Surface treatment method

Abstract

The present disclosure relates to a surface treatment method comprising: supplying a slurry (S) containing at least abrasive particles between a treatment surface (W1) of a workpiece (W) and a treatment pad (3); planarizing the treated surface of the workpiece by chemical and mechanical actions by moving the workpiece and the treatment pad relative to each other with the slurry interposed between the treated surface of the workpiece and the treatment pad; and cleaning the treatment pad with a cleaning solution (L). In the method, during the planarization process, the slurry is circulated through a circulating flow channel (R) for the slurry comprising a slurry supply flow channel (63) to supply the slurry to the processing pad and a slurry recovery flow channel (652) to recover the used slurry. When cleaning the treatment pad with the cleaning solution, the cleaning solution is discharged through a waste liquid flow channel (653) separate from the circulating flow channel, allowing liquid waste to flow through the waste liquid flow channel.

Description

Technical Field

[0001] This disclosure relates to a surface treatment method for planarizing the processed surface of a workpiece through chemical and mechanical action. Background Technology

[0002] JP 2016-175138 A (Japanese Unexamined Patent Application Publication No. 2016-175138) discloses a method for recovering abrasive from a slurry containing abrasive used in a chemical mechanical polishing (CMP) process, in which a slurry containing abrasive is supplied between a polishing component, such as a polishing pad, and a polishing target to perform polishing.

[0003] Specifically, the recovery method described in JP 2016-175138 A is a method for recovering abrasive from a slurry that has been used to polish a polishing target containing silicon as a main component. In this recovery method, the abrasive is recovered from the slurry by removing the polishing target component through at least the following processes 1 to 3 without the application of a pH adjuster.

[0004] Step 1: Add solvent to the slurry used as a grinding agent;

[0005] Process 2: Dissolving the polishing target particles (i.e., the worn material) in the polishing target components contained in the slurry; and

[0006] Process 3: Collect the grinding agent by filtering the slurry. Summary of the Invention

[0007] As described in JP 2016-175138 A, conventional methods of recycling and reusing slurry result in lower costs compared to processing used slurry without recycling and reuse. However, conventional methods require complex processes, such as adding solvents and chemicals to dissolve or separate the target polishing particles. Therefore, there is room for improvement in the cost aspects of conventional methods.

[0008] This disclosure is made in view of the foregoing and other factors. In other words, this disclosure provides a technique for improving the cost-effectiveness of recycling and reusing used slurry.

[0009] According to one aspect of this disclosure, a surface treatment method includes:

[0010] A slurry (S) containing at least abrasive particles is supplied between the treated surface (W1) of the workpiece (W) and the treated pad (3);

[0011] By moving the workpiece and the treatment pad relative to each other while the slurry is placed between the treatment surface of the workpiece and the treatment pad, the treatment surface of the workpiece is flattened through chemical and mechanical action; and

[0012] Clean the treatment pad with cleaning solution (L).

[0013] The method also includes the following procedures, processes, or procedures.

[0014] During the leveling process, the slurry is circulated through a circulation flow channel (R) for the slurry, which includes a slurry supply flow channel (63) for supplying slurry to the treatment pad and a slurry recovery flow channel (652) for recovering the used slurry.

[0015] When the treatment pad is cleaned with a cleaning solution, the cleaning solution is discharged through a waste liquid flow channel (653) that is separate from the circulation flow channel, thereby allowing liquid waste to flow through the waste liquid flow channel.

[0016] In the various paragraphs of this specification, each element may be identified by a bracketed reference numeral. In this case, the reference numeral indicates an example of the correspondence between the same element and a particular configuration described in the following embodiments. Therefore, this disclosure is not limited to the reference numerals. Attached Figure Description

[0017] In the attached diagram:

[0018] Figure 1 A schematic diagram of a surface treatment apparatus for performing a surface treatment method according to an embodiment of the present disclosure is shown;

[0019] Figure 2 It is a flowchart illustrating a procedure, process or process of a surface treatment method according to the present disclosure;

[0020] Figure 3 This is a flowchart illustrating the slurry circulation process according to the present disclosure;

[0021] Figure 4 A flowchart illustrating the cleaning process according to this disclosure is provided; and

[0022] Figure 5 It is a graph illustrating the results of evaluating the fluctuation of the processing rate of the surface treatment method according to the present disclosure. Detailed Implementation

[0023] The following is a description of embodiments of the present disclosure, appropriately referenced to the accompanying drawings. These embodiments, variations thereof, and the associated drawings are illustrative or simplified to briefly explain the contents of this disclosure. Therefore, the contents of this disclosure are not limited to these statements. The descriptions in the drawings may not always correspond to a specific device configuration actually manufactured and sold. In other words, unless expressly limited by the applicant during the course of this application, the contents of this disclosure should not be construed as being limited by the descriptions in the drawings or descriptions corresponding to the configuration, function, operation, and similar aspects of the device described below.

