JP5772243B2 - Slurry circulating apparatus and flushing method of slurry circulating apparatus - Google Patents

Description

  The present invention relates to a slurry circulating apparatus and a flushing method for the slurry circulating apparatus.

Conventionally, a configuration in which slurry is supplied to a CMP (Chemical Mechanical Polishing) apparatus is known (for example, see Patent Documents 1 and 2).
In the configurations of Patent Documents 1 and 2, two supply lines of slurry are provided. When the slurry is supplied from one supply line to the CMP apparatus, the other supply line is flushed (washed) with pure water. In addition, when one supply line is flushed, the slurry is supplied from the other supply line.
However, in such a configuration, since the supply line is flushed only with pure water, there is a possibility that the fixed substance of the slurry may remain in the supply line. Therefore, a method for solving such a problem has been studied (for example, see Patent Document 3).
Patent Document 3 discloses a configuration in which an organic alkaline solution is supplied and discharged to at least a part from a polishing stock solution supply line to a slurry supply line, and then hydrogen peroxide solution is supplied and discharged.

JP 2004-96013 A JP 2000-326225 A JP 2009-34809 A

  However, when the cleaning liquid as in Patent Document 3 is used in the configurations of Patent Documents 1 and 2, although the foreign substances in the piping can be removed by alternately flushing the two supply lines, the slurry discharged from the CMP apparatus is removed. Since the slurry contains a polishing agent such as silica and a chemically reactive component instead of the structure to be circulated, the fixed substance of the slurry is deposited in various places on the inside or on the surface of the CMP apparatus to which the slurry is supplied. Foreign matter such as slurry remaining on the surface cannot be removed. In addition, since one tank is used for flushing the supply line, flushing cannot be started until pure water is stored in the tank, and the flushing time cannot be shortened.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a slurry circulation device capable of reliably removing slurry residues remaining in a pipe to which slurry is supplied, a polishing device, etc., and shortening the flushing time, and flushing of the slurry circulation device. It is to provide a method.

The slurry circulating apparatus of the present invention is a slurry circulating apparatus that supplies slurry to a polishing apparatus and collects slurry discharged from the polishing apparatus, and includes a first supply tank and a second supply that can store and drain liquid. A tank, a supply line for supplying the liquid stored in the first supply tank and the second supply tank to the polishing apparatus, a pump provided in the supply line, and a supply of liquid supplied to the polishing apparatus A supply source switching unit that switches between the first supply tank and the second supply tank, and a recovery line that recovers the liquid discharged from the polishing apparatus to the first supply tank and the second supply tank; A recovery destination switching unit that switches a recovery destination of the liquid by the recovery line between the first supply tank and the second supply tank; the first supply tank; and A slurry replenishing unit that replenishes at least one of the two supply tanks, a pure water replenishing unit that replenishes the first supply tank and the second supply tank with pure water, the first supply tank, and the second supply. An alkaline solution replenishing unit that replenishes the tank with an alkaline solution; and a controller that controls the pump, the supply source switching unit, the recovery destination switching unit, the slurry replenishing unit, the pure water replenishing unit, and the alkaline solution replenishing unit; The first supply tank, the supply line, and the recovery line constitute a first circulation line that circulates liquid between them, and the second supply tank, the supply line, and the recovery line are A second circulation line configured to circulate liquid between them, and the control device circulates pure water stored in the first supply tank in the first circulation line. After performing the first slurry removal step for removing the slurry and the first slurry removal step, the second slurry removal for removing the slurry by circulating the pure water stored in the second supply tank in the second circulation line. And after the second slurry removing step, the first stuck matter removing step of removing the stuck matter of the slurry by circulating the alkaline solution stored in the first supply tank in the first circulation line; After performing the first fixed matter removing step, the second fixed matter removing step of removing the fixed matter in the slurry by circulating the alkaline aqueous solution stored in the second supply tank in the second circulation line, and the second solid matter removing step. After performing the kimono removing step, the first residue removing step for removing the residue of the slurry by circulating the pure water stored in the first supply tank in the first circulation line, and the first residue removing step The And a second residue removing step of removing the slurry residue by circulating the pure water stored in the second supply tank in the second circulation line. And

  On the other hand, the flushing method of the slurry circulating apparatus of the present invention is a flushing method of the slurry circulating apparatus that supplies the slurry to the polishing apparatus and collects the slurry discharged from the polishing apparatus. A first supply tank and a second supply tank that can be stored and drained, a supply line that supplies the liquid stored in the first supply tank and the second supply tank to the polishing apparatus, and discharged from the polishing apparatus. And a recovery line that recovers the liquid to be collected in the first supply tank and the second supply tank, and the first supply tank, the supply line, and the recovery line circulate liquid between them. The second supply tank, the supply line, and the recovery line constitute a second circulation line that circulates liquid between them. The first supply tank is configured to circulate pure water stored in the first supply tank in the first circulation line to remove the slurry, and after performing the first slurry removal process, the second supply tank The pure water stored in the second circulation line is circulated in the second circulation line to remove the slurry, and after performing the second slurry removal step, the alkaline solution stored in the first supply tank is After the first fixed matter removing step of removing the fixed matter of the slurry by circulating in the first circulation line and the first fixed matter removing step, the aqueous alkaline solution stored in the second supply tank is recycled to the second circulation tank. Circulated in the line to remove the fixed matter in the slurry and after the second fixed matter removal step, the pure water stored in the first supply tank is circulated in the first circulation line. Let After performing the first residue removal step for removing the slurry residue and the first residue removal step, the pure water stored in the second supply tank is circulated in the second circulation line to obtain the slurry residue. And performing a second residue removing step for removing the product.

  According to the above slurry circulation device and the flushing method thereof, in addition to the supply line and the recovery line, the polishing device is flushed with pure water and an alkaline solution, so that the foreign matter remaining in the polishing device is removed. Can be removed. The first supply tank and the second supply tank are used to perform the first and second supply of the first and second slurry removal processes, the first and second fixed substance removal processes, and the first and second residue removal processes. Can be carried out alternately in the tank. For this reason, as compared with the configuration in which only one supply tank is provided, flushing can be performed with more pure water or an alkaline solution, and the cleaning ability can be improved.

