Substrate processing device and substrate processing method

Abstract

The present invention addresses the problem of providing a technique for suppressing the increase of particulate matter. The substrate processing apparatus of the present invention includes a liquid tank, a circulation pipeline, a branch pipeline, a processing unit, a discharge unit, a supply unit, and a control unit. The control unit includes a first determination unit, a first replenishment control unit, a calculation unit, and a second replenishment control unit. The first determination unit determines whether the storage level of the processing liquid in the liquid tank has not reached a lower limit. When the first determination unit determines that the storage level has not reached the lower limit, the first replenishment control unit replenishes the liquid tank with the processing liquid via the supply unit. The calculation unit calculates the amount of processing liquid replenished to the liquid tank by the supply unit at set intervals. When the calculated replenishment amount by the calculation unit does not reach a set value, the second replenishment control unit reduces the storage level of the liquid tank via the discharge unit and replenishes the liquid tank with the processing liquid via the supply unit.

Description

[Technical Field]

[0001] The present invention relates to a substrate processing apparatus and a substrate processing method. [Previous Technology]

[0002] Patent Document 1's substrate processing system includes one or more processing units, a memory unit, a liquid storage unit, an acquisition unit, a setting unit, a detection unit, an identification unit, and a detection unit. One or more processing units use a processing liquid to process the substrate. The memory unit stores and displays processing plan information for multiple consecutive processing times of multiple substrate groups of the one or more processing units. The liquid storage unit stores the processing liquid. The acquisition unit acquires values ​​regarding the state of the processing liquid. The setting unit sets the replacement period of the processing liquid in the liquid storage unit based on the values ​​acquired by the acquisition unit and rules regarding the lifespan of the processing liquid. During the replacement period, the detection unit detects a standby state where continuous processing has not been performed by one or more processing units. The identification unit identifies the duration of the standby state based on the processing plan information. The detection unit detects a liquid replacement state where the duration is longer than a preset reference time. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2018-181881 [Summary of the Invention]

[0004] [The problem the invention aims to solve]

[0005] The first embodiment of the present invention provides a technique for suppressing the increase of particulate matter caused by the circulation of the treatment fluid. Furthermore, the second embodiment of the present invention provides a technique for suppressing the increase of particulate matter caused by the replacement of the treatment fluid. [Means for Solving the Problem]

[0006] A substrate processing apparatus of the first aspect of the present invention includes a liquid tank, a circulation pipeline, a branch pipeline, a processing unit, a discharge unit, a supply unit, and a control unit. The liquid tank stores processing liquid. The circulation pipeline removes the processing liquid from the liquid tank and returns it to the liquid tank. The branch pipeline branches off from the circulation pipeline. The processing unit supplies the processing liquid to the substrate at the front end of the branch pipeline. The discharge unit reduces the amount of processing liquid stored in the liquid tank. The supply unit supplies new processing liquid to the liquid tank. The control unit controls the processing unit, the discharge unit, and the supply unit. The control unit includes a first determination unit, a first replenishment control unit, a calculation unit, and a second replenishment control unit. The first determination unit determines whether the amount of processing liquid stored in the liquid tank has not reached a lower limit. When the first determination unit determines that the amount of processing liquid has not reached the lower limit, the first replenishment control unit replenishes the liquid tank with processing liquid by the supply unit. The calculation unit calculates the amount of treatment fluid to be replenished to the liquid tank by the supply unit at set intervals. When the calculated value of the replenishment amount by the calculation unit does not reach the set value, the second replenishment control unit reduces the storage amount in the liquid tank by the discharge unit and replenishes the treatment fluid in the liquid tank by the supply unit.