[0024] (Surface treatment equipment)

[0025] Reference Figure 1 Surface treatment equipment 1 is configured to planarize the treated surface W1 of workpiece W through chemical and mechanical actions. The term "planarization" refers to processes such as grinding or polishing. CMP, ECMP, and ECMG are known as planarization methods of the above types. ECMP stands for electrochemical mechanical polishing; ECMG stands for electrochemical mechanical grinding. Please remember that CMP can be understood as a general concept that includes ECMP. CMP in a broad sense includes ECMP, unless explicitly stated that CMP in a narrow sense does not include ECMP.

[0026] In this embodiment, the surface treatment apparatus 1 is configured as a CMP or ECMP device to polish a workpiece W, which is a single-crystal SiC wafer. The workpiece W is, for example, a silicon-based material, typically a semiconductor material, such as a silicon carbide semiconductor. Specifically, the surface treatment apparatus 1 includes a workpiece support device 2, a treatment pad 3, a pad support device 4, a housing 5, a slurry circulation supply mechanism 6, a cleaning solution supply device 7, and a control device 8. These components constituting the surface treatment apparatus 1 are explained sequentially in the following description.

[0027] The workpiece support device 2 is positioned opposite the treatment pad 3. The workpiece support device 2 is configured to rotate about a rotation axis 21 while pressing the workpiece W towards the treatment pad 3, wherein the workpiece W is positioned from the surface facing the treatment pad 3 (i.e., Figure 1 The workpiece support 2 is held on its lower surface. The treatment pad 3 is also referred to as a "polishing pad". The treatment pad 3 can be a well-known pad used for CMP or ECMP, such as nonwoven fabric, polyurethane, suede, etc. The treatment pad 3 is supported by the pad support 4. The workpiece support 2 and / or the pad support 4 are equipped with adjustment mechanisms (not shown) for adjusting the treatment conditions. The treatment conditions include, for example, temperature, pressure, rotation speed, etc.

[0028] The housing 5 is configured to at least cover the processing area where the workpiece W and the processing pad 3 face each other. The housing 5 is configured to prevent the slurry S supplied to the processing pad 3 or the processing area from spilling outside the surface treatment equipment 1. The housing 5 is configured to function as a receiver or recycling container for receiving the slurry S used in the planarization process of the processing area, thereby preventing used slurry S from leaking outside the surface treatment equipment 1. Therefore, the surface treatment equipment 1 is configured such that the slurry S is placed between the processing surface W1 of the workpiece W and the processing pad 3, and the workpiece W and the processing pad 3 move relative to each other while the slurry S is in place. In this way, the surface treatment equipment 1 is configured to perform the planarization process of the processing surface W1 by chemical and mechanical action.

[0029] The slurry circulation supply mechanism 6 is configured to supply slurry S to the treatment pad 3 or the treatment area, recover used slurry S (hereinafter referred to as used slurry S for convenience), and reuse the recovered slurry S during the leveling process. Specifically, the slurry circulation supply mechanism 6 includes a slurry tank 61, a stirrer 62, a slurry supply flow channel 63, a supply pump 64, a slurry discharge flow channel 65, a waste liquid container 66, and a three-way valve 67.

[0030] The slurry tank 61 is configured to store a specific amount of slurry S to be supplied to the treatment pad 3 or the treatment area. The slurry S comprises at least abrasive particles as well as solvents and various reagents, such as oxidants and electrolytes, to facilitate chemical reactions. These chemical reactions include electrochemical processes. The stirrer 62 is equipped with a rotating component called a stirring rod 621, which agitates the slurry S within the slurry tank 61. This agitation helps prevent the abrasive particles from settling, thereby ensuring that the abrasive particles remain uniformly dispersed throughout the slurry S.

[0031] The slurry supply flow channel 63 is configured to supply slurry S from the slurry tank 61 to the treatment pad 3. Specifically, the base end (first end) of the slurry supply flow channel 63 is disposed in the slurry tank 61. A slurry nozzle 631 is disposed at the tip end (second end) of the slurry supply flow channel 63. The base end refers to the portion of the flow channel near the fluid inlet port (e.g., inlet port). On the other hand, the tip end refers to the portion of the flow channel near the fluid outlet port (e.g., outlet port). The slurry nozzle 631 is designed to spray the slurry S toward the treatment pad 3. A supply pump 64 pressurizes the slurry S, thereby discharging the slurry S toward the slurry nozzle 631. The slurry supply flow channel 63 is provided with a supply pump 64, and the supply pump 64 is disposed between the base end and the tip end of the slurry supply flow channel 63.