  In the slurry circulating apparatus of the present invention, the supply line is provided with a heat exchanger that exchanges heat with the liquid flowing through the supply line, and the heat exchanger supplies cold water to the heat exchanger. It is preferable that the cold water supply part which performs and the warm water supply part which supplies warm water are connected.

According to this invention, when supplying an alkaline solution with a supply line, the said alkaline solution can be heated by supplying warm water to a heat exchanger. For this reason, the ability to remove solids can be improved by heating the alkaline solution, and the flushing time can be shortened.
In general, the supply line is provided with a heat exchanger for cooling the slurry with cold water. In the present invention, the alkaline solution can be heated only by connecting the hot water supply unit to the heat exchanger used for cooling the slurry, and the capital investment for shortening the flushing time can be minimized. it can.

  In the flushing method for the slurry circulating apparatus according to the present invention, pure water is stored in the second supply tank during the actual operation of the first slurry removal step, and the first supply tank is used during the execution of the second slurry removal step. The pure water is drained and an alkaline solution is stored in the first supply tank, and the pure water in the second supply tank is drained and the second supply tank is alkalinized during the first fixed substance removing step. The solution is stored, and the alkaline solution in the first supply tank is drained and pure water is stored in the first supply tank during the second fixed matter removing step, and the first residue removing step is performed. Preferably, the alkaline solution in the second supply tank is drained and pure water is stored in the second supply tank.

  According to the present invention, during the first slurry removal step in the first supply tank, pure water is stored in the second supply tank for preparation of the second slurry removal step, and immediately after the completion of the first slurry removal step. 2 The slurry removal process can be started. That is, when performing the same process in the first supply tank and the second supply tank, the second supply tank is prepared during the process in the first supply tank, and the second process is completed after the process in the first supply tank is completed. Processing in the supply tank can be started. Therefore, flushing of the first and second circulation lines can be performed in a short time.

  In the flushing method of the slurry circulating apparatus of the present invention, the supply line includes a pump that controls the flow rate of the liquid by rotating a rotor, and a pressure detector that detects the pressure of the liquid downstream from the pump. And a rotation speed adjustment step for adjusting the rotation speed of the rotor of the pump so that the pressure of the liquid becomes a preset pressure value based on the detection result of the pressure by the pressure detector, A flushing determination step for determining that the flushing of the supply line is necessary when the rotation number of the rotor is equal to or higher than a preset rotation number, and it is determined that the flushing is necessary in the flushing determination step. Then, it is preferable to implement an alarming step for alarming that.

According to the present invention, for example, in a configuration in which a filter is provided on the downstream side of the pump, even if the pressure of the liquid is reduced due to an increase in the amount of foreign matter captured by the filter, the rotational speed of the rotor is reduced. By increasing the pressure, the pressure of the liquid can be increased. Therefore, the pressure of the liquid during flushing can be made substantially constant, and a predetermined cleaning ability can be maintained.
Also, if the filter is clogged during flushing or polishing, and the rotor speed is too high, the operator should be informed that flushing is necessary to eliminate clogging of the filter. I can inform you. Therefore, the operator can take appropriate measures such as performing flushing again or stopping polishing.

  In the flushing method of the slurry circulating apparatus of the present invention, the supply line includes a pump that controls the flow rate of the liquid by rotating a rotor, and a pressure detector that detects the pressure of the liquid downstream from the pump. And a rotation speed adjustment step for adjusting the rotation speed of the rotor of the pump so that the pressure of the liquid becomes a preset pressure value based on the detection result of the pressure by the pressure detector, A flushing determination step for determining that the supply line needs to be flushed when the number of rotations of the rotor exceeds a preset number of rotations, and determining whether the wafer is being polished in the polishing apparatus In the polishing determination step, the flushing determination step determines that flushing is necessary, and the polishing determination step determines that the wafer is not being polished. When, it is preferred to carry out the flushing start control step of starting the first slurry removal step.

  According to the present invention, for example, when the rotation speed of the rotor increases due to clogging of the filter and the polishing apparatus is not polishing, flushing is started, so that the operator's hand is not troubled, or Even if there is no worker, flushing can be started at an appropriate timing.

1 is a block diagram showing a schematic configuration of a CMP system according to an embodiment of the present invention. Sectional drawing which shows schematic structure of the CMP apparatus in the said one Embodiment. FIG. 3 is a plan view taken along line III-III in FIG. 2. The block diagram which shows the controller in the said one Embodiment, and its control object. The timing chart which shows the outline operation | movement of the flushing in the said one Embodiment. The timing chart which shows the outline operation | movement of the flushing in the said one Embodiment. The timing chart which shows the detailed operation | movement of the flushing in the said one Embodiment. The timing chart which shows the detailed operation | movement of the flushing in the said one Embodiment. The flowchart which shows the abnormality detection process in the said one Embodiment. The graph which shows the elapsed time and the rotation speed of a rotary control pump in the said one Embodiment.

An embodiment of the present invention will be described with reference to the drawings.
[Configuration of CMP system]
As shown in FIG. 1, the CMP system 1 polishes the wafer W (see FIG. 2) with slurry. In addition, flushing using an alkaline solution (potassium hydroxide (KOH) solution) or pure water is performed in order to prevent the wafer W from being damaged and to smoothly supply the slurry. The CMP system 1 includes a first CMP apparatus 21 and a second CMP apparatus 22 as polishing apparatuses, and a slurry circulation apparatus 3.

