Polishing apparatus and control method for polishing apparatus

Abstract

The invention relates to a polishing apparatus and a control method of the polishing apparatus. The polishing apparatus is controlled to perform dressing at a proper time. A controller of the polishing apparatus determines a timing at which the polishing capability of the polishing pad is predicted to be lower than a threshold level on the basis of the state of the polishing surface of the polishing pad measured by the measurement apparatus, determines an idle time period before the predicted timing comes from a plurality of idle time periods in the operation plan, and in the determined idle time period, the polishing capability of the polishing pad is predicted to be lower than the threshold level. The polishing pad is trimmed by the trimming device.

Description

Technical Field

[0001] This invention relates to a grinding apparatus and a control method for the grinding apparatus. Background Technology

[0002] When grinding substrates or other objects in a grinding apparatus, abrasive grains and grinding debris adhere to the surface of the grinding pad. Furthermore, the surface condition of the grinding pad changes, leading to a deterioration in grinding performance. To restore the surface condition of the grinding pad, a dressing device is used to dress the grinding pad. Conventionally, dressing is performed after grinding a predetermined number of substrates (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-112194 Summary of the Invention

[0006] (The technical problem the invention aims to solve)

[0007] At the current dredging times, the productivity of the grinding unit sometimes decreases due to the dredging performed. Additionally, the grinding pads are sometimes over-consumed due to dredging. Therefore, it is necessary to control the grinding unit to perform dredging at the appropriate time.

[0008] (Methods used to solve technical problems)

[0009] According to one embodiment, a grinding apparatus is provided, comprising: one or more grinding units; one or more functional units for performing pre-processing or post-processing for grinding; one or more conveying units for conveying a workpiece to be ground at least between the grinding units and the functional units; and a controller that controls the grinding units, the functional units, and the conveying units to operate according to a predetermined action plan to grind the workpiece, the action plan including multiple idle time periods during which the grinding units cannot perform processing due to operational limitations between the grinding units, the functional units, and the conveying units. Each of the one or more grinding units comprises: a grinding pad configured to be pressed against the grinding object during grinding; a measuring device for measuring the state of the grinding surface of the grinding pad; and a dressing device configured to dress the grinding pad. The controller is configured to: determine, based on the state of the grinding surface of the grinding pad measured by the measuring device, a predicted time when the grinding ability of the grinding pad is below a threshold level is determined; determine an idle time period before the predicted time period arrives from the plurality of idle time periods in the action plan; and, during the determined idle time period, cause the dressing device to dress the grinding pad.

[0010] According to one embodiment, a grinding apparatus is provided, comprising: one or more grinding units; one or more functional units for performing pre-processing or post-processing for grinding; one or more conveying units for conveying a grinding object at least between the grinding units and the functional units; and a controller that controls the grinding units, the functional units, and the conveying units to operate according to a predetermined action plan for grinding the grinding object, the action plan including a plurality of idle time periods during which the grinding units cannot perform processing due to operational limitations between the grinding units, the functional units, and the conveying units, each of the one or more grinding units comprising: a grinding pad configured to be pressed against the grinding object when grinding the grinding object; and a dressing device configured to dress the grinding pad, the controller being configured to cause the dressing device to dress the grinding pad during each of the plurality of idle time periods. Attached Figure Description

[0011] Figure 1 This is a top view showing the overall structure of a grinding apparatus according to one embodiment of the present invention.

[0012] Figure 2This is a perspective view showing the structure of a grinding unit according to one embodiment.

[0013] Figure 3 It is a schematic representation. Figure 2 Side view of the grinding unit.

[0014] Figure 4 This is a flowchart illustrating an example of the processing flow of the controller in a grinding apparatus.

[0015] Figure 5 This is an example of a control plan used to control the operation of a grinding device.

[0016] Figure 6 This is a graph showing an example of how the pad condition index value of the grinding pad changes over time in a specific grinding unit of a grinding apparatus.

[0017] Figure 7 This is a flowchart illustrating an exemplary control flow of a grinding apparatus according to one embodiment of the present invention.

[0018] Figure 8 This is an exemplary action plan for controlling the grinding apparatus used in this embodiment.

[0019] Figure 9 This is a graph showing an example of how the pad condition index value of a specific grinding unit of the grinding apparatus in this embodiment changes over time.

[0020] Figure 10 This embodiment controls the change of wavelength composition ratio over time in the polishing unit during the idle period TS303 when performing trimming.