[0032] The housing 5 receives used slurry S and a cleaning solution L for cleaning the treatment pad 3. A slurry discharge flow channel 65 is configured to discharge the cleaning solution L from the housing 5. For example, pure water can be used as the cleaning solution L. Specifically, the slurry discharge flow channel 65 has a main discharge flow channel 651, a slurry recovery flow channel 652, and a waste liquid flow channel 653. The slurry discharge flow channel 65 is configured to branch from the main discharge flow channel 651 into the slurry recovery flow channel 652 and the waste liquid flow channel 653.

[0033] The base end (first end) of the main discharge flow channel 651 is connected to a discharge port, which is formed as a through hole in the bottom of the housing 5. The tip end (second end) of the main discharge flow channel 651 is connected to a three-way valve 67. The three-way valve 67 switches the flow of fluid from the main discharge flow channel 651 to either the slurry recovery flow channel 652 or the waste liquid flow channel 653. Therefore, the three-way valve 67 is disposed between the main discharge flow channel 651 and either the slurry recovery flow channel 652 or the waste liquid flow channel 653, and is located in the slurry discharge flow channel 65. The slurry recovery flow channel 652 is configured to recover the used slurry S flowing from the main discharge flow channel 651 (i.e., to return the used slurry S to the slurry tank 61). The waste liquid flow path 653 is configured to allow the cleaning solution L to flow from the main discharge flow channel 651 to the waste liquid container 66. The waste liquid container 66 is configured to store the cleaning solution L. When the planarization process of the treatment surface W1 is performed, the three-way valve 67, controlled by the control device 8, is connected and communicates with the main discharge flow channel 651 and the slurry recovery flow channel 652. On the other hand, when the cleaning process of the treatment pad 3 is performed, the three-way valve 67 is connected and communicates with the main discharge flow channel 651 and the waste liquid flow channel 653.

[0034] Therefore, the slurry circulation supply mechanism 6 is configured to circulate the slurry S in the circulation flow channel R during the planarization process of the treated surface W1. The circulation flow channel R includes a slurry supply flow channel 63 and a slurry recovery flow channel 652. During the cleaning process of the treated pad 3, the slurry circulation supply mechanism 6 is configured to discharge the cleaning solution L into the waste liquid container 66 through the waste liquid flow channel 653, which is separate from the slurry recovery flow channel 652 (i.e., the waste liquid flow channel 653 is separate from the slurry recovery flow channel 652). The cleaning solution supply device 7 is configured to supply the cleaning solution L to the treated pad 3 to clean it.

[0035] The control device 8 is a microcomputer having one or more CPUs and one or more storage media (hereinafter referred to as memory for convenience). Note that the memory includes non-transitory tangible storage media. The control device 8 is configured to control each operation of the workpiece support device 2, the pad support device 4, the slurry circulation supply mechanism 6, and the cleaning solution supply device 7. For example, the CPU executes a program stored in the memory, thereby controlling each operation of these devices by sending corresponding control signals to the workpiece support device 2, the pad support device 4, the slurry circulation supply mechanism 6, and the cleaning solution supply device 7. Specifically, the control device 8 sets the processing conditions and controls the slurry circulation supply mechanism 6 based on measurements of the characteristics of the slurry S measured by a measuring device 81 (e.g., a sensor) disposed in the slurry supply flow channel 63. The measuring device 81 measures the characteristics of the slurry S flowing through the slurry supply flow channel 63. Note that the measuring device 81 may be configured to include an introducer for introducing the slurry S into the measuring device. The measurable characteristics of the slurry S include, for example, at least one of the following: pH, conductivity, zeta potential, concentration of abrasive particles, and particle size distribution of abrasive particles. The control device 8 also controls the operation of the supply pump 64 and the three-way valve 67.

[0036] (Surface treatment method)

[0037] There are disposal methods where the slurry S used for treatment is disposed of each time, rather than being recycled or reused. This disposal method presents problems related to environmental issues due to waste generation and costs. Therefore, there are reuse methods where the slurry S used for treatment is recycled or reused. However, in such reuse methods, additional processing is necessary, such as adding solvents or chemicals to the used slurry S to dissolve or separate the polishing target particles (i.e., abrasive material). Therefore, such reuse methods result in higher costs. From this perspective, in reuse methods, it is preferable to use the used slurry S as is in the cycle. However, scratches caused by foreign matter such as abrasive particles and clumps of abrasive material contained in the recycled slurry S may pose a risk.

[0038] Therefore, the surface treatment method of this disclosure uses a surface treatment apparatus 1 having the above-described configuration to flatten the treated surface W1, while using the used slurry S as is in a cycle. Specifically, the surface treatment method includes the following procedures, treatments, or processes.

