Substrate polishing method, substrate polishing apparatus, and computer-readable recording medium having a program recorded thereon

Abstract

To provide a substrate polishing method which can exactly predict an amount of a polishing tape used in actually polishing.SOLUTION: In a substrate polishing method, an actual polishing condition of a substrate which was polished in the past and an actual used amount of a polishing tape under the actual polishing condition are stored in a database 21a by relating the actual polishing condition and the actual used amount. The actual polishing condition matching with a previously set polishing condition of the substrate to be polished is retrieved from the database 21a before polishing the substrate to be polished, and the actual used amount of the polishing tape related to the actual polishing condition matching with the previously set polishing condition is determined as a predicted used amount of the polishing tape necessary to polish the substrate to be polished. A remaining amount of the polishing tape used in polishing the substrate to be polished and the determined predicted used amount are compared. When the remaining amount of the polishing tape is equal to the predicted used amount or more, the substrate to be polished is polished by polishing modules 4A, 4B.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to a substrate polishing method for polishing a substrate such as a wafer, and more particularly to a substrate polishing method for polishing the substrate by pressing a polishing tape against the substrate. The present invention also relates to a substrate polishing apparatus including a polishing module for polishing the substrate by pressing a polishing tape against the substrate. The present invention also relates to a program for polishing a substrate with a polishing tape. [Background technology]

[0002] In recent years, managing the surface condition of substrates has attracted attention from the perspective of improving yield in semiconductor device manufacturing. During the semiconductor device manufacturing process, various materials are deposited on silicon wafers. As a result, unwanted films and surface roughness form around the periphery of the substrate. In recent years, a method of transporting a substrate by holding only the periphery of the substrate with an arm has become common. Under these circumstances, the unwanted films remaining on the periphery peel off during various processes and adhere to devices formed on the substrate, reducing yield. Therefore, to remove the unwanted films formed around the periphery of the substrate, the periphery of the substrate is polished using a substrate polishing apparatus.

[0003] This type of substrate polishing apparatus polishes the peripheral edge of a substrate by sliding a polishing tape against the peripheral edge of the substrate. More specifically, the substrate is held by a substrate holder and rotated, while the polishing head presses the polishing tape against the peripheral edge of the substrate, polishing the peripheral edge of the substrate. During polishing of the substrate, the polishing tape is fed by a polishing tape supply mechanism from a tape unwinding reel to a tape take-up reel via the polishing head. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-87136 Summary of the Invention [Problem to be solved by the invention]

[0005] An end mark is provided near the rear end of the polishing tape wound around the tape winding reel of the polishing tape supply mechanism, and an end mark detection sensor capable of detecting this end mark is attached near the tape winding reel. If the end mark detection sensor detects the end mark on the polishing tape while polishing the peripheral edge of the substrate, the control unit of the substrate polishing apparatus stops the supply of polishing tape to the polishing head by the polishing tape supply mechanism, thereby stopping polishing of the peripheral edge of the substrate. In other words, polishing of the peripheral edge of the substrate is interrupted. This error, in which polishing of the substrate is interrupted due to the detection of the end mark on the polishing tape, is sometimes referred to as an "end mark error."

[0006] Substrates whose polishing has been interrupted due to an end mark error have been discarded because it is difficult to grasp the progress of polishing at the time of the interruption and perform additional polishing. The processing device described in Patent Document 1 detects the remaining amount of polishing tape from the outer diameter of the polishing tape roll. However, conventional processing devices cannot accurately calculate the amount of polishing tape used in actual polishing, and determine whether to replace the polishing tape based solely on the remaining amount of polishing tape. As a result, there are cases where the polishing tape is replaced even when there is enough polishing tape left on the tape unwinding reel to polish the next substrate.

[0007] Therefore, the present invention provides a substrate polishing method that accurately predicts the amount of polishing tape actually used in polishing, thereby maximizing the consumption of polishing tape and preventing tape end errors, thereby reducing the number of discarded substrates. The present invention also provides a substrate polishing apparatus that polishes substrates using this polishing method. The present invention also provides a computer-readable recording medium having a program recorded thereon for executing this polishing method. [Means for solving the problem]

[0008] In one aspect, a substrate polishing method is provided, which includes storing actual polishing conditions for at least one substrate previously polished and an actual usage amount of polishing tape under the actual polishing conditions in a database, associating the actual polishing conditions with the actual usage amount; searching the database for actual polishing conditions that match the preset polishing conditions for the substrate to be polished before polishing the substrate to be polished; determining the actual usage amount of polishing tape associated with the actual polishing conditions that match the preset polishing conditions as a predicted usage amount of polishing tape required to polish the substrate to be polished; comparing the remaining amount of polishing tape to be used for polishing the substrate to be polished with the determined predicted usage amount; and polishing the substrate to be polished in a polishing module when the remaining amount of polishing tape is equal to or greater than the predicted usage amount. In one aspect, the predicted usage amount is determined by calculating the predicted usage amount of the polishing tape to be used for polishing the substrate to be polished based on the preset polishing conditions when no actual polishing conditions matching the preset polishing conditions exist in the database.

[0009] In one aspect, the actual polishing conditions include a polishing head identifier for identifying a polishing head among multiple polishing heads that was used to polish at least one substrate that was polished in the past, and the preset polishing conditions include a polishing head identifier for identifying a polishing head that will be used to polish the substrate to be polished. In one embodiment, the actual polishing conditions include a polishing tape identifier for identifying the type of polishing tape used to polish at least one substrate that has been polished in the past, among multiple types of polishing tapes, and the preset polishing conditions include a polishing tape identifier for identifying the type of polishing tape to be used to polish the substrate to be polished. In one embodiment, the actual polishing conditions include polishing conditions for multiple polishing steps included in polishing at least one substrate previously polished, the actual usage amount is the actual usage amount of polishing tape used from the start to the end of polishing including the multiple polishing steps, and the preset polishing conditions include polishing conditions for multiple polishing steps applied to polishing the substrate to be polished. In one aspect, the substrate polishing method generates a hash value corresponding to the actual polishing conditions, associates the actual usage amount with the hash value and stores it in the database, generates a search hash value corresponding to the preset polishing conditions of the substrate to be polished, searches the database for a hash value that matches the search hash value, and determines the predicted usage amount by determining the actual usage amount of the polishing tape associated with the hash value that matches the search hash value as the predicted usage amount of the polishing tape required to polish the substrate to be polished.

[0010] In one embodiment, the present invention includes a polishing module that polishes a substrate with a polishing tape, and a control system that includes a database and a computing device, and the control system stores actual polishing conditions of at least one substrate that has been polished in the past and an actual amount of polishing tape used under the actual polishing conditions in the database, with the actual polishing conditions and the actual amount of polishing tape used associated with each other. , Ken A substrate polishing apparatus is provided which is configured to, before polishing a substrate to be polished, search the database for actual polishing conditions that match preset polishing conditions for the substrate to be polished, determine the actual usage amount of the polishing tape associated with the actual polishing conditions that match the preset polishing conditions as a predicted usage amount of the polishing tape required to polish the substrate to be polished, compare the remaining amount of the polishing tape to be used for polishing the substrate to be polished with the determined predicted usage amount, and when the remaining amount of the polishing tape is equal to or greater than the predicted usage amount, give a command to the polishing module to polish the substrate to be polished. In one aspect, the control system is configured to calculate a predicted usage amount of the polishing tape to be used for polishing the substrate to be polished based on the preset polishing conditions when there are no actual polishing conditions in the database that match the preset polishing conditions.

[0011] In one aspect, the actual polishing conditions include a polishing head identifier for identifying a polishing head among multiple polishing heads that was used to polish at least one substrate that was polished in the past, and the preset polishing conditions include a polishing head identifier for identifying a polishing head that will be used to polish the substrate to be polished. In one embodiment, the actual polishing conditions include a polishing tape identifier for identifying the type of polishing tape used to polish at least one of the substrates previously polished, among multiple types of polishing tapes, and the preset polishing conditions include a polishing tape identifier for identifying the type of polishing tape used to polish the substrate to be polished. In one embodiment, the actual polishing conditions include polishing conditions for multiple polishing steps included in polishing at least one substrate previously polished, the actual usage amount is the actual usage amount of polishing tape used from the start to the end of polishing including the multiple polishing steps, and the preset polishing conditions include polishing conditions for multiple polishing steps applied to polishing the substrate to be polished. In one aspect, the control system is configured to generate a hash value corresponding to the actual polishing conditions, associate the actual usage amount with the hash value and store it in the database, generate a search hash value corresponding to the preset polishing conditions of the substrate to be polished, search the database for a hash value that matches the search hash value, and determine the actual usage amount of the polishing tape associated with the hash value that matches the search hash value as the predicted usage amount of the polishing tape required to polish the substrate to be polished.