The first CMP apparatus 21 simultaneously polishes the front and back surfaces of the wafer W, and as shown in FIGS. 2 and 3, an annular lower surface plate 211, an annular upper surface plate 212 facing the lower surface plate 211, The sun gear 213 arrange | positioned inside the lower surface plate 211, and the 1st drain tank 61 which comprises the liquid collection | recovery part 6 mentioned later are provided.
The lower surface plate 211 is rotationally driven by a motor (not shown). Further, three carriers 214 are set on the upper surface of the lower surface plate 211. Each carrier 214 is provided with a hole 215 for accommodating the wafer W.
The upper surface plate 212 is suspended from the cylinder 216 via a joint 217 and is rotationally driven in a direction opposite to the lower surface plate 211. The upper surface plate 212 communicates with a first downstream line 434 of a supply line 43 described later. When polishing the wafer W, the slurry is supplied through the first downstream line 434. Further, at the time of flushing, an alkaline solution or pure water is supplied via the first downstream line 434.
Hereinafter, the slurry, the alkaline solution, and the pure water may be referred to as “liquid” without being particularly distinguished.

Further, a polishing pad is affixed to the opposing surfaces of the lower surface plate 211 and the upper surface plate 212.
On the other hand, the first drain tank 61 is formed in a cylindrical shape whose bottom surface is substantially closed. An internal gear 218 is provided on the inner surface on the upper end side of the first drainage tank 61. The sun gear 213 and the first drain tank 61 are rotationally driven by independent motors.
The second CMP apparatus 22 has the same mechanism as the first CMP apparatus 21, and includes a lower surface plate 211, an upper surface plate 212 that communicates with the second downstream line 435 of the supply line 43, and a second drainage tank. 62.

  In order to polish the wafer W, a plurality of carriers 214 are set on the lower surface plate 211 with the upper surface plate 212 raised, and the wafer W is set in the hole 215 of each carrier 214. The upper surface plate 212 is lowered and a predetermined pressure is applied to each wafer W. In this state, the lower platen 211, the upper platen 212, the sun gear 213, and the first drain tank 61 are set in a predetermined manner while the first downstream line 435 is turned to supply slurry between the lower platen 211 and the upper platen 212. Rotate at a predetermined speed in the direction of.

  The slurry circulating device 3 supplies the liquid to the first CMP device 21 and the second CMP device 22 for recovery and reuses them. As shown in FIGS. 1 and 4, the slurry circulation device 3 includes a liquid supply unit 4 that supplies liquid, a liquid supply unit 5 that supplies liquid to the liquid supply unit 4, and a first CMP performed by the liquid supply unit 4. A liquid recovery unit 6 that recovers the liquid supplied to the apparatus 21 and the second CMP apparatus 22 and a controller 7 that controls the entire CMP system 1 are provided.

The liquid supply unit 4 includes a first supply tank 41 and a second supply tank 42 that can store liquid, respectively, and distributes the liquid stored in the first supply tank 41 and the second supply tank 42 so as to circulate the first CMP apparatus 21. And a supply line 43 that supplies the second CMP apparatus 22 and a liquid temperature adjusting unit 45 that adjusts the temperature of the liquid flowing through the supply line 43.
The first supply tank 41 is provided with a first drain part 411. The first drainage section 411 includes a first drainage line 412 communicating with the lower side of the first supply tank 41 and a first drainage valve 413 provided in the first drainage line 412. And the 1st drainage part 411 drains the liquid in the 1st supply tank 41 because the 1st drainage valve 413 is controlled by controller 7. Further, the second drain tank 421, the second drain line 422, and the second drain valve having the same configuration as the first drain section 411, the first drain line 412, and the first drain valve 413 are also provided in the second supply tank 42. 423 is provided.

  The first supply tank 41 and the second supply tank 42 are also provided with a liquid level sensor (not shown). Although details will be described later, since a high-temperature alkaline solution is used in flushing, bubbling of the alkaline solution and steam are generated. This foaming and steam may cause false detection of the liquid level sensor. Therefore, the first supply tank 41 and the second supply tank 42 are provided with a partition plate that prevents foaming from approaching the liquid level sensor and a fan that exhausts steam.

The supply line 43 communicates with both the first upstream line 431 and the second upstream line 432 that communicate with the lower surfaces of the first supply tank 41 and the second supply tank 42, and both the first upstream line 431 and the second upstream line 432, respectively. An intermediate line 433 that communicates with the upper surface plate 212 of the intermediate line 433 and the first CMP apparatus 21, and a second downstream line 435 that communicates with the upper surface plate 212 of the intermediate line 433 and the second CMP apparatus 22. With.
The first upstream line 431 and the second upstream line 432 are respectively provided with a first circulation valve 436 and a second circulation valve 437 as a supply source switching unit.
The intermediate line 433 is provided with a rotation control pump 438, a filter 440, and a pressure detector 441 in order from the upstream in the liquid flow direction.
The rotation control pump 438 has a rotor 439 (see FIG. 4). The flow rate of the liquid is adjusted by adjusting the rotation speed of the rotor 439 by the controller 7.
The filter 440 captures foreign matters in the liquid. The pressure detector 441 detects the pressure of the liquid and outputs the result to the controller 7.

The liquid temperature adjustment unit 45 includes a heat exchanger 451 (shown as “HEX” in FIG. 1) provided between the rotation control pump 438 and the filter 440 in the intermediate line 433. This heat exchanger 451 is of a so-called shell and tube type, and has a structure in which a plurality of tubes through which a heat medium flows are provided in a shell (body). The heat medium introduction part in the heat exchanger 451 is communicated with the lead-out part of the introduction three-way valve 453 via the water introduction line 452. A cold water supply unit 455 is connected to one introduction part of the introduction three-way valve 453 via a cold water introduction line 454, and a hot water supply part 457 is connected to the other introduction part via a hot water introduction line 456. Has been.
On the other hand, the heat medium outlet in the heat exchanger 451 is connected to the inlet of the outlet three-way valve 459 via a water outlet line 458. A chilled water supply unit 455 is connected to one derivation part of the derivation three-way valve 459 via a cold water derivation line 460, and a hot water supply part 457 is connected to the other derivation part via a hot water derivation line 461. Has been.
With such a configuration, heat exchange is performed between the cold water as a heat medium circulating between the heat exchanger 451 and the cold water supply unit 455 and the slurry flowing through the intermediate line 433, and the slurry is cooled. . In addition, heat exchange is performed between hot water as a heat medium circulated between the heat exchanger 451 and the hot water supply unit 457 and an alkaline solution flowing through the intermediate line 433, and the alkaline solution is heated.
In addition, the structure which cools a slurry with the cold water circulated between the heat exchanger 451 and the cold water supply part 455 is generally used conventionally.

