Patent Application
20200269385
This application claims the priority of Japan patent application serial no. 2019-029543, filed on Feb. 21, 2019. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The disclosure relates to a polishing device, a polishing method for polishing a substrate such as a wafer, and a recording medium in which a program for determining a position for supplying a polishing liquid is recorded.
In a manufacturing process of a semiconductor device, planarization techniques for surfaces of a device have become increasingly important. The most important technique of the planarization techniques is chemical mechanical polishing (hereinafter referred to as CMP). The CMP uses a polishing device to perform polishing by bringing a substrate such as a wafer into sliding contact with a polishing surface while supplying a polishing liquid (slurry) containing abrasive such as silica (SiO2) and ceria (CeO2) to a polishing pad.
A polishing device including a polishing liquid supply nozzle (a single tube nozzle) for supplying a polishing liquid (slurry) onto a polishing pad is known (for example, see Patent Document 2, Japanese Patent Application Laid-Open No. 2010-247258). In such a polishing device, a substrate is polished while the polishing liquid is supplied from the polishing liquid supply nozzle onto the polishing pad.
[Patent Document 1] Japanese Patent Application Laid-Open No. 2003-1559
A polishing rate of a substrate depends on a distribution in a flow rate of a polishing liquid. Therefore, it is very important to control a supply position of a polishing liquid on a substrate in order to improve uniformity of a polishing rate within a substrate. However, a polishing liquid supply nozzle, which is a single tube nozzle, locally supplies a polishing liquid to a narrow region on a polishing pad. Therefore, when such a polishing liquid supply nozzle is used, a distribution in a flow rate of the polishing liquid at the supply position becomes large on a surface of the polishing pad. This becomes a factor that causes large distribution in a polishing rate within a substrate.
In addition, in the case of supplying a polishing liquid at a fixed position, if the polishing liquid is supplied to an outer peripheral side of a polishing pad, a large amount of polishing liquid is discharged to the outside of the polishing pad, and thus a polishing rate within a substrate decreases. Therefore, a polishing liquid supply nozzle is required to swing during polishing within a substrate, but a polishing table supporting a polishing pad rotates during polishing within a substrate. Therefore, distribution in supply positions of the polishing liquid in a radial direction of the substrate does not become uniform in a circumferential direction of the polishing pad.
According to one aspect of the embodiment, a polishing device is provided. The polishing device includes a polishing pad, a top ring which presses a substrate against the polishing pad to polish the substrate, a liquid injection nozzle which injects a polishing liquid in a fan shape on the polishing pad, a nozzle moving device which moves the liquid injection nozzle in a radial direction of the polishing pad, and an operation control unit which controls an operation of the nozzle moving device. The operation control unit includes a storage device which stores a program, and a processing device which performs a calculation in accordance with the program. The program includes commands of: obtaining a correlation between a supply position of the polishing liquid in the radial direction of the polishing pad using the liquid injection nozzle and an average polishing rate of the substrate and an distribution of the polishing rate within the substrate; determining a movable range of the liquid injection nozzle on the basis of a predetermined range of an allowable average polishing rate and the correlation between the supply position of the polishing liquid and the average polishing rate; determining an optimal supply position of the polishing liquid from the correlation between the supply position of the polishing liquid and the distribution of the polishing rate within the substrate within the determined movable range of the liquid injection nozzle; and moving the liquid injection nozzle to the determined supply position to polish the substrate.
According to one aspect of the embodiment, a polishing method is provided. The polishing method includes obtaining a correlation between a supply position of a polishing liquid in a radial direction of a polishing pad using a liquid injection nozzle which injects the polishing liquid onto the polishing pad in a fan shape and an average polishing rate of a substrate and an distribution of a polishing rate within the substrate, determining a movable range of the liquid injection nozzle from a predetermined range of an allowable average polishing rate and the correlation between the supply position of the polishing liquid and the average polishing rate, determining an optimal supply position of the polishing liquid from the correlation between the supply position of the polishing liquid and the distribution of the polishing rate within the substrate within the determined movable range of the liquid injection nozzle, and moving the liquid injection nozzle to the determined supply position to polish the substrate.
