Wafer photoelectrochemical mechanical polishing device and method and controller

Abstract

The invention is suitable for the technical field of semiconductor ultra-precision machining, and provides a wafer photoelectrochemical mechanical polishing device and method and a controller. The device comprises a conveying module, a cleaning module and a polishing module. The transmission module comprises a wafer bearing box and a manipulator; the cleaning module comprises an X-side cleaning module, a Y-side cleaning module and a wafer transmission station; each of the X-side cleaning module and the Y-side cleaning module comprises a cleaning and drying module and a combined manipulator; the polishing module comprises an X-side photoelectrochemical mechanical polishing module, a Y-side photoelectrochemical mechanical polishing module, a polishing buffer disc and a manipulator; the cleaning module and the photoelectrochemical mechanical polishing module on the X side and the Y side run independently; the mechanical arm or the combined mechanical arm is used for conveying wafers among the wafer conveying station, the polishing buffer disc, the cleaning and drying module and the polishing module. The problems of low polishing efficiency and poor surface type quality of the SiC wafer can be solved.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor ultra-precision processing technology, and in particular, relates to a wafer photoelectrochemical mechanical polishing device, method and controller. Background Art

[0002] As the third generation semiconductor material, single crystal silicon carbide (SiC) has the characteristics of high thermal conductivity, high critical breakdown electric field, high saturated electron drift velocity, high bonding energy and wide bandgap compared with traditional semiconductor materials. It is the preferred material for high-frequency, high-temperature, high-power, radiation-resistant electronic devices and sensor devices. It is also an ideal substrate material for manufacturing large-size, ultra-high brightness white light, blue light diodes and laser diodes. It has important applications in aviation, aerospace exploration, nuclear energy development, radar and communications.

[0003] With the rapid development of optoelectronics, micro-electromechanical systems and information technology, the surface processing accuracy and surface quality of single-crystal SiC substrates used in related devices have been proposed to meet the requirements of sub-nanometer manufacturing accuracy and ultra-smooth surface manufacturing without sub-surface defects. However, due to the high hardness, high brittleness and high stability of SiC crystals themselves, it is difficult to ensure the polishing efficiency of SiC wafers. At present, for the polishing process of SiC wafers, the traditional chemical mechanical polishing (CMP) device has a large polishing pressure, and the wafer is easily deformed under the action of cutting force, which leads to damage to the wafer surface and low wafer polishing efficiency.

[0004] Therefore, new polishing devices and processes are urgently needed to solve the problems of low polishing efficiency and poor surface quality of SiC wafers. Summary of the invention

[0005] In order to overcome the problems existing in the related art, the embodiments of the present application provide a wafer photoelectrochemical mechanical polishing device, method and controller, which can solve the problems of low polishing efficiency and poor surface quality of SiC wafers.

[0006] This application is implemented through the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides a wafer photoelectrochemical mechanical polishing device, including a transmission module, a cleaning module and a polishing module;

[0008] The transfer module includes a wafer carrier box, a first upper robot and a first lower robot; the first upper robot and the first lower robot are used to transfer the wafer between the wafer carrier box and the cleaning module;

[0009] The cleaning module includes an X-side cleaning module, a Y-side cleaning module and a wafer transfer station; the X-side cleaning module and the Y-side cleaning module operate independently; the X-side cleaning module includes a first cleaning and drying module and a first combined robot; the Y-side cleaning module includes a second cleaning and drying module and a second combined robot; the first combined robot is used to transfer the wafer from the wafer transfer station to the polishing buffer tray, and from the polishing buffer tray to the first cleaning and drying module; the second combined robot is used to transfer the wafer from the wafer transfer station to the polishing buffer tray, and from the polishing buffer tray to the second cleaning and drying module;

[0010] The polishing module includes an X-side photoelectrochemical mechanical polishing module, a Y-side photoelectrochemical mechanical polishing module, a polishing buffer tray, a second upper robot and a second lower robot; the X-side photoelectrochemical mechanical polishing module and the Y-side photoelectrochemical mechanical polishing module operate independently; the second upper robot is used to transfer the wafer between the polishing buffer tray and the X-side photoelectrochemical mechanical polishing module; the second lower robot is used to transfer the wafer between the polishing buffer tray and the Y-side photoelectrochemical mechanical polishing module.

[0011] In one embodiment, the first cleaning and drying module includes a first acid cleaning station, a first alkaline cleaning station and a first drying station;

[0012] The first combined robot includes a third upper robot, a fourth upper robot and a third lower robot; the third upper robot is used to transfer wafers between the polishing buffer tray and the first acid cleaning station, and between the first acid cleaning station and the first alkaline cleaning station; the fourth upper robot is used to transfer wafers between the first alkaline cleaning station and the first drying station; the third lower robot is used to transfer wafers between the wafer transfer station and the polishing buffer tray.

[0013] In one embodiment, the wafer transfer station includes a first-level wafer placement location and a second-level wafer placement location;

[0014] The first layer of wafer placement is used to place wafers that are polished by the photoelectrochemical mechanical polishing module on the X side; the second layer of wafer placement is used to place wafers that are polished by the photoelectrochemical mechanical polishing module on the Y side;

[0015] The polishing buffer plate includes four layers of wafer placement positions, namely the first wafer entry placement position, the first wafer exit placement position, the second wafer entry placement position and the second wafer exit placement position; the first wafer entry placement position is used to place wafers going to the X-side photoelectrochemical mechanical polishing module for polishing; the first wafer exit placement position is used to place wafers leaving the X-side photoelectrochemical mechanical polishing module after polishing; the second wafer entry placement position is used to place wafers going to the Y-side photoelectrochemical mechanical polishing module for polishing; the second wafer exit placement position is used to place wafers leaving the Y-side photoelectrochemical mechanical polishing module after polishing.

[0016] In one embodiment, the X-side photoelectrochemical mechanical polishing module includes an X-side wafer placement station and an X-side polishing station; the X-side wafer placement station includes a first wafer placement station, a second wafer placement station and a third wafer placement station; the X-side polishing station includes a first polishing station and a second polishing station;

[0017] The first wafer placement station is used to place unpolished wafers; the second wafer placement station is used to place wafers polished by the first polishing station; the third wafer placement station is used to place wafers polished by the second polishing station;

[0018] The second upper robot is used to transfer the wafer between the polishing buffer plate and the first wafer placement station, and between the third wafer placement station and the polishing buffer plate.