[0012] In one aspect, the method includes the steps of: issuing a command to a control system to store actual polishing conditions of at least one substrate previously polished and an actual usage amount of polishing tape under the actual polishing conditions in a database in association with the actual polishing conditions and the actual usage amount; searching the database for actual polishing conditions that match the preset polishing conditions of the substrate to be polished before polishing the substrate to be polished; determining the actual usage amount of polishing tape associated with the actual polishing conditions that match the preset polishing conditions as a predicted usage amount of polishing tape required to polish the substrate to be polished; comparing the remaining amount of polishing tape used to polish the substrate to be polished with the determined predicted usage amount; and, when the remaining amount of polishing tape is equal to or greater than the predicted usage amount, , Ken A computer-readable recording medium is provided that stores a program that causes a computer to execute the step of issuing instructions to a polishing module to polish the target substrate. [Effects of the Invention]

[0013] According to the present invention, the actual usage amount of the polishing tape associated with the actual polishing conditions that match the polishing conditions of the substrate to be polished is used as the predicted usage amount of the polishing tape, which allows the substrate polishing apparatus to determine an accurate predicted usage amount that also reflects changes in the tape feed speed during polishing, the feed amount of the polishing tape when the polishing head moves between head positions, and the feed amount of the polishing tape between different polishing processes.

[0014] Furthermore, according to the present invention, the substrate polishing apparatus can consume as much polishing tape as possible by comparing the determined predicted usage amount with the remaining amount of polishing tape before polishing the substrate to be polished, and can prevent the occurrence of tape end errors and reduce the number of substrates that are discarded. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a plan view showing an embodiment of a substrate polishing apparatus. [Figure 2]2(a) and 2(b) are enlarged cross-sectional views showing the peripheral edge of the substrate. [Figure 3] FIG. 2 is a schematic diagram illustrating an embodiment of a polishing module. [Figure 4] FIG. 2 is a schematic diagram showing an embodiment of a polishing head. [Figure 5] FIG. 2 is a plan view showing an embodiment of a tilt mechanism. [Figure 6] FIG. 10 is a diagram showing a state in which a substrate is continuously polished. [Figure 7] FIG. 10 is a diagram showing a state in which a substrate is fixed and polished. [Figure 8] 1 is a flow chart illustrating one embodiment of a process for polishing a substrate. [Figure 9] 9 is a table showing an example of polishing conditions for the polishing step shown in FIG. 8. [Figure 10] 10 is a flowchart illustrating an embodiment of a processing operation of the substrate polishing apparatus. [Figure 11] 10 is a diagram illustrating a process of storing actual polishing conditions for substrates polished in the past and the amount of polishing tape actually used in a database. FIG. [Figure 12] 10A and 10B are diagrams illustrating a process of searching a database for actual polishing conditions that match preset polishing conditions for a substrate to be polished, and determining a predicted amount of use. [Figure 13] FIG. 10 is a diagram illustrating a search method using a search hash value. [Figure 14] FIG. 2 is a plan view illustrating one embodiment of an arrangement of multiple substrates to be polished. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing one embodiment of a substrate polishing apparatus. The substrate polishing apparatus of this embodiment is an apparatus for polishing the peripheral portion, including the bevel portion, of a substrate. In one embodiment, the substrate polishing apparatus may be an apparatus for polishing the notch portion of a substrate. The substrate polishing apparatus includes polishing modules 4A and 4B, waiting stages 5A and 5B, a cleaning and drying section 7, a load port 10, a first transfer robot 16, a second transfer robot 17, a third transfer robot 18, and a fourth transfer robot 19. The polishing modules 4A and 4B, waiting stages 5A and 5B, the cleaning and drying section 7, the first transfer robot 16, the second transfer robot 17, the third transfer robot 18, and the fourth transfer robot 19 are arranged in a housing 100.

[0017] The substrates to be polished are stored in a substrate cassette 2, and the substrate cassette 2 is placed on a load port 10. A first transfer robot 16 is disposed adjacent to the load port 10. The first transfer robot 16 removes the substrate to be polished from the substrate cassette 2 on the load port 10 and hands it over to a second transfer robot 17.

[0018] In this embodiment, the substrate polishing apparatus includes two polishing modules 4A and 4B, but in another embodiment, the substrate polishing apparatus may include only one polishing module or three or more polishing modules. Similarly, in this embodiment, the substrate polishing apparatus includes two waiting stages 5A and 5B, but in another embodiment, the substrate polishing apparatus may include only one waiting stage or three or more waiting stages.

[0019] The polishing modules 4A, 4B and waiting stages 5A, 5B are arranged along the longitudinal direction of the housing 100. The substrate to be polished is placed on the waiting stages 5A, 5B before being polished by the polishing modules 4A, 4B. In one embodiment, the waiting stage 5A and / or the waiting stage 5B may be equipped with a notch aligner (not shown). The notch aligner is a device for detecting a notch (cutout) in the substrate and aligning the notch in the substrate to a predetermined position. The specific configuration of the notch aligner is not particularly limited as long as it can detect the notch in the substrate and align the notch in the substrate to a predetermined position.

[0020] The peripheral edge of the substrate to be polished is polished by at least one of the polishing modules 4 A and 4 B. The peripheral edge of the substrate to be polished may be polished by only one of the polishing modules 4 A and 4 B, or may be polished by both the polishing modules 4 A and 4 B.

[0021] The polishing module 4A is equipped with two polishing heads 33A and 33B. Polishing of the substrate to be polished in the polishing module 4A may be performed by only one polishing head 33A or 33B, or by both polishing heads 33A and 33B. The polishing module 4B is equipped with two polishing heads 33C and 33D. Polishing of the substrate to be polished in the polishing module 4B may be performed by only one polishing head 33C or 33D, or by both polishing heads 33C and 33D.

[0022] The second transport robot 17 is disposed adjacent to the polishing modules 4A and 4B, the standby stages 5A and 5B, and the cleaning and drying section 7. The second transport robot 17 transports substrates received from the first transport robot 16 and transfers the substrates between the polishing modules 4A and 4B and the standby stages 5A and 5B. Furthermore, the second transport robot 17 transfers the substrates received from the polishing modules 4A and 4B to the cleaning and drying section 7.

[0023] The cleaning and drying unit 7 includes a first cleaning module 12 and a second cleaning module 13 that clean substrates whose peripheral edges have been polished by the polishing modules 4A and 4B, and a drying module 14 that dries the cleaned substrates. The first cleaning module 12, the second cleaning module 13, and the drying module 14 are arranged along the longitudinal direction of the housing 100. The first cleaning module 12 is configured to perform scrubbing using a roll-shaped sponge member. The second cleaning module 13 is configured to perform scrubbing using a pencil-shaped sponge member. In this embodiment, the cleaning and drying unit 7 includes the first cleaning module 12 and the second cleaning module 13. However, in another embodiment, the cleaning and drying unit 7 may include either the first cleaning module 12 or the second cleaning module 13.

[0024] The third transfer robot 18 is disposed between the first cleaning module 12 and the second cleaning module 13. The fourth transfer robot 19 is disposed between the second cleaning module 13 and the drying module 14. The third transfer robot 18 transfers substrates between the first cleaning module 12 and the second cleaning module 13. The fourth transfer robot 19 transfers substrates between the second cleaning module 13 and the drying module 14.

[0025] The substrate polishing apparatus polishes a plurality of substrates by polishing the peripheral portion of each of the plurality of substrates in polishing module 4A and / or 4B, and then cleaning and drying the substrate in cleaning / drying section 7 in that order.

[0026] The substrate polishing apparatus further includes a control system 20 electrically connected to the polishing modules 4A, 4B, waiting stages 5A, 5B, cleaning and drying section 7, first transfer robot 16, second transfer robot 17, third transfer robot 18, and fourth transfer robot 19. The control system 20 is configured to control the operations of the polishing modules 4A, 4B, waiting stages 5A, 5B, cleaning and drying section 7, first transfer robot 16, second transfer robot 17, third transfer robot 18, and fourth transfer robot 19.

[0027] The control system 20 includes a storage device 21 that stores a database 21a and a program, which will be described later, and an arithmetic device 22 that executes calculations according to the program. The storage device 21 includes a main storage device (e.g., random access memory) accessible by the arithmetic device 22, and an auxiliary storage device (e.g., a hard disk drive or solid state drive) that stores the database 21a and the program. The arithmetic device 22 includes a CPU (central processing unit) or a GPU (graphics processing module) that executes calculations according to instructions included in the program stored in the storage device 21.

[0028] In one embodiment, the control system 20 may include a display screen (not shown) for displaying the processing results and processed data by the computing device 22, and an input device (not shown) for inputting data, programs, and various information into the memory device 21.