According to one aspect of the embodiment, a non-transitory computer-readable recording medium for recording a program is provided. The program causes a computer to execute steps of: obtaining a correlation between a supply position of a polishing liquid in a radial direction of a polishing pad using a liquid injection nozzle which injects the polishing liquid onto the polishing pad in a fan shape and an average polishing rate of a substrate and an distribution of a polishing rate within the substrate; determining a movable range of the liquid injection nozzle from a predetermined range of an allowable average polishing rate and the correlation between the supply position of the polishing liquid and the average polishing rate; determining an optimal supply position of the polishing liquid from the correlation between the supply position of the polishing liquid and the distribution of the polishing rate within the substrate within the determined movable range of the liquid injection nozzle; and moving the liquid injection nozzle to the determined supply position to polish the substrate.
Part (a) of
Part (a) of
Parts (a) to (c) of
Parts (a) to (c) of
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The disclosure provides a polishing device and a polishing method in which a liquid injection nozzle can be moved to make distribution in supply positions of a polishing liquid uniform and to adjust the supply positions of the polishing liquid to correspond to a target polishing amount (a target control range or a target polishing rate distribution) during polishing, thereby improving uniformity of a polishing rate within a substrate. The disclosure provides a recording medium for recoding a program which can command the liquid injection nozzle to move to adjust the supply positions of the polishing liquid to correspond to the target polishing amount (the target control range or the target polishing rate distribution) during polishing, thereby improving uniformity of the polishing rate within the substrate.
According to one aspect of the embodiment, the polishing device includes a film thickness measurement sensor which measures a film thickness within the substrate, and the program includes commands of: measuring a remained film thickness distribution within the substrate using the film thickness measurement sensor; determining distribution of a target polishing amount on the basis of a difference between the measured remained film distribution and a predetermined target remained film distribution; determining the optimal supply position of the polishing liquid within the determined movable range of the liquid injection nozzle from the target polishing amount distribution and the correlation between the supply position of the polishing liquid and the distribution of the polishing rate within the substrate; and moving the liquid injection nozzle to the determined supply position.
According to one aspect of the embodiment, the program includes commands of: obtaining a polishing rate distribution during actual polishing from a change with a lapse of time of the measured remained film distribution; and determining a target control range corresponding to the target polishing amount on the basis of the polishing rate distribution during the actual polishing.
According to one aspect of the embodiment, the program obtains the polishing rate distribution during the actual polishing from the change with the lapse of time of the measured remained film distribution, and determines the target polishing rate distribution corresponding to the target polishing amount on the basis of the polishing rate distribution during the actual polishing.
According to one aspect of the embodiment, the polishing method includes measuring a remained film thickness distribution within the substrate using a film thickness measurement sensor which measures a film thickness within the substrate, determining a target polishing amount distribution on the basis of a difference between the measured remained film distribution and a predetermined target film distribution, determining the optimal supply position of the polishing liquid within the determined movable range of the liquid injection nozzle from the target polishing amount distribution and the correlation between the supply position of the polishing liquid and the distribution of the polishing rate within the substrate, and moving the liquid injection nozzle to the determined supply position.
According to one aspect of the embodiment, the polishing method includes obtaining the polishing rate distribution during actual polishing from a change with a lapse of time of the measured remained film distribution, and determining a target control range corresponding to the target polishing amount distribution on the basis of the polishing rate distribution during the actual polishing.
According to one aspect of the embodiment, the polishing method includes obtaining the polishing rate distribution during the actual polishing from the change with the lapse of time of the measured remained film distribution, and determining the target polishing rate distribution corresponding to the target polishing amount on the basis of the polishing rate distribution during the actual polishing.
According to one aspect of the embodiment, the program includes steps of: measuring a remained film thickness distribution within the substrate using a film thickness measurement sensor which measures a film thickness within the substrate; determining a target polishing amount distribution on the basis of a difference between the measured remained film distribution and a predetermined target remained film distribution; determining the optimal supply position of the polishing liquid within the determined movable range of the liquid injection nozzle from the target polishing amount distribution and the correlation between the supply position of the polishing liquid and the distribution of the polishing rate within the substrate; and moving the liquid injection nozzle to the determined supply position.
