CN219945750U

CN219945750U - Electrochemical mechanical polishing and planarization equipment applied to conductive wafer substrate

Info

Publication number: CN219945750U
Application number: CN202222977123.3U
Authority: CN
Inventors: 邓耀敏; 郑晟良; 杨渊思
Original assignee: Hangzhou Zhonggui Electronic Technology Co ltd
Current assignee: Hangzhou Zhonggui Electronic Technology Co ltd
Priority date: 2022-11-03
Filing date: 2022-11-03
Publication date: 2023-11-03
Anticipated expiration: 2032-11-03

Abstract

The utility model discloses electrochemical mechanical polishing and planarization equipment applied to a conductive wafer substrate, which comprises a polishing table and a polishing device, wherein the polishing table can rotate around the axis of the polishing table; the polishing pad is arranged on the upper surface of the polishing table and at least comprises an action layer which can be attached to the polishing surface of the conductive wafer substrate, and the action layer is made of an insulating material; the lower surface of the polishing head can be attached to the back surface of the conductive wafer substrate polishing surface; the conductive wafer substrate has a first working state and a second working state, when the conductive wafer substrate is in the first working state, the polishing surface of the conductive wafer substrate forms an electrochemical reaction layer in the electrochemical channel, and when the conductive wafer substrate is in the second working state, the polishing belt drives the conductive wafer substrate to move relative to the acting layer of the polishing pad so as to realize the chemical mechanical polishing of the electrochemical reaction layer. The utility model introduces the electrochemical reaction on the surface of the wafer substrate, the substrate material removal rate and the polishing/flattening speed are obviously improved, and the equipment operation cost is obviously reduced; the circuit design is simpler.

Description

Electrochemical mechanical polishing and planarization equipment applied to conductive wafer substrate

Technical Field

The utility model belongs to the field of semiconductor integrated circuit chip manufacturing, and particularly relates to electrochemical mechanical polishing and planarization equipment applied to a conductive wafer substrate.

Background

The wafer substrate and semiconductor device manufacturing process comprises polishing, surface planarization and other processes, and usually adopts mechanical polishing, chemical mechanical polishing or planarization and other technologies, and the wafer substrate carrier (polishing head) is used for pressurizing the wafer back, controlling parameters such as pressure, polishing head rotating speed, polishing disk rotating speed, polishing liquid flow and the like, and polishing or planarization treatment is carried out 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 realize higher polishing or planarization efficiency, including higher flatness, lower defectivity and the like, by adjusting the formulation of the polishing liquid to generate chemical reaction on the surface of the wafer substrate.

The conductive wafer substrate is classified into bulk conductive type (conductive type substrate) and surface conductive type (surface layer conductive wafer substrate) according to conductive type, and bulk conductive type wafer substrate material itself has good conductive characteristics and may include doped type 4H-SiC and the like. The surface conductive wafer substrate may be bulk non-conductive but the surface layer conductive, such as a thin metal film deposited on the surface of a silicon wafer substrate.

The polishing and planarization process of the conductive substrate or surface layer conductive wafer substrate may employ special electrochemical mechanical polishing and planarization techniques. Based on chemical mechanical polishing and planarization, the electrochemical mechanical polishing and planarization can further utilize the conductive property of the wafer substrate or the film on the surface of the wafer substrate to form a current path, and perform electrochemical reaction on the surface of the wafer substrate or the film, so that the chemical reaction speed of the surface is improved through precise control of a circuit system, and further the mechanical polishing and planarization efficiency is improved. In the electrochemical mechanical polishing and planarization equipment process, the polishing solution for realizing the mechanical polishing and planarization functions is also electrolyte for realizing the electrochemical reaction of the surface of the wafer substrate, and the chemical components of the liquid, the conductivity of the liquid and the like are correspondingly adjusted.