[0029] The control system 20 includes at least one computer. For example, the control system 20 may be an edge server connected to the substrate polishing apparatus via a communication line, or a cloud server connected to the substrate polishing apparatus via a network such as the Internet. The control system 20 may also be a combination of multiple servers. For example, the control system 20 may be a combination of an edge server and a cloud server connected to each other via a communication network such as the Internet or a local area network, or a combination of multiple servers not connected by a communication network. However, the specific configuration of the control system 20 is not limited to these examples. In one embodiment, the control system 20 may be configured with multiple devices, each of which may include a storage device 21 and a computing device 22.

[0030] Next, the configuration of the polishing modules 4A and 4B will be described in detail. Since the polishing modules 4A and 4B have basically the same configuration, only the polishing module 4A will be described below. The polishing module 4A of this embodiment is configured to polish the peripheral portion of the substrate W shown in FIGS. 2(a) and 2(b). FIGS. 2(a) and 2(b) are enlarged cross-sectional views showing the peripheral portion of the substrate W. More specifically, FIG. 2(a) is a cross-sectional view of a so-called straight-type substrate, and FIG. 2(b) is a cross-sectional view of a so-called round-type substrate. The bevel portion B has a chamfered or rounded shape.

[0031] In the substrate W of FIG. 2(a), the bevel portion B is the outermost peripheral surface of the substrate W, which is composed of an upper inclined surface (upper bevel portion) B1, a lower inclined surface (lower bevel portion) B2, and a side portion (apex) B3. In the substrate W of FIG. 2(b), the bevel portion B is a portion having a curved cross section that constitutes the outermost peripheral surface of the substrate W. The top edge portion E1 is an annular flat portion located radially inward of the bevel portion B. The bottom edge portion E2 is an annular flat portion located opposite the top edge portion E1 and radially inward of the bevel portion B. The top edge portion E1 may include a region in which a device is formed. In this specification, the peripheral portion of the substrate W refers to a region including any of the top edge portion E1, the bevel portion B, and the bottom edge portion E2.

[0032] 3 is a schematic diagram showing one embodiment of a polishing module 4A. The polishing module 4A includes a substrate holder 40 that holds and rotates a substrate W to be polished, two polishing heads 33A and 33B that press polishing tapes 32A and 32B against the peripheral edge of the substrate W rotated by the substrate holder 40 to polish the peripheral edge of the substrate W, a lower supply nozzle 42 that supplies liquid to the lower surface of the substrate W, and an upper supply nozzle 43 that supplies liquid to the upper surface of the substrate W. An example of the liquid that can be supplied to the substrate W is pure water. During polishing of the substrate W, the liquid is supplied to the lower surface of the substrate W from the lower supply nozzle 42, and the liquid is supplied to the upper surface of the substrate W from the upper supply nozzle 43.

[0033] In this embodiment, the polishing module 4A has two polishing heads 33A and 33B, but in another embodiment, the polishing module 4A may have only one polishing head or three or more polishing heads. The peripheral edge of the substrate W to be polished is polished by at least one of the polishing heads 33A and 33B of the polishing module 4A. When the polishing head 33A is located at the polishing position, the polishing head 33B is located at the retracted position. When the polishing head 33B is located at the polishing position, the polishing head 33A is located at the retracted position.

[0034] 3 shows a state in which polishing head 33A is positioned at the polishing position and polishing head 33B is positioned at the retracted position. Polishing head 33A faces the peripheral edge of substrate W. Substrate holder 40 holds substrate W. Substrate holder 40 includes holding stage 34 that holds substrate W by vacuum suction, shaft 35 connected to the center of holding stage 34, and holding stage drive mechanism 37 that rotates and moves holding stage 34 up and down. Holding stage drive mechanism 37 is configured to rotate holding stage 34 about its axis Cr and move it up and down along axis Cr.

[0035] The substrate W is placed on the substrate holding surface of the holding stage 34 by the second transport robot 17 (see FIG. 1) so that the center O1 of the substrate W is positioned on the axis Cr of the holding stage 34. The substrate holding part 40 can rotate the substrate W around the axis Cr of the holding stage 34 (i.e., the axis of the substrate W) and can raise and lower the substrate W along the axis Cr of the holding stage 34.

[0036] The polishing module 4A further includes a polishing tape supply mechanism 46A that supplies the polishing tape 32A to the polishing head 33A and collects it from the polishing head 33A. The polishing module 4A further includes a polishing tape supply mechanism 46B that supplies the polishing tape 32B to the polishing head 33B and collects it from the polishing head 33B. Since the polishing tape supply mechanisms 46A and 46B basically have the same configuration, only the polishing tape supply mechanism 46A will be described below.

[0037] The polishing tape supply mechanism 46A includes a tape supply reel 47 that supplies the polishing tape 32A to the polishing head 33A, and a tape take-up reel 48 that collects the polishing tape 32A that has been used to polish the substrate W. Tension motors (not shown) are connected to the tape supply reel 47 and the tape take-up reel 48. Each tension motor applies a predetermined torque to the tape supply reel 47 and the tape take-up reel 48, so that a predetermined tension can be applied to the polishing tape 32A.

[0038] The polishing tape 32A is supplied to the polishing head 33A so that the polishing surface of the polishing tape 32A faces the peripheral edge of the substrate W. The polishing tape 32A is supplied to the polishing head 33A from a tape supply reel 47, and the used polishing tape 32A is collected by a tape take-up reel 48. The polishing tape supply mechanism 46A further includes a plurality of guide rollers 50, 51, 52, and 53 for supporting the polishing tape 32A. The traveling direction of the polishing tape 32A is guided by the guide rollers 50, 51, 52, and 53.

[0039] Next, the configuration of the polishing heads 33A and 33B will be described in detail. The polishing heads 33A and 33B have essentially the same configuration, so only the polishing head 33A will be described below. The polishing heads 33C and 33D of the polishing module 4B also have essentially the same configuration as the polishing head 33A described below, so redundant description will be omitted. FIG. 4 is a schematic diagram showing one embodiment of the polishing head 33A. The polishing head 33A includes a tape feed device 56 that feeds the polishing tape 32A from the tape supply reel 47 (see FIG. 3) to the tape take-up reel 48 (see FIG. 3). The polishing head 33A includes multiple guide rollers 60, 61, 62, 63, 64, 65, and 66. These guide rollers guide the polishing tape 32A so that it advances in a direction perpendicular to the tangential direction of the substrate W.

[0040] The tape feed device 56 provided in the polishing head 33A includes a tape feed roller 56a, a tape gripping roller 56b, and a tape feed motor M that rotates the tape feed roller 56a. The tape feed motor M is provided on the side of the polishing head 33A, and the tape feed roller 56a is attached to the rotation shaft of the tape feed motor M. The tape gripping roller 56b is disposed adjacent to the tape feed roller 56a. The tape gripping roller 56b is supported by a mechanism (not shown) so as to generate a force in the direction indicated by arrow NF in FIG. 4 (the direction toward the tape feed roller 56a), and is configured to press against the tape feed roller 56a.

[0041] 4, the tape feed roller 56a rotates, feeding the polishing tape 32A in its longitudinal direction. The tape gripping roller 56b is configured to be rotatable about its axis, and rotates as the polishing tape 32A is fed. The tape feed motor M has a rotary encoder (not shown) that can count the number of rotations of the tape feed motor M.

[0042] The polishing head 33A further includes a pressing member 68 that presses the polishing tape 32A against the substrate W, and an air cylinder 54 that serves as an actuator that moves the pressing member 68 toward the peripheral edge of the substrate W. The pressing force of the polishing tape 32A against the substrate W is adjusted by controlling the air pressure supplied to the air cylinder 54. The pressing member 68 is disposed behind the polishing surface 32p (the surface having abrasive grains) of the polishing tape 32A. When the pressing member 68 is moved toward the substrate W by the air cylinder 54, the pressing member 68 presses the polishing tape 32A from its back side against the peripheral edge of the substrate W. In this way, the polishing head 33A polishes the peripheral edge of the substrate W.

[0043] 5 is a plan view showing one embodiment of tilt mechanisms 70A and 70B that tilt the polishing heads 33A and 33B. As shown in FIG. 5, the polishing module 4A further includes two tilt mechanisms 70A and 70B that tilt the polishing heads 33A and 33B to a predetermined angle. The tilt mechanism 70A is connected to the polishing head 33A, and the tilt mechanism 70B is connected to the polishing head 33B. The tilt mechanism 70A that tilts the polishing head 33A and the tilt mechanism 70B that tilts the polishing head 33B basically have the same configuration, so the tilt mechanism 70A will be described below.

[0044] The tilt mechanism 70A is configured to tilt the polishing head 33A relative to the substrate holding surface of the holding stage 34. More specifically, the tilt mechanism 70A includes a crank arm 72 connected to the polishing head 33A and an arm rotation device 73 that rotates the crank arm 72. One end of the crank arm 72 is located at substantially the same height as the substrate holding surface of the holding stage 34 and is connected to the arm rotation device 73. The other end of the crank arm 72 is connected to the polishing head 33A.