[0039] Figure 2 This is a flowchart illustrating the procedure, process, or process of the surface treatment method according to this embodiment. Figure 2In the steps shown, at least steps S12 to S15 are achieved by controlling each operation of the workpiece support device 2, the pad support device 4, and the slurry circulation supply mechanism 6 via the control device 8. Figure 2 As shown, the workpiece W is fixed to the workpiece support device 2 in the surface treatment apparatus 1 (S11). In the surface treatment apparatus 1, the workpiece support device 2 and the pad support device 4 are moved relative to each other to bring them closer together, thereby making contact between the treatment surface W1 and the treatment pad 3 (S12). Typically, for example, the surface treatment apparatus 1 moves the workpiece support device 2 toward the treatment pad 3 in the axial direction of the rotation axis 21. The surface treatment apparatus 1 supplies slurry S to the treatment pad 3 through the slurry supply flow channel 63 to place the slurry S containing at least abrasive particles between the treatment surface W1 and the treatment pad 3 (S13). In the surface treatment apparatus 1, the workpiece W and the treatment pad 3 move relative to each other while the slurry is placed between the treatment surface W1 and the treatment pad 3. In other words, in the surface treatment apparatus 1, for example, the workpiece W rotates about the rotation axis 21. In this way, the surface treatment apparatus 1 plans the treatment surface W1 by chemical and mechanical action (S14). During the planarization process (S14), the slurry S circulates in the circulating flow channel R.

[0040] Figure 3 This is a flowchart illustrating the slurry circulation process according to this embodiment. The control device 8, which controls the operation of the slurry circulation supply mechanism 6, implements... Figure 3 Each step in the steps shown. Figure 3 As shown, the slurry circulation supply mechanism 6 supplies slurry S from the slurry tank 61 to the treatment pad 3 through the slurry supply flow channel 63 (S21). Used slurry S is received by the housing 5. In the slurry circulation supply mechanism 6, a three-way valve 67 switches the outflow of used slurry S from the main discharge flow channel 651 to the slurry recovery flow channel 652. Therefore, the slurry circulation supply mechanism 6 recovers used slurry S and returns it to the slurry tank 61 through the main discharge flow channel 651 and the slurry recovery flow channel 652 (S22).

[0041] Back Figure 2 The explanation is as follows: After the planarization process is completed, the workpiece support device 2 and the pad support device 4 are moved relative to each other to separate the processed surface W1 from the processed pad 3 (S15). Thereafter, the workpiece W is removed from the workpiece support device 2 in the surface treatment equipment 1 (S16).

[0042] Figure 4 This is a flowchart illustrating the cleaning process according to this embodiment. The control device 8, which controls the operation of the slurry circulation supply mechanism 6 and the cleaning solution supply device 7, implements... Figure 4 Each step in the steps shown. Figure 4 As shown, the control device 8 determines whether the leveling process has been performed N times (a predetermined number of times) (S31). When the control device 8 determines that the leveling process has been performed N times (S31: Yes), the control device 8 commands the cleaning solution supply device 7 to start the cleaning process. Therefore, the cleaning process is performed whenever the leveling process is performed a predetermined number of times (every N times). N is an integer greater than or equal to 1. For example, N is one of 1 to 3. When the workpiece support device 2 is separated from the treatment pad 3, the cleaning solution supply device 7 supplies the cleaning solution L to the treatment pad 3 to clean the treatment pad 3 (S32). The used cleaning solution L (hereinafter referred to as the used cleaning solution L for convenience) is received by the housing 5. In the slurry circulation supply mechanism 6, the three-way valve 67 switches the outflow of the used cleaning solution L from the main discharge flow channel 651 to the waste liquid flow channel 653. Therefore, the slurry circulation supply mechanism 6 discharges the used cleaning solution L through a waste liquid flow channel 653, which is different from the slurry recovery flow channel 652, into a waste liquid container 66, which is different from the slurry tank 61 (S33). During the period when the leveling process is performed, the cleaning process is not performed. In other words, the cleaning process is performed during periods when no slurry S is supplied. Therefore, the slurry S and the cleaning solution L do not mix in the housing 5, the main discharge channel 651, etc. The used slurry S mixed with the cleaning solution L is not recycled in the slurry tank 61 and is not subsequently reused. According to this embodiment, in the surface treatment equipment 1, the used slurry S that is not mixed with the cleaning solution L is recycled in the slurry tank 61 and supplied from the slurry tank 61 for reuse.