The liquid replenishment unit 5 supplies the first slurry supply unit 51 and the second slurry supply unit 52 that supply slurry to the first supply tank 41 and the second supply tank 42, respectively, and the first supply tank 41 and the second supply tank 42. A first DIW replenishing unit 53 and a second DIW replenishing unit 54 for supplying pure water and an alkaline solution replenishing unit 55 for supplying an alkaline solution to the first supply tank 41 are provided.
The first and second slurry replenishing units 51 and 52 guide slurry stored in the slurry tanks 511 and 521 to the first and second supply tanks 41 and 42, respectively. And slurry lines 512 and 522. In the slurry lines 512 and 522, slurry pumps 513 and 523 for sending the slurry in the slurry tanks 511 and 521, blending units 514 and 524 for blending the sent slurry and pure water, and slurry valves 515 and 525 are provided. Is provided.
The first DIW supply unit 53 and the second DIW supply unit 54 are DIW tanks 531 and 541 capable of storing pure water, and the pure water stored in the DIW tanks 531 and 541 is supplied to the first supply tank 41 and the second supply tank 42. And DIW lines 532 and 542, and a first DIW valve 533 and a second DIW valve 543, respectively.
The alkaline solution replenishing unit 55 includes an alkaline tank 551 that can store an alkaline solution, and an alkaline line 552 that guides the alkaline solution stored in the alkaline tank 551 to the first supply tank 41. The alkali line 552 is provided with an alkali pump 553 for sending out the alkali solution in the alkali tank 551 and an alkali valve 554.

The liquid recovery unit 6 includes a first drain tank 61 and a second drain tank 62 that receive liquid flowing down from the lower surface plate 211 of the first CMP apparatus 21 and the second CMP apparatus 22, and the first drain tank 61 and the second drain tank 62. A recovery line 63 that guides the received liquid to above the first supply tank 41 and the second supply tank 42, and recovery destination switching that returns the liquid guided by the recovery line 63 to the first supply tank 41 or the second supply tank 42. And a separator 64 as a part. The recovery line 63 communicates with both the first upstream line 631 and the second upstream line 632 that communicate with the lower surfaces of the first drainage tank 61 and the second drainage tank 62, and both the first upstream line 631 and the second upstream line 632. And a downstream line 633. The first upstream line 631 and the second upstream line 632 are provided with an on-off valve 634 that switches between a state in which liquid is circulated and a state in which liquid is not circulated.
The separator 64 includes a rotation shaft and a plate-like member provided on the outer peripheral surface of the rotation shaft. By tilting the plate-like member, the liquid discharged from the downstream line 633 is discharged from the first supply tank 41 or the separator 64. Return to the second supply tank 42.
The supply line 43 excluding the second upstream line 432, the first supply tank 41, and the recovery line 63 constitute the first circulation line of the present invention, and the supply line 43 excluding the first upstream line 431, The second supply tank 42 and the recovery line 63 constitute the second circulation line of the present invention.

As shown in FIG. 4, the controller 7 includes an input unit 71 configured by a touch panel, a keyboard, and the like, a warning unit 72 that notifies a warning by sound, light, or video, and a control device 73 that is a computer.
The control device 73 includes a CMP control means 731, a flushing control means 732, and a heat exchange control means 733 configured by processing a program and data stored in a storage means (not shown) by a CPU (Central Processing Unit). , Pump adjusting means 734 and flushing determining means 735 are provided.

  The CMP control means 731 controls the first CMP device 21 and the second CMP device 22 based on the input operation of the input unit 71 by the worker, and the slurry stored in the first supply tank 41 or the second supply tank 42. Is used to polish the wafer W.

The flushing control unit 732 performs flushing based on an input operation of the input unit 71 or a command to start flushing in the flushing determination unit 735.
The heat exchange control means 733 controls the liquid temperature adjusting unit 45 during the polishing of the wafer W to cool the slurry. Further, the liquid temperature adjusting unit 45 is controlled during the flushing to heat the alkaline solution.
The pump adjustment means 734 adjusts the rotation speed of the rotor 439 based on the liquid pressure detection result in the pressure detector 441 so that the pressure becomes substantially the same as a preset pressure value.
The flushing determination unit 735 outputs a command to start flushing to the flushing control unit 732 based on the number of rotations of the rotor 439.

[Operation of CMP system]
Next, the operation of flushing will be described as an operation of the above-described CMP system 1.
Although the interval of time T in FIGS. 5 to 8 is illustrated in the same manner for convenience, the interval does not represent the length of the period.

(Flushing based on operator instructions)
First, an outline of flushing based on an operator's command will be described.
At time T0 after the end of polishing, as shown in FIG. 5, slurry remains in the first supply tank 41 and the first and second circulation lines, and pure water remains in the second supply tank. Further, the separator 64 faces the first supply tank 41 side, and the collected liquid can be returned to the first supply tank 41.

Then, when a command to start flushing is given by an input operation of the input unit 71 by the operator at time T1, the flushing control means 732 of the control device 73 uses the second supply tank 42 to perform the second operation. A slurry eviction process is performed to expel the slurry remaining on the circulation line.
Next, when the flushing control means 732 detects that the preset time has elapsed from time T1 and has reached time T2, the first supply tank 41 is used to remove the slurry that could not be driven out in the slurry ejection process. Then, the first slurry removing process for removing from the first circulation line is started.
Further, when the flushing control means 732 detects that the time T3 is reached, the flushing control means 732 starts circulation of pure water in the first circulation line. Further, when it is detected that the time T4 is reached in the middle of the first slurry removal step, the second slurry removal step of removing the slurry from the second circulation line is started using the second supply tank 42.
By performing the above-described slurry eviction process and the first and second slurry removal processes, the slurry remaining in the first and second circulation lines, the first CMP apparatus 21, and the second CMP apparatus 22 is removed, Pure water remains. Moreover, the fixed substance of the slurry may remain.