[0019] In one embodiment, the first polishing station includes a first light source; the first light source is an ultraviolet light source; the second polishing station includes a second light source; the second light source is a blue light source.

[0020] In one embodiment, during the first photoelectrochemical mechanical polishing under the irradiation of the ultraviolet light source of the first polishing station, the polishing liquid used is CeO2 photocatalyst and KMnO4 electron capture agent, and the pH of the polishing liquid is 2-4; the polishing pad used is a hollow polishing pad, the opening shape of the hollow part is a circular hole, the opening diameter is 3mm-5mm, and the opening rate is 40%-50%; the polishing voltage is less than 30V, the polishing current is less than 5A, the polishing time ranges from 2min to 5min, the main polishing pressure ranges from 0.5psi to 7psi, the polishing liquid flow ranges from 50mL / min to 200mL / min, the polishing disc speed ranges from 50rpm-110rpm, and the polishing head speed ranges from 40rpm to 100rpm.

[0021] In one embodiment, the X-side cleaning module and the Y-side cleaning module are symmetrically arranged on both sides of the wafer transfer station; the X-side photoelectrochemical mechanical polishing module and the Y-side photoelectrochemical mechanical polishing module are symmetrically arranged on both sides of the polishing buffer plate.

[0022] In a second aspect, an embodiment of the present application provides a wafer photoelectrochemical mechanical polishing method, which is applied to the wafer photoelectrochemical mechanical polishing device of the first aspect. The wafer photoelectrochemical mechanical polishing method includes:

[0023] Control the first upper robot and the first lower robot to take out wafer A and wafer B from the wafer carrying box respectively, and transfer wafer A and wafer B to the wafer transfer station;

[0024] Control the first combined robot to take out wafer A from the wafer transfer station, and the second combined robot to take out wafer B from the wafer transfer station, and transfer them to the polishing buffer plate;

[0025] Control the second upper robot to take out wafer A from the polishing buffer tray and transfer it to the X-side photoelectrochemical mechanical polishing module for polishing; and control the second lower robot to take out wafer B from the polishing buffer tray and transfer it to the Y-side photoelectrochemical mechanical polishing module for polishing;

[0026] Control the second upper robot to transfer the polished A wafer from the X-side photoelectrochemical mechanical polishing module to the polishing buffer plate; and control the second lower robot to transfer the polished B wafer from the Y-side photoelectrochemical mechanical polishing module to the polishing buffer plate;

[0027] Control the first combined robot to take out the polished A wafer from the polishing buffer tray and transfer it to the first cleaning and drying module for processing; and control the second combined robot to take out the polished B wafer from the polishing buffer tray and transfer it to the second cleaning and drying module for processing;

[0028] The first upper robot is controlled to put the processed A wafer back from the first cleaning and drying module to the wafer carrier box; and the first lower robot is controlled to put the processed B wafer back from the second cleaning and drying module to the wafer carrier box.

[0029] In one embodiment, the X-side photoelectrochemical mechanical polishing module includes an X-side wafer placement station and an X-side polishing station; the X-side wafer placement station includes a first wafer placement station, a second wafer placement station and a third wafer placement station; the X-side polishing station includes a first polishing station and a second polishing station;

[0030] The first polishing station includes a first light source; the first light source is an ultraviolet light source; the second polishing station includes a second light source; the second light source is a blue light source;

[0031] Control the second upper robot to take out wafer A from the polishing buffer tray and transfer it to the X-side photoelectrochemical mechanical polishing module for polishing, including:

[0032] Control the second upper robot to take out wafer A from the polishing buffer tray and transfer it to the first wafer placement station;

[0033] The A wafer is adsorbed from the first wafer placement station to the first polishing station by the polishing head of the first polishing station, and the first photoelectrochemical mechanical polishing is performed under the irradiation of an ultraviolet light source; the wavelength range of the ultraviolet light source is 300nm to 400nm;

[0034] Using the polishing head of the first polishing station, placing the A wafer after the first photoelectrochemical mechanical polishing at the second wafer placement station;

[0035] The wafer A after the first photoelectrochemical mechanical polishing is adsorbed from the second wafer placement station by the polishing head of the second polishing station and transferred to the second polishing station, and the wafer A after the second photoelectrochemical mechanical polishing is subjected to the second photoelectrochemical mechanical polishing under the irradiation of a blue light source, so as to obtain the wafer A after the second photoelectrochemical mechanical polishing; the wavelength range of the blue light source is 400nm to 450nm;

[0036] The A wafer after the second photoelectrochemical mechanical polishing is placed in the third wafer placement station by using the polishing head of the second polishing station.

[0037] In a third aspect, an embodiment of the present application provides a controller for executing a wafer photoelectrochemical mechanical polishing method as described in any one of the second aspects.

[0038] Compared with the related art, the embodiments of the present application have the following beneficial effects:

[0039] In the embodiment of the present application, by designing the cleaning module and the polishing module as multiple independently operated modules, each part is allowed to work independently, and different modules can be optimized and adjusted in a targeted manner according to the specific characteristics and polishing requirements of the SiC wafer. At the same time, the polishing module adopts the photoelectric chemical mechanical polishing technology, which combines the advantages of the photoelectric effect and chemical mechanical polishing, and reduces the deformation and damage of the wafer during the polishing process through a more refined polishing method. The photoelectric effect in the photoelectric chemical mechanical polishing technology helps to remove the material on the surface of the wafer more evenly, thereby improving the polishing efficiency and surface quality. The first combined manipulator and the second combined manipulator are used between the cleaning module and the polishing module for wafer transfer, which reduces the risk of damage to the wafer during the transfer process, and improves the continuity and efficiency of the polishing process. Through the coordinated work of the X-side and Y-side cleaning modules and the polishing modules, contaminants and defects on the wafer surface can be removed more effectively, providing a better foundation for the polishing process. This synergy helps to reduce wafer damage caused by contaminants during the polishing process, and further improves the polishing efficiency and surface quality.

[0040] The beneficial effects of the second to third aspects mentioned above refer to the beneficial effects of the wafer photoelectrochemical mechanical polishing device of the first aspect, which will not be repeated here.