Taking silicon carbide substrate material polishing process as an example: the silicon carbide material has high hardness, such as polishing the polishing surface on the polishing pad by using simple mechanical polishing, needs to apply high pressure to the back of the crystal, has harsh conditions, extremely low removal rate, low production efficiency of equipment, large consumption of worn products such as the polishing pad, and high cost. The chemical mechanical polishing process can carry out chemical modification such as oxidation on the surface of the silicon carbide substrate, so that the surface hardness is reduced, the material polishing speed is further improved, and the production efficiency of polishing equipment is improved. However, because silicon carbide materials have stable chemical properties and low surface oxidation speed, the chemical mechanical polishing process needs to select polishing solution with strong oxidizing property, and high requirements are put on corrosion resistance and the like of equipment hardware, so that the manufacturing cost and the operation reliability of the equipment are directly affected. Also, because silicon carbide materials have stable chemical properties and low surface oxidation speed, the removal rate of silicon carbide chemical mechanical polishing is still low, and the requirement of mass production is not completely met at present. For the conductive silicon carbide substrate material, in order to break through the bottleneck of chemical mechanical polishing efficiency, an electrochemical mechanical polishing technology can be adopted to oxidize the silicon carbide surface through electrochemical reaction, if a certain current density can be realized, the oxidation efficiency of the silicon carbide surface can be remarkably accelerated, synchronous mechanical polishing can be continuously matched, the removal rate of the silicon carbide material can be remarkably improved, the equipment operation efficiency is correspondingly improved, and the equipment operation cost is reduced. Meanwhile, the electrochemical mechanical polishing process does not need to rely on strong oxidizing polishing solution/electrolyte, so that the material selection range of equipment can be enlarged, the equipment cost is reduced, the service life of parts is prolonged, the operation reliability of the equipment is improved, the continuous operation time is prolonged, and the operation cost is further reduced.

Disclosure of Invention

In order to overcome the defects in the prior art, the utility model provides electrochemical mechanical polishing and planarization equipment applied to a conductive wafer substrate, which can realize high performance, high efficiency and low cost of polishing and planarization of the conductive wafer substrate.

The technical scheme adopted for solving the technical problems is as follows: an electrochemical mechanical polishing and planarization apparatus for a conductive wafer substrate, comprising:

a polishing table rotatable about a polishing table axis;

the polishing pad is arranged on the upper surface of the polishing table and at least comprises an action layer which can be attached to the polishing surface of the conductive wafer substrate, and the action layer is made of an insulating material;

the lower surface of the polishing head can be attached to the back surface of the conductive wafer substrate polishing surface;

the conductive wafer substrate has a first working state and a second working state, when the conductive wafer substrate is in the first working state, the polishing surface of the conductive wafer substrate forms an electrochemical reaction layer in the electrochemical channel, and when the conductive wafer substrate is in the second working state, the polishing belt drives the conductive wafer substrate to move relative to the acting layer of the polishing pad so as to realize chemical mechanical polishing of the electrochemical reaction layer.

Further, the first working state and the second working state are sequentially and independently carried out; alternatively, the first operating state and the second operating state are performed simultaneously.

Further, when the first working state and the second working state are sequentially and independently carried out, the conductive wafer substrate respectively carries out the first working state and the second working state in different polishing units; or when the first working state and the second working state are sequentially and independently carried out, the conductive wafer substrate carries out the first working state and the second working state in the same polishing unit.

Further, in the electrified state, the polished surface of the conductive wafer substrate forms an electrochemical reaction layer in the electrochemical channel, and meanwhile, the electrochemical reaction layer is subjected to chemical mechanical polishing;

or alternatively, the process may be performed,

in the electrified state, the polished surface of the conductive wafer substrate firstly forms an electrochemical reaction layer in the electrochemical channel, and then carries out chemical mechanical polishing on the electrochemical reaction layer;

or alternatively, the process may be performed,

in the power-on state, the polishing surface of the conductive wafer substrate forms an electrochemical reaction layer in the electrochemical channel, and in the power-off state, the electrochemical reaction layer is subjected to chemical mechanical polishing.

Further, the device also comprises a power supply;

the polishing table and the polishing head are respectively connected with the power supply and have conductivity;

the action layer is provided with holes penetrating through the thickness direction, chemical liquid is contained in the holes, and the chemical liquid has conductivity;

the power supply, the polishing table, the chemical liquid, the conductive wafer substrate and the polishing head can form an electrified loop so as to form an electrochemical reaction layer on the polishing surface of the conductive wafer substrate.

Further, the number of the holes is a plurality of holes.

Further, the total area of the holes accounts for 5-50% of the area of the acting layer.

Further, the diameter of the hole is more than or equal to 3mm.

Further, the polishing pad is an active layer; or the polishing pad is of a double-layer or multi-layer structure, the uppermost layer is an action layer, one or more lower layers are insulating layers, and the holes penetrate through the entire thickness direction of the polishing pad.

Further, the polishing pad has a double-layer or multi-layer structure, wherein the uppermost layer is an active layer, and one or more lower layers are conductive layers, and the conductive layers are sealed or provided with perforations communicated with the holes.

Further, the power supply is direct current or alternating current.