[0007] A second embodiment of the substrate processing apparatus of the present invention includes a liquid tank, a circulation pipeline, a pump, a branch pipeline, a processing unit, a discharge unit, a supply unit, and a control unit. The liquid tank stores processing liquid. The circulation pipeline removes the processing liquid from the liquid tank and returns it to the liquid tank. The pump is provided in the circulation pipeline. The branch pipeline branches off from the circulation pipeline. The processing unit supplies the processing liquid to the substrate at the front end of the branch pipeline. The discharge unit reduces the amount of processing liquid stored in the liquid tank. The supply unit supplies new processing liquid to the liquid tank. The control unit controls the pump, the processing unit, the discharge unit, and the supply unit. The control unit has a first liquid replacement control unit. When the first liquid replacement control unit receives a liquid replacement command to replace the circulating processing liquid, while the processing liquid is being circulated by the pump, it performs the operation of reducing the amount of processing liquid stored in the liquid tank by the discharge unit and the operation of supplying processing liquid to the liquid tank by the supply unit. [Effects of the Invention]

[0008] According to the first embodiment of the present invention, the increase in particulate matter caused by the circulation of the treatment fluid can be suppressed. Furthermore, according to the second embodiment of the present invention, the increase in particulate matter caused by the replacement of the treatment fluid can be suppressed.

Implementation Method

[0010] [Form used to implement the invention]

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, there are cases in which the same or corresponding structures are given the same symbol in each drawing, and the description is omitted.

[0012] Referring to FIG1, the substrate processing apparatus 1 of this embodiment will be described. The substrate processing apparatus 1 includes a processing unit 10. The processing unit 10 processes the substrate by supplying a processing liquid to the substrate. In this embodiment, the processing unit 10 is a single-piece type that processes substrates one by one.

[0013] Furthermore, the processing unit 10 can also be a batch type that processes multiple substrates simultaneously. The batch type processing unit 10 has a processing liquid tank, and the substrates can be immersed in the processing liquid stored in the processing liquid tank. At this time, the substrates W can also be immersed in the processing liquid in a vertical position.

[0014] As shown in FIG2, the single-piece processing unit 10 includes, for example, a processing container 11, a holding part 12 for holding the substrate W horizontally, a rotating part 13 for rotating the holding part 12 around a vertical rotating axis 14, and a nozzle 16 for spraying liquid onto the top of the substrate W held in the holding part 12.

[0015] The processing container 11 houses the substrate W inside. The processing container 11 has a gate (not shown) and a gate valve (not shown) for opening and closing the gate. The substrate W is moved into the processing container 11 via the gate, processed with the processing liquid L inside the processing container 11, and then moved out of the processing container 11 via the gate.

[0016] The holding part 12 holds the substrate W, which has been moved into the processing container 11, horizontally. The holding part 12 holds the substrate W horizontally with the side of the substrate W on which the polysilicon film is formed facing upwards, and the center of the substrate W is aligned with the rotation center line of the rotation axis 14. The holding part 12 in FIG2 is a mechanical chuck, but it can also be a vacuum chuck or an electrostatic chuck, etc. The holding part 12 can be any rotatable rotary chuck.

[0017] The rotating part 13 includes, for example, a vertical rotating shaft 14 and a rotary motor 15 that rotates the rotating shaft 14. The rotational driving force of the rotary motor 15 can also be transmitted to the rotating shaft 14 by a rotational transmission mechanism such as a timing belt or gear. When the rotating shaft 14 is rotated, the holding part 12 is also rotated.

[0018] The nozzle 16 has an outlet for spraying processing liquid L onto the substrate W held in the holding portion 12. For example, the nozzle 16 is positioned above the substrate W with the outlet facing downwards, and supplies processing liquid L to the center of the substrate W. The processing liquid L is supplied to the center of the rotating substrate W, and by centrifugal force, it expands and wets the entire surface of the substrate W, forming a liquid film. The processing portion 10 may also include a moving portion 19 for moving the nozzle 16. The moving portion 19 can move the nozzle 16 radially along the substrate W, and can also move the nozzle 16 vertically.