In addition, when the flushing control means 732 detects that the time T5 is reached, the separator 64 is tilted toward the second supply tank 42 side, and circulation of pure water in the second circulation line is started. And if it detects that it became time T6 in the middle of the 2nd slurry removal process, the 1st fixed matter removal process which removes a fixed matter from the 1st circulation line using the 1st supply tank 41 will be started.
Thereafter, when it is detected that the time T7 is reached, the separator 64 is tilted toward the first supply tank 41 to start the circulation of the alkaline solution in the first circulation line. Further, when it is detected that the time T8 is reached during the first fixed matter removing step, the separator 64 is tilted toward the second supply tank 42, and the alkaline solution discharged from the first supply tank 41 is supplied to the second supply tank 41. The second fixed substance removing step of removing the fixed substance from the second circulation line using the second supply tank 42 is started.
In the first and second fixed matter removing steps described above, an alkaline solution heated by the liquid temperature adjusting unit 45 based on the control of the heat exchange control means 733 is used. By carrying out these steps, the pure water and the fixed matter remaining in the first and second circulation lines, the first CMP apparatus 21 and the second CMP apparatus 22 are removed, and the alkaline solution remains. To do. In the remaining alkaline solution, a slurry containing a residue remains.

Next, as shown in FIG. 6, when the flushing control means 732 detects that the time T9 is reached, the flushing control means 732 starts circulation of the alkaline solution in the second circulation line. And if it detects that it became time T10 in the middle of the 2nd fixed thing removal process, the 1st residue removal process which removes a residue from the 1st circulation line using the 1st supply tank 41 will be started.
Thereafter, when it is detected that the time T11 is reached, the separator 64 is tilted toward the first supply tank 41, and the circulation of pure water in the first circulation line is started. Further, when it is detected that the time T12 is reached during the first residue removal step, the second residue removal step of removing the residue from the second circulation line is started using the second supply tank 42.
By performing the first and second residue removal steps, the alkaline solution and the residue remaining in the first and second circulation lines, the first CMP apparatus 21, and the second CMP apparatus 22 are removed. In some cases, pure water may remain.

Further, when the flushing control means 732 detects that the time T13 is reached, the separator 64 is tilted toward the second supply tank 42 side, and the circulation of pure water in the second circulation line is started. And if it detects that it became time T14 in the middle of the 2nd residue removal process, the slurry substitution process which supplies a slurry to the 1st circulation line using the 1st supply tank 41 will be started.
By performing this slurry replacement step, pure water is removed from the first circulation line and the first CMP apparatus 21, and the slurry remains.
Thus, the flushing is completed.

Next, a detailed operation of the CMP system 1 at the time of flushing will be described.
At time T0, as shown in FIG. 7, all valves are closed and all pumps are stopped. The introduction three-way valve 453 and the lead-out three-way valve 459 are in a state where cold water can be supplied to the heat exchanger 451.
Then, the flushing control means 732 opens the first drain valve 413 to drain the slurry in the first supply tank 41 when starting the slurry purge process at time T1. When the liquid level sensor of the first supply tank 41 detects that the remaining amount of slurry in the first supply tank 41 has become a predetermined amount or less, the second circulation valve 437 is opened and the rotation control pump 438 is turned on. The pure water in the second supply tank 42 is caused to flow on the second circulation line. With this pure water, the slurry remaining in the second circulation line is pushed out and drained from the first supply tank 41 together with the pure water.

Next, at time T2, the flushing control means 732 starts the first slurry removal step, closes the first drain valve 413, and only supplies a predetermined amount of pure water in the first supply tank 41. The first DIW valve 533 is opened and pure water is stored in the first supply tank 41. Further, the second circulation valve 437 is closed and the rotation control type pump 438 is stopped. And the 2nd drain valve 423 is opened, the pure water in the 2nd supply tank 42 is drained, and if it drains to predetermined amount, the 2nd drain valve 423 will be closed.
Thereafter, at time T3, the flushing control means 732 opens the first circulation valve 436 and drives the rotation control pump 438 to circulate the pure water in the first supply tank 41 through the first circulation line.

Then, at time T4, the flushing control means 732 starts the second slurry removal step, opens the second DIW valve 543, stores pure water in the second supply tank 42, and stores the pure water up to a predetermined amount. The valve 543 is closed.
Next, at time T5, the flushing control means 732 closes the first circulation valve 436 to end the circulation of pure water in the first circulation line, and opens the first drain valve 413 to open the first supply tank 41. Drain the pure water inside. And if it drains to predetermined amount, the 1st drain valve 413 will be closed and a 1st slurry removal process will be complete | finished. Further, the flushing control means 732 tilts the separator 64 toward the second supply tank 42 and opens the second circulation valve 437 to circulate the pure water in the second supply tank 42 through the second circulation line.
Thereafter, at time T6, the flushing control means 732 starts the first fixed matter removing step and stores the alkaline solution in the first supply tank 41. When storing the alkaline solution, first, the alkaline valve 554 is opened and the first DIW valve 533 is driven to replenish the first supply tank 41 with the alkaline solution. The liquid level sensor causes the alkaline solution to reach a predetermined amount. When this is detected, the alkali valve 554 is closed and the alkali pump 553 is stopped. Thereafter, the first DIW valve 533 is opened, pure water is supplied to the first supply tank 41, and the first DIW valve 533 is closed when the alkali concentration reaches the set concentration.