[0021] Symbol Explanation

[0022] 10: Grinding device

[0023] 100: Loading / Unloading Unit

[0024] 200: First conveying unit

[0025] 300: Second conveyor unit

[0026] 400: Third Conveying Unit

[0027] 500: Grinding unit

[0028] 600: Chip Station

[0029] 700: Cleaning Unit

[0030] 800: Controller

[0031] 352: Grinding pad

[0032] 356: Repair Unit

[0033] 502: Measurement unit. Detailed Implementation

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0035] Figure 1 This is a top view showing the overall structure of a polishing apparatus 10 according to one embodiment of the present invention. The polishing apparatus 10 may be, for example, a CMP (Chemical Mechanical Polishing) apparatus. CMP apparatuses are used to polish semiconductor substrates or glass substrates, or metal or semiconductor thin films formed on their surfaces, etc. Figure 1 As shown, the CMP apparatus (i.e., polishing apparatus) 10 includes: a loading / unloading unit 100, a first conveying unit 200, a second conveying unit 300, a third conveying unit 400, one or more polishing units 500, a wafer station 600, one or more cleaning units 700, and a controller 800.

[0036] The loading / unloading unit 100 is a component used to move substrates, which are the objects to be polished, into and out of the polishing apparatus 10. For example, a FOUP or similar container (not shown) holding multiple substrates before polishing is mounted on the loading / unloading unit 100, and the substrates removed from the container are transported into the polishing apparatus 10. After polishing, the substrates are returned to the container, and the container is removed from the polishing apparatus 10. Furthermore, in... Figure 1 In the example, the grinding device 10 has four loading / unloading units 100, but the number of loading / unloading units 100 can be arbitrary.

[0037] The first conveying unit 200 is arranged adjacent to the loading / unloading unit 100 and the second conveying unit 300, and is configured to take out the substrate before grinding from the box mounted on the loading / unloading unit 100 and hand it over to the second conveying unit 300, and receive the substrate after grinding from the second conveying unit 300 and store it in the box of the loading / unloading unit 100.

[0038] The second transport unit 300, in addition to the first transport unit 200, is also configured adjacent to each of the polishing units and wafer stations 600 in one or more polishing units 500. For example... Figure 1As shown, the second transport unit 300 can be arranged along the arrangement direction of a plurality of polishing units 500 arranged side by side in one direction. The second transport unit 300 is configured to receive a substrate before polishing from the first transport unit 200, transport it to a designated polishing unit among one or more polishing units 500, and house it within that polishing unit. Furthermore, the second transport unit 300 is configured to remove the substrate after polishing in the polishing unit 500 from the polishing unit 500, transport it to the wafer station 600, and hand it over to the wafer station 600.

[0039] One or more polishing units 500 are units that polish a substrate, which is the object of polishing; details of these units will be described later. Additionally, in Figure 1 In the example, the grinding device 10 has four grinding units 500, but the number of grinding units 500 can be arbitrary.

[0040] The wafer station 600 is a unit configured to temporarily hold a substrate that has been polished in the polishing unit 500. Alternatively, the wafer station 600 may also be configured as part of a second transport unit 300 or a third transport unit 400.

[0041] The third transport unit 400 is configured adjacent to the wafer station 600 and each of the cleaning units in one or more cleaning units 700. For example... Figure 1 As shown, the third transport unit 400 can be arranged along the arrangement direction of a plurality of cleaning units 700 arranged side by side in one direction. The third transport unit 400 is configured to transport a substrate temporarily held in the wafer station 600 to a designated cleaning unit among one or more cleaning units 700, and house it in that cleaning unit. Alternatively, the third transport unit 400 can be configured to remove the substrate after cleaning in the cleaning unit 700 and return it to the wafer station 600. The third transport unit 400 can also be configured to hand over the cleaned substrate to the first transport unit 200 instead of returning it to the wafer station 600. Furthermore, the third transport unit 400 can be configured to, after removing the substrate after cleaning in a certain cleaning unit 700, transport the substrate, for example, to another cleaning unit 700 for a higher degree of cleaning.

[0042] One or more cleaning units 700 are units for cleaning the polished substrate, used to rinse away polishing fluid, polishing debris, etc., that adhered to the substrate surface during the polishing process of the polishing unit 500. Each of the one or more cleaning units 700 can be configured to operate using different cleaning solutions or cleaning conditions, for example, to clean a substrate at different cleanliness levels. Furthermore, in Figure 1 In the example, the grinding device 10 has four cleaning units 700, but the number of cleaning units 700 can be arbitrary.

[0043] The cleaning unit 700 is an example of a functional unit that performs post-processing on the substrate polished by the polishing unit 500 (i.e., cleaning is an example of post-processing). In addition to the cleaning unit 700, the polishing apparatus 10 may also include other functional units configured to perform other types of post-processing besides cleaning (e.g., a drying unit for drying the cleaned substrate) and / or other functional units configured to perform a predetermined pre-processing on the substrate before polishing (e.g., a pre-cleaning unit for cleaning the substrate before polishing).