According to one aspect of the embodiment, the program includes steps of: obtaining the polishing rate distribution during actual polishing from a change with a lapse of time of the measured remained film distribution; and determining a target control range corresponding to the target polishing amount distribution on the basis of the polishing rate distribution during the actual polishing.
According to one aspect of the embodiment, the program includes steps of: obtaining the polishing rate distribution during the actual polishing from the change with the lapse of time of the measured remained film distribution; and determining the target polishing rate distribution corresponding to the target polishing amount on the basis of the polishing rate distribution during the actual polishing.
According to one reference example, a polishing device is provided. The polishing device includes a polishing pad, a top ring which presses a substrate against the polishing pad to polish the substrate, a liquid injection nozzle which injects a polishing liquid in a fan shape on the polishing pad, a nozzle moving device which moves the liquid injection nozzle in a radial direction of the polishing pad, and an operation control unit which controls an operation of the nozzle moving device. The operation control unit includes a storage device which stores a program, and a processing device which performs a calculation in accordance with the program. The program obtains a correlation between a supply position of the polishing liquid in the radial direction of the polishing pad using the liquid injection nozzle and an average polishing rate of the substrate and an distribution of the polishing rate within the substrate, determines a movable range of the liquid injection nozzle on the basis of a predetermined range of an allowable average polishing rate and the correlation between the supply position of the polishing liquid and the average polishing rate, determines an optimal supply position of the polishing liquid from the correlation between the supply position of the polishing liquid and the distribution of the polishing rate within the substrate within the determined movable range of the liquid injection nozzle, and causes the operation control unit to perform an operation of moving the liquid injection nozzle to the determined supply position to polish the substrate.
The operation control unit moves the liquid injection nozzle which injects the polishing liquid over a wide region to the supply position of the polishing liquid determined from the correlation between the supply position of the polishing liquid and the distribution of the polishing rate within the substrate within the determined movable range of the liquid injection nozzle. Therefore, the operation control unit can adjust the supply position of the polishing liquid to be optimally arranged with respect to the target polishing amount (target control range or target polishing rate distribution), thereby improving uniformity of the polishing rate within the substrate.
Hereinafter, embodiments of the disclosure will be described with reference to the drawings. Also, in the figures described below, the same or corresponding components are denoted by the same reference signs, and repeated descriptions thereof will be omitted.
The polishing table 2 is connected to a table motor (not shown), which rotates the polishing table 2, via a table shaft (not shown) that supports the polishing table 2. The polishing pad 1 is affixed to an upper surface of the polishing table 2, and an upper surface of the polishing pad 1 constitutes a polishing surface 1a that polishes the substrate W.
The top ring 3 is fixed to a lower end of a top ring shaft (not shown). The top ring 3 is configured such that the substrate W can be held by vacuum suction on a lower surface thereof. The top ring shaft is connected to a rotation mechanism (not shown) installed in a top ring arm 8. The top ring 3 is rotated by the rotation mechanism via the top ring shaft.
The top ring arm 8 is connected to a top ring swing shaft 9 which swings the top ring arm 8. The top ring swing shaft 9 is disposed outside the polishing pad 1. The top ring 3, the top ring arm 8, and the top ring swing shaft 9 constitute a top ring device 5.
The polishing device PA further includes a dressing device 10 for dressing the polishing pad 1. The dressing device 10 includes a dresser 15 brought into sliding contact with the polishing surface 1a of the polishing pad 1, a dresser arm 11 supporting the dresser 15, and a dresser swing shaft 12 which swings the dresser arm 11. The dresser swing shaft 12 is disposed outside the polishing pad 1.
The dresser 15 swings on the polishing surface 1a with rotation of the dresser arm 11. A lower surface of the dresser 15 constitutes a dressing surface configured of many abrasive such as diamond particles. The dresser 15 rotates while swinging on the polishing surface 1a and dresses the polishing surface 1a by slightly scraping off the polishing pad 1. During dressing of the polishing pad 1, the liquid supply mechanism 4 (more specifically, a dressing liquid supply device 60) supplies pure water onto the polishing surface 1a of the polishing pad 1. Details of a configuration of the liquid supply mechanism 4 will be described later.