[0043] As described above, the surface treatment method according to this embodiment can use the surface treatment equipment 1 having the above configuration to recycle and reuse the used slurry S without any additional processing (addition of solvents, chemicals, etc.). The characteristics and conditions for using the slurry S are specified below to ensure optimal treatment quality and processing rate (i.e., processing cost per unit time). For example, the slurry S in this embodiment is made of manganese dioxide (MnO2) abrasive particles dispersed in a potassium permanganate (KMnO4) solution.

[0044] Considering the processing rate, the slurry S is preferably a neutral slurry with a pH range of 7 to 9, where the concentration of the oxidant is unlikely to decrease. The flow rate of the slurry S supplied through the slurry supply flow channel 63 is preferably higher than a predetermined flow rate to prevent abrasive particle sedimentation. Specifically, the flow rate of the slurry S is preferably 0.15 m / s or higher, preferably 0.2 m / s or higher. Furthermore, the treatment pad 3 can use a polishing pad capable of withstanding a planarization process of more than 10 hours. The following can be used as the treatment pad 3: for example, a soft polishing pad made of nonwoven fabric impregnated with polyurethane resin, a hard polishing pad made of foamed polyurethane, a double-layer pad consisting of a soft polishing pad and a hard polishing pad bonded together, etc., wherein a polishing pad with high durability (e.g., high heat resistance) can be used. More specifically, it is suitable to use a polishing pad with heat resistance capable of withstanding temperatures up to 90°C as the treatment pad 3.

[0045] Considering processing quality, it is preferable to use abrasive particles that are unlikely to cause scratching. Specifically, abrasive particles with a Mohs hardness of 10 or less, preferably 4 or less, are preferred. The particle size of the abrasive particles in the slurry S flowing through the slurry supply flow channel 63 is preferably 20 μm or less. The concentration of abrasive particles in the slurry S is preferably 15% or less by weight. Cleaning of the surface of the treatment pad 3 is preferably performed after each planarization process (i.e., N=1). The cleaning solution L is discharged through a flow channel different from the circulation flow channel R of the slurry S (a waste liquid flow channel 653 separate from the slurry recovery flow channel 652) to remove foreign matter, such as abrasive materials.

[0046] Furthermore, the surface treatment apparatus 1 according to this embodiment uses a measuring device 81 to measure characteristics such as concentration fluctuations and particle size distribution of the abrasive particles in the slurry S flowing through the slurry supply flow channel 63. Then, the control device 8 controls the stirring conditions, flow rate, and processing conditions (e.g., temperature) of the slurry S used in the planarization process based on the measurement results from the measuring device 81. In other words, the control device 8 performs feedback control of the stirring conditions, flow rate, and processing conditions based on the measurement results from the measuring device 81.

[0047] Figure 5 The results of evaluating the processing rate fluctuations in CMP are shown for two examples and one comparative example. Figure 5 In the graph, the horizontal axis represents the polishing amount (total processing amount) [μm] since the start of using (initial) unused slurry S. The vertical axis represents the processing rate [%], which is normalized by setting the initial processing rate of slurry S to 100% for unused slurry S. A comparison example is using no slurry S. Figure 1The waste liquid flow channel 653 and waste liquid container 66 shown are examples of surface treatment apparatus used to perform surface treatment methods. Therefore, a comparative example is the following: in this example, used slurry S and cleaning solution L are collected in slurry tank 61, and used slurry S is reused. Examples 1 and 2 show cases where the surface treatment apparatus 1 of the above embodiment is used to perform a surface treatment method. The processing rates differ between Examples 1 and 2. Specifically, the processing rate in Example 2 is higher than each of the processing rates in the comparative example and Example 1. That is, the processing rate conditions of the comparative example and Example 1 are lower than those of Example 2, while the processing rate conditions of Example 2 are higher than those of Examples 1 and the comparative example. The initial processing rates are the same between the comparative example and Example 1.

[0048] like Figure 5 As shown, the processing rate in the comparative examples decreased significantly as the overall throughput increased (processing time elapsed). Conversely, no significant decrease in processing rate was observed in Examples 1 and 2, even with the increase in overall throughput. In the comparative examples, the decrease in processing rate exceeded 15%. In contrast, the surface treatment method according to this embodiment effectively limits the decrease in processing rate to within 15%. Additionally, the increase in scraping is limited to within 15%. Therefore, this surface treatment method allows for a leveling process of 10 hours or longer without the need to add or replace the slurry S, while still maintaining high processing quality and efficiency.

[0049] (Modified)

[0050] This disclosure is not limited to the embodiments described above. Therefore, modifications can be appropriately made to the embodiments described above. Typical modifications are described below. In the following description of the modifications, the differences from the embodiments described above are mainly explained. In the embodiments and modifications described above, parts that are the same or equivalent to each other are indicated by the same reference numerals. Therefore, in the following description of modifications concerning parts having the same reference numerals as those in the embodiments described above, the descriptions in the embodiments described above can be appropriately supplemented unless there is a technical contradiction or a specific additional explanation.