[0044] The controller 800 is a device used to control the operation of the aforementioned elements in the grinding apparatus 10. The controller 800 can be configured as a general-purpose computer equipped with a processor and memory. A prescribed program for controlling the grinding apparatus 10 is stored in the memory; the processor reads the program from the memory and executes it, thereby controlling each part of the grinding apparatus 10. Details regarding the control by the controller 800 will be described later.

[0045] Next, the details of the grinding unit 500 provided in the grinding apparatus 10 will be explained. Figure 2 This is a perspective view showing the structure of a grinding unit 500 according to one embodiment. Figure 3 It is a schematic representation Figure 2 A side view of the grinding unit 500. Furthermore, when the grinding apparatus 10 has multiple grinding units 500, each grinding unit 500 can have all the same... Figure 2 and Figure 3 Same structure. For example... Figure 2 As shown, the polishing unit 500 includes a polishing table 350 and a top ring 302. The top ring 302 forms a polishing head, which holds the substrate, which is the object to be polished, and presses it onto the polishing surface of the polishing table 350. The polishing table 350 is connected to a polishing table rotary motor (not shown) disposed below it via a table shaft 351, and can rotate around the table shaft 351. A polishing pad 352 is attached to the upper surface of the polishing table 350, and the surface 352a of the polishing pad 352 forms the polishing surface of the substrate.

[0046] A polishing slurry supply nozzle 354 is provided above the polishing table 350, through which polishing slurry is supplied to the polishing pad 352 on the polishing table 350. Additionally, as... Figure 2As shown, a passage 353 for supplying polishing fluid is provided on the polishing table 350 and the table spindle 351. The passage 353 communicates with an opening 355 on the surface of the polishing table 350. At a position corresponding to the opening 355 of the polishing table 350, a through hole 357 is formed in the polishing pad 352. Polishing fluid is supplied from the opening 355 of the polishing table 350 and the through hole 357 of the polishing pad 352 through the passage 353 to the surface of the polishing pad 352. Furthermore, there may be one or more openings 355 of the polishing table 350 and through holes 357 of the polishing pad 352. In addition, the positions of the openings 355 of the polishing table 350 and through holes 357 of the polishing pad 352 are arbitrary, but in one embodiment, they are arranged near the center of the polishing table 350.

[0047] The top ring 302 is connected to the top ring shaft 18, which moves vertically relative to the swing arm 360 via a vertical movement mechanism 319. The vertical movement of the top ring shaft 18 positions the top ring 302 relative to the swing arm 360. The top ring shaft 18 is rotated by a top ring rotary motor (not shown). The top ring 302 rotates about the top ring shaft 18 as a center. Furthermore, a rotary joint 323 is mounted on the upper end of the top ring shaft 18.

[0048] The top ring 302 is capable of holding the substrate, which is the object to be ground, on its lower surface. The swing arm 360 is configured to rotate about the pivot 362. The top ring 302 can be moved by the rotation of the swing arm 360 to a transport unit (not shown) (e.g., see reference 1). Figure 1 The second conveying unit 300 described herein moves between the substrate junction position and above the polishing table 350. By lowering the top ring shaft 18, the top ring 302 can be lowered to press the substrate onto the surface (polishing surface) 352a of the polishing pad 352. At this time, the top ring 302 and the polishing table 350 are rotated respectively, and polishing liquid is supplied to the polishing pad 352 from the polishing liquid supply nozzle 354 provided above the polishing table 350 and / or from the opening 355 provided above the polishing table 350. In this way, the substrate can be pressed against the polishing surface 352a of the polishing pad 352, and the surface of the substrate can be polished. During the polishing of the substrate, the arm 360 can be fixed in such a way that the top ring 302 covers the through hole 357 of the polishing pad 352, or the arm 360 can be swung so that the top ring 302 passes through the center of the polishing pad 352.

[0049] The up-and-down movement mechanism 319, which moves the top ring shaft 18 and the top ring 302 up and down, includes: a bridge 28 that supports the top ring shaft 18 for rotation via a bearing 321; a ball screw 32 mounted on the bridge 28; a support platform 29 supported by a support column 130; and an AC servo motor 38 mounted on the support platform 29. The support platform 29 supporting the servo motor 38 is fixed to the swing arm 360 via the support column 130.

[0050] The ball screw 32 includes a screw shaft 32a connected to the servo motor 38 and a nut 32b screwed into the screw shaft 32a. The top ring shaft 18 moves up and down integrally with the bridge 28. Therefore, when the servo motor 38 is driven, the bridge 28 moves up and down via the ball screw 32, thereby causing the top ring shaft 18 and the top ring 302 to move up and down.