[0041] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0043] Figure 1 It is a structural schematic diagram of a wafer photoelectrochemical mechanical polishing device provided in one embodiment of the present application;

[0044] Figure 2 It is a schematic diagram of the specific structure of a wafer photoelectrochemical mechanical polishing device provided in one embodiment of the present application;

[0045] Figure 3 It is a process flow diagram of a wafer photoelectrochemical mechanical polishing method provided in one embodiment of the present application;

[0046] Figure 4 It is a further process flow diagram of the wafer photoelectrochemical mechanical polishing method provided in one embodiment of the present application;

[0047] Figure 5 It is a schematic diagram of the structure of a controller provided in one embodiment of the present application. DETAILED DESCRIPTION

[0048] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, methods, and controllers are omitted to prevent unnecessary details from obstructing the description of the present application.

[0049] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0050] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0051] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0052] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0053] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0054] SiC wafers are known for being difficult to grow and process. Their Mohs hardness is slightly lower than that of diamond, and they are chemically inert to all polishing solutions except the most oxidizing ones. These characteristics make SiC a difficult-to-polish material. In order to solve the problem of SiC wafer polishing, the current SiC polishing processes mainly use chemical mechanical polishing (CMP), electrochemical mechanical polishing (ECMP) and photocatalytic chemical mechanical polishing (PCMP).

[0055] (1) Chemical Mechanical Polishing (CMP)

[0056] Chemical mechanical polishing is an important means of semiconductor processing at present. It is also the most effective process method that can process the wafer surface to atomic level smoothness. It is a practical technology that can achieve local and global flattening during the processing. CMP combines two external forces, chemical and mechanical. During the polishing process, the rotating wafer is pressed on the polishing pad that rotates with the worktable with a certain pressure, and the polishing liquid composed of submicron or nano abrasives and chemical solutions flows between the workpiece and the polishing pad, and produces a softening film on the wafer surface. The softening film formed on the wafer surface is removed by the mechanical friction of the abrasives. The processing efficiency of CMP is mainly determined by the chemical reaction rate on the wafer surface. The current polishing device is a multi-disk multi-head CMP, without superimposing other polishing processes. Therefore, it is still a pain point in the industry in terms of polishing efficiency, wafer yield and output.

[0057] (2) Electrochemical Mechanical Polishing (ECMP)

[0058] Electrochemical polishing is a method of adding positive electricity to the wafer in the polishing liquid, removing the surface material of the wafer by anode dissolution, and oxidizing the wafer surface. The processing effect of electrochemical polishing mainly depends on the composition of the polishing liquid, the current intensity and the length of processing time. On the basis of electrochemical polishing, electrochemical polishing is organically combined with mechanical grinding and polishing. This method is called electrochemical mechanical polishing. ECMP takes advantage of the advantages of both electrochemical and mechanical polishing. It is not restricted by the size and shape of the wafer and can polish large-sized wafers. However, the disadvantage of the ECMP process is the poor quality of the polishing surface.

[0059] (3) Photocatalytic assisted chemical mechanical polishing (PCMP)

[0060] Photocatalytic assisted chemical mechanical polishing is to add photocatalyst TiO2 to the polishing liquid. When the polishing liquid is distributed on the polishing pad, under the irradiation of ultraviolet light, strong oxidizing hydroxyl radicals will be generated in the polishing liquid, and contact with silicon carbide to react chemically, oxidizing its surface to generate SiO2. Since SiO2 is relatively soft in texture, it is mechanically removed by the abrasive in the polishing liquid under the action of external pressure, but the PCMP process makes the wafer surface quality unsatisfactory.

[0061] In summary, the polishing pressure required by traditional CMP is relatively high, and wafers are prone to deformation, cracking and other defects under high polishing pressure. Due to the high hardness, difficulty in oxidation and removal of SiC wafers, the CMP polishing effect is slightly slow. The polishing devices on the market are multi-disc multi-head CMP, which makes the overall polishing rate of traditional CMP low.

[0062] The electrochemical mechanical polishing process organically couples electrochemical polishing with mechanical abrasive polishing, and ECMP is also single-sided oxidation polishing. At present, due to the material properties of SiC wafers that are difficult to oxidize and remove, the shape control of SiC wafers cannot be guaranteed under dynamic electrochemical action.

[0063] Photocatalytic chemical mechanical polishing introduces an ultraviolet light source, which irradiates the photocatalyst TiO2 to produce strongly oxidizing hydroxyl radicals in the solution. However, the high viscosity of the TiO2 polishing solution on the market poses a challenge to post-cleaning, and the process makes it impossible to meet wafer surface quality requirements.

[0064] In order to solve the problems of low polishing efficiency and poor surface quality of SiC wafers, the present invention provides a wafer photoelectrochemical mechanical polishing device and a wafer photoelectrochemical mechanical polishing method. By combining the dual process means of PCMP and ECMP, photoelectrochemical mechanical polishing (PECMP) can be applied to third-generation semiconductors (such as SiC and GaN wafers), and global flattening of wafers can be quickly achieved under the condition of coupling of optical field and electric field, giving birth to a new polishing device. Compared with traditional polishing technology, the device and process method have many advantages, can improve wafer polishing efficiency and surface quality, and have great prospects in the new SiC wafer polishing process.

[0065] Next, the present invention provides a wafer photoelectrochemical mechanical polishing device and method which are described in detail.

[0066] Figure 1 It is a structural schematic diagram of a wafer photoelectrochemical mechanical polishing device provided in one embodiment of the present application.

[0067] Reference Figure 1 , the wafer photoelectrochemical mechanical polishing device is described in detail as follows:

[0068] A wafer photoelectrochemical mechanical polishing device comprises a transmission module, a cleaning module and a polishing module.

[0069] The transfer module includes a wafer carrying box, a first upper robot and a first lower robot; the first upper robot and the first lower robot are used to transfer the wafer between the wafer carrying box and the cleaning module.

[0070] Exemplarily, there are multiple wafer carriers, and four are taken as an example. Figure 1 As shown in LP1, LP2, LP3 and LP4 in FIG. Each wafer carrier box contains a sequence of SiC wafers.

[0071] The cleaning module includes an X-side cleaning module, a Y-side cleaning module and a wafer transfer station TS; the X-side cleaning module and the Y-side cleaning module operate independently; the X-side cleaning module includes a first cleaning and drying module and a first combined robot; the Y-side cleaning module includes a second cleaning and drying module and a second combined robot; the first combined robot is used to transfer the wafer from the wafer transfer station TS to the polishing buffer disk PB, and from the polishing buffer disk PB to the first cleaning and drying module; the second combined robot is used to transfer the wafer from the wafer transfer station TS to the polishing buffer disk PB, and from the polishing buffer disk PB to the second cleaning and drying module.