The polishing device PA further includes an atomizer 20 which sprays a mist-like cleaning fluid onto the polishing surface 1a of the polishing pad 1 to clean the polishing surface 1a. The cleaning fluid is configured of a mixed fluid of a liquid (usually pure water) and a gas (for example, an inert gas such as nitrogen gas). The atomizer 20 extends in a radial direction of the polishing pad 1 (or the polishing table 2) and is positioned above the polishing surface 1a of the polishing pad 1. The atomizer 20 removes polishing debris and abrasive contained in the polishing liquid from the polishing surface 1a of the polishing pad 1 by injecting a high-pressure cleaning fluid onto the polishing surface 1a.
Hereinafter, a configuration of the liquid supply mechanism 4 will be described with reference to the drawings. Part (a) of
The liquid supply mechanism 4 includes a nozzle arm 30 which is movable in the radial direction of the polishing table 2, a first slurry nozzle 31 and a second slurry nozzle 32 which are disposed at a tip part 30a of the nozzle arm 30, and a liquid injection nozzle 33 which is disposed on an arm part 30b of the nozzle arm 30.
The nozzle arm 30 is connected to a nozzle moving device 35 which moves the nozzle arm 30 (see
As shown in part (a) of
When the nozzle arm 30 is at the processing position, the liquid injection nozzle 33 is disposed above a region between the center CL of the polishing pad 1 and an outer circumferential part 1b of the polishing pad 1 so that the injection ports face the region.
In one embodiment, the liquid injection nozzle 33 is made of a resin. As an example of a material of the liquid injection nozzle 33, polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), or polypropylene (PP) can be exemplified.
The liquid injection nozzle 33 supplies a slurry A, the first slurry nozzle 31 supplies a slurry B, and the second slurry nozzle 32 supplies a slurry C. The slurry A, the slurry B, and the slurry C are different types of liquids.
Part (a) of
As shown in part (b) of
As shown in part (a) of
The liquid injection nozzle 33 is inclined toward the outer circumferential part 1b (that is, away from the center CL of the polishing pad 1) of the polishing pad 1 with respect a vertical direction. In one embodiment, an inclination angle of the liquid injection nozzle 33 is 13 degrees.
In a direction in which the slurry A flows, an upstream side of the connecting member 48 may be referred to as an upstream flow path of the third slurry line 46, and a downstream side of the connecting member 48 may be referred to as a downstream flow path of the third slurry line 46.
The connecting member 48 is disposed adjacent to the liquid injection nozzle 33. Pure water flowing through the flushing line 47 and a tip part of the third slurry line 46 (in other words, the downstream flow path of the third slurry line 46) is injected from the liquid injection nozzle 33. The liquid (slurry A or pure water) flowing through any one of the third slurry line 46 and the flushing line 47 is injected from the liquid injection nozzle 33.
The pure water flowing through the flushing line 47 passes through the tip part of the third slurry line 46 and the liquid injection nozzle 33 and is injected to the outside. This pure water is a flushing liquid for cleaning the tip part of the third slurry line 46 and the liquid injection nozzle 33. The pure water vigorously flows inside the liquid injection nozzle 33 as the flushing liquid and instantaneously removes the slurry remaining at the tip part of the third slurry line 46 and inside the liquid injection nozzle 33. As a result, adhesion of the slurry inside the tip part of the third slurry line 46 and inside the liquid injection nozzle 33 is prevented.
The connecting member 48 is disposed adjacent to the liquid injection nozzle 33 at a position close to a slurry injection position. With such an arrangement, the polishing device PA can minimize an amount of replacing the slurry with pure water (that is, a slurry replacement amount) and maintain a throughput of the polishing device PA (the number of processed substrates W).