[0051] One embodiment of the grinding unit 500 includes a dressing unit 356 that dresses the grinding surface 352a of the grinding pad 352. The dressing unit 356 includes: a dresser 50 that slides in contact with the grinding surface 352a; a dresser shaft 51 connected to the dresser 50; a cylinder 53 located at the upper end of the dresser shaft 51; and a swing arm 55 that supports the dresser shaft 51 for free rotation. The lower part of the dresser 50 is composed of a dressing component 50a, on the lower surface of which needle-shaped diamond particles are attached. The cylinder 53 is disposed on a support platform 57 supported by pillars 56, which are fixed to the swing arm 55.

[0052] The swing arm 55 is driven by a motor (not shown) and is configured to rotate around a support shaft 58. The dresser shaft 51 is rotated by a motor (not shown), and the dresser 50 rotates around the dresser shaft 51 as a result of the rotation of the dresser shaft 51. The cylinder 53 moves the dresser 50 up and down via the dresser shaft 51, pressing the dresser 50 against the grinding surface 352a of the grinding pad 352 with a specified pressing force.

[0053] The dressing of the grinding surface 352a of the grinding pad 352 is performed as follows. The dresser 50 is pressed against the grinding surface 352a by the cylinder 53, and at the same time, pure water is supplied to the grinding surface 352a by a pure water supply nozzle (not shown). In this state, the dresser 50 rotates about the dresser shaft 51, causing the lower surface (diamond particles) of the dressing component 50a to slide into contact with the rotating grinding surface 352a, and causing the swing arm 55 to swing on the grinding surface 352a. In this way, the grinding pad 352 is cut by the dresser 50, and the grinding surface 352a is dressed.

[0054] One embodiment of the grinding unit 500 further includes a measuring unit 502. Figure 2(Not shown in the figure), the measuring unit 502 is used to measure the state of the abrasive surface 352a of the abrasive pad 352. For example, as... Figure 3 As shown, a measurement unit 502 is disposed above the polishing surface 352a of the polishing pad 352. The measurement unit 502 is configured, for example, to emit a measurement light L1 toward the polishing pad 352 and detect reflected light L2 from the polishing surface 352a of the polishing pad 352. In one embodiment, the measurement unit 502 may be configured to provide a detection signal of the reflected light L2 to a controller 800. The controller 800 is able to identify the state of the polishing surface 352a of the polishing pad 352 based on the detection signal of the reflected light L2 from the polishing pad 352 obtained from the measurement unit 502. For example, an index value (hereinafter referred to as a pad state index value) representing the state of the polishing surface 352a of the polishing pad 352 can be calculated by analyzing the intensity or spatial spectrum of the reflected light L2 from the polishing pad 352.

[0055] The pad condition index value can be calculated by analyzing the intensity or spatial spectrum of the reflected light L2 from the abrasive pad 352 using an appropriate method. In one example, the "wavelength composition ratio" disclosed in Japanese Patent Application Publication No. 2022-112194 can be used as the pad condition index value. Specifically, the wavelength composition ratio can be calculated from the measured reflected light L2 according to the following formula (1).

[0056] [Formula 1]

[0057]

[0058] Here, I(ξ) is the spatial spectral distribution of the reflected light L2 from the abrasive pad 352, and ξ is the reciprocal of the spatial frequency of the reflected light L2. Furthermore, ξ3 < ξ1 < ξ2 < ξ4 is assumed. The greater the roughness of the abrasive surface 352a of the abrasive pad 352 (i.e., the higher the abrasive capability of the abrasive pad 352), the smaller the wavelength composition ratio. Conversely, the greater the smoothness of the abrasive surface 352a of the abrasive pad 352 (i.e., the greater the abrasive capability due to wear of the abrasive pad 352), the greater the wavelength composition ratio. Therefore, by knowing the value of the wavelength composition ratio, the state of the abrasive surface 352a of the abrasive pad 352 (or the abrasive capability of the abrasive pad 352) can be determined.

[0059] Furthermore, instead of the wavelength composition ratio described above, other suitable indicators can be used as pad condition index values. Additionally, although the method of measurement using optical methods has been described above, the measurement unit 502 can also be configured to perform measurements using other methods, such as acoustic methods. The measurement unit 502 can be configured to perform measurements using optical methods, acoustic methods, or other methods, and send its measurement signals or data to the controller 800. The controller 800 can be configured to calculate or determine pad condition index values ​​representing the state of the polishing surface 352a of the polishing pad 352 based on the measurement signals or data from the measurement unit 502. Alternatively, the measurement unit 502 itself (or the polishing unit 500) can be configured to have a computational function (e.g., a processor) for calculating pad condition index values ​​based on measurement signals or data, and provide the calculated pad condition index values ​​to the controller 800.

[0060] Figure 4 This is a flowchart illustrating an example of the processing flow of the controller 800 in the aforementioned grinding apparatus 10. (Refer to...) Figure 4 This describes a series of actions performed by the grinding device 10 when grinding the object being ground.