[0072] The polishing module includes an X-side photoelectrochemical mechanical polishing module, a Y-side photoelectrochemical mechanical polishing module, a polishing buffer plate PB, a second upper robot and a second lower robot; the X-side photoelectrochemical mechanical polishing module and the Y-side photoelectrochemical mechanical polishing module operate independently; the second upper robot is used to transfer the wafer from the polishing buffer plate PB to the X-side photoelectrochemical mechanical polishing module; the second lower robot is used to transfer the wafer from the polishing buffer plate PB to the Y-side photoelectrochemical mechanical polishing module.

[0073] In the embodiment of the present application, by designing the cleaning module and the polishing module as multiple independently operated modules, each part is allowed to work independently, and different modules can be optimized and adjusted in a targeted manner according to the specific characteristics and polishing requirements of the SiC wafer. At the same time, the polishing module adopts the photoelectric chemical mechanical polishing technology, which combines the advantages of the photoelectric effect and chemical mechanical polishing, and reduces the deformation and damage of the wafer during the polishing process through a more refined polishing method. The photoelectric effect in the photoelectric chemical mechanical polishing technology helps to remove the material on the surface of the wafer more evenly, thereby improving the polishing efficiency and surface quality. The first combined manipulator and the second combined manipulator are used between the cleaning module and the polishing module for wafer transfer, which reduces the risk of damage to the wafer during the transfer process, and improves the continuity and efficiency of the polishing process. Through the coordinated work of the X-side and Y-side cleaning modules and the polishing modules, contaminants and defects on the wafer surface can be removed more effectively, providing a better foundation for the polishing process. This synergy helps to reduce wafer damage caused by contaminants during the polishing process, and further improves the polishing efficiency and surface quality.

[0074] In one embodiment, see Figure 2 The first cleaning and drying module includes a first acid cleaning station LD1, a first alkaline cleaning station LD2 and a first drying station Dryer1.

[0075] The first combined robot includes a third upper robot, a fourth upper robot and a third lower robot; the third upper robot is used to transfer wafers between the polishing buffer plate PB and the first acid cleaning station LD1, and between the first acid cleaning station LD1 and the first alkaline cleaning station LD2; the fourth upper robot is used to transfer wafers between the first alkaline cleaning station LD2 and the first drying station Dryer1; the third lower robot is used to transfer wafers between the wafer transfer station TS and the polishing buffer plate PB.

[0076] Exemplarily, the wafer transfer station TS includes a first-layer wafer placement location TS-Upper and a second-layer wafer placement location TS-Lower.

[0077] The first-layer wafer placement TS-Upper is used to place wafers that are polished in the X-side photoelectrochemical mechanical polishing module; the second-layer wafer placement TS-Lower is used to place wafers that are polished in the Y-side photoelectrochemical mechanical polishing module.

[0078] The polishing buffer tray PB includes four layers of wafer placement positions, namely the first wafer entry placement position PBX-In, the first wafer exit placement position PBX-Out, the second wafer entry placement position PBY-In and the second wafer exit placement position PBY-Out; the first wafer entry placement position PBX-In is used to place wafers going to the X-side photoelectrochemical mechanical polishing module for polishing; the first wafer exit placement position PBX-Out is used to place wafers leaving the X-side photoelectrochemical mechanical polishing module after polishing; the second wafer entry placement position PBY-In is used to place wafers going to the Y-side photoelectrochemical mechanical polishing module for polishing; the second wafer exit placement position PBY-Out is used to place wafers leaving the Y-side photoelectrochemical mechanical polishing module after polishing.

[0079] In one embodiment, in one embodiment, the X-side cleaning module and the Y-side cleaning module are symmetrically arranged on both sides of the wafer transfer station TS; the X-side photoelectrochemical mechanical polishing module and the Y-side photoelectrochemical mechanical polishing module are symmetrically arranged on both sides of the polishing buffer plate PB.

[0080] The X-side photoelectrochemical mechanical polishing module includes an X-side wafer placement station and an X-side polishing station; the X-side wafer placement station includes a first wafer placement station WD1, a second wafer placement station WD2 and a third wafer placement station WD3; the X-side polishing station includes a first polishing station P1 and a second polishing station P2.

[0081] The first wafer placement station WD1 is used to place unpolished wafers; the second wafer placement station WD2 is used to place wafers polished by the first polishing station P1; and the third wafer placement station WD3 is used to place wafers polished by the second polishing station P2.

[0082] The second upper robot is used to transfer the wafer between the polishing buffer plate PB and the first wafer placement station WD1, and between the third wafer placement station WD3 and the polishing buffer plate PB.

[0083] The Y-side photoelectrochemical mechanical polishing module includes a Y-side wafer placement station and a Y-side polishing station; the Y-side wafer placement station includes a fourth wafer placement station WD4, a fifth wafer placement station WD5 and a sixth wafer placement station WD6; the Y-side polishing station includes a third polishing station P3 and a fourth polishing station P4.

[0084] The fourth wafer placement station WD4 is used to place unpolished wafers; the fifth wafer placement station WD5 is used to place wafers polished by the third polishing station P3; and the sixth wafer placement station WD6 is used to place wafers polished by the fourth polishing station P4.

[0085] The second lower robot is used to transfer the wafer between the polishing buffer plate PB and the third wafer placement station WD3, and between the sixth wafer placement station WD6 and the polishing buffer plate PB.

[0086] The advantage of setting up the X / Y side polishing device in this embodiment is that the two sides of "X / Y" operate independently, and the polishing disc on one side is also independent, that is, the polishing discs of the four polishing stations operate independently, which improves the output rate of wafers. At the same time, a transmission unit formed by a wafer transfer station, a polishing buffer disc and a manipulator is configured on both sides of "X / Y", which increases the transmission performance of the wafer and improves the transmission efficiency of the wafer.

[0087] In one embodiment, the first polishing station P1 includes a first light source; the first light source is an ultraviolet light source; the second polishing station P2 includes a second light source; the second light source is a blue light source.

[0088] The third polishing station P3 can have the same function as the first polishing station P1, and the fourth polishing station P4 can have the same function as the second polishing station P2. The third polishing station P3 includes a third light source, which is an ultraviolet light source; the fourth polishing station P4 includes a fourth light source, which is a blue light source.

[0089] Each polishing station is also equipped with a polishing plate, a polishing head station HS, a polishing liquid guide arm Slurry Arm and a polishing pad conditioner Pad Conditioner, etc.