The liquid throttle surface 34c is disposed between the liquid passage surface 34a and the liquid injection surface 34b. The liquid throttle surface 34c is connected to the liquid passage surface 34a and the liquid injection surface 34b, and has a tapered shape. More specifically, the liquid throttle surface 34c has a shape in which an inner diameter of the liquid injection nozzle 33 gradually decreases from the liquid passage surface 34a toward the liquid injection surface 34b.
When the liquid injection nozzle 33 is a fan-shaped nozzle, there is a possibility that the slurry containing fine abrasive may adhere to the inside of the liquid injection nozzle 33. In the present embodiment, the liquid injection nozzle 33 has the tapered liquid throttle surface 34c formed on the inner surface 34 thereof. Therefore, the slurry inside the liquid injection nozzle 33 flows smoothly on the liquid throttle surface 34c without remaining on the liquid throttle surface 34c. In this way, staying of the slurry inside the liquid injection nozzle 33 is prevented. As a result, adhesion of the slurry inside the liquid injection nozzle 33 is prevented.
According to the present embodiment, the liquid injection nozzle 33 can inject a small amount of slurry over a wide range. Therefore, an amount of slurry used can be reduced, and a polishing rate of the substrate with respect to the amount of slurry used can be improved.
As shown in
Operation of the polishing device PA including the nozzle moving device 35 is controlled by the operation control unit 200. In the present embodiment, the operation control unit 200 is configured of a computer.
The storage device 210 includes a main storage device 211 that can be accessed by the processing device 220 and an auxiliary storage device 212 that stores data and programs. The main storage device 211 is, for example, a random access memory (RAM), and the auxiliary storage device 212 is a storage device such as a hard disk drive (HDD) or a solid state drive (SSD).
The input device 230 includes a keyboard and a mouse, and further includes a recording medium reading device 232 for reading data from a recording medium and a recording medium port 234 to which the recording medium is connected. The recording medium is a computer-readable recording medium that is a non-transitory tangible medium, for example, such as an optical disk (for example, a CD-ROM, a DVD-ROM, or the like) or a semiconductor memory (for example, a USB flash drive, a memory card, or the like). Examples of the recording medium reading device 232 include an optical drive such as a CD-ROM drive and a DVD-ROM drive, and a memory reader. An example of the recording medium port 234 is a USB port. The programs and/or data stored in the recording medium are introduced into the operation control unit 200 via the input device 230 and are stored in the auxiliary storage device 212 of the storage device 210. The output device 240 includes a display device 241 and a printing device 242.
Parts (a) to (c) of
As shown in part (a) of
As shown in part (b) of
As shown in part (c) of
In Parts (a) to (c) of
As shown in part (a) of
As shown in Parts (a) to (c) of
The operation control unit 200 including a computer operates in accordance with a program electrically stored in the storage device 210. That is, the operation control unit 200 is configured to determine a movable range of the liquid injection nozzle 33 on the basis of the correlation stored in the storage device 210 and a predetermined range of an allowable average polishing rate, and to move the liquid injection nozzle 33 within the determined movable range of the liquid injection nozzle 33 to polish the substrate W.
The program for causing the operation control unit 200 to execute these steps is recorded on the computer-readable recording medium that is a non-temporary tangible medium and is provided to the operation control unit 200 via the recording medium. Alternatively, the program may be input from the communication device 250 to the operation control unit 200 via the communication network such as the Internet or a local area network.
The range of the allowable average polishing rate is set to include a desired average polishing rate in accordance with polishing conditions of the substrate W. According to the example of
Part (a) of
The eddy current sensor is a sensor that detects a linkage magnetic flux formed by eddy current of the substrate W and detects a thickness of a processing target film of the substrate W (that is, a remained film distribution of the processing target film) on the basis of the detected linkage magnetic flux. The optical sensor is a sensor that irradiates the substrate W with light and measures interference waves reflected from the substrate W to detect a thickness of a processing target film (that is, a remained film distribution of the processing target film).
The film thickness measurement sensor 300 is electrically connected to the operation control unit 200 and sends sensor data (sensor signals) having a correlation with the film thickness of the substrate W to the operation control unit 200. When the sensor data from the film thickness measurement sensor 300 is input to the operation control unit 200, the operation control unit 200 converts the sensor data into a film thickness value of the substrate W. In addition, the film thickness measurement sensor 300 may be used to detect a polishing end point and to end the polishing performed by the polishing device PA in accordance with a predetermined setting.