Further, the polishing head comprises a polishing head body,

the first pressure medium cavity is used for controlling the up-and-down movement stroke of the conductive wafer substrate;

the second pressure medium cavity is used for controlling the adsorption component, and the adsorption component can adsorb or release the conductive wafer substrate by changing the air pressure in the second pressure medium cavity;

the adsorption component comprises a flexible piece capable of being deformed and a supporting piece for supporting the flexible piece, and is provided with an access point of a power supply.

Further, the flexible member is a conductive flexible film, and the support member is a metal member that forms an access point for a power supply.

Further, the flexible piece comprises a light metal plate and a flexible film, a plurality of holes for installing the flexible film are formed in the light metal plate, and the light metal plate forms an access point of a power supply.

Further, the flexible member comprises a lightweight metal plate that forms an access point for a power source.

Further, the surface of the light metal plate is provided with a platinized layer.

Further, the flexible piece is an insulating flexible film, a conductive coil is wrapped in the flexible piece, and the conductive coil forms an access point of a power supply.

Further, the polishing table comprises a polishing upper disc and a polishing lower disc which are concentrically and coaxially arranged, and the polishing lower disc is connected with the rotating central shaft.

Further, the polishing upper disc is made of metal or alloy materials.

Further, the surface of the polishing upper disc is provided with a platinized layer.

Further, a wire connected with the power supply passes through the rotation center shaft and is connected with the polishing upper disc.

Further, a chemical liquid supply system is included for delivering chemical liquid to the polishing pad, which can deliver chemical liquid to the upper surface of the polishing pad.

Further, a chemical liquid supply system is also included, which can transfer chemical liquid from the polishing upper plate to the bottom of the hole.

Further, the chemical liquid is a polishing liquid, which is a solution of grinding nano particles dispersed in an acidic or alkaline solution, and the pH is >8 or pH <5.

Further, the power supply is a steady-flow power supply, and the current of the power supply is less than or equal to 20A; or the power supply is a stabilized voltage power supply, and the voltage of the stabilized voltage power supply is less than or equal to 220V.

The polishing pad made of insulating material is attached to the upper surface of the conductive polishing table, and has holes penetrating the thickness direction, and chemical liquid which is supplied from the liquid supply arm to the polishing pad is contained in the holes and has conductivity. There is no need for a conductive contact design on the polishing pad, but the wafer substrate carrier (polishing head) is conductive. When the polishing head pressurizes the wafer back, the front surface of the wafer substrate is attached to the polishing pad, and an electrical circuit between the first electrode, the conductive polishing table, the chemical liquid in the holes penetrating the thickness of the polishing pad, the conductive wafer substrate, the conductive polishing head and the second electrode can be established. The polarity of the first electrode and the second electrode is determined by the designed electrochemical reaction of the wafer substrate surface. For example, when the hole of the polishing pad is filled with a conductive chemical liquid, and the upper plate of the polishing table is a cathode and the surface of the wafer substrate (polishing head) is an anode in the electrochemical reaction, the surface of the conductive silicon carbide wafer substrate can be oxidized.

In the electrochemical mechanical polishing/planarization process of a conductive wafer substrate, a polishing table and a polishing pad bonded to the upper surface of the polishing table are rotated around the axis of the polishing table; the polishing head substrate rotates around the axis of the polishing head and can move relative to the polishing table; the wafer substrate is rotated with the polishing head, engages the polishing pad but moves relative to the polishing pad. The surface of the conductive wafer substrate undergoes an electrochemical reaction as it passes through the perforated areas on the polishing pad and is mechanically polished/planarized as it passes through the non-perforated areas on the polishing pad. When the wafer substrate rotates along with the polishing head and moves relative to the polishing table, electrochemical reaction and mechanical polishing/planarization can be continuously and repeatedly completed on the surface of the conductive wafer substrate, so that electrochemical mechanical polishing/planarization of the surface of the conductive wafer substrate is realized.

The utility model has the advantages that 1) the electrochemical mechanical polishing conductive wafer substrate is compared with mechanical polishing or conventional chemical mechanical polishing/planarization, the electrochemical reaction of the surface of the wafer substrate is introduced, the substrate material removal rate and the polishing/planarization speed are obviously improved, and the equipment operation cost is obviously reduced; 2) The circuit design is simpler. The polishing pad has no conductive contact on the upper surface, so that the defect rate of the polished surface of the wafer substrate can be obviously reduced, the surface smoothness is improved, the surface metal pollution and the particle pollution are reduced, the service life of the polishing pad is prolonged, and the consumable cost is reduced; 3) The electrochemical reaction and the mechanical polishing rate in the electrochemical mechanical polishing process are independently controllable and adjustable, including regional adjustment of the surface of the wafer substrate; 4) The first working state and the second working state are carried out step by step, and the process conditions can be configured according to the two working states, so that the two process procedures of electrochemical reaction in the first working state and chemical mechanical polishing in the second working state are more stable and uniform, and the influence of the single-step side reaction on the other step is smaller; the first working state and the second working state are higher in polishing efficiency at the same time, transmission between at least two polishing tables is not needed, and the number of the wafers in unit time is increased.