At time T7, the flushing control means 732 closes the second circulation valve 437 to end the circulation of pure water in the second circulation line, opens the second drain valve 423, and opens the second supply tank 42. Drain pure water. And if it drains to predetermined amount, the 2nd drain valve 423 will be closed and a 2nd slurry removal process will be complete | finished. Further, the flushing control means 732 instructs the heat exchange control means 733 to heat the alkaline solution, and tilts the separator 64 toward the first supply tank 41 side.
The heat exchange control means 733 switches the introduction three-way valve 453 and the lead-out three-way valve 459 based on a command from the flushing control means 732, for example, hot water of about 75 ° C. between the heat exchanger 451 and the hot water supply unit 457. Circulate.
Then, the flushing control means 732 opens the first circulation valve 436 to circulate the alkaline solution in the first supply tank 41 in the first circulation line.
The alkaline solution circulating in the first circulation line is heated to 45 ° C. to 65 ° C. by heat exchange with the heat exchanger 451. The reason why the alkaline solution is heated to the above temperature is that when the temperature is lower than 45 ° C., the fixed matter is difficult to dissolve, and when the temperature exceeds 65 ° C., the load of the rotation control pump 438 increases.
Thereafter, at time T8, the flushing control means 732 starts the second fixed matter removing step, tilts the separator 64 toward the second supply tank 42, and secondly circulates the alkaline solution circulating in the first circulation line. It is stored in the second supply tank 42 for reuse in the line.

Next, as shown in FIG. 8, the flushing control means 732 closes the first circulation valve 436 to end the circulation of the alkaline solution in the first circulation line and opens the first drain valve 413 at time T9. The alkaline solution in the first supply tank 41 is drained. Thereafter, when the water is drained to a predetermined amount, the first drain valve 413 is closed, and the first fixed matter removing step is finished. Further, the second circulation valve 437 is opened, and the alkaline solution in the second supply tank 42 is circulated in the second circulation line.
Thereafter, at time T10, the first residue removal process is started, the first DIW valve 533 is opened, pure water is stored in the first supply tank 41, and when the predetermined amount is stored, the first DIW valve 533 is closed.
At time T11, the flushing control means 732 closes the second circulation valve 437 to end the circulation of the alkaline solution in the second circulation line, opens the second drain valve 423, and opens the second supply tank 42. Drain the alkaline solution. Thereafter, when the water is drained to a predetermined amount, the second drain valve 423 is closed. Further, the heat exchange control means 733 switches the introduction three-way valve 453 and the lead-out three-way valve 459 based on a command from the flushing control means 732 to circulate cold water between the heat exchanger 451 and the cold water supply unit 455. Thus, the second fixed object removing step is completed. Switching between the introduction three-way valve 453 and the lead-out three-way valve 459 may be performed at any timing as long as the polishing process is started.
Further, the flushing control means 732 tilts the separator 64 toward the first supply tank 41, opens the first circulation valve 436, and circulates pure water in the first supply tank 41 through the first circulation line.

Thereafter, at time T12, the flushing control means 732 starts the second residue removal process, opens the second DIW valve 543, stores pure water in the second supply tank 42, and stores it to a predetermined amount. The second DIW valve 543 is closed.
At time T13, the first circulation valve 436 is closed to terminate the circulation of pure water in the first circulation line, and the first drain valve 413 is opened to drain the pure water in the first supply tank 41. Thereafter, when the water is drained to a predetermined amount, the first drain valve 413 is closed, and the first residue removing process is ended. Further, the separator 64 is tilted toward the second supply tank 42 and the second circulation valve 437 is opened, whereby the pure water in the second supply tank 42 is circulated in the second circulation line.
Thereafter, at time T14, the flushing control means 732 starts the slurry replacement step, opens the slurry valve 515, and drives the slurry pump 513 to store the slurry in the first supply tank 41. Next, when a predetermined amount is stored, the slurry valve 515 is closed and the slurry pump 513 is stopped.

At time T15, the flushing control means 732 closes the second circulation valve 437 to end the circulation of pure water in the second circulation line, and ends the second residue removal step. Further, the separator 64 is tilted toward the first supply tank 41, the first circulation valve 436 is opened, and the slurry in the first supply tank 41 is circulated in the first circulation line.
Thereafter, at time T <b> 16, the flushing control unit 732 stops the rotation control type pump 438 and closes the first circulation valve 436, thereby completing the slurry replacement process.

(Flushing when an abnormality is detected)
Next, flushing when an abnormality is detected regardless of the operator's command will be described. The interval at which the following processing is performed may be several hours or several days.
During the flushing based on the operator's command as described above or during the polishing of the wafer W by the first CMP apparatus 21 and the second CMP apparatus 22, the pressure detector 441 is driven. As shown in FIG. 9, the pressure of the circulating liquid (slurry, pure water, or alkaline solution flowing through the intermediate line 433) is detected (step S1), and the result is output to the pump adjusting means 734. Based on the detection result from the pressure detector 441, the pump adjustment means 734 adjusts the rotation speed of the rotor 439 so that the pressure of the liquid flowing through the supply line 43 becomes substantially the same as the set pressure value (step). S2).

  Here, clogging occurs in the filter 440 due to the residue of the slurry flowing along with the liquid in the supply line 43, or the residue is fixed between the tubes of the heat exchanger 451. Since the clogging amount and the sticking amount increase with the passage of time, the pressure of the circulating liquid gradually decreases. Therefore, as shown in FIG. 10, the pump adjusting means 734 gradually increases the rotational speed of the rotor 439 so that the pressure of the circulating liquid becomes substantially constant.

Next, as shown in FIG. 9, the flushing determination means 735 determines that the rotational speed of the rotor 439 of the rotation control type pump 438 is set to a preset rotational speed M based on the adjustment result of the pump adjustment means 734. It is determined whether or not the above has been reached (step S3).
Such a determination process is performed when the rotation speed of the rotor 439 is equal to or higher than the set rotation speed M, because the filter 440 is clogged or there are many residues adhering to the heat exchanger 451. It is necessary to do it.