When the polishing device PA starts polishing the substrate W, the operation control unit 200 measures the remained film distribution of the processing target film of the substrate W using the film thickness measurement sensor 300, and obtains a polishing amount distribution on the basis of a change with a lapse of time of the measured remained film distribution. Then, the operation control unit 200 determines a target polishing amount from a difference from a predetermined target film distribution. The operation control unit 200 determines an optimal supply position of the polishing liquid within the movable range of the liquid injection nozzle 33 from the correlation between the supply position of the polishing liquid 210 and the distribution of the polishing rate within the substrate stored in the storage device with respect to the determined target polishing amount, and moves the liquid injection nozzle 33 to a determined supply position.
More specifically, as shown in part (b) of
In one embodiment, the operation control unit 200 may determine the target control range related to the remained film of the substrate W on the basis of the measured remained film distribution. In one embodiment, the operation control unit 200 may determine the target film distribution related to the remained film of the substrate W on the basis of the measured remained film distribution. Each of the target control range and the target film distribution corresponds to the target polishing amount distribution.
Thereafter, the operation control unit 200 determines whether or not the calculated polishing rate distribution is within the target control range (see step S103 in
When the polishing rate distribution is within the target control range (see “YES” in step S103 in
The change of the supply position of the polishing liquid is determined as follows. For example, when a part of the polishing rate in the radial direction of the substrate W is larger (or smaller) than the target control range (or target polishing rate distribution), the operation control unit 200 moves the liquid injection nozzle 33 within the movable range of the liquid injection nozzle 33 to reduce (or increase) the part of the polishing rate on the basis of data indicating the correlation between the supply position of the polishing liquid and the polishing rate distribution within the substrate W.
When a plurality of parts of the polishing rate in the radial direction of the substrate W are larger (or smaller) than the target control range (or the target polishing rate distribution), the operation control unit 200 moves the liquid injection nozzle 33 within the movable range of the liquid injection nozzle 33 so that the largest part of the polishing rate (or the smallest part of the polishing rate) is minimized (or maximized).
As described above, the operation control unit 200 determines an extreme value (maximum value or minimum value) of the polishing rate on the basis of a deviation amount of the polishing rate from the target control range (or the target polishing rate distribution), and changes the supply position of the polishing liquid so that the extreme value varies.
When a remained film thickness of the processing target film of the substrate W is extremely small, the remained film thickness cannot be further reduced. Accordingly, the operation control unit 200 changes the supply position of the polishing liquid so that the part having the smallest polishing rate is maximized.
After step S104 in
After step S106 in
Data related to the feedback control (associated data) is input to the storage device 210 of the operation control unit 200 as information necessary for generating a polishing recipe (including conditions for polishing the substrate W). The polishing device PA polishes the substrate W in accordance with the polishing recipe. The associated data includes elements as described below.
When the operation control unit 200 determines the target polishing amount on the basis of the change with the lapse of time of the remained film distribution measured by the film thickness measurement sensor 300, the associated data may include the target film distribution within the substrate W and/or a sensor signal corresponding to the remained film.
The associated data may include a correlation between the position of the liquid injection nozzle 33 (that is, the supply position of the polishing liquid) and the polishing rate distribution within the substrate W, and the movable range of the liquid injection nozzle 33 determined on the basis of the correlation. The associated data may include the target control range for the polishing rate.
Since a polishing state is not stable immediately after the polishing device PA starts polishing the substrate W, the operation control unit 200 may not be able to obtain accurate data worth performing the feedback control. Therefore, the associated data includes a time (start time) at which the operation control unit 200 starts the feedback control. The start time is a time for determining how many seconds after the start of the polishing of the substrate W the feedback control is to be started.
The associated data may include a feedback cycle for performing the feedback control. In one embodiment, the feedback cycle may be determined on the basis of the rotation of the polishing table 2 or time. The associated data may include an effective time of the feedback control. In one embodiment, the effective time may be any time equal to or less than the polishing time of the substrate W, or may be determined on the basis of the remained film of the substrate W.