[0061] First, in step 402, the controller 800 generates an action plan based on predetermined scheme information, which enables the conveying units 200, 300, 400, grinding units 500, and cleaning units 700 of the grinding apparatus 10 to operate in an appropriate sequence. In the subsequent step 404, the controller 800 controls the operation of each unit of the grinding apparatus 10 according to the generated action plan.

[0062] Information specified for creating the action plan may include, for example, the number of substrates to be ground in the processing batch, the target thickness of the polishing film on the substrates, the material of the polishing film, the expected grinding time for each substrate, the number of polishing units 500 in operation, the polishing operation conditions of each polishing unit 500 (e.g., the rotational speed of the polishing table 350 and the top ring 302, the pressing pressure of the top ring 302 relative to the polishing table 350, the type and amount of polishing fluid used, etc.), the number of cleaning units 700 in operation, and the cleaning conditions in each cleaning unit 700 (e.g., the type of cleaning fluid, temperature, cleaning time, etc.).

[0063] Figure 5 This is an example of a method used to control the operation plan of the grinding device 10. Specifically, Figure 5 This indicates the action plan for the four grinding target substrates, from the Nth to the N+3rd. Figure 5 The horizontal axis represents time. Figure 5 The longitudinal direction corresponds to different substrates. Figure 5In the example operation plan, for instance, the Nth substrate to be polished (bottom of the figure) is conveyed by the first conveying unit 200 from the loading / unloading unit 100 to the second conveying unit 300 during time period TS101, and further conveyed by the second conveying unit 300 to a designated polishing unit (let's call it polishing unit A) among one or more polishing units 500 during time period TS102. Then, during time period TS103, the polishing pad 352 is periodically polished by the dressing unit 356. This periodic polishing can be determined, for example, based on the cumulative usage time of the polishing pad 352 during its use.

[0064] Then, during time period TS104, the polishing unit A polishes the Nth substrate. At the end of polishing the Nth substrate, since the second transport unit 300 is transporting the (N+1)th substrate to the wafer station 600 (refer to time period TS204 for the (N+1)th substrate), the Nth substrate remains in polishing unit A as is during the next time period TS105. During the time period TS106 when the wafer station 600 is usable, the Nth substrate is removed from polishing unit A by the second transport unit 300 and transported to the wafer station 600, where it is temporarily held during time period TS107.

[0065] Next, in time period TS108, the Nth substrate to be polished is transported by the third transport unit 400 from the wafer station 600 to one of the cleaning units 700 (designated as cleaning unit A). In time period TS109, the Nth substrate to be polished is cleaned by cleaning unit A. Then, in time period TS110, the Nth substrate to be polished is transported by the third transport unit 400 from cleaning unit A to another cleaning unit B. In time period TS111, cleaning unit B performs a second cleaning. Afterwards, through the same process in time periods TS112 and TS113, a third cleaning is performed by cleaning unit C. Finally, in time period TS114, the Nth substrate to be polished is returned by the first transport unit 200 to the loading / unloading unit 100.

[0066] For the (N+1)th substrate to be polished, the operation of each part of the polishing apparatus 10 is also performed during time periods TS201 to TS212. However, the polishing unit that polishes the (N+1)th substrate to be polished is polishing unit B, which is different from polishing unit A that polishes the Nth substrate to be polished (refer to time period TS203). Furthermore, since the first transport unit 200 can start transporting the (N+1)th substrate to be polished from the loading / unloading unit 100 after the first transport unit 200 hands over the Nth substrate to the second transport unit 300 as the previous substrate, the start time of time period TS201 for the first transport unit 200 to transport the (N+1)th substrate to be polished is later than the end time of time period TS101 (or TS102) for the Nth substrate to be polished.

[0067] Similarly, for the N+2 and N+3th polishing substrates, the process is also as follows: Figure 5 The operation of each part of the polishing apparatus 10 is carried out in each time period shown. Among them, the N+2th substrate is polished by polishing unit A, and the N+3rd substrate is polished by polishing unit B (refer to time periods TS304 and TS403).

[0068] Here, during the time period TS302 when the (N+2)th substrate to be polished is being transported to polishing unit A, polishing unit A is still processing the previous substrate (i.e., the Nth substrate). Therefore, the (N+2)th substrate to be polished remains in the first transport unit 200 during the next time period TS303 (i.e., before the polishing of the Nth substrate in polishing unit A is completed). This delay is due to the introduction of a time period TS103 for periodically adjusting the polishing pad 352 before polishing the Nth substrate by polishing unit A, thus postponing the processing of the Nth substrate by polishing unit A. Furthermore, as a result of the (N+2)th substrate to be polished remaining in the first transport unit 200 during time period TS303, the start of the time period TS401 for the first transport unit 200 to transport the next (N+3)th substrate from the loading / unloading unit 100 is delayed until the end of time period TS303.