[0045] When the arm rotation device 73 rotates the crank arm 72, the entire polishing head 33A can be tilted at a predetermined tilt speed relative to the substrate W on the substrate holding surface of the holding stage 34. Therefore, the polishing head 33A can polish the peripheral portion of the substrate W while tilting at the predetermined tilt speed. The tilt speed is the angle of the polishing head tilted per unit time. For example, the unit of the tilt speed is expressed in degrees per minute. Furthermore, the tilt mechanism 70A is configured to maintain the polishing head 33A at a predetermined tilt angle. Therefore, the polishing head 33A can polish the peripheral portion of the substrate W while maintaining the predetermined tilt angle. Note that the specific configuration of the tilt mechanism 70A is not limited to the embodiment shown in FIG. 5, as long as it can tilt the polishing head 33A relative to the substrate holding surface of the holding stage 34 and the substrate W.

[0046] The polishing module 4A is electrically connected to a control system 20 that controls the operation of each component of the polishing module 4A. The polishing heads 33A and 33B, the substrate holder 40, the lower supply nozzle 42, the upper supply nozzle 43, the polishing tape supply mechanisms 46A and 46B, and the tilt mechanisms 70A and 70B are electrically connected to the control system 20. The operation of the polishing heads 33A and 33B, the substrate holder 40, the lower supply nozzle 42, the upper supply nozzle 43, the polishing tape supply mechanisms 46A and 46B, and the tilt mechanisms 70A and 70B is controlled by the control system 20.

[0047] Polishing of the peripheral edge of the substrate by the polishing modules 4A and 4B is classified into two polishing modes, continuous polishing and fixed polishing, depending on the operation of the polishing head during polishing. In this specification, the polishing mode in which the peripheral edge of the substrate is polished while the polishing head is continuously tilted at a predetermined tilt speed by the tilt mechanism is referred to as "continuous polishing." Furthermore, the polishing mode in which the peripheral edge of the substrate is polished while the polishing head is maintained at a predetermined tilt angle by the tilt mechanism is referred to as "fixed polishing."

[0048] FIG. 6 is a diagram showing how the polishing head 33A of the polishing module 4A continuously polishes the peripheral edge of the substrate W. In continuous polishing, the tilt mechanism 70A (see FIG. 5) continuously changes the tilt angle of the polishing head 33A, while the polishing head 33A presses the polishing tape 32A against the peripheral edge of the substrate W. More specifically, as shown in FIG. 6, the tilt mechanism 70A continuously changes the tilt angle of the polishing head 33A at a predetermined tilt speed from head position G1, where the tilt angle of the polishing head 33A is α1 (e.g., 60 degrees), to head position G2, where the tilt angle of the polishing head 33A is α2 (e.g., −60 degrees). While the tilt mechanism 70A tilts the polishing head 33A, the pressing member 68 of the polishing head 33A presses the polishing tape 32A against the peripheral edge of the substrate W using the air cylinder 54. In this way, the polishing head 33A polishes the peripheral edge of the substrate W. The tilt mechanism 70A reciprocates the polishing head 33A between head positions G1 and G2 a predetermined number of times. During polishing of the substrate W, the polishing tape 32A is fed at a predetermined speed by the tape feed device 56 (see FIG. 4).

[0049] FIG. 7 is a diagram showing how the polishing head 33A of the polishing module 4A performs fixed polishing on the peripheral edge of the substrate W. In the example of fixed polishing shown in FIG. 7, the polishing head 33A is pressed against the peripheral edge of the substrate W while the tilt mechanism 70A shown in FIG. 5 sequentially maintains the polishing head 33A at a plurality of predetermined tilt angles. More specifically, as shown in FIG. 7, the tilt mechanism 70A maintains the polishing head 33A at head position G1, where the tilt angle of the polishing head 33A is α1 (e.g., 60 degrees), for a predetermined polishing time. Next, the tilt mechanism 70A moves the polishing head 33A from head position G1 to head position G2, where the tilt angle of the polishing head 33A is α2 (e.g., 30 degrees), at a predetermined tilt speed, and maintains the polishing head 33A at head position G2 for a predetermined polishing time. Next, the tilt mechanism 70A moves the polishing head 33A from head position G2 to head position G3 where the tilt angle of the polishing head 33A is α3 (e.g., −30 degrees) at a predetermined tilt speed, and maintains the polishing head 33A at head position G3 for a predetermined polishing time. Furthermore, the tilt mechanism 70A moves the polishing head 33A from head position G3 to head position G4 where the tilt angle of the polishing head 33A is α4 (e.g., −60 degrees) at a predetermined tilt speed, and maintains the polishing head 33A at head position G4 for a predetermined polishing time.

[0050] While the polishing head 33A moves between head positions, the polishing tape 32A is spaced apart from the substrate W. After the polishing head 33A is positioned at a predetermined head position, the polishing head 33A presses the polishing tape 32A against the substrate W to polish the peripheral edge of the substrate W. While the substrate W is being polished and while the polishing head 33A moves between head positions, the polishing tape 32A is fed at a predetermined speed by the tape feed device 56 (see FIG. 4). In one embodiment, the polishing head 33A may polish the peripheral edge of the substrate W by pressing the polishing tape 32A against the substrate W even while it moves between head positions.

[0051] In this embodiment, the polishing head 33A has four head positions, head position G1 to head position G4, but in another embodiment, the polishing head 33A may have three or less head positions, or five or more head positions.

[0052] The substrate polishing apparatus of this embodiment may supply different types of polishing tapes to the polishing heads 33A and 33B of the polishing module 4A and the polishing heads 33C and 33D of the polishing module 4B. For example, the polishing head 33A of the polishing module 4A may roughly polish the entire peripheral edge of the substrate W, including the top edge E1, bevel B, and bottom edge E2 (see FIG. 2), and then the polishing head 33B may finish polish the entire peripheral edge of the substrate W, including the top edge E1, bevel B, and bottom edge E2. In this case, the polishing tape supply mechanism 46A supplies the polishing head 33A with a polishing tape for rough polishing (i.e., a polishing tape with large abrasive grains), and the polishing head 33B supplies the polishing tape for finish polishing (i.e., a polishing tape with small abrasive grains) from the polishing tape supply mechanism 46B. Alternatively, the entire peripheral portion of the substrate W, including the top edge portion E1, bevel portion B, and bottom edge portion E2, may be roughly polished using polishing head 33A of polishing module 4A, followed by finish polishing of the top edge portion E1 using polishing head 33B, followed by finish polishing of the bevel portion B using polishing head 33C of polishing module 4B, and finish polishing of the bottom edge portion E2 using polishing head 33D.

[0053] The peripheral edge of the substrate W is polished under preset polishing conditions. The preset polishing conditions are input to the control system 20 by, for example, a user via an input device (not shown) and stored in a memory device 21 of the control system 20. The control system 20 controls the operation of the polishing module 4A (and / or polishing module 4B) in accordance with the polishing conditions stored in the memory device 21, causing the polishing module 4A (and / or polishing module 4B) to polish the peripheral edge of the substrate W.

[0054] FIG. 8 is a flowchart showing one embodiment of a process for polishing a substrate W. In this embodiment, polishing a substrate W includes four polishing processes: a first polishing process, a second polishing process, a third polishing process, and a fourth polishing process. First, in the first polishing process, continuous polishing of the substrate W is performed by the polishing head 33A of the polishing module 4A. Then, in the second polishing process, fixed polishing of the substrate W is performed by the same polishing head 33A. Then, continuous polishing of the substrate W is performed by the polishing head 33C of the polishing module 4B. Finally, fixed polishing of the substrate W is performed by the polishing head 33D of the polishing module 4B. As in the first polishing process and the second polishing process, different polishing modes, continuous polishing and fixed polishing, may be performed for a single substrate by a single polishing head 33A. In one embodiment, polishing of a substrate W may include only a single polishing process.

[0055] Fig. 9 is a table showing an example of polishing conditions for the polishing step shown in Fig. 8. The polishing conditions in this embodiment include a recipe name, a recipe update date and time, a polishing module identifier, a polishing head identifier, a polishing tape identifier, a polishing mode, a tape feed speed, a tilt speed, a number of tilts, tilt angles α1 to α4 for each head position, and polishing times T1 to T4 for each head position. The parameters shown in Fig. 9 are an example of polishing conditions, and the polishing conditions are not limited to these as long as they include parameters necessary for controlling the operation of the polishing modules 4A and 4B.

[0056] The recipe name is the name (e.g., a character string) of the polishing recipe created by the user, and functions as an identifier for identifying the polishing conditions. The polishing recipe includes a combination of parameter values ​​of the polishing conditions in all polishing processes performed by the polishing modules 4A and 4B. The recipe name is associated with the parameter value of each polishing condition, and the recipe name uniquely identifies the value of each parameter. In the embodiment shown in FIG. 9, the polishing recipe represented by the recipe name "ABC" includes parameter values ​​included in the polishing conditions for the first to fourth polishing processes.