[0090] Exemplarily, during the first photoelectrochemical mechanical polishing under the irradiation of the ultraviolet light source of the first polishing station P1, the polishing liquid used is CeO2 photocatalyst and KMnO4 electron capture agent, and the pH of the polishing liquid is 2-4; the polishing pad used is a hollow polishing pad, the opening shape of the hollow part is a circular hole, the opening diameter is 3mm-5mm, and the opening rate is 40%-50%; the polishing voltage is less than 30V, the polishing current is less than 5A, the polishing time ranges from 2min to 5min, the main polishing pressure ranges from 0.5psi to 7psi, the polishing liquid flow ranges from 50mL / min to 200mL / min, the polishing disk speed ranges from 50rpm-110rpm, and the polishing head speed ranges from 40rpm to 100rpm.

[0091] During the second photoelectrochemical mechanical polishing under the irradiation of the blue light source of the second polishing station P2, the polishing liquid used is CeO2 photocatalyst and KMnO4 electron capture agent, and the pH of the polishing liquid is 2-4; the polishing pad used is a hollow polishing pad, the opening shape of the hollow part is a circular hole, the opening diameter is 3mm-5mm, and the opening rate is 40%-50%; the polishing voltage is less than 30V, the polishing current is less than 5A, the polishing time ranges from 2min to 5min, the main polishing pressure ranges from 0.5psi to 7psi, the polishing liquid flow ranges from 50mL / min to 200mL / min, the polishing disc speed ranges from 50rpm-110rpm, and the polishing head speed ranges from 40rpm to 100rpm. Among them, the polishing voltage range can be specifically 5-30V, and the polishing current ranges from 1-5A.

[0092] This embodiment uses two PECMP polishing stations equipped on each side of the compound semiconductor composite efficiency enhancement device, one of which uses ultraviolet light irradiation to improve the SiC wafer material removal rate, and the other module uses blue light irradiation to improve the wafer surface quality, so that the wafer output yield is improved. The present invention combines a cleaning and drying module, in which LD1 and LD3 can be cleaned with organic acids (such as acetic acid, citric acid), and LD2 and LD4 can be cleaned with NH4OH and H2O, which enables the wafer to achieve a "dry in and dry out" mode.

[0093] Second, see Figure 3 and Figure 4 , Figure 3 It is a process flow diagram of the wafer photoelectrochemical mechanical polishing method; Figure 4 The present invention provides a wafer photoelectrochemical mechanical polishing method, which is applied to the wafer photoelectrochemical mechanical polishing device of the first aspect. The wafer photoelectrochemical mechanical polishing method includes:

[0094] The first upper robot and the first lower robot are controlled to take out wafer A and wafer B from the wafer carrying box respectively, and transfer wafer A and wafer B to the wafer transfer station TS.

[0095] Exemplarily, the SiC wafer to be polished is placed in the wafer carrier with the Si surface facing upward and the C surface facing downward.

[0096] The first combined robot is controlled to take out wafer A from the wafer transfer station TS, and the second combined robot is controlled to take out wafer B from the wafer transfer station TS and transfer them to the polishing buffer plate PB.

[0097] Control the second upper robot to take out wafer A from the polishing buffer tray PB and transfer it to the X-side photoelectrochemical mechanical polishing module for polishing; and control the second lower robot to take out wafer B from the polishing buffer tray PB and transfer it to the Y-side photoelectrochemical mechanical polishing module for polishing.

[0098] Control the second upper robot to transfer the polished A wafer from the X-side photoelectrochemical mechanical polishing module to the polishing buffer plate PB; and control the second lower robot to transfer the polished B wafer from the Y-side photoelectrochemical mechanical polishing module to the polishing buffer plate PB.

[0099] Control the first combined robot to take out the polished A wafer from the polishing buffer tray PB and transfer it to the first cleaning and drying module for processing; and control the second combined robot to take out the polished B wafer from the polishing buffer tray PB and transfer it to the second cleaning and drying module for processing.

[0100] The first upper robot is controlled to put the processed A wafer back from the first cleaning and drying module to the wafer carrier box; and the first lower robot is controlled to put the processed B wafer back from the second cleaning and drying module to the wafer carrier box.

[0101] For example, see Figure 4 The X-side photoelectrochemical mechanical polishing module includes an X-side wafer placement station and an X-side polishing station; the X-side wafer placement station includes a first wafer placement station WD1, a second wafer placement station WD2 and a third wafer placement station WD3; the X-side polishing station includes a first polishing station P1 and a second polishing station P2.

[0102] The first polishing station P1 includes a first light source, which is an ultraviolet light source; the second polishing station P2 includes a second light source, which is a blue light source.

[0103] Take the example of polishing the C surface of wafer A using the X-side photoelectrochemical mechanical polishing module:

[0104] XS1. Control the first upper robot to take out wafer A from the wafer carrier box, and transfer wafer A to TS-Upper, the first layer wafer placement location of the wafer transfer station TS.

[0105] XS2, control the third lower robot to take out wafer A from the first wafer placement position TS-Upper of the wafer transfer station TS, and place wafer A to the first wafer entry placement position PBX-In of the polishing buffer plate PB.

[0106] XS3, control the second upper robot to take out wafer A from the polishing buffer plate PB, and transfer it to the X-side photoelectrochemical mechanical polishing module for polishing, including:

[0107] XS31, control the second upper robot to take out wafer A from the polishing buffer plate PB and transfer it to the first wafer placement station WD1.

[0108] Exemplarily, the second upper robot is controlled to take out wafer A from the first wafer entry placement location PBX-In of the polishing buffer tray PB, and transfer it to the first wafer placement station WD1.

[0109] XS32. Use the polishing head of the first polishing station P1 to adsorb wafer A from the first wafer placement station WD1 and transfer it to the first polishing station P1, and perform the first photoelectrochemical mechanical polishing under the irradiation of an ultraviolet light source; the wavelength range of the ultraviolet light source is 300nm~400nm.

[0110] Exemplarily, PCMP utilizes the principle of using ultraviolet light source to irradiate wafers or abrasives to generate OH free radicals, and combines PCMP and ECMP dual process means, namely PECMP, to catalyze and corrode SiC through ultraviolet light. In addition, ultraviolet light is an electromagnetic wave. In the electromagnetic spectrum, the wavelength range of ultraviolet light is roughly between 100nm and 400nm. The ultraviolet light within this range is further divided into three bands: UVA (wavelength range of 320nm to 400nm), UVB (wavelength range of 290nm to 320nm) and UVC (wavelength range of 100nm to 290nm). The ultraviolet light used in this embodiment is to promote the corrosion of the wafer. Compared with the electric field, the ultraviolet light promotes corrosion secondly. Therefore, the present invention adopts a wavelength of 300nm to 400nm that is not obviously harmful to the human body. If short-wavelength ultraviolet light is used, it is harmful to the human body.