[0069] Thus, if the polishing pad 352 is tidied up at regular intervals, the operation of a certain unit in the polishing apparatus 10 will be delayed, which may cause a decrease in the productivity of the polishing apparatus 10 (the number of substrates processed per unit time). In addition, as explained below, it is also contemplated that the consumption of the polishing pad 352 may be accelerated.

[0070] Figure 6This is a graph showing an example of how the pad condition index value (e.g., wavelength composition ratio) of the polishing pad 352 in a specific polishing unit 500 (e.g., polishing unit A) of the polishing apparatus 10 changes over time. Figure 6 The text also shows the same time scale as the chart. Figure 5 Example action plan, Figure 6 The time change of the pad condition index value indicates that when based on Figure 5 The example motion plan causes a time variation in the operation of the grinding device 10. Additionally, in Figure 6 The chart also depicts a dashed line 602 representing the upper limit of the appropriate range of pad condition index values ​​and a dashed line 604 representing the lower limit. As described above, as wear on the polished surface 352a increases due to the use of the polishing pad 352, the wavelength composition ratio increases, and as the roughness of the polished surface 352a recovers due to the finishing of the polishing pad 352, the wavelength composition ratio decreases. Figure 6 This illustrates the decrease in the wavelength composition ratio during the time period TS103 when the polishing pad 352 is polished by the polishing unit 356. However, in Figure 6 In the example, at the beginning of time period TS103, the wavelength composition ratio still has a margin relative to the upper limit of the appropriate range (dashed line 602) (i.e., the polishing pad 352 still has sufficient polishing capability), and the substrate polishing can be performed directly even without trimming the polishing pad 352. That is, Figure 5 The operation plan was designed to perform the necessary over-treatment of the polishing pad 352 too quickly. Therefore, there is a concern that if the number of treatments is increased, the polishing pad 352 may reach the end of its life prematurely.

[0071] Figure 7 This is a flowchart illustrating an exemplary control flow of a grinding apparatus 10 according to one embodiment of the present invention, which enables the grinding apparatus 10 to operate more efficiently relative to the aforementioned points. (Refer to...) Figure 7 An example of an improved operation of the grinding apparatus 10 will be described.

[0072] First, in step 702, the controller 800, based on prescribed scheme information, generates an action plan for the conveying units 200, 300, 400, grinding units 500, and cleaning units 700 of the grinding apparatus 10 to operate in an appropriate sequence. This is consistent with the above-mentioned... Figure 5 The action plan differs from the one created in step 702; the action plan does not include the time period for dressing the polishing pad 352. In the subsequent step 704, the controller 800 begins to control the operation of each unit of the polishing apparatus 10 according to the action plan created in step 702.

[0073] Figure 8This is an exemplary action plan for controlling the grinding device 10, which was created and used in this embodiment. Figure 8 Action plan in accordance with Figure 5 The action plan is described using the same general rules. Therefore, to avoid unnecessary complexity, details regarding the action plan are omitted. Figure 8 Detailed description of the action plan. It should be noted that... Figure 8 The operational plan includes several "idle periods." An idle period refers to a time when a specific grinding unit 500 cannot perform processing due to operational limitations between the units in the grinding apparatus 10 (e.g., grinding unit 500, cleaning unit 700, and conveying units 200, 300, 400). For example, in Figure 8 In the example operation plan, the time period TS303 for the N+2th substrate to be polished becomes an idle time period for the following reason: During the time period TS302 when the N+2th substrate to be polished is being transported to polishing unit A, polishing unit A is still processing the Nth substrate, which is the previous substrate (as described above). Figure 5 (The example is the same). The plan is that during time period TS105, when the Nth substrate is removed from polishing unit A by the second transport unit 300, the second transport unit 300 transports the (N+3)th substrate to be polished during time period TS402, before removing the Nth substrate from polishing unit A. Therefore, after time period TS302, until the polishing of the Nth substrate in polishing unit A (time period TS103) ends, and the second transport unit 300 transports the (N+3)th substrate during time period TS402, and further until the removal of the Nth substrate from polishing unit A is completed during time period TS105, the polishing process of polishing unit A on the (N+2)th substrate is retained (time period TS304). Thus, in... Figure 8 In the example action plan, an idle period TS303 is generated where grinding unit A cannot perform an action.

[0074] Returning to the flowchart, when the operation control of the polishing apparatus 10 begins, in step 706, the controller 800 obtains the state of the polishing surface 352a of the polishing pad 352 in each polishing unit 500 from the measurement unit 502 of that polishing unit 500. For example, the controller 800 obtains a measurement signal from each measurement unit 502 indicating the state of the polishing surface 352a of the polishing pad 352. In the next step 708, the controller 800 calculates a pad state index value for the polishing pad 352 of each polishing unit 500 based on the measurement signals obtained from each measurement unit 502. An exemplary calculation method for the pad state index value is as described above (e.g., referring to the calculation formula (1) for the wavelength composition ratio).

