction layer is not in the hole, and the cycle is repeated.

[0073] (g) Repeat (d) to (f) until the requirement for the removal amount of the target material to be polished on the polishing surface of the conductive wafer substrate is reached.

[0074] (h) The polishing head clamps the conductive wafer substrate to the polishing head and transfers it to the unloading table by controlling the pressures of the first and second pressure medium chambers, and completes the unloading of the conductive wafer substrate by controlling the pressures of the first and second pressure medium chambers.

[0075] The above specific embodiments are for interpreting and explaining the present invention and do not limit the present invention. Any modification or change made to the present invention within the scope claimed by the spirit of the present invention and the claims is included in the claims of the present invention.

Claims

1. A power supply having a first electrode and a second electrode, A polishing table connected to the first electrode and having conductivity, A polishing pad provided on the upper surface of the polishing table, capable of being superposed on one polishing surface of a conductive wafer substrate, and including at least an action layer made of an insulating material and having a hole penetrating in its thickness direction and having conductivity for containing a chemical liquid, A polishing head including a suction assembly connected to the second electrode and having conductivity, with its lower surface directly clamping the conductive wafer substrate, and capable of being directly superposed on the back surface of the polishing surface of the conductive wafer substrate, The polishing table includes a polishing upper plate installed concentrically and coaxially and a polishing lower plate installed concentrically and coaxially. The polishing lower plate is connected to the rotation central axis, and the first electrode is directly connected to the polishing upper plate of the polishing table through the rotation central axis, The second electrode is electrically connected to the back surface of the polishing surface of the conductive wafer substrate through another rotation central axis disposed on the back side of the polishing head and through the suction assembly, The first electrode, the polishing table, the chemical liquid, the polishing surface of the conductive wafer substrate, the conductive wafer substrate, the back surface of the polishing surface of the conductive wafer substrate, the polishing head, and the second electrode sequentially form an energization circuit to form an electrochemical reaction layer on the polishing surface of the conductive wafer substrate, The polishing head can drive the conductive wafer substrate to move relative to the polishing pad in order to realize chemical mechanical polishing of the electrochemical reaction layer, An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate, characterized in that.

2. The polishing table can rotate around the axis of the polishing table, and the polishing head can rotate around the axis of the polishing head and can move relative to the polishing table, An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that.

3. The number of the holes is plural, An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1 or 2, characterized in that.

4. The total area of the holes occupies 5% to 70% of the action layer area, An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 3, characterized in that.

5. The polishing pad is a working layer, or the polishing pad has a two-layer or multi-layer structure in which the uppermost layer is a working layer, one or more lower layers are insulating layers, and the holes penetrate the entire thickness direction of the polishing pad. The electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that.

6. The polishing pad has a two-layer or multi-layer structure in which the uppermost layer is a working layer and one or more lower layers are conductive layers having perforations that are closed or communicate with the holes. The electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that.

7. The polishing head a first pressure medium chamber for controlling the vertical movement stroke of the conductive wafer substrate; a second pressure medium chamber for controlling the suction assembly and realizing suction or release of the suction assembly with respect to the conductive wafer substrate by changing the air pressure inside the second pressure medium chamber. The suction assembly includes a deformable flexible member and a support member for supporting the flexible member, and an access point for power is provided in the suction assembly. The electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that.

8. The flexible member is a conductive flexible film, and the support member is a metal member forming an access point for power. The electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 7, characterized in that.

9. The flexible member is an insulating flexible film, and a conductive coil forming an access point for power is coated inside the flexible member. The electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 7, characterized in that.

10. The polishing upper plate is made of a metal material or an alloy material. The electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that.

11. The polishing table has a heating or cooling function. The electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that.

12. Further comprising a chemical liquid supply system used for transferring a chemical liquid to a polishing pad, capable of transferring the chemical liquid to the upper surface of the polishing pad An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that

13. Further comprising a chemical liquid supply system capable of transferring the chemical liquid from the upper polishing plate to the bottom of the hole An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that

14. The chemical liquid is a polishing liquid in which polishing nanoparticles are dispersed in an acidic or alkaline solution, and its pH > 8 or pH < 5 An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that

15. When forming an electrochemical reaction layer on the polishing surface of the conductive wafer substrate, the second electrode connected to the polishing head of the wafer substrate is the positive electrode, and the first electrode connected to the polishing table is the negative electrode An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that

16. The power supply is a constant current power supply with a current ≤ 20 A, or the power supply is a constant voltage power supply with a voltage ≤ 220 V An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that

17. The outer edge of the polishing pad is arranged on the polishing table, or the outer edge of the polishing pad forms ribs with a height H ≤ 3 mm with respect to the upper surface of the polishing pad An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that

18. The holes are circular or rectangular or regular hexagonal or star-shaped, and are distributed in an array or concentrically An electrochemical mechanical polishing and planarization apparatus for processing a conductive wafer substrate according to claim 1, characterized in that

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