[0057] The recipe update date and time is the date and time when the parameter values ​​of the polishing conditions associated with the recipe name were updated. When polishing conditions of a new recipe name are registered in the control system 20, or when the parameter values ​​of the polishing conditions associated with an already registered recipe name are changed, the recipe update date and time is automatically registered (recorded) by the control system 20.

[0058] The polishing module identifier is a value (a number, a letter, or a combination thereof) for identifying the polishing module used in each polishing step. In one example, the polishing module identifiers are "4A" and "4B."

[0059] The polishing head identifier is a value (a number, a letter, or a combination thereof) for identifying the polishing head used in each polishing step. In one example, the polishing head identifiers are "33A," "33B," "33C," and "33D."

[0060] The polishing tape identifier is a value (a number, a letter, or a combination thereof) that identifies the type of polishing tape used in each polishing process. There are various types of polishing tapes depending on the coarseness of the abrasive grains on the polishing surface, the width of the polishing tape, etc. In one example, the polishing tape identifiers are "32A," "32B," "32C," and "32D."

[0061] The polishing mode is a value (a number, a letter, or a combination thereof) for specifying the polishing mode applied in each polishing step. In the embodiment shown in Figure 9, the polishing mode of the first polishing step is "continuous polishing," the polishing mode of the second polishing step is "fixed polishing," the polishing mode of the third polishing step is "continuous polishing," and the polishing mode of the fourth polishing step is "fixed polishing."

[0062] The tape feed speed is the set value of the feed speed of each polishing tape in each polishing step. In the embodiment shown in Fig. 9, the polishing tape feed speed is "50 mm / min."

[0063] The tilt speed is the set value of the tilt speed of each polishing head in each polishing step. In the embodiment shown in Figure 9, the tilt speed is "2000 degrees / min."

[0064] The tilting number is the set value of the number of tilts of the polishing head when the polishing mode is continuous polishing. In the embodiment shown in Fig. 9, the number of tilts in the first polishing step and the third polishing step (continuous polishing) is "5 times." That is, as shown in Fig. 6, the polishing head reciprocates between head position G1 and head position G2 five times.

[0065] The tilt angles α1 to α4 of head positions G1 to G4 are the set values ​​of the tilt angles of the polishing head at each head position. In the embodiment shown in FIG. 9, the tilt angle α1 of head position G1 in the first polishing step and the third polishing step (continuous polishing) is 60 degrees, and the tilt angle α2 of head position G2 is −60 degrees. That is, in the continuous polishing shown in FIG. 6, the tilt angle α1 of head position G1 is 60 degrees, and the tilt angle α2 of head position G2 is −60 degrees. In the second polishing step and the fourth polishing step (fixed polishing), the tilt angle α1 of head position G1 is 60 degrees, the tilt angle α2 of head position G2 is 30 degrees, the tilt angle α3 of head position G3 is −30 degrees, and the tilt angle α4 of head position G4 is −60 degrees. That is, in the fixed polishing shown in FIG. 7, the tilt angle α1 at head position G1 is 60 degrees, the tilt angle α2 at head position G2 is 30 degrees, the tilt angle α3 at head position G3 is −30 degrees, and the tilt angle α4 at head position G4 is −60 degrees.

[0066] The polishing times T1 to T4 at head positions G1 to G4 are set values ​​for the polishing time at each head position when the polishing mode is fixed polishing. In the embodiment shown in Fig. 9, the polishing times T1 to T4 at head positions G1 to G4 in the second polishing step and the fourth polishing step (fixed polishing) are each 2 seconds. That is, in the fixed polishing shown in Fig. 7, the polishing heads 33A and 33D are maintained at head positions G1 to G4 for 2 seconds each.

[0067] The control system 20 controls the operation of the polishing modules 4A and 4B based on the values ​​of the parameters included in the polishing conditions thus preset, and polishes the peripheral edge of the substrate.

[0068] Next, a description will be given of the processing operation of the substrate polishing apparatus shown in Fig. 1. The processing operation of the substrate polishing apparatus described below includes the polishing operation of the peripheral portion of the substrate in the above-mentioned polishing modules 4A and 4B, and is controlled by the control system 20 shown in Fig. 1.

[0069] FIG. 10 is a flowchart showing one embodiment of the processing operation of the substrate polishing apparatus. The control system 20 stores the actual polishing conditions and actual usage amounts of substrates previously polished by the polishing modules 4A and 4B in the database 21a (see FIG. 1) in association with the actual polishing conditions and actual usage amounts (step 1). In this specification, the polishing conditions used when substrates were previously polished by the polishing modules 4A and 4B are referred to as "actual polishing conditions." The actual usage amount of polishing tape consumed under the actual polishing conditions of the substrate previously polished is referred to as "actual usage amount." The actual polishing conditions and actual usage amounts are stored in the database 21a each time a polishing recipe is executed. The substrate previously polished is at least one substrate. If multiple substrates have been polished in the past, multiple actual polishing conditions and multiple actual usage amounts are stored in the database 21a.

[0070] Before polishing the substrate to be polished, the control system 20 searches the database 21a for actual polishing conditions that match the preset polishing conditions of the substrate to be polished (step 2). When polishing conditions that match the preset polishing conditions of the substrate to be polished exist in the database 21a ("Yes" in step 3), the control system 20 determines the actual usage amount associated with the actual polishing conditions that match the preset polishing conditions as the predicted usage amount of the polishing tape to be used in polishing the substrate to be polished (step 4).

[0071] When there are no actual polishing conditions in the database 21a that match the preset polishing conditions of the substrate to be polished ("No" in step 3), the control system 20 calculates the predicted usage amount of the polishing tape to be used for polishing the substrate to be polished using the method described below, and determines the predicted usage amount (step 5).

[0072] The control system 20 compares the remaining amount of polishing tape used in polishing the target substrate with the predicted usage amount determined in step 4 or step 5 (step 6), and if the remaining amount of polishing tape is equal to or greater than the predicted usage amount ("Yes" in step 6), it issues a command to polishing module 4A or polishing module 4B to polish the target substrate under the preset polishing conditions (step 7). After the target substrate has been polished, the control system 20 may store the actual polishing conditions and actual usage amount used when the target substrate was polished in database 21a (step 1).

[0073] When the remaining amount of polishing tape used to polish the target substrate is less than the predicted amount used ("No" in step 6), the control system 20 issues a tape-out alarm to prompt the user to replace the polishing tape (step 8). After the user replaces the polishing tape (step 9) and the tape-out condition is resolved, the control system 20 issues a command to the polishing module 4A or the polishing module 4B to polish the target substrate under the preset polishing conditions (step 7). After the target substrate has been polished, the control system 20 may store the actual polishing conditions and actual amount used when the target substrate was polished in the database 21a (step 1).

[0074] The control system 20 operates according to instructions included in a program electronically stored in the storage device 21 (see FIG. 1). Specifically, the control system 20 executes the following steps: storing actual polishing conditions for at least one substrate previously polished and the actual usage amount of polishing tape under the actual polishing conditions in the database 21a in association with the actual polishing conditions (see step 1 above); searching the database 21a for actual polishing conditions that match the preset polishing conditions for the substrate to be polished before polishing the substrate to be polished (see step 2 above); determining the actual usage amount of polishing tape associated with the actual polishing conditions that match the preset polishing conditions as the predicted usage amount of polishing tape required to polish the substrate to be polished (see step 4 above); comparing the remaining amount of polishing tape to be used for polishing the substrate to be polished with the determined predicted usage amount (see step 6 above); and, when the remaining amount of polishing tape is equal to or greater than the predicted usage amount, issuing a command to the polishing module 4A or 4B to polish the substrate to be polished under the preset polishing conditions (see step 7 above).

[0075] When the database 21a does not contain actual polishing conditions that match the preset polishing conditions, the control system 20 executes a step of determining the preset polishing conditions by calculating the predicted amount of polishing tape to be used based on the preset polishing conditions (see step 5 above).The control system 20 also executes a step of issuing a tape out alarm to prompt the user to replace the polishing tape when the remaining amount of polishing tape is smaller than the predicted amount to be used for polishing the target substrate (see step 8 above), and a step of issuing a command to the polishing module 4A or polishing module 4B to polish the target substrate under the preset polishing conditions after the tape out state is resolved (see step 7 above).

[0076] A program for causing the control system 20 to execute these steps is recorded in a computer-readable recording medium, which is a non-transitory tangible item, and is provided to the control system 20 via the recording medium. Alternatively, the program may be input to the control system 20 via a communication network such as the Internet or a local area network.