If the flushing determination means 735 determines in step S3 that the rotation speed is not higher than the set rotational speed M, the process returns to step S1, and if it is determined in step S3 that the rotation speed is higher than the set rotation speed M, the CMP control means 731 is performed. Under the control, it is determined whether or not the first CMP apparatus 21 and the second CMP apparatus 22 are operating (step S4).
When it is determined that the first CMP apparatus 21 or the like is operating, the flushing determination unit 735 controls the warning unit 72 to warn that flushing is necessary (step S5). When an operator who has recognized the warning performs an input operation for stopping the polishing by the first CMP apparatus 21 and the second CMP apparatus 22, the CMP control unit 731 ends the polishing. Furthermore, when an input operation for starting flushing is performed by the worker, the flushing control means 732 starts flushing based on the above-described command of the worker.

On the other hand, if the flushing determination unit 735 determines that the first CMP apparatus 21 or the like is not in operation, the flushing determination unit 735 instructs the flushing control unit 732 to start flushing. The flushing control means 732 starts flushing (automatic flushing) similar to the above-described flushing based on the operator's instruction based on the instruction from the flushing determination means 735 (step S6).
When flushing is performed, clogging of the filter 440 and fixed matter of the heat exchanger 451 are removed, so that the pressure detected by the pressure detector 441 becomes low. For this reason, the rotation of the rotor 439 is adjusted to be low as shown in FIG.

[Effects of Embodiment]
In the present embodiment as described above, the following operational effects can be achieved.
(1) In addition to the supply line 43 and the recovery line 63, the first CMP apparatus 21 and the second CMP apparatus 22 that are in contact with the slurry are also flushed, so that the foreign matters in the first CMP apparatus 21 and the second CMP apparatus 22 are removed. it can. For example, foreign substances adhering to the liquid supply port of the upper surface plate 212, the outer peripheral side surface portion of the lower surface plate 211, and various gears can be removed. Further, as compared with a configuration in which only one supply tank is provided, flushing can be performed with a large amount of pure water or an alkaline solution, and the cleaning ability can be improved. Furthermore, since the operator only has to operate the input unit 71 in performing the flushing, the risk of chemical injury due to direct handling of the alkaline solution can be reduced, and variations in work by the operator can also be reduced.

(2) Since the first supply tank 41 and the second supply tank 42 are provided, the first supply tank 41 and the second supply tank 42 perform the same processing, for example, the first supply tank when performing the slurry removal step. Pure water is stored in the second supply tank 42 during the circulation of pure water in the tank 41, and the pure water is immediately circulated in the second supply tank 42 after the circulation of pure water in the first supply tank 41 is completed. You can start. Therefore, flushing of the first and second circulation lines can be performed in a short time.

(3) Since flushing is performed using a heated alkaline solution, the ability to remove solids from the alkaline solution can be improved, and the flushing time can be shortened. Moreover, since the alkaline solution is heated by introducing warm water into the heat exchanger 451 used for cooling the slurry, it is only necessary to provide a configuration for introducing warm water into the existing equipment, thereby minimizing capital investment. Can do.

(4) Even if the pressure of the liquid flowing through the supply line 43 decreases due to clogging of the filter 440 or the like, the rotational speed of the rotor 439 is increased by the control of the pump adjusting means 734 so that the liquid pressure becomes substantially constant. Therefore, a predetermined cleaning ability can be maintained. Further, when the rotational speed of the rotor 439 becomes equal to or higher than the set rotational speed M, the flushing determination unit 735 warns the operator to that effect by the warning unit 72. For this reason, the operator can take an appropriate response.

(5) The flushing determination means 735 starts flushing to the flushing control means 732 when the rotational speed of the rotor 439 is equal to or higher than the set rotational speed M and the first CMP apparatus 21 and the second CMP apparatus 22 are not operating. Let For this reason, flushing can be started at an appropriate timing without bothering the operator's hand or even when the operator is absent.

[Other Embodiments]
Note that the present invention is not limited to the above-described embodiment, and various improvements and design changes can be made without departing from the scope of the present invention.
In other words, the pressure detector 441 and the pump adjusting unit 734 may not be provided, and the pressure of the liquid flowing through the supply line 43 may not be adjusted. Further, even when the rotational speed of the rotor 439 is high and the first CMP apparatus 21 is not operating, it is only necessary to issue a warning without automatically starting the flushing.
Furthermore, the alkaline solution need not be heated. Moreover, as a structure which heats an alkaline solution, you may provide the heat exchanger different from the heat exchanger 451 which cools a slurry, or a heater.
Further, without providing the first circulation valve 436 and the second circulation valve 437, a three-way valve of one CMP system may be provided as a supply source switching unit at the connection point between the first upstream line 431 and the second upstream line 432. Good.
Further, without providing the separator 64, a three-way valve is provided in the discharge hole of the downstream line 633 as a collection destination switching unit, and liquid is supplied to the first supply tank 41 and the second supply tank 42 in the outlet part of the three-way valve. A line for discharging may be provided. Furthermore, without providing the separator 64, the discharge side of the downstream line 633 may be branched into two as a collection destination switching unit, and a valve may be provided in each of the branched lines.
Further, when the same processing is performed in the first supply tank 41 and the second supply tank 42, for example, in the slurry removal process, the pure water in the second supply tank 42 is circulated during the circulation of pure water in the first supply tank 41. It is not necessary to store water.
Further, the present invention may be applied to a single-side polishing apparatus that polishes one side of the wafer W.