Drawings

Fig. 1 is a schematic structural view of the present utility model.

FIG. 2 is a top view of an active layer of the present utility model.

Fig. 3 is a cross-sectional view of a polishing pad of the present utility model, in which the polishing pad has a single-layer structure.

Fig. 4 is a cross-sectional view of a polishing pad of the present utility model, in which the polishing pad has a double layer structure and the lower layer is an insulating layer.

Fig. 5 is a cross-sectional view of a polishing pad of the present utility model, in which the polishing pad has a double-layered structure and the lower layer has a conductive layer.

FIG. 6 is a cross-sectional view of a polishing pad of the present utility model with a flange on the outer periphery and the flange being of a homogenous material.

FIG. 7 is a cross-sectional view of a polishing pad of the present utility model with a rim on the outer periphery and a heterogeneous material.

Fig. 8 is a cross-sectional view of a polishing head in accordance with the present utility model.

Fig. 9 is a top view of a lightweight metal plate according to the present utility model.

Fig. 10 is a cross-sectional view of a lightweight metal plate according to the present utility model.

Fig. 11 is a schematic view of the structure of the polishing table of the present utility model.

The polishing device comprises a 1-power supply, a 11-access point, a 12-wire, a 2-polishing table, a 21-polishing upper disc, a 22-polishing lower disc, a 23-rotation center shaft, a 3-polishing pad, a 31-acting layer, a 311-hole, a 32-insulating layer, a 33-conducting layer, a 34-flange, a 4-chemical liquid, a 41-chemical liquid supply system, a 5-conducting type wafer substrate, a 51-conducting type wafer substrate polishing surface, a 6-polishing head, a 71-first pressure medium cavity, a 72-second pressure medium cavity and a 73-adsorption component.

Detailed Description

In order to make the present utility model better understood by those skilled in the art, the following description will make clear and complete descriptions of the technical solutions of the embodiments of the present utility model with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present utility model without making any inventive effort, shall fall within the scope of the present utility model.

An electrochemical mechanical polishing and planarization apparatus for a conductive wafer substrate includes a polishing table 2, a polishing pad 3 disposed on an upper surface of the polishing table 2, and a polishing head 6. The polishing table 2 is rotatable about a polishing table axis, and the polishing head 6 is rotatable about a polishing head axis and movable relative to the polishing table 2.

The polishing pad 3 includes at least an active layer 31 that can be bonded to one polishing surface 51 of the conductive wafer substrate 5, and the active layer 31 is made of an insulating material. The lower surface of the polishing head 6 may be attached to the back surface of the polishing surface 51 of the conductive wafer substrate 5, so as to drive the conductive wafer substrate 5 to move relative to the polishing pad 3.

The conductive wafer substrate 5 has a first working state and a second working state, in the first working state, the polishing surface 51 of the conductive wafer substrate 5 forms an electrochemical reaction layer in the electrochemical channel, and in the second working state, the polishing head 6 drives the conductive wafer substrate 5 to move relative to the acting layer 31 of the polishing pad 3, so that the chemical mechanical polishing of the electrochemical reaction layer is realized.

The first working state and the second working state can be sequentially and independently carried out; alternatively, the first operating state and the second operating state are performed simultaneously.

The first working state and the second working state are sequentially and independently performed, that is, when the conductive wafer substrate 5 is in the first working state on the acting layer 31 of the polishing pad 3 to form the electrochemical reaction layer, the mechanical polishing effect of the second working state on the electrochemical reaction layer cannot exist, otherwise, the process that the conductive wafer substrate 5 is in the second working state to form the electrochemical reaction layer cannot exist under the mechanical polishing effect of the second working state on the electrochemical reaction layer. In other words, only one working state exists on the conductive wafer substrate 5 at the same time, when the conductive wafer substrate 5 is in the first working state, the polishing surface 51 of the conductive wafer substrate 5 is on the acting layer 31 of the polishing pad 3, only different areas of the conductive wafer substrate 5 move along with the relative motion of the polishing head 6 and the polishing table 2 and rotate on themselves, and an electrochemical reaction layer (realized by the electrolyte without abrasive particles) is sequentially formed on the electrochemical channel, and during the process, no mechanical polishing exists on the electrochemical reaction layer or the original polishing surface 51; conversely, in the second working state, the electrochemical reaction module is electrified to apply pressure to the conductive wafer substrate 5, and chemical mechanical polishing is realized under the participation of a certain flow of polishing solution