[0075] Next, in step 710, the controller 800 tracks the time-varying changes in the pad condition index value for each polishing unit 500, predicting when the pad condition index value will exceed a predetermined appropriate range. As described above, as wear on the polishing surface 352a progresses due to the use of the polishing pad 352, the wavelength composition ratio increases. That is, an increase in the wavelength composition ratio corresponds to a decrease in the polishing capability of the polishing pad 352. For example, for each polishing unit 500, the controller 800 tracks the time-varying changes in the wavelength composition ratio value to predict when the polishing capability of the polishing pad 352 will fall below a predetermined threshold level.

[0076] Figure 9 This is a graph showing an example of how the pad condition index value (e.g., wavelength composition ratio) of a specific polishing unit 500 (e.g., polishing unit A) of the polishing apparatus 10 changes over time. Figure 9 The text also shows the same time scale as the chart. Figure 8 Example action plan. The upper and lower limits of the appropriate range of pad state index values ​​are represented by dashed lines 902 and 904, respectively. Figure 9 In this context, the wavelength composition ratio increases over time (i.e., as the polishing pad 352 is used for longer periods). The controller 800, for example, at an appropriate time before the end of the time period TS302 of the N+2th polished substrate, predicts the wavelength composition ratio at a time after that moment (e.g., by extrapolation) based on the time change of the wavelength composition ratio up to that moment, and determines the timing tx when the predicted wavelength composition ratio exceeds the upper limit (dashed line 902).

[0077] Next, in step 712, the controller 800 searches the action plan for each grinding unit 500 for the timing determined by the prediction in step 710 (e.g., Figure 9 The idle period before the arrival of the timing tx. In the next step 714, the controller 800 designates this idle period before arrival as the dressing implementation segment and controls each grinding unit 500 to perform dressing of the grinding pad 352 during the dressing implementation segment. For example, in Figure 9 In the example described above, the timing tx is determined (predicted) based on the wavelength composition ratio of polishing unit A. The idle time period of polishing unit A before the arrival of this timing tx is time period TS303. Therefore, this idle time period TS303 is designated as the trimming implementation unit of polishing unit A, and the trimming unit 356 of polishing unit A is controlled to perform trimming of polishing pad 352 during the idle time period TS303. The timing of trimming implementation in other polishing units 500 (e.g., polishing unit B) is also controlled in the same manner.

[0078] Figure 10This is an example of how the wavelength composition ratio in polishing unit A changes over time during the idle period TS303, as described above. (The last sentence appears to be incomplete and possibly contains errors.) Figure 6 Compared to the examples, in Figure 10 In this example, since the adjustment is performed after the pad condition index value (wavelength composition ratio) approaches the limit of the appropriate range, the polishing ability of the polishing pad 352 can be utilized more effectively (i.e., until the polishing ability becomes below a specified level). This prevents the polishing pad 352 from being adjusted too quickly beyond what is necessary, thus extending the lifespan of the polishing pad 352. Furthermore, in the control of this embodiment, since the adjustment is performed using an "idle time period," the polishing pad 352 can be adjusted without delaying the operation of other units of the polishing apparatus 10. This effectively prevents a decrease in the productivity of the polishing apparatus 10.

[0079] In another embodiment, the controller 800 can also control the grinding pad 352 to be trimmed during any idle time period (e.g., all idle time periods). In this case, although the total number of trimmings increases, by setting the trimming time for each trimming to be shorter, excessive consumption of the grinding pad 352 due to trimming can be prevented, and the overall operation plan of the grinding device 10 can be made more efficient.

[0080] The embodiments of the present invention have been illustrated above based on several examples. However, these embodiments are provided for ease of understanding and are not intended to limit the invention. The present invention can be modified and improved without departing from its spirit, and its equivalents are naturally included. Furthermore, within the scope of solving at least a portion of the aforementioned problems or achieving at least a portion of the effect, the scope of protection claimed and the constituent elements described in the specification can be arbitrarily combined or omitted.

Claims

1. A grinding device, characterized by, Possessing: one or more polishing units; one or more functional units for performing pre- or post-processing of polishing; one or more conveyance units for conveying a polishing object at least between the polishing units and the functional units; and a controller that controls the polishing units, the functional units, and the conveyance units in such a manner that the polishing units, the functional units, and the conveyance units act in accordance with a prescribed action plan including a plurality of idle time periods in which the polishing units cannot perform processing due to action restrictions among the polishing units, the functional units, and the conveyance units, to polish the polishing object, each of the one or more polishing units possesses: a polishing pad configured to be pressed against the polishing object when polishing the polishing object; a measurement device for measuring a state of a polishing surface of the polishing pad; and a dressing device configured to perform a dressing process on the polishing pad, the controller is configured to: determine a timing at which the polishing ability of the polishing pad is predicted to be below a threshold level, based on the state of the polishing surface of the polishing pad measured by the measurement device, determine an idle time period in which the predicted timing is before, from among the plurality of idle time periods in the action plan, in the determined idle time period, cause the dressing device to perform a dressing process on the polishing pad.