[0111] Preferably, the wavelength range of ultraviolet light is 320nm to 400nm.

[0112] XS33, using the polishing head of the first polishing station P1, place the A wafer after the first photoelectrochemical mechanical polishing at the second wafer placement station WD2.

[0113] The A wafer after the first photoelectrochemical mechanical polishing is adsorbed from the second wafer placement station WD2 by the polishing head of the second polishing station P2 and transferred to the second polishing station P2, and a second photoelectrochemical mechanical polishing is performed under the irradiation of a blue light source to obtain A wafer after the second photoelectrochemical mechanical polishing; the wavelength range of the blue light source is 400nm~450nm.

[0114] For example, the distribution of electrons on the wafer surface is originally disordered, random and relatively rough. Blue light irradiation can balance the distribution of electrons on the wafer surface, so that the wafer obtains a continuous and stable electric field under the action of electrochemistry.

[0115] Preferably, the wavelength range of blue light is 440nm to 450nm, and this wavelength range has low harm to the human body.

[0116] Exemplarily, during the first photoelectrochemical mechanical polishing process under the irradiation of the ultraviolet light source of the first polishing station P1 or during the second photoelectrochemical mechanical polishing process under the irradiation of the blue light source of the second polishing station P2, the polishing liquid used is CeO2 photocatalyst and KMnO4 electron capture agent, and the pH of the polishing liquid is 2-4; the polishing pad used is a hollow polishing pad, the opening shape of the hollow part is a circular hole, the opening diameter is 3mm-5mm, and the opening rate is 40%-50%; the polishing voltage is less than 30V, the polishing current is less than 5A, the polishing time ranges from 2min to 5min, the main polishing pressure ranges from 0.5psi to 7psi, the polishing liquid flow ranges from 50mL / min to 200mL / min, the polishing disc speed ranges from 50rpm-110rpm, and the polishing head speed ranges from 40rpm to 100rpm. Among them, the above parameters can all be set in the parameter menu.

[0117] XS34. Place the A wafer after the second photoelectrochemical mechanical polishing at the third wafer placement station WD3 using the polishing head of the second polishing station P2.

[0118] XS4, control the second upper robot to take the polished A wafer from the third wafer placement station WD3, flip it over and send it back to the first wafer leaving the placement position PBX-Out of the polishing buffer plate PB.

[0119] Exemplarily, at this time, the state of the SiC wafer is that the Si surface faces upward and the C surface faces downward.

[0120] XS5. Control the fourth upper robot to take out the polished A wafer from the first wafer leaving placement PBX-Out of the polishing buffer tray PB, and transfer it to the first acid cleaning station LD1 for cleaning. Control the third upper robot to transfer the cleaned A wafer from the first acid cleaning station LD1 to the first alkaline cleaning station LD2 for cleaning. Control the third upper robot to transfer the cleaned A wafer from the first alkaline cleaning station LD2 to the first drying station Dryer1 for drying.

[0121] XS6. Control the first upper robot to transfer the dried A wafer from the first drying station Dryer1 back to the wafer carrier box.

[0122] Exemplarily, in step XS5, LD1 is cleaned with an organic acid (such as acetic acid, citric acid), and LD2 is cleaned with NH4OH and H2O. Steps XS5 and XS6 complete the polishing process of the C surface of wafer A and achieve "dry in and dry out" of wafer A throughout the entire process.

[0123] Next, the Si surface of wafer A is polished by the X-side photoelectrochemical mechanical polishing module, and the whole process is consistent with steps XS1 to XS6. The total polishing time for polishing both sides of wafer A is 10 minutes to 20 minutes.

[0124] Then, while the X-side photoelectrochemical mechanical polishing module is polishing the Si surface of wafer A, the Y-side photoelectrochemical mechanical polishing module can be polishing wafer B.

[0125] Take the example of polishing the C surface of wafer B using the Y-side photoelectrochemical mechanical polishing module:

[0126] YS1, control the first lower robot to take out wafer B from the wafer carrier box, and transfer wafer B to the second-layer wafer placement location TS-Lower of the wafer transfer station TS.

[0127] Exemplarily, the first upper manipulator and the first lower manipulator can be set on the same movable slide rail to achieve simultaneous grasping of two wafers, reducing the cost and weight of the machine. Of course, the first upper manipulator and the first lower manipulator can take wafers from the same wafer carrier box at the same time, or they can take wafers from different wafer carrier boxes. Different wafer carrier boxes can be equipped with wafers of the same specifications, or they can be equipped with wafers of different specifications. When there are wafers of different specifications, they can be adapted by adjusting the parameters of the polishing module.

[0128] YS2. Control the fourth lower robot to take out wafer B from the second wafer placement position TS-Lower of the wafer transfer station TS, and place wafer B to the second wafer placement position PBY-In of the polishing buffer plate PB.

[0129] YS3, control the second upper robot to take out the B wafer from the polishing buffer plate PB, and transfer it to the Y-side photoelectrochemical mechanical polishing module for polishing, including:

[0130] YS31, control the second upper robot to take out wafer B from the polishing buffer tray PB and transfer it to the fourth wafer placement station WD4.

[0131] Exemplarily, the second upper robot is controlled to take out wafer B from the second wafer entering placement position PB Y-In of the polishing buffer tray PB, and transfer it to the fourth wafer placement station WD4.

[0132] YS32. Use the polishing head of the third polishing station P3 to adsorb wafer B from the fourth wafer placement station WD4 and transfer it to the third polishing station P3, and perform the first photoelectrochemical mechanical polishing under the irradiation of an ultraviolet light source; the wavelength range of the ultraviolet light source is 300nm~400nm.

[0133] YS33. Use the polishing head of the third polishing station P1 to place the A wafer after the first photoelectrochemical mechanical polishing at the fifth wafer placement station WD5.

[0134] The B wafer after the first photoelectrochemical mechanical polishing is adsorbed by the polishing head of the fourth polishing station P4 from the wafer-free placement station WD5 and transferred to the fourth polishing station P4, and a second photoelectrochemical mechanical polishing is performed under the irradiation of a blue light source to obtain the B wafer after the second photoelectrochemical mechanical polishing; the wavelength range of the blue light source is 400nm~450nm.