The first operation state and the second operation state are performed simultaneously, which means that different areas of the conductive wafer substrate 5 are simultaneously in the same time, and an electrochemical reaction layer is formed on the active layer 31 of the polishing pad 3 in the first operation state and a mechanical polishing effect in the second operation state exists. At different times, the same area of the conductive wafer substrate 5 will have alternating first and second operating conditions on the active layer 31 of the polishing pad 3. In other words, under the action of the polishing solution having a certain conductivity, the conductive wafer substrate 5 is electrochemically reacted in the region corresponding to the electrochemical reaction channel at the same time in the active layer 31 of the polishing pad 3 to form an electrochemical reaction forming layer, and is chemically and mechanically polished in other regions. At the next time, the region on the conductive wafer substrate 5 where the electrochemical reaction forming layer has been formed will be rotated to the non-electrochemical channel region for chemical mechanical polishing in the relative motion of rotation of the polishing table 2, rotation of the polishing head 6, and swinging of the polishing head 6 with respect to the polishing table 2; conversely, the region where the electrochemical reaction forming layer was not formed will rotate to the electrochemical channel region to form the electrochemical reaction forming layer. The same area of the polishing surface 51 of the conductive wafer substrate 5 will repeatedly alternate between these two states during polishing.

Under the condition that the first working state and the second working state are sequentially and independently carried out, the method is divided into a first working state and a second working state respectively carried out by the conductive wafer substrate 5 in different polishing units, or the first working state and the second working state are carried out by the conductive wafer substrate 5 in the same polishing unit. The different polishing units herein may be different polishing tables, or may be different areas, such as an area or space around the polishing table, or a carrier, and are not particularly limited, as long as the first operation state or the second operation state of the conductive wafer substrate 5 can be achieved.

In view of the above, in the power-on state, the polishing surface 51 of the conductive wafer substrate 5 forms an electrochemical reaction layer in the electrochemical channel, and simultaneously, chemical mechanical polishing is performed on the electrochemical reaction layer, and at this time, the first working state and the second working state are performed in the same polishing unit, and the power supply may use ac or dc. Or, in the power-on state, the polishing surface 51 of the conductive wafer substrate 5 forms an electrochemical reaction layer in the electrochemical channel, and then performs chemical mechanical polishing on the electrochemical reaction layer, where the first working state and the second working state may be performed in the same polishing unit, or may be performed in different polishing units, and the power supply may use ac or dc. Alternatively, in the power-on state, the polishing surface 51 of the conductive wafer substrate 5 may form an electrochemical reaction layer in the electrochemical channel, and in the power-off state, the electrochemical reaction layer is subjected to chemical mechanical polishing, where the first working state and the second working state may be performed in the same polishing unit, and the power supply may use direct current or alternating current.

More specifically, an electrochemical mechanical polishing and planarization apparatus for a conductive wafer substrate further includes a power source 1 having a first electrode and a second electrode, a polishing table 2 connected to the first electrode, and a polishing head 6 connected to the second electrode, wherein the first electrode is a negative electrode and the second electrode is a positive electrode in this embodiment. In other embodiments, the first electrode may be a positive electrode and the second electrode may be a negative electrode. The power supply 1 provides stable constant current or constant voltage for the electrochemical loop; the power supply 1 can be a constant-current power supply, and the current is less than or equal to 20A; or the power supply 1 is a regulated power supply, and the voltage is less than or equal to 220V. When the power supply 1 is alternating current, the amplitude voltage of the alternating current constant voltage source is less than or equal to 220V, or the amplitude current of the alternating current constant current source is less than or equal to 20A.

The polishing head 6 and the polishing table 2 are connected to the power source 1, respectively, and have conductivity. The active layer 31 has holes 311 penetrating the thickness direction, and the holes 311 hold a chemical liquid 4 therein, and the chemical liquid 4 has conductivity. The wafer substrate surface is electrochemically reacted in the hole area of the active layer 31, that is, electrochemical channels are formed in the hole area, and chemical mechanical polishing is performed in the non-hole area of the active layer 31.