[0051] This disclosure is not limited to the specific device configuration shown in the above embodiments. In other words, Figure 1 and utilization Figure 1 The above description is specifically simplified to explain the following: the surface treatment method that can be performed using the surface treatment apparatus 1; and the illustrative configuration and function of the surface treatment apparatus 1 according to this embodiment. Therefore, the surface treatment apparatus 1 does not necessarily correspond to a specific equipment configuration that is actually manufactured and sold. The actual equipment configuration that is manufactured and sold can be selected from... Figure 1 The exemplary configuration shown is modified.

[0052] For example, the treatment pad 3 and the pad support device 4 supporting the treatment pad can be configured to allow for rotatable drive. There are no particular limitations on the shape of the housing 5, the slurry circulation supply mechanism 6, the flow channels, or similar components. Specifically, for example, the agitator 62 is not limited to a configuration where a stirring rod 621 rotates within the slurry tank 61. The main discharge flow channel 651 and the slurry recovery flow channel 652 can be configured to extend in the same direction. The main discharge flow channel 651 and the waste liquid flow channel 653 can be configured to extend in the same direction.

[0053] The slurry S can be used as a cleaning solution L. In this case, the surface treatment equipment 1 does not need a cleaning solution supply device 7. Additionally, among other things, a configuration is needed to return the slurry S from the waste liquid container 66 to the slurry tank 61 after removing foreign matter. To achieve this, the following can be provided: a stirring mechanism located in the waste liquid container 66; and a mechanism to return the upper portion of the slurry S stirred in the waste liquid container 66 (the slurry without foreign matter that has settled at the bottom of the container) to the slurry tank 61.

[0054] This disclosure is not limited to the specific processes shown in the above embodiments. That is, for example, the technology of this disclosure does not completely exclude any additional processing of the used slurry S. The technology in this disclosure allows for additional processing to maintain processing quality and processing rate. Specifically, for example, replenishing or replacing unused slurry S, adding dispersants, or similar processing may be performed at each predetermined number of processing cycles or within an appropriate processing time.

[0055] Each element in the above embodiments is not necessarily an essential element unless explicitly stated as particularly essential or critical in principle. When the numerical values, quantities, ranges, etc., of elements are described, this disclosure is not limited to these values ​​unless explicitly stated as particularly essential or limited to specific values ​​in principle. Similarly, when the shape, orientation, positional relationship, etc., of elements are described, this disclosure is not limited to such shape, orientation, positional relationship, etc., unless explicitly stated as particularly essential or limited in principle to specific shapes, orientations, positional relationships, etc.

[0056] These modifications are not limited to those described above. For example, multiple embodiments other than those described above can be combined with each other, provided that there are no technical contradictions between the multiple embodiments. Similarly, various modifications can be combined with each other, provided that there are no technical contradictions between the multiple modifications.

[0057] (Aspects disclosed herein)

[0058] As will be apparent from the description of the above embodiments and modifications, at least the following aspects are disclosed herein.

[0059] [Aspect 1-1]

[0060] A surface treatment method, comprising:

[0061] A slurry (S) containing at least abrasive particles is supplied between the treated surface (W1) of the workpiece (W) and the treated pad (3);

[0062] By moving the workpiece and the treatment pad relative to each other while the slurry is placed between the treated surface of the workpiece and the treatment pad, the treated surface of the workpiece is planarized through chemical and mechanical action; and

[0063] The treatment pad is cleaned with a cleaning solution (L), wherein...

[0064] During the planarization process, the slurry is circulated through a circulation flow channel (R) for the slurry, the circulation flow channel including a slurry supply flow channel (63) for supplying the slurry to the treatment pad and a slurry recovery flow channel (652) for recovering the used slurry, and

[0065] When the treatment pad is cleaned with the cleaning solution, the cleaning solution is discharged through a waste liquid flow channel (653) that is separate from the circulation flow channel, thereby allowing liquid waste to flow through the waste liquid flow channel.

[0066] [Aspects 1-2]

[0067] According to the surface treatment method described in aspect 1-1, wherein,

[0068] The abrasive particles have a Mohs hardness of 10 or higher.

[0069] [Aspects 1-3]

[0070] According to the surface treatment method described in aspects 1-2, wherein,

[0071] The abrasive particles in the slurry include manganese dioxide abrasive particles.

[0072] [Aspects 1-4]

[0073] The surface treatment method according to any one of aspects 1-1 to 1-3, wherein,

[0074] The pH range of the slurry is greater than or equal to 7 and less than or equal to 9.