3 ... Slurry circulation device 21, 22 ... CMP device (polishing device)
41 ... 1st supply tank 42 ... 2nd supply tank 43 ... Supply line 51, 52 ... 1st, 2nd slurry supply part 53, 54 ... 1st, 2nd DIW supply part (pure water supply part)
55 ... Alkaline solution replenishment part 63 ... Collection line 64 ... Separator (collection destination switching part)
436, 437 ... First and second circulation valves (supply source switching unit)
438 ... Rotation control type pump (pump)
439 ... Rotor 441 ... Pressure detector 451 ... Heat exchanger 455 ... Cold water supply unit 457 ... Hot water supply unit

Claims (6)

A slurry circulation device for supplying slurry to a polishing apparatus and recovering slurry discharged from the polishing apparatus,
A first supply tank and a second supply tank capable of storing and draining liquid;
A supply line for supplying liquid stored in the first supply tank and the second supply tank to the polishing apparatus;
A pump provided in the supply line;
A supply source switching unit that switches a supply source of the liquid supplied to the polishing apparatus between the first supply tank and the second supply tank;
A collection line for collecting the liquid discharged from the polishing apparatus into the first supply tank and the second supply tank;
A recovery destination switching unit for switching a liquid recovery destination by the recovery line between the first supply tank and the second supply tank;
A slurry replenishing section for replenishing slurry to at least one of the first supply tank and the second supply tank;
A pure water replenishing section for replenishing the first supply tank and the second supply tank with pure water;
An alkaline solution replenishment unit that replenishes the first supply tank and the second supply tank with an alkaline solution ;
A controller for controlling the pump, the supply source switching unit, the recovery destination switching unit, the slurry supply unit, the pure water supply unit, and the alkaline solution supply unit ;
The first supply tank, the supply line, and the recovery line constitute a first circulation line that circulates liquid between them,
The second supply tank, the supply line, and the recovery line constitute a second circulation line that circulates liquid between them,
The control device includes:
A first slurry removal step of removing the slurry by circulating pure water stored in the first supply tank in the first circulation line;
A second slurry removing step of removing the slurry by circulating the pure water stored in the second supply tank in the second circulation line after performing the first slurry removing step;
After performing the second slurry removing step, a first stuck matter removing step of removing the stuck matter of the slurry by circulating the alkaline solution stored in the first supply tank in the first circulation line;
After performing the first fixed matter removing step, a second fixed matter removing step of removing the fixed matter in the slurry by circulating the alkaline aqueous solution stored in the second supply tank in the second circulation line;
A first residue removal step of removing the slurry residue by circulating the pure water stored in the first supply tank in the first circulation line after performing the second fixed matter removal step;
After performing the first residue removal step, the second residue removal step of removing the slurry residue by circulating the pure water stored in the second supply tank in the second circulation line is performed. The slurry circulating apparatus characterized by the above-mentioned. The slurry circulating apparatus according to claim 1, wherein
The supply line is provided with a heat exchanger that exchanges heat with the liquid flowing through the supply line,
A slurry circulating apparatus, wherein a cold water supply unit that supplies cold water to the heat exchanger and a hot water supply unit that supplies hot water are connected to the heat exchanger. A slurry circulating apparatus flushing method for supplying slurry to a polishing apparatus and recovering slurry discharged from the polishing apparatus,
The slurry circulating apparatus is
A first supply tank and a second supply tank capable of storing and draining liquid;
A supply line for supplying liquid stored in the first supply tank and the second supply tank to the polishing apparatus;
A recovery line for recovering the liquid discharged from the polishing apparatus to the first supply tank and the second supply tank;
The first supply tank, the supply line, and the recovery line constitute a first circulation line that circulates liquid between them,
The second supply tank, the supply line, and the recovery line constitute a second circulation line that circulates liquid between them,
A first slurry removal step of removing the slurry by circulating pure water stored in the first supply tank in the first circulation line;
A second slurry removing step of removing the slurry by circulating the pure water stored in the second supply tank in the second circulation line after performing the first slurry removing step;
After performing the second slurry removing step, a first stuck matter removing step of removing the stuck matter of the slurry by circulating the alkaline solution stored in the first supply tank in the first circulation line;
After performing the first fixed matter removing step, a second fixed matter removing step of removing the fixed matter in the slurry by circulating the alkaline aqueous solution stored in the second supply tank in the second circulation line;
A first residue removal step of removing the slurry residue by circulating the pure water stored in the first supply tank in the first circulation line after performing the second fixed matter removal step;
After the first residue removal step is performed, a second residue removal step is performed in which pure water stored in the second supply tank is circulated in the second circulation line to remove slurry residue. A flushing method for a slurry circulating apparatus. In the flushing method of the slurry circulating apparatus according to claim 3,
During the practice of the first slurry removal step, pure water is stored in the second supply tank,
During the execution of the second slurry removal step, the pure water in the first supply tank is drained and the alkaline solution is stored in the first supply tank,
During the implementation of the first fixed matter removing step, the pure water in the second supply tank is drained and an alkaline solution is stored in the second supply tank,
During the implementation of the second fixed matter removing step, the alkaline solution in the first supply tank is drained and pure water is stored in the first supply tank,
During the execution of the first residue removing step, the alkaline solution in the second supply tank is drained and pure water is stored in the second supply tank. In the flushing method of the slurry circulating apparatus according to claim 3 or 4,
The supply line is provided with a pump that controls the flow rate of the liquid by rotating a rotor, and a pressure detector that detects the pressure of the liquid on the downstream side of the pump,
Based on the detection result of the pressure by the pressure detector, a rotation speed adjustment step of adjusting the rotation speed of the rotor of the pump so that the pressure of the liquid becomes a preset pressure value,
A flushing determination step for determining that the flushing of the supply line is necessary when the rotational speed of the rotor is equal to or higher than a preset rotational speed;
A flushing method for a slurry circulating apparatus, comprising: performing an alarming step of alarming if flushing is determined to be necessary in the flushing determination step. In the flushing method of the slurry circulating apparatus according to claim 3 or 4,
The supply line is provided with a pump that controls the flow rate of the liquid by rotating a rotor, and a pressure detector that detects the pressure of the liquid on the downstream side of the pump,
Based on the detection result of the pressure by the pressure detector, a rotation speed adjustment step of adjusting the rotation speed of the rotor of the pump so that the pressure of the liquid becomes a preset pressure value,
A flushing determination step for determining that the flushing of the supply line is necessary when the rotational speed of the rotor is equal to or higher than a preset rotational speed;
Polishing determination step for determining whether or not the wafer is being polished in the polishing apparatus;
Performing a flushing start control step for starting the first slurry removal step when it is determined in the flushing determination step that flushing is necessary and it is determined in the polishing determination step that the wafer is not being polished. A flushing method for a slurry circulating apparatus.

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