Therefore, the polishing surface 51 of the conductive wafer substrate 5 is subjected to electrochemical reaction in the hole region of the active layer 31 to form an electrochemical reaction layer, and is subjected to chemical mechanical polishing in the non-hole region of the active layer 31; the two steps can be performed simultaneously, namely, electrochemical reaction in the hole area can exist at the same time to form an electrochemical reaction forming layer, and chemical mechanical polishing can be performed in other non-hole areas; the two steps may be performed asynchronously, i.e. the polishing surface of the conductive wafer substrate 5 first undergoes electrochemical reaction in the hole region of the active layer 31 to form an electrochemical reaction layer, then chemical mechanical polishing is performed in the non-hole region of the active layer 31, and the above steps are repeated again.

The conductive polishing head 6 is loaded with a conductive wafer substrate 5 and is transmitted to the polishing pad 3, the polishing surface 51 of the conductive wafer substrate 5 and conductive chemical liquid 4 in a large number of holes 311 uniformly distributed in the polishing pad 3 perform electrochemical reaction, and a power supply 1, a polishing table 2, the chemical liquid 4, the conductive wafer substrate 5, the polishing head 6 and the power supply 1 sequentially form a power-on loop by applying downward pressure to the back surface of the conductive wafer substrate 5, so that an electrochemical reaction layer is formed on the polishing surface 51 of the conductive wafer substrate 5. The electrochemical reaction layer interacts with the non-apertured region of the active layer 31 as the polishing head 6 moves the conductive wafer substrate 5 relative to the polishing pad 3, thereby effecting mechanical polishing of the electrochemical reaction layer.

As shown in FIG. 2, the number of holes 311 is plural, and the diameter thereof is 3mm or more, that is, R is 3mm or more in FIG. 2. The holes 311 are circular, and are distributed in an array or in concentric circles. The holes 311 may be any other shape, and may be distributed at will. The total area of the holes 311 is 5-70% of the area of the active layer 31, and preferably, the total area of the holes 311 is 5-50% of the area of the active layer 31. The above-described area arrangement allows for optimizing the electrochemical reaction rate while achieving a formation rate of the electrochemical reaction layer that matches the rate at which it is mechanically polished.

The shape of the hole 311 is not limited, and it may be rectangular, regular hexagonal or star-shaped.

The polishing pad 3 may be an insulating polishing pad of a single-layer structure, in which case the entire polishing pad 3 is the active layer 31, as shown in fig. 3.

The polishing pad 3 may also be of a double-layer or multi-layer structure, in which the uppermost layer is the active layer 31 and the lower layer or layers are the insulating layers 32, and the holes 311 extend through the entire thickness of the polishing pad 3, i.e., the holes 311 extend downward from the active layer 31 to the insulating layers 32, as shown in fig. 4.

The polishing pad 3 may also be of a double-layer or multi-layer structure, whether it is of a double-layer structure or a multi-layer structure, with the uppermost layer being the active layer 31 and the lower layer or layers being the conductive layer 33; the conductive layer 33 may be a fully enclosed structure as shown in fig. 5; alternatively, the conductive layer 33 may have perforations that communicate with the holes 311, where the communication may be entirely or partially directly.

The polishing table 2 is placed on the outer edge of the polishing pad 3 to form a flange 34 along or at the outer edge of the polishing pad 3, the flange 34 protrudes upwards from the upper surface of the polishing pad 3, and the height of the flange relative to the upper surface of the polishing pad is H less than or equal to 3mm, namely, the height of the flange is about 3mm higher than the height of the upper surface of the polishing pad 3; as shown in fig. 6, the polishing pad 3 may have an edge-raised structure of the same material as the polishing pad; as shown in fig. 7, the polishing pad 3 may be covered with a heterogeneous material raised layer, and the heterogeneous material raised ribs 34 may be made of a hard corrosion-resistant material, such as plastic, or may be made of a flexible material, such as rubber.

As shown in fig. 8, the polishing head 6 includes a first pressure medium chamber 71 for controlling the up-and-down movement stroke of the conductive wafer substrate 5, and at least one second pressure medium chamber 72 for controlling the adsorption assembly 73, and the adsorption or release of the adsorption assembly 73 to the conductive wafer substrate 5 can be achieved by changing the air pressure inside the second pressure medium chamber 72, that is, by pressurizing or vacuum-operating the second pressure medium chamber 72 to change the shape or stroke of the adsorption assembly 73, and the specific function is realized in the prior art and will not be repeated.

As shown in fig. 11, the polishing table 2 includes a polishing upper plate 21 and a polishing lower plate 22, which are concentrically and coaxially disposed, and are also concentrically and coaxially disposed with a rotation center shaft 23, and the polishing lower plate 22 is connected to the rotation center shaft 23. The transmission device drives the lower polishing upper plate 21 and the polishing lower plate 22 to coaxially rotate, and the rotation speed is controllable.