[0135] Exemplarily, the parameters involved in polishing at the third polishing station P3 and the fourth polishing station P4 can be set in the parameter menu with reference to the above embodiment.

[0136] YS34. Use the polishing head of the fourth polishing station P4 to place the B wafer after the second photoelectrochemical mechanical polishing at the sixth wafer placement station WD6.

[0137] YS4, control the second lower robot to take the polished B wafer from the sixth wafer placement station WD6, flip it over and send it back to the second wafer leaving the placement position PBY-Out of the polishing buffer plate PB.

[0138] Exemplarily, at this time, the state of the SiC wafer is that the Si surface faces upward and the C surface faces downward.

[0139] YS5. Control the sixth upper robot to take out the polished B wafer from the second wafer leaving placement PBY-Out of the polishing buffer tray PB, and transfer it to the second acid cleaning station LD3 for cleaning. Control the sixth upper robot to transfer the cleaned B wafer from the second acid cleaning station LD3 to the second alkaline cleaning station LD4 for cleaning. Control the fifth upper robot to transfer the cleaned B wafer from the second alkaline cleaning station LD2 to the second drying station Dryer1 for drying.

[0140] YS6, control the first lower robot to transfer the dried B wafer from the second drying station Dryer1 back to the wafer carrier box.

[0141] Illustratively, steps YS5 and YS6 complete the polishing process of the C surface of wafer B and achieve “dry in and dry out” of wafer B throughout the entire process.

[0142] Next, the Si surface of wafer B is polished by the photoelectrochemical mechanical polishing module on the Y side. The whole process is consistent with steps YS1 to YS6. The total polishing time for polishing both sides of wafer B is 10 to 20 minutes.

[0143] The wafer photoelectrochemical mechanical polishing method of the embodiment of the present application uses two PECMP polishing modules equipped on a single side, one of which uses ultraviolet light irradiation to improve the SiC wafer material removal rate, and the other module uses blue light irradiation to improve the wafer surface quality, thereby improving the wafer output yield and solving the problems of low SiC wafer polishing efficiency and poor surface quality.

[0144] It should be understood that the execution order of the above processes should be determined by their functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. In order to reduce the complexity of the patent description, the present invention provides a detection method involved in a compound wafer photoelectrochemical mechanical polishing device, and the types of sensors used and the calculation process are all included in the scope of protection of this patent.

[0145] Of course, the X / Y sides in this application may operate independently, or the X / Y sides may operate in superposition, such as a three-disc polishing process, PECMP1+PECMP2 on the X side, PECMP2 on the Y side, etc., which is still within the protection scope of this application.

[0146] It should be noted that the information interaction, execution process and other contents between the above-mentioned devices are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0147] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0148] See also Figure 5 One embodiment provides a controller, which is used to execute the wafer photoelectrochemical mechanical polishing method as described in the above embodiment.

[0149] The present application also provides a controller, see Figure 5The controller 200 may include: at least one processor 210 and a memory 220, wherein the memory 220 stores a computer program that can be run on at least one processor 210, and when the processor 210 executes the computer program, the steps in any of the above method embodiments are implemented.

[0150] Exemplarily, the computer program may be divided into one or more modules / units, one or more modules / units are stored in the memory 220, and executed by the processor 210 to complete the present application. One or more modules / units may be a series of computer program segments capable of completing specific functions, and the program segments are used to describe the execution process of the computer program in the controller 200.

[0151] Those skilled in the art will understand that Figure 5 These are merely examples of controllers and do not constitute a limitation of the controller, which may include more or fewer components than those shown in the figure, or a combination of certain components, or different components, such as input and output devices, network access devices, buses, etc.

[0152] The processor 210 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0153] The memory 220 may be an internal storage unit of the controller or an external storage device of the controller, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. The memory 220 is used to store computer programs and other programs and data required by the controller. The memory 220 may also be used to temporarily store data that has been output or is to be output.

[0154] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of the present application is not limited to only one bus or one type of bus.

[0155] The wafer photoelectrochemical mechanical polishing method provided in the embodiments of the present application can be applied to controllers such as computers, tablet computers, laptops, netbooks, personal digital assistants (PDAs), etc. The embodiments of the present application do not impose any restrictions on the specific type of controller.

[0156] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0157] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A wafer photoelectrochemical mechanical polishing device, It is characterized in that Including transmission module, cleaning module and polishing module; The transmission module includes a wafer carrier box, a first upper robot and a first lower robot; the first upper robot and the first lower robot are used to transfer the wafer between the wafer carrier box and the cleaning module; The cleaning module includes an X-side cleaning module, a Y-side cleaning module and a wafer transfer station; the X-side cleaning module and the Y-side cleaning module operate independently; the X-side cleaning module includes a first cleaning and drying module and a first combined robot; the Y-side cleaning module includes a second cleaning and drying module and a second combined robot; the first combined robot is used to transfer the wafer from the wafer transfer station to the polishing buffer tray, and from the polishing buffer tray to the first cleaning and drying module; The second combined robot is used to transfer the wafer from the wafer transfer station to the polishing buffer tray, and from the polishing buffer tray to the second cleaning and drying module; The polishing module includes an X-side photoelectrochemical mechanical polishing module, a Y-side photoelectrochemical mechanical polishing module, the polishing buffer tray, a second upper robot and a second lower robot; the X-side photoelectrochemical mechanical polishing module and the Y-side photoelectrochemical mechanical polishing module operate independently; the second upper robot is used to transfer the wafer between the polishing buffer tray and the X-side photoelectrochemical mechanical polishing module; the second lower robot is used to transfer the wafer between the polishing buffer tray and the Y-side photoelectrochemical mechanical polishing module.

2. The wafer photoelectrochemical mechanical polishing device according to claim 1, It is characterized in that The first cleaning and drying module includes a first acid cleaning station, a first alkaline cleaning station and a first drying station; The first combined robot includes a third upper robot, a fourth upper robot and a third lower robot; the third upper robot is used to transfer wafers between the polishing buffer plate and the first acid cleaning station, and between the first acid cleaning station and the first alkaline cleaning station; the fourth upper robot is used to transfer wafers between the first alkaline cleaning station and the first drying station; the third lower robot is used to transfer wafers between the wafer transfer station and the polishing buffer plate.