According to the present embodiment, the liquid injection nozzle 33 is configured to inject the polishing liquid in a fan shape over a wide area, unlike a single pipe nozzle that locally supplies a polishing liquid. Therefore, there is no variation in distribution of supply positions of the polishing liquid. Further, since the operation control unit 200 does not need to swing the liquid injection nozzle 33, the distribution of the supply positions of the polishing liquid in the radial direction of the substrate W becomes uniform in the circumferential direction of the polishing pad 1. As a result, a decrease in the polishing rate of the substrate W can be inhibited.
The operation control unit 200 controls the position of the liquid injection nozzle 33 that injects the polishing liquid. Therefore, the use of the liquid injection nozzle 33 enables a wide flow rate distribution of the polishing liquid without swinging the nozzle unlike a single tube nozzle. Further, the operation control unit 200 moves the liquid injection nozzle 33 within the movable range of the liquid injection nozzle 33 determined on the basis of the range of the allowable average polishing rate. Therefore, the operation control unit 200 can improve uniformity of the polishing rate within the substrate W.
The polishing rate of the substrate W can vary depending not only on the supply positions of the polishing liquid, but also on the flow rate (supply amount) of the polishing liquid supplied onto the polishing pad 1. Therefore, there is also a correlation between the supply amount of the polishing liquid and the polishing rate distribution within the substrate W, and the operation control unit 200 may control the flow rate of the polishing liquid together with the supply positions.
In one embodiment, the operation control unit 200 may obtain the correlation in advance and store data indicating the correlation in the storage device 210 as a database. The associated data may include data indicating the correlation. In this case, the operation control unit 200 may change the supply position of the polishing liquid and change the supply amount of the polishing liquid within the movable range of the liquid injection nozzle 33. More specifically, the operation control unit 200 operates a flow rate adjusting device (not shown) attached to the third slurry line 46 (see
The polishing rate of the substrate W can vary depending not only on the supply position of the polishing liquid but also on a pressing force of the substrate W against the polishing surface 1a. Therefore, there is a correlation between the pressing force of the substrate W against the polishing surface 1a and the polishing rate distribution within the substrate W, and the pressing force of the substrate W may be controlled by the operation control unit 200 together with the supply position.
In one embodiment, the operation control unit 200 may obtain the correlation in advance and store data indicating the correlation in the storage device 210 as a database. The associated data may include data indicating the correlation. In this case, the operation control unit 200 may change the supply position of the polishing liquid within the movable range of the liquid injection nozzle 33 and may change the pressing force of the substrate W against the polishing surface 1a. This pressing force changes on the basis of the flow rate of the fluid supplied to a plurality of pressure chambers formed by elastic films (membranes) provided on the top ring 3. Therefore, the operation control unit 200 operates the flow rate adjusting device (not shown) to adjust the flow rate of the fluid supplied to the pressure chambers to be pressurized.
In the present embodiment, the liquid injection nozzle 33 is a nozzle that injects the polishing liquid in a fan shape. Therefore, when the liquid injection nozzle 33 is inclined with respect to the polishing surface 1a of the polishing pad 1 (see
In one embodiment, the operation control unit 200 may obtain the correlation in advance and store data indicating the correlation in the storage device 210 as a database. The associated data may include data indicating the correlation. In this case, the operation control unit 200 may change the supply position of the polishing liquid within the movable range of the liquid injection nozzle 33 and may change the inclination angle of the liquid injection nozzle 33. More specifically, the operation control unit 200 may change the inclination angle of the liquid injection nozzle 33 using an actuator (for example, a motor) that adjusts the inclination angle of the liquid injection nozzle 33.
The above embodiments have been described for the purpose of enabling a person having ordinary knowledge in the technical field to which the disclosure pertains to carry out the disclosure. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the disclosure can be applied to other embodiments. Accordingly, the disclosure is not limited to the embodiments described, but is to be accorded the widest scope consistent with the spirit as defined by the appended claims. It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-029543 | Feb 2019 | JP | national |