[0075] [Aspects 1-5]

[0076] The surface treatment method according to any one of aspects 1-1 to 1-4, wherein,

[0077] The abrasive particles in the slurry flowing through the slurry supply channel have a particle size of 20 μm or smaller.

[0078] [Aspects 1-6]

[0079] The surface treatment method according to any one of aspects 1-1 to 1-5, wherein,

[0080] The concentration of the abrasive particles in the slurry is 15% or less by weight.

[0081] [Aspects 1-7]

[0082] The surface treatment method according to any one of aspects 1-1 to 1-6, wherein,

[0083] The flow velocity of the slurry flowing through the slurry supply channel is 0.15 m / s or higher.

[0084] [Aspects 1-8]

[0085] The surface treatment method according to any one of aspects 1-1 to 1-7 further includes:

[0086] The characteristics of the slurry flowing through the slurry supply flow channel are measured; and

[0087] The processing conditions for the flattening process are controlled based on the measurement results.

[0088] [Aspects 1-9]

[0089] The surface treatment method according to any one of aspects 1-1 to 1-8, wherein,

[0090] The processing pad uses a polishing pad that can withstand the planarization process for more than 10 hours.

[0091] [Aspects 1-10]

[0092] The surface treatment method according to any one of aspects 1-1 to 1-9, wherein,

[0093] The workpiece is made of a material containing SiC.

[0094] [Aspect 2-1]

[0095] A surface treatment method, comprising:

[0096] A slurry (S) containing at least abrasive particles is supplied between the treated surface (W1) of the workpiece (W) and the treated pad (3); and

[0097] The treated surface of the workpiece is planarized by chemical and mechanical action by moving the workpiece and the treatment pad relative to each other while the slurry is placed between the treated surface of the workpiece and the treatment pad, wherein...

[0098] A planarization process is performed when the slurry, with a pH range of greater than or equal to 7 and less than or equal to 9, is circulated through a circulation flow channel (R) for the slurry, the circulation flow channel (R) including a slurry supply flow channel (63) for supplying the slurry to the treatment pad and a slurry recovery flow channel (652) for recovering the used slurry.

[0099] [Aspect 2-2]

[0100] According to the surface treatment method described in aspect 2-1, wherein,

[0101] The abrasive particles have a Mohs hardness of 10 or higher.

[0102] [Aspects 2-3]

[0103] According to the surface treatment method described in aspect 2-2, wherein,

[0104] The abrasive particles in the slurry include manganese dioxide abrasive particles.

[0105] [Aspects 2-4]

[0106] The surface treatment method according to any one of aspects 2-1 to 2-3, wherein,

[0107] During the leveling process, the slurry circulates through the circulation flow channel.

[0108] The surface treatment method further includes cleaning the treatment pad with a cleaning solution (L), wherein,

[0109] When the treatment pad is cleaned with the cleaning solution, the cleaning solution is discharged through a waste liquid flow channel (653) that is separate from the circulation flow channel, thereby allowing liquid waste to flow through the waste liquid flow channel.

[0110] [Aspects 2-5]

[0111] The surface treatment method according to any one of aspects 2-1 to 2-4, wherein,

[0112] The abrasive particles in the slurry flowing through the slurry supply channel have a particle size of 20 μm or smaller.

[0113] [Aspects 2-6]

[0114] The surface treatment method according to any one of aspects 2-1 to 2-5, wherein,

[0115] The concentration of the abrasive particles in the slurry is 15% or less by weight.

[0116] [Aspects 2-7]

[0117] The surface treatment method according to any one of aspects 2-1 to 2-6, wherein,

[0118] The flow velocity of the slurry flowing through the slurry supply channel is 0.15 m / s or higher.

[0119] [Aspects 2-8]

[0120] The surface treatment method according to any one of aspects 2-1 to 2-7 further includes:

[0121] The characteristics of the slurry flowing through the slurry supply flow channel are measured; and

[0122] The processing conditions for the flattening process are controlled based on the measurement results.

[0123] [Aspects 2-9]

[0124] The surface treatment method according to any one of aspects 2-1 to 2-8, wherein,

[0125] The processing pad uses a polishing pad that can withstand the planarization process for more than 10 hours.

[0126] [Aspects 2-10]

[0127] The surface treatment method according to any one of aspects 2-1 to 2-9, wherein,

[0128] The workpiece is made of a material containing SiC.

[0129] [Aspect 3-1]

[0130] A surface treatment method, comprising:

[0131] A slurry (S) containing at least abrasive particles is supplied between the treated surface (W1) of the workpiece (W) and the treated pad (3); and

[0132] By moving the workpiece and the treatment pad relative to each other while the slurry is placed between the treated surface of the workpiece and the treatment pad, the treated surface of the workpiece is planarized through chemical and mechanical action, wherein...