2. The polishing apparatus according to claim 1, wherein the timing is determined based on extrapolation interpolation of an index indicating the state of the polishing surface of the polishing pad.

3. The polishing apparatus according to claim 1, wherein the controller is configured to, for each of the plurality of idle time periods in the action plan, predict whether the polishing ability of the polishing pad is below the threshold level by extrapolation interpolation, and in a case where it is predicted that the polishing ability is below the threshold level, cause the dressing device to perform a dressing process on the polishing pad in the idle time period.

4. The polishing apparatus according to any one of claims 1 to 3, wherein the functional units include a cleaning unit for cleaning the polishing object after being polished by the polishing units.

5. The polishing apparatus according to claim 1, wherein the controller is further configured to create the prescribed action plan based on prescribed scheme information. Possessing: one or more polishing units; 6. A polishing apparatus characterized by comprising: one or more functional units for performing pre- or post-processing of polishing; one or more conveyance units for conveying a polishing object at least between the polishing units and the functional units; and a controller that controls the polishing units, the functional units, and the conveyance units in such a manner that the polishing units, the functional units, and the conveyance units act in accordance with a prescribed action plan including a plurality of idle time periods in which the polishing units cannot perform processing due to action restrictions among the polishing units, the functional units, and the conveyance units, to polish the polishing object, each of the one or more polishing units possesses: a polishing pad configured to be pressed against the polishing object when polishing the polishing object; a measurement device for measuring a state of a polishing surface of the polishing pad; and a dressing device configured to perform a dressing process on the polishing pad, the controller is configured to: determine a timing at which the polishing ability of the polishing pad is predicted to be below a threshold level, based on the state of the polishing surface of the polishing pad measured by the measurement device, determine an idle time period in which the predicted timing is before, from among the plurality of idle time periods in the action plan, in the determined idle time period, cause the dressing device to perform a dressing process on the polishing pad. a controller configured to control the polishing unit, the functional unit, and the conveyance unit so as to perform polishing of the polishing target in accordance with a prescribed action plan including a plurality of idle time periods in which the polishing unit cannot perform processing due to an action restriction among the polishing unit, the functional unit, and the conveyance unit, each of the one or more polishing units includes: a polishing pad configured to be pressed against the polishing target when polishing the polishing target; a measurement device configured to measure a state of a polishing surface of the polishing pad; and a dressing device configured to perform a dressing process on the polishing pad, the controller is configured to determine, based on the state of the polishing surface of the polishing pad measured by the measurement device, a timing at which the polishing ability of the polishing pad is predicted to be below a threshold level, the controller is configured to determine, from the plurality of idle time periods in the action plan, an idle time period in which the determined timing is prior to the timing, the controller is configured to cause the dressing device to perform the dressing process on the polishing pad in the determined idle time period. the polishing device includes: one or more polishing units; one or more functional units configured to perform a pre-process or a post-process of polishing; one or more conveyance units configured to convey a polishing target between at least the polishing unit and the functional unit; and a controller configured to control the polishing unit, the functional unit, and the conveyance unit so as to perform polishing of the polishing target in accordance with a prescribed action plan including a plurality of idle time periods in which the polishing unit cannot perform processing due to an action restriction among the polishing unit, the functional unit, and the conveyance unit, each of the one or more polishing units includes: a polishing pad configured to be pressed against the polishing target when polishing the polishing target; a measurement device configured to measure a state of a polishing surface of the polishing pad; and a dressing device configured to perform a dressing process on the polishing pad, the controller is configured to determine, based on the state of the polishing surface of the polishing pad measured by the measurement device, a timing at which the polishing ability of the polishing pad is predicted to be below a threshold level, the controller is configured to determine, from the plurality of idle time periods in the action plan, an idle time period in which the determined timing is prior to the timing, the controller is configured to cause the dressing device to perform the dressing process on the polishing pad in the determined idle time period. ​ ​ ​ 8. A control method of a polishing apparatus, characterized by , ​ ​ ​ ​ ​ ​ Each of the one or more polishing units is provided with: a polishing pad configured to be pressed against the polishing object when polishing the polishing object; and a dressing device configured to perform a dressing process on the polishing pad, The method causes, by the controller, the dressing device to perform a dressing process on the polishing pad in each of the plurality of idle time periods. ​

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