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 reaction to occur, and the non-hole areas of the polishing pad 3 provide polishing bearing surfaces for mechanical polishing.

The polishing upper plate 21 may be made of a metal material or an alloy material, and the lead 12 connected to the power source 1 is connected to the polishing upper plate 21 through the rotation center shaft 23. Specifically, polishing upper plate 21 may be made of aluminum alloy or titanium alloy, or may be coated with a platinum layer on the surface of aluminum alloy or titanium alloy.

The polishing upper disc 21 is connected with a temperature control device, a temperature regulation command is issued by an upper computer through a polishing pad temperature sensor feedback value, and the temperature control of the polishing pad is realized through the temperature control device, wherein the temperature control comprises heating and cooling. The heating or cooling is realized by adjusting the water temperature of the circulating water path on the back surface of the polishing upper disc through a temperature device.

The circulating waterway system of the polishing disk comprises one or more water inlets and one or more water outlets, and the circulating waterway can be an independent annular cavity or an intercommunicating cavity.

In order to provide the electrochemical mechanical polishing and planarization apparatus with a desired chemical liquid, a chemical liquid supply system for delivering the chemical liquid 4 to the polishing pad 3, the chemical liquid 4 may be delivered to the upper surface of the polishing pad 3 by rotation of the polishing table 2 during the process, and the chemical liquid supply system uniformly 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 polishing upper plate 21 to the bottom of the hole 311, and the polishing upper plate 21 needs to have a liquid supply channel.

The chemical liquid supply system 41 may also be provided with a flow control unit, and the flow opening of the chemical liquid can be controlled by detecting the conductivity of the chemical liquid centrifugally thrown out along with the polishing table 2 after polishing, so as to adjust the output of the chemical liquid 4; or the polishing machine also can be provided with a temperature control unit, and the temperature of the chemical liquid can be controlled by detecting the temperature of the chemical liquid centrifugally thrown out along with the polishing table 2 after polishing, so as to adjust the output temperature of the chemical liquid 4; or may also be provided with a concentration control unit for adjusting the output concentration of the chemical liquid 4.

The chemical liquid 4 may be a polishing liquid, in particular, abrasive nanoparticles dispersed in an acidic or alkaline solution having a pH >8 or a pH <5. The chemical liquid 4 may also be a mixed solution of a polishing liquid and an electrolyte, the electrolyte providing anions and cations necessary for the polishing liquid to conduct electricity. The chemical liquid 4 can be added with strengthening solvent such as potassium permanganate or hydrogen peroxide.

The implementation method for the electrochemical mechanical polishing and planarization equipment comprises the following steps:

(a) The conductive polishing head loads the conductive wafer substrate on the loading platform through pressure control of a second pressure medium cavity in the polishing head, and transfers the conductive wafer substrate to the position right above the electrochemical polishing pad;

(b) The chemical liquid supply system transmits chemical liquid to the position right above the polishing pad, and uniformly scrapes the chemical liquid into grooves of the polishing pad which coaxially rotate along with the polishing table through the trimmer;

(c) The polishing head is pressurized by the first pressure medium cavity air bag and the second pressure medium cavity air bag, the conductive wafer substrate is pressed onto the polishing pad along with the flexible piece, wherein the back surface of the conductive wafer substrate is contacted with the flexible piece and directly connected to the second electrode after passing through the polishing head lead wire to the rotation center shaft, the polishing surface of the conductive wafer substrate is contacted with chemical liquid in the hole, the chemical liquid is contacted with the polishing upper disc, and the polishing upper disc lead wire directly connected to the first electrode after passing through the polishing lower disc to the rotation center shaft, so that an electrochemical mechanical polishing and flattening current conducting loop is formed; the surface conductive wafer substrate is subjected to alternating current control by the conductive coil coated in the flexible piece, so that an eddy current is formed on the surface conductive wafer substrate, and a current loop can be established between the eddy current and the polishing table.