[0133] A planarization process is performed when the slurry is circulated through a circulation flow channel (R) for the slurry, the circulation flow channel including a slurry supply flow channel (63) for supplying the slurry to the treatment pad and a slurry recovery flow channel (652) for recovering the used slurry.

[0134] The flow velocity of the slurry flowing through the slurry supply channel is 0.15 m / s or higher.

[0135] [Aspect 3-2]

[0136] According to the surface treatment method described in aspect 3-1, wherein,

[0137] The abrasive particles have a Mohs hardness of 10 or higher.

[0138] [Aspect 3-3]

[0139] According to the surface treatment method described in aspect 3-2, wherein,

[0140] The abrasive particles in the slurry include manganese dioxide abrasive particles.

[0141] [Aspects 3-4]

[0142] According to the surface treatment method described in any one of aspects 3-1 to 3-3, wherein,

[0143] The pH range of the slurry is greater than or equal to 7 and less than or equal to 9.

[0144] [Aspects 3-5]

[0145] According to any one of aspects 3-1 to 3-4, the surface treatment method wherein,

[0146] During the planarization process, the slurry is circulated through the circulation flow channel.

[0147] The surface treatment method further includes cleaning the treatment pad with a cleaning solution (L), wherein,

[0148] When the treatment pad is cleaned with the cleaning solution, the cleaning solution is discharged through a waste liquid flow channel (653) that is separate from the circulation flow channel, thereby allowing liquid waste to flow through the waste liquid flow channel.

[0149] [Aspects 3-6]

[0150] According to the surface treatment method described in any one of aspects 3-1 to 3-5, wherein,

[0151] The abrasive particles in the slurry flowing through the slurry supply channel have a particle size of 20 μm or smaller.

[0152] [Aspects 3-7]

[0153] According to the surface treatment method described in any one of aspects 3-1 to 3-6, wherein,

[0154] The concentration of the abrasive particles in the slurry is 15% or less by weight.

[0155] [Aspects 3-8]

[0156] The surface treatment method according to any one of aspects 3-1 to 3-7 further includes:

[0157] The characteristics of the slurry flowing through the slurry supply flow channel are measured; and

[0158] The processing conditions for the flattening process are controlled based on the measurement results.

[0159] [Aspects 3-9]

[0160] According to any one of aspects 3-1 to 3-8, the surface treatment method wherein,

[0161] The processing pad uses a polishing pad that can withstand a planarization process of more than 10 hours.

[0162] [Aspects 3-10]

[0163] According to any one of aspects 3-1 to 3-9, the surface treatment method wherein,

[0164] The workpiece is made of a material containing SiC.

Claims

1. A surface treatment method, comprising: A slurry containing at least abrasive particles is supplied between the treated surface of the workpiece and the treatment pad; The treated surface of the workpiece is flattened by chemical and mechanical action by moving the workpiece and the treatment pad relative to each other while the slurry is placed between the treated surface of the workpiece and the treatment pad. as well as The treatment pad is cleaned with a cleaning solution, wherein... During the planarization process, the slurry is circulated through a circulation flow channel for the slurry, the circulation flow channel including a slurry supply flow channel for supplying the slurry to the treatment pad and a slurry recovery flow channel for recovering the used slurry. When the treatment pad is cleaned with the cleaning solution, the cleaning solution is discharged through a waste liquid flow channel that is separate from the circulation flow channel, thereby allowing liquid waste to flow through the waste liquid flow channel.

2. The surface treatment method according to claim 1, wherein, The abrasive particles have a Mohs hardness of 10 or higher.

3. The surface treatment method according to claim 2, wherein, The abrasive particles in the slurry include manganese dioxide abrasive particles.

4. The surface treatment method according to any one of claims 1 to 3, wherein, The pH range of the slurry is greater than or equal to 7 and less than or equal to 9.

5. The surface treatment method according to any one of claims 1 to 3, wherein, The abrasive particles in the slurry flowing through the slurry supply channel have a particle size of 20 μm or smaller.

6. The surface treatment method according to any one of claims 1 to 3, wherein, The concentration of the abrasive particles in the slurry is 15% or less by weight.

7. The surface treatment method according to any one of claims 1 to 3, wherein, The flow velocity of the slurry flowing through the slurry supply channel is 0.15 m / s or higher.

8. The surface treatment method according to any one of claims 1 to 3, further comprising: The characteristics of the slurry flowing through the slurry supply flow channel are measured; as well as The processing conditions for the flattening process are controlled based on the measurement results.

9. The surface treatment method according to any one of claims 1 to 3, wherein, The processing pad uses a polishing pad that can withstand the planarization process for more than 10 hours.

10. The surface treatment method according to any one of claims 1 to 3, wherein, The workpiece is made of a material containing SiC.

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