3. The wafer photoelectrochemical mechanical polishing device according to claim 1, It is characterized in that The wafer transfer station includes a first-layer wafer placement location and a second-layer wafer placement location; The first layer of wafer placement is used to place wafers to be polished by the X-side photoelectrochemical mechanical polishing module; The second layer of wafer placement is used to place wafers to be polished by the Y-side photoelectrochemical mechanical polishing module; The polishing buffer plate includes four layers of wafer placement positions, which are a first wafer entry placement position, a first wafer exit placement position, a second wafer entry placement position, and a second wafer exit placement position; the first wafer entry placement position is used to place wafers that are polished by the X-side photoelectrochemical mechanical polishing module; the first wafer exit placement position is used to place wafers that leave the X-side photoelectrochemical mechanical polishing module after polishing; The second wafer entry placement is used to place wafers that are going to the Y-side photoelectrochemical mechanical polishing module for polishing; the second wafer exit placement is used to place wafers that leave the Y-side photoelectrochemical mechanical polishing module after polishing.

4. The wafer photoelectrochemical mechanical polishing device according to claim 1, It is characterized in that The X-side photoelectrochemical mechanical polishing module includes an X-side wafer placement station and an X-side polishing station; the X-side wafer placement station includes a first wafer placement station, a second wafer placement station and a third wafer placement station; the X-side polishing station includes a first polishing station and a second polishing station; The first wafer placement station is used to place unpolished wafers; the second wafer placement station is used to place wafers polished by the first polishing station; the third wafer placement station is used to place wafers polished by the second polishing station; The second upper robot is used to transfer the wafer between the polishing buffer plate and the first wafer placement station, and between the third wafer placement station and the polishing buffer plate.

5. The wafer photoelectrochemical mechanical polishing device according to claim 4, It is characterized in that The first polishing station includes a first light source; the first light source is an ultraviolet light source; the second polishing station includes a second light source; the second light source is a blue light source.

6. The wafer photoelectrochemical mechanical polishing device according to claim 5, It is characterized in that During the first photoelectrochemical mechanical polishing process under the irradiation of the ultraviolet light source of the first polishing station, the polishing liquid used is CeO 2 Photocatalyst and KMnO 4 Electron capture agent, the pH of the polishing liquid is 2-4; the polishing pad used is a hollow polishing pad, the opening shape of the hollow part is a circular hole, the opening diameter is 3mm-5mm, and the opening rate is 40%-50%; the polishing voltage is less than 30V, the polishing current is less than 5A, the polishing time ranges from 2min to 5min, the main polishing pressure ranges from 0.5psi to 7psi, the polishing liquid flow ranges from 50mL / min to 200mL / min, the polishing disc speed ranges from 50rpm-110rpm, and the polishing head speed ranges from 40rpm to 100rpm.

7. The wafer photoelectrochemical mechanical polishing device according to any one of claims 1 to 6, It is characterized in that The X-side cleaning module and the Y-side cleaning module are symmetrically arranged on both sides of the wafer transfer station; the X-side photoelectrochemical mechanical polishing module and the Y-side photoelectrochemical mechanical polishing module are symmetrically arranged on both sides of the polishing buffer plate.

8. A wafer photoelectrochemical mechanical polishing method, It is characterized in that Applied to the wafer photoelectrochemical mechanical polishing device as claimed in any one of claims 1 to 7, the wafer photoelectrochemical mechanical polishing method comprises: Control the first upper robot and the first lower robot to take out wafer A and wafer B from the wafer carrying box respectively, and transfer the wafer A and wafer B to the wafer transfer station; Controlling the first combined robot to take out the A wafer from the wafer transfer station, and the second combined robot to take out the B wafer from the wafer transfer station, and transfer them to the polishing buffer tray; Control the second upper robot to take out the A wafer from the polishing buffer plate and transfer it to the X-side photoelectrochemical mechanical polishing module for polishing; and control the second lower robot to take out the B wafer from the polishing buffer plate and transfer it to the Y-side photoelectrochemical mechanical polishing module for polishing; Control the second upper robot to transfer the polished A wafer from the X-side photoelectrochemical mechanical polishing module to the polishing buffer plate; and control the second lower robot to transfer the polished B wafer from the Y-side photoelectrochemical mechanical polishing module to the polishing buffer plate; Control the first combined robot to take out the polished A wafer from the polishing buffer tray and transfer it to the first cleaning and drying module for processing; and control the second combined robot to take out the polished B wafer from the polishing buffer tray and transfer it to the second cleaning and drying module for processing; Control the first upper robot to put the processed A wafer back from the first cleaning and drying module to the wafer carrying box; and control the first lower robot to put the processed B wafer back from the second cleaning and drying module to the wafer carrying box.

9. The wafer photoelectrochemical mechanical polishing method according to claim 8, It is characterized in that The X-side photoelectrochemical mechanical polishing module includes an X-side wafer placement station and an X-side polishing station; the X-side wafer placement station includes a first wafer placement station, a second wafer placement station and a third wafer placement station; the X-side polishing station includes a first polishing station and a second polishing station; The first polishing station includes a first light source; the first light source is an ultraviolet light source; the second polishing station includes a second light source; the second light source is a blue light source; The controlling the second upper robot to take out the A wafer from the polishing buffer plate and transfer it to the X-side photoelectrochemical mechanical polishing module for polishing includes: Controlling the second upper robot to take out the A wafer from the polishing buffer plate and transfer it to the first wafer placement station; Using the polishing head of the first polishing station to absorb wafer A from the first wafer placement station to the first polishing station, and performing a first photoelectrochemical mechanical polishing under the irradiation of the ultraviolet light source; the wavelength range of the ultraviolet light source is 300nm to 400nm; Using the polishing head of the first polishing station, placing the A wafer after the first photoelectrochemical mechanical polishing at the second wafer placement station; The wafer A after the first photoelectrochemical mechanical polishing is adsorbed from the second wafer placement station by the polishing head of the second polishing station and transferred to the second polishing station, and a second photoelectrochemical mechanical polishing is performed under the irradiation of the blue light source to obtain the wafer A after the second photoelectrochemical mechanical polishing; the wavelength range of the blue light source is 400nm to 450nm; The A wafer after the second photoelectrochemical mechanical polishing is placed in the third wafer placement station by using the polishing head of the second polishing station.

10. A controller, It is characterized in that Used to perform the wafer photoelectrochemical mechanical polishing method as described in any one of claims 8 to 9.

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