[0077] The tape feed speed of the polishing tape when polishing a substrate is not actually constant, and in continuous polishing, the tape feed speed can change due to friction when the polishing head tilts. Furthermore, in fixed polishing, the polishing tape is also fed when the polishing head moves between head positions, and the tape feed amount changes depending on the movement distance between head positions. Furthermore, the polishing tape is also fed during the transition period between continuous polishing and fixed polishing. For this reason, it has been difficult to accurately calculate the predicted amount of polishing tape used using conventional techniques.

[0078] Therefore, the substrate polishing apparatus of this embodiment uses the actual usage amount of the polishing tape associated with the actual polishing conditions that match the polishing conditions of the substrate to be polished as the predicted usage amount of the polishing tape. This allows the substrate polishing apparatus to determine an accurate predicted usage amount that reflects changes in the tape feed speed during polishing, the feed amount of the polishing tape when the polishing head moves between head positions, and the feed amount of the polishing tape between different polishing processes. Furthermore, by comparing the remaining amount of polishing tape with the determined predicted usage amount before polishing the substrate to be polished, the substrate polishing apparatus can consume as much polishing tape as possible, prevent tape end errors, and reduce the number of discarded substrates.

[0079] Next, the details of each of the above-mentioned processing operations will be described. Fig. 11 is a diagram illustrating the process of storing the actual polishing conditions AP1, AP2, AP3 and the actual amounts of polishing tape AU1, AU2, AU3 used for previously polished substrates W1, W2, W3 in the database 21a (see step 1 in Fig. 10). As shown in Fig. 11, when polishing of the substrate W1 is completed, the control system 20 stores the actual polishing conditions AP1 and the actual amount of polishing tape AU1 used when polishing the substrate W1 in the database 21a. For example, as described with reference to Fig. 8, if polishing of the substrate W1 includes the first to fourth polishing steps, the actual polishing conditions AP1 and the actual amount of polishing tape AU1 used for polishing tapes 32A, 32C, 32D are stored in the database 21a when the fourth polishing step is completed.

[0080] The actual polishing conditions AP1 for polishing the substrate W1 include the polishing conditions for the first to fourth polishing steps. As described with reference to Fig. 9, the actual polishing conditions include at least one of the recipe name, recipe update date and time, polishing module identifier, polishing head identifier, polishing tape identifier, polishing mode, tape feed speed, tilt speed, number of tilts, tilt angles α1 to α4 at each head position, and polishing times T1 to T4 at each head position.

[0081] The actual amount of polishing tape used is calculated for each polishing head used in polishing the substrate. That is, in polishing the substrate W1, the amount of polishing tape 32A actually used by the polishing head 33A in the first polishing step and the second polishing step, the amount of polishing tape 32C actually used by the polishing head 33C in the third polishing step, and the amount of polishing tape 32D actually used by the polishing head 33D in the fourth polishing step are calculated.

[0082] A rotary encoder (not shown) provided on the tape feed motor M (see FIG. 4) of each of the polishing heads 33A to 33D is configured to count the number of rotations of the tape feed motor M. The control system 20 calculates the actual usage amount of the polishing tape 32A to 33D from the number of rotations of the tape feed motor M of each of the polishing heads 33A to 33D and the outer circumferential length of the tape feed roller 56a (see FIG. 4). For example, if the tape feed motor M of the polishing head 33A rotates 5.7 times between the first polishing step and the second polishing step, the control system 20 can calculate the actual usage amount of the polishing tape 32A by multiplying the outer circumferential length of the tape feed roller 56a by 5.7.

[0083] Similarly, when polishing of substrate W2 is completed, the control system 20 stores the actual polishing conditions AP2 and the actual amount of polishing tape AU2 used when polishing substrate W2 in the database 21a. Furthermore, when polishing of substrate W3 is completed, the control system 20 stores the actual polishing conditions AP3 and the actual amount of polishing tape AU3 used when polishing substrate W3 in the database 21a. When storing the actual polishing conditions and the actual amount of polishing tape in the database 21a, the control system 20 may store the registration date and time indicating the date and time when the actual polishing conditions and the actual amount of polishing tape were stored in association with the actual polishing conditions and the actual amount of polishing tape.

[0084] The control system 20 may generate hash values ​​HV1, HV2, and HV3 corresponding to the actual polishing conditions AP1, AP2, and AP3, respectively, using the arithmetic unit 22 (see FIG. 1), and store the actual polishing conditions AP1, AP2, and AP3 in the database 21a in association with the generated hash values ​​HV1, HV2, and HV3. The hash values ​​are identifiers generated based on the parameter values ​​of each actual polishing condition according to an algorithm included in a program stored in the storage device 21 (see FIG. 1). The hash values ​​are composed of numbers, characters, or a combination of these, and uniquely correspond to a combination of multiple parameter values ​​for each actual polishing condition. By using the hash values, the control system 20 can speed up the process of searching the database 21a for actual polishing conditions that match the polishing conditions for the substrate to be polished.

[0085] In one embodiment, when the actual polishing conditions include polishing conditions for polishing processes using multiple polishing heads, the control system 20 may generate a hash value corresponding to the actual polishing conditions for each polishing head. The multiple hash values ​​generated for each polishing head are associated with the multiple polishing heads, respectively. Furthermore, the control system 20 may associate the actual usage amount of polishing tape calculated for each polishing head with the hash value generated for each polishing head and store them in the database 21a.

[0086] 8, if the actual polishing conditions AP1 for the substrate W1 include the polishing conditions for the first to fourth polishing processes, the same number of hash values ​​as the number of polishing heads are generated for each of the polishing heads 33A, 33C, and 33D. More specifically, the control system 20 generates three hash values: a hash value associated with the polishing head 33A corresponding to the actual polishing conditions for the first polishing process and the second polishing process, a hash value associated with the polishing head 33C corresponding to the actual polishing conditions for the third polishing process, and a hash value associated with the polishing head 33D corresponding to the actual polishing conditions for the fourth polishing process.

[0087] Furthermore, the control system 20 associates the actual usage amount of the polishing tape 32A by the polishing head 33A with the hash value associated with the polishing head 33A and stores them in the database 21a, associates the actual usage amount of the polishing tape 32C by the polishing head 33C with the hash value associated with the polishing head 33C and stores them in the database 21a, and associates the actual usage amount of the polishing tape 32D by the polishing head 33D with the hash value associated with the polishing head 33C and stores them in the database 21a. 33D The hash value associated with the ID is stored in the database 21a.

[0088] In this way, the control system 20 stores the actual polishing conditions, the actual amount of polishing tape used, and the hash value in the database 21a every time all polishing processes for one substrate are completed. The database 21a is constructed in the storage device 21 from data on the actual polishing conditions, the actual amount of polishing tape used, and the hash value for substrates polished in the past. The calculation device 22 can read the actual polishing conditions, the actual amount used, and the hash value stored in the database 21a.

[0089] Fig. 12 is a diagram illustrating the process of searching database 21a for actual polishing conditions that match the preset polishing conditions for the substrate to be polished and determining the predicted usage (see steps 2 to 4 in Fig. 10). As described with reference to Fig. 11, database 21a shown in Fig. 12 stores data including actual polishing conditions AP1, actual usage amount of polishing tape AU1, and hash value HV1 for substrate W1 that was polished in the past, actual polishing conditions AP2, actual usage amount of polishing tape AU2, and hash value HV2 for substrate W2 that was polished in the past, and actual polishing conditions AP3, actual usage amount of polishing tape AU3, and hash value HV3 for substrate W3 that was polished in the past.

[0090] Before polishing the substrate to be polished, the control system 20 searches the database 21a for actual polishing conditions that match the preset polishing conditions for the substrate to be polished. As described with reference to Fig. 9, the preset polishing conditions for the substrate to be polished include at least one of the recipe name, recipe update date and time, polishing module identifier, polishing head identifier, polishing tape identifier, polishing mode, tape feed speed, tilt speed, number of tilts, tilt angles α1 to α4 for each head position, and polishing times T1 to T4 for each head position.

[0091] When actual polishing conditions that match the preset polishing conditions of the substrate to be polished exist in the database 21a, the control system 20 determines the actual usage amount associated with the actual polishing conditions that match the preset polishing conditions as the predicted usage amount of the polishing tape to be used in polishing the substrate to be polished. For example, as shown in Fig. 12, when the preset polishing conditions SP match the actual polishing conditions AP1 stored in the database 21a, the control system 20 determines the actual usage amount AU1 associated with the actual polishing conditions AP1 as the predicted usage amount of the polishing tape to be used in polishing the target substrate.

[0092] The preset polishing conditions for the substrate to be polished used in the search include at least one of the recipe name, polishing module identifier, polishing head identifier, polishing tape identifier, polishing mode, tape feed speed, tilt speed, number of tilts, tilt angles α1 to α4 for each head position, and polishing times T1 to T4 for each head position. The polishing conditions used in the search may be only the recipe name, or may be a part of the parameters of the polishing conditions. The user can arbitrarily select the polishing conditions to be used in the search using an input device (not shown) of the control system 20.