(d) The rotation and swing of the polishing head and the rotation of the polishing pad realize that all parts of the polishing surface of the conductive wafer substrate are fully contacted with the chemical liquid in the holes;

(e) Under the action of chemical liquid and a current loop, the polished surface of the conductive wafer substrate carries out electrochemical reaction to generate an electrochemical reaction layer;

(f) The electrochemical reaction layer can alternately exchange an electrochemical reaction contact point and a mechanical polishing point in the rotation process of the polishing head and the polishing pad, and the electrochemical reaction layer is mechanically polished in a non-hole area; the reaction layer is polished and then transferred to a hole area for electrochemical reaction;

(g) Repeating the steps (d) - (f) until the removal amount requirement of the target polishing is met;

(h) The polishing head clamps the conductive wafer substrate to the polishing head to transfer to the loading platform through pressure control on the first pressure medium cavity and the second pressure medium cavity, and the conductive wafer substrate is unloaded through the pressure control on the first pressure medium cavity and the second pressure medium cavity.

The foregoing detailed description is provided to illustrate the present utility model and not to limit the utility model, and any modifications and changes made to the present utility model within the spirit of the present utility model and the scope of the appended claims fall within the scope of the present utility model.

Claims

1. An electrochemical mechanical polishing and planarization apparatus for a conductive wafer substrate, comprising:

a polishing table rotatable about a polishing table axis;

2. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 1, wherein: the first working state and the second working state are sequentially and independently carried out; alternatively, the first operating state and the second operating state are performed simultaneously.

3. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 2, wherein: when the first working state and the second working state are sequentially and independently carried out, conducting type wafer substrates respectively carry out the first working state and the second working state in different polishing units; or when the first working state and the second working state are sequentially and independently carried out, the conductive wafer substrate carries out the first working state and the second working state in the same polishing unit.

4. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 2, wherein:

in the electrified state, the polished surface of the conductive wafer substrate forms an electrochemical reaction layer in the electrochemical channel, and meanwhile, the electrochemical reaction layer is subjected to chemical mechanical polishing;

or alternatively, the process may be performed,

5. Electrochemical mechanical polishing and planarizing apparatus for conductive wafer substrates according to claim 1 or 2, characterized in that:

the power supply is also included;

6. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 5, wherein: the number of the holes is a plurality of.

7. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 5, wherein: the total area of the holes accounts for 5-50% of the area of the active layer.

8. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 5, wherein: the diameter of the hole is more than or equal to 3mm.

9. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 5, wherein: the polishing pad is an active layer; or the polishing pad is of a double-layer or multi-layer structure, the uppermost layer is an action layer, one or more lower layers are insulating layers, and the holes penetrate through the entire thickness direction of the polishing pad.

10. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 5, wherein: the polishing pad has a double-layer or multi-layer structure, wherein the uppermost layer is an action layer, one or more layers of the lower layer is/are conductive layers, and the conductive layers are sealed or provided with perforations communicated with the holes.

11. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 5, wherein: the power supply is direct current or alternating current.

12. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 5, wherein: the polishing head comprises a polishing head and a polishing head,

13. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 12, wherein: the flexible member is a conductive flexible film, and the support member is a metal member that forms an access point for a power supply.

14. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 12, wherein: the flexible piece comprises a light metal plate and a flexible film, wherein a plurality of holes for installing the flexible film are formed in the light metal plate, and the light metal plate forms an access point of a power supply.

15. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 12, wherein: the flexible member comprises a lightweight metal plate that forms an access point for a power source.

16. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 15, wherein: the surface of the light metal plate is provided with a platinized layer.

17. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 12, wherein: the flexible piece is an insulating flexible film, a conductive coil is wrapped in the flexible piece, and the conductive coil forms an access point of a power supply.

18. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 1, wherein: the polishing table comprises a polishing upper disc and a polishing lower disc which are concentrically and coaxially arranged, and the polishing lower disc is connected with a rotating central shaft.

19. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 18, wherein: the polishing upper disc is made of metal or alloy materials.

20. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 19, wherein: the surface of the polishing upper disc is provided with a platinized layer.

21. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 17, wherein: and a lead wire connected with the power supply penetrates through the rotating central shaft to be connected with the polishing upper disc.

22. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 5, wherein: a chemical liquid supply system is also included for delivering chemical liquid to the polishing pad, which can be delivered to the upper surface of the polishing pad.

23. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 18, wherein: a chemical liquid supply system is also included that can deliver chemical liquid from the polishing top plate to the bottom of the hole.

24. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 5, wherein: the chemical liquid is polishing liquid, wherein the polishing nano particles are dispersed in an acidic or alkaline solution, and the pH value of the chemical liquid is more than 8 or less than 5.

25. The electrochemical mechanical polishing and planarizing apparatus for a conductive wafer substrate of claim 11, wherein: the power supply is a steady-flow power supply, and the current of the power supply is less than or equal to 20A; or the power supply is a stabilized voltage power supply, and the voltage of the stabilized voltage power supply is less than or equal to 220V.