[0093] For example, when a search is performed using a recipe name, there may be a plurality of recipe names in the database 21a that match the recipe name of the preset polishing conditions for the substrate to be polished. The control system 20 may determine, among the plurality of actual polishing conditions that match the preset polishing conditions, the actual polishing condition with the most recent recipe update date and time as the actual polishing condition that matches the preset polishing conditions.

[0094] Furthermore, when searching using a recipe name, even if the recipe name of the preset polishing conditions for the substrate to be polished matches the recipe name of the actual polishing conditions, the values ​​of the polishing conditions associated with the recipe name may have been changed in the past, and the actual values ​​of the polishing conditions may not match. To accurately determine the predicted usage, all values ​​of the polishing conditions for the substrate to be polished must match all values ​​of the actual polishing conditions for substrates previously polished. However, using all values ​​of the polishing conditions for the search results in a huge amount of data, which increases the processing load of the control system 20. Therefore, the control system 20 generates a hash value of the polishing conditions and uses it as a search hash value, thereby speeding up the processing of the control system 20 during the search.

[0095] 13 is a diagram illustrating a search method using a search hash value. The control system 20 may generate a search hash value SH corresponding to preset polishing conditions SP for the substrate to be polished by the arithmetic unit 22 (see FIG. 1). The search hash value SH is an identifier generated in accordance with an algorithm included in a program stored in the storage unit 21 (see FIG. 1) based on parameter values ​​of the preset polishing conditions for the substrate to be polished. This algorithm is the same as the algorithm for generating hash values ​​to be stored in the database 21a described with reference to FIG. 11.

[0096] When a hash value matching the search hash value SH exists in the database 21a, the control system 20 determines the actual usage amount associated with the hash value matching the search hash value SH as the predicted usage amount of the polishing tape to be used for polishing the target substrate. For example, as shown in Fig. 13, when the search hash value SH matches the hash value HV1 stored in the database 21a, the control system 20 determines the actual usage amount AU1 associated with the hash value HV1 as the predicted usage amount of the polishing tape to be used for polishing the target substrate.

[0097] In one embodiment, when the preset polishing conditions include polishing conditions for a polishing process using multiple polishing heads, the control system 20 may generate a search hash value corresponding to the preset polishing conditions for each polishing head. The multiple search hash values ​​generated for each polishing head are associated with the multiple polishing heads, respectively. Furthermore, when a hash value matching the search hash value generated for each polishing head exists in the database 21a, the control system 20 may determine the actual usage amount of the polishing tape associated with the hash value matching the search hash value generated for each polishing head as the predicted usage amount of the polishing tape to be used for polishing the target substrate.

[0098] Next, a method for determining the predicted usage amount of the polishing tape to be used for polishing the substrate to be polished when the database 21a does not contain actual polishing conditions that match the preset polishing conditions of the substrate to be polished (see step 5 in FIG. 10) will be described. When the database 21a does not contain actual polishing conditions that match the preset polishing conditions of the substrate to be polished, the control system 20 calculates the predicted usage amount of the polishing tape based on the preset polishing conditions.

[0099] The method for calculating the predicted amount of polishing tape used varies depending on the polishing mode. When the polishing mode is continuous polishing, the predicted amount is calculated from the preset polishing conditions for the substrate to be polished, including the tape feed speed, tilt speed, number of tilts, tilt angle α1 at head position G1, and tilt angle α2 at head position G2 (see Figure 6). The tilt time Ta required to tilt from tilt angle α1 at head position G1 to tilt angle α2 at head position G2 is calculated by subtracting the tilt angle α2 at head position G2 from the tilt angle α1 at head position G1 and dividing the result by the tilt speed TS (Ta = (α1 - α2) / TS). The tilt time Ta corresponds to half the time it takes for the polishing head to make one round trip between head positions G1 and G2, so the time required for the polishing head to make one round trip is twice the tilt time Ta. Therefore, the predicted usage amount EUa during continuous polishing is calculated by multiplying the tilting time Ta by twice the number of tilting times TC and then multiplying the result by the tape feed speed FS (EUa=Ta×2×TC×FS).

[0100] When the polishing mode is fixed polishing, the predicted usage is calculated from the preset polishing conditions for the substrate to be polished: the tape feed speed, polishing time T1 at head position G1, polishing time T2 at head position G2, polishing time T3 at head position G3, and polishing time T4 at head position G4 (see Figure 7). The total polishing time is calculated by adding up all the polishing times T1 to T4 at each head position G1 to G4. Therefore, the predicted usage EUb during fixed polishing is calculated by multiplying the sum of all the polishing times T1 to T4 by the tape feed speed FS (EUb = (T1 + T2 + T3 + T4) × FS).

[0101] Next, the process of comparing the remaining amount of polishing tape with the determined predicted usage amount (see step 6 in Figure 10) will be described. When the polishing tape is replaced with a new one, the control system 20 stores the initial length of the new polishing tape in the storage device 21. The initial length is known in advance from the polishing tape specifications provided by the polishing tape manufacturer. Each time polishing of a substrate using that polishing tape is completed, the remaining amount of polishing tape is calculated by subtracting the actual usage amount of the polishing tape used in the previous polishing from the initial length. The control system 20 compares the calculated remaining amount of polishing tape with the determined predicted usage amount.

[0102] The remaining amount of polishing tape is compared with the determined predicted usage amount for each polishing head 33A-33D. More specifically, the control system 20 compares the remaining amount of polishing tape 32A-32D supplied to each polishing head 33A-33D with the predicted usage amount for each polishing tape 32A-32D. When the remaining amount of polishing tape 32A-32D supplied to all polishing heads 33A-33D is equal to or greater than the corresponding predicted usage amount, the control system 20 uses the polishing modules 4A and 4B to polish the target substrate under preset polishing conditions. When any one of the polishing tapes 32A-32D has a remaining amount less than the corresponding predicted usage amount, a tape out alarm is issued for the corresponding polishing head, prompting the user to replace the polishing tape.

[0103] The substrate polishing apparatus of the embodiment shown in FIG. 1 can polish multiple substrates simultaneously. Therefore, at the time when control system 20 compares the remaining amount of polishing tape with the determined predicted usage amount, other substrates may be present in the substrate polishing apparatus before or during polishing in addition to the substrate being polished. In this case, the remaining amount of polishing tape does not reflect the actual usage amount of polishing tape for the other substrates before or during polishing. Control system 20 may calculate the remaining amount of polishing tape by subtracting both the actual usage amount of polishing tape used in past polishing and the predicted usage amount of polishing tape for the other substrates before or during polishing from the initial length.

[0104] 14 is a plan view showing one embodiment of the arrangement of multiple substrates W1 to W5 to be polished. Substrate W1 is placed in a substrate cassette 2 of a load port 10. Substrate W2 is placed on a waiting stage 5A. Substrate W3 is placed on a waiting stage 5B. Substrate W4 is being polished by polishing head 33A of polishing module 4A. Substrate W5 is being polished by polishing head 33C of polishing module 4B.

[0105] In this embodiment, substrates W1, W2, W3, W4, and W5 are polished in the same manner by polishing modules 4A and 4B. More specifically, substrates W1, W2, W3, W4, and W5 are polished by polishing head 33A and polishing head 33B of polishing module 4A, and then polished by polishing head 33C and polishing head 33D of polishing module 4B. Substrates W1, W2, and W3 are all shown in a state before polishing, while substrates W4 and W5 are shown in a state after polishing.

[0106] Substrate W5 is polished by polishing head 33C of polishing module 4B, and then polished by polishing head 33D. After polishing of substrate W5 is completed, substrate W5 is transported from polishing module 4B to the cleaning and drying part 7 by the second transport robot 17. Thereafter, substrate W5 is cleaned and dried in the cleaning and drying part 7.

[0107] Substrate W4 is polished by polishing head 33A of polishing module 4A, and then polished by polishing head 33B. After polishing of substrate W4 is completed and substrate W5 is removed from polishing module 4B, substrate W4 is transported from polishing module 4A to polishing module 5A by second transport robot 17. Thereafter, substrate W4 is polished by polishing head 33C of polishing module 4B, and then further polished by polishing head 33D.

[0108] After the substrate W4 is removed from the polishing module 4A, the substrate W3 is transferred from the standby stage 5B to the polishing module 4A by the second transfer robot 17. Thereafter, the substrate W3 is polished by the polishing head 33A of the polishing module 4A, and then further polished by the polishing head 33B.

[0109] After substrate W3 is removed from waiting stage 5B, substrate W2 is transferred from waiting stage 5A to waiting stage 5B by second transfer robot 17. After substrate W2 is removed from waiting stage 5A, substrate W1 is handed over to second transfer robot 17 by first transfer robot 16 and placed on waiting stage 5A by second transfer robot 17. In this manner, the multiple substrates W1 to W5 are processed by moving in the order of load port 10, waiting stage 5A, waiting stage 5B, polishing module 4A, polishing module 4B, and cleaning / drying section 7.

[0110] The operations of steps 2 to 6 described with reference to Fig. 10 are performed before the plurality of polishing target substrates W1 to W5 are each transported from the substrate cassette 2 of the load port 10. The control system 20 determines the predicted usage amounts of the polishing tapes 32A to 32D to be used by the polishing heads 33A to 33D, and when the remaining amounts of all of the polishing tapes 32A to 32D are equal to or greater than the predicted usage amounts, the control system 20 issues a command to the first transport robot 16 to transport the substrate W1 shown in Fig. 14 from the substrate cassette 2 to the second transport robot 17.

[0111] At the time when control system 20 compares the remaining amounts of polishing tapes 32A-32D with the determined predicted usage amounts, polishing of substrates W2, W3, W4, and W5 has not yet been completed, and therefore the actual usage amounts of polishing tapes 32A-32D to be used for polishing substrates W2-W5 have not yet been determined. Control system 20 calculates the remaining amounts of polishing tapes 32A-32D by subtracting the predicted usage amounts of polishing tapes 32A-32D for substrates W2-W5 from the current remaining amounts of polishing tapes 32A-32D. Control system 20 compares the calculated remaining amounts of polishing tapes 32A-32D with the determined predicted usage amounts.

[0112] According to this embodiment, before polishing a substrate to be polished, even if there are other substrates that have not yet been polished or are being polished, the control system 20 compares the remaining amount of polishing tape, which reflects the predicted amount of polishing tape that has been used for the other substrates that have not yet been polished or are being polished, with the predicted amount of polishing tape that has been used for the substrate to be polished. This allows the polishing tape to be consumed as much as possible, prevents tape end errors, and reduces the number of discarded substrates.

[0113] The above-described embodiments have been described for the purpose of enabling a person of ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments would be obvious to a person skilled in the art, and the technical concept of the present invention may be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope in accordance with the technical concept defined by the claims. [Explanation of symbols]

[0114] 2 PCB cassettes 4A, 4B Polishing Module 5A, 5B waiting stage 7 Washing and drying section 10 Loading Port 12 First cleaning module 13 Second cleaning module 14 Drying Module 16 First transport robot 17 Second transport robot 18 Third Transport Robot 19 Fourth Transport Robot 20 Control System 21 Storage device 21a database 22 Arithmetic unit 32A, 32B, 32C, 32D Polishing Tape 33A, 33B, 33C, 33D Polishing head 34 Holding stage 35 shaft 37 Holding stage drive mechanism 40 Board holding part 42 Lower supply nozzle 43 Upper supply nozzle 46A, 46B Polishing tape supply mechanism 47 Tape unwinding reel 48 Tape take-up reel 50, 51, 52, 53 Guide rollers 54 Air cylinder 56 Tape feeder 56a Tape feed roller 56b Tape gripping roller 60, 61, 62, 63, 64, 65, 66 Guide rollers 68 Pressing member 70A, 70B tilt mechanism 72 crank arm 73 Arm rotation device 100 Housing M Tape feed motor

Claims

1. storing actual polishing conditions for at least one substrate previously polished and an actual amount of polishing tape used under the actual polishing conditions in a database in association with the actual polishing conditions and the actual amount of polishing tape used; Before polishing the substrate to be polished, searching the database for actual polishing conditions that match the preset polishing conditions for the substrate to be polished; determining an actual usage amount of the polishing tape associated with actual polishing conditions that match the preset polishing conditions as a predicted usage amount of the polishing tape required to polish the substrate to be polished; comparing the remaining amount of the polishing tape used to polish the substrate to be polished with the determined predicted amount of use; a polishing module for polishing the substrate when the remaining amount of the polishing tape is equal to or greater than the predicted amount of use;

2. 2. The substrate polishing method of claim 1, wherein determining the predicted usage amount is determined by calculating the predicted usage amount of the polishing tape to be used for polishing the substrate to be polished based on the preset polishing conditions when actual polishing conditions that match the preset polishing conditions are not present in the database.

3. the actual polishing conditions include a polishing head identifier for identifying a polishing head used to polish at least one substrate that has been polished in the past, among a plurality of polishing heads; 2. The substrate polishing method according to claim 1, wherein the preset polishing conditions include a polishing head identifier for identifying a polishing head used to polish the target substrate.

4. the actual polishing conditions include a polishing tape identifier for identifying the type of polishing tape used in polishing at least one substrate that has been polished in the past, from among a plurality of types of polishing tapes; 2. The substrate polishing method according to claim 1, wherein the preset polishing conditions include a polishing tape identifier for specifying the type of polishing tape used to polish the target substrate.

5. the actual polishing conditions include polishing conditions of a plurality of polishing steps included in polishing at least one substrate previously polished; The actual usage amount is the actual usage amount of the polishing tape used from the start to the end of polishing including the plurality of polishing steps, 2. The substrate polishing method according to claim 1, wherein the preset polishing conditions include polishing conditions for a plurality of polishing steps applied to polish the target substrate.

6. generating a hash value corresponding to the actual polishing conditions, and storing the hash value in the database in association with the actual usage amount; generating a search hash value corresponding to the preset polishing conditions of the substrate to be polished, and searching the database for a hash value that matches the search hash value; The substrate polishing method of claim 1, wherein determining the predicted usage amount comprises determining the actual usage amount of the polishing tape associated with a hash value that matches the search hash value as the predicted usage amount of the polishing tape required to polish the substrate to be polished.

7. a polishing module for polishing the substrate with a polishing tape; a control system including a database and a computing device; The control system includes: storing actual polishing conditions for at least one substrate previously polished and an actual amount of polishing tape used under the actual polishing conditions in the database in association with the actual polishing conditions and the actual amount of polishing tape used; Before polishing the substrate to be polished, searching the database for actual polishing conditions that match the preset polishing conditions for the substrate to be polished; determining an actual usage amount of the polishing tape associated with actual polishing conditions that match the preset polishing conditions as a predicted usage amount of the polishing tape required to polish the substrate to be polished; comparing the remaining amount of the polishing tape used to polish the substrate to be polished with the determined predicted amount of use; a polishing module for polishing the target substrate when the remaining amount of the polishing tape is equal to or greater than the predicted amount of use;

8. 8. The substrate polishing apparatus according to claim 7, wherein the control system is configured to calculate a predicted usage amount of the polishing tape to be used in polishing the substrate to be polished based on the preset polishing conditions when actual polishing conditions that match the preset polishing conditions are not present in the database.

9. the actual polishing conditions include a polishing head identifier for identifying a polishing head used to polish at least one substrate that has been polished in the past, among a plurality of polishing heads; 8. The substrate polishing apparatus according to claim 7, wherein the preset polishing conditions include a polishing head identifier for identifying a polishing head used to polish the target substrate.

10. the actual polishing conditions include a polishing tape identifier for identifying the type of polishing tape used in polishing at least one substrate that has been polished in the past, from among a plurality of types of polishing tapes; 8. The substrate polishing apparatus according to claim 7, wherein the preset polishing conditions include a polishing tape identifier for specifying the type of polishing tape used for polishing the target substrate.

11. the actual polishing conditions include polishing conditions of a plurality of polishing steps included in polishing at least one substrate previously polished; The actual usage amount is the actual usage amount of the polishing tape used from the start to the end of polishing including the plurality of polishing steps, 8. The substrate polishing apparatus according to claim 7, wherein the preset polishing conditions include polishing conditions for a plurality of polishing processes applied to polish the target substrate.

12. The control system includes: generating a hash value corresponding to the actual polishing conditions, and storing the hash value in the database in association with the actual usage amount; generating a search hash value corresponding to the preset polishing conditions of the substrate to be polished, and searching the database for a hash value that matches the search hash value; The substrate polishing apparatus of claim 7, wherein the actual usage amount of the polishing tape associated with the hash value that matches the search hash value is determined as the predicted usage amount of the polishing tape required to polish the substrate to be polished.

13. Give commands to the control system storing actual polishing conditions for at least one substrate previously polished and an actual amount of polishing tape used under the actual polishing conditions in a database in association with the actual polishing conditions and the actual amount of polishing tape used; Before polishing a substrate to be polished, searching the database for actual polishing conditions that match preset polishing conditions for the substrate to be polished; determining an actual usage amount of the polishing tape associated with actual polishing conditions that match the preset polishing conditions as a predicted usage amount of the polishing tape required to polish the substrate to be polished; comparing the remaining amount of the polishing tape used to polish the target substrate with the determined predicted usage amount; A computer-readable recording medium having recorded thereon a program for causing a computer to execute a step of giving an instruction to a polishing module to polish the substrate to be polished when the remaining amount of the polishing tape is equal to or greater than the predicted amount of use.

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