[0019] The processing liquid L includes, for example, a chemical solution, a cleaning solution, and a drying solution. A plurality of processing liquids L can be sequentially sprayed from a single nozzle 16, or a plurality of nozzles 16 can sequentially spray different processing liquids L. A plurality of chemical solutions can be sequentially supplied to the substrate W, or a cleaning solution can be supplied to the substrate W between the chemical solutions.

[0020] The solution is not particularly limited and may be DHF (dilute hydrofluoric acid), SC-1 (an aqueous solution containing ammonium hydroxide and hydrogen peroxide), SC-2 (an aqueous solution containing hydrogen chloride and hydrogen peroxide), or SPM (an aqueous solution containing sulfuric acid and hydrogen peroxide), etc. The solution may also be an etching solution for etching the substrate W.

[0021] The cleaning solution is, for example, DIW (deionized water). The cleaning solution is used to remove the chemical solution. The cleaning solution is supplied to the center of the rotating substrate W, and by centrifugal force, it expands to wet the entire surface of the substrate W, rinsing away any chemical solution remaining on the substrate W. As a result, a liquid film of cleaning solution is formed on the surface of the substrate W. Alternatively, the cleaning solution can be supplied to the substrate W after one chemical solution has been supplied to the substrate W and before other chemical solutions have been supplied to the substrate W.

[0022] The drying solution is an organic solvent such as IPA (isopropanol). Organic solvents have a lower surface tension than the cleaning solution. Therefore, damage to the uneven pattern caused by surface tension can be suppressed. The drying solution is supplied to the center of the rotating substrate W, and by centrifugal force, it expands to wet the entire surface of the substrate W, replacing the cleaning solution remaining on the substrate W. As a result, a liquid film of drying solution is formed on the surface of the substrate W.

[0023] The processing unit 10 has a cup 17 for recovering the processing liquid L supplied to the substrate W. The cup 17 surrounds the periphery of the substrate W held in the holding unit 12 and receives the processing liquid L that spills from the periphery of the substrate W. In this embodiment, the cup 17 does not rotate with the rotation axis 14, but it may rotate with the rotation axis 14. A drain pipe 17a for discharging liquid accumulated inside the cup 17 and an exhaust pipe 17b for discharging gas accumulated inside the cup 17 are provided on the bottom wall of the cup 17.

[0024] As shown in FIG. 1, the substrate processing apparatus 1 includes a liquid tank 20 for storing processing liquid L, a circulation pipe 21 for taking out processing liquid L from the liquid tank 20 and returning it to the liquid tank 20, and a branch pipe 22 branching from the circulation pipe 21. The processing unit 10 supplies processing liquid L to the substrate W at the front end of the branch pipe 22. The processing liquid L is not particularly limited, and is, for example, IPA.

[0025] The liquid tank 20 stores the treatment liquid L. The treatment liquid L circulates from the liquid tank 20 through the circulation pipeline 21 back to the liquid tank 20. Along the circulation pipeline 21, for example, a pump 23, a flow meter 24, a heater 25, a thermometer (not shown in the figure), and a filter 26 are provided. Furthermore, the configuration of these machines 23 to 26 is not limited to the configuration shown in Figure 1.

[0026] Pump 23 circulates the processing fluid L. Flow meter 24 measures the flow rate of the processing fluid L. Control unit 90 controls pump 23 so that the flow meter 24's measurement value is a set value. Heater 25 heats the processing fluid L. Temperature meter measures the temperature of the processing fluid L. Control unit 90 controls heater 25 so that the temperature meter's measurement value is a set value. The desired temperature of the processing fluid L can then be supplied to the substrate W. Filter 26 collects foreign matter from the processing fluid L.

[0027] The branch line 22 connects the circulation line 21 to the nozzle 16 of the processing unit 10. The branch line 22 is provided for each processing unit 10. In addition, when the processing unit 10 is batch-type, the branch line 22 connects the circulation line 21 to the processing liquid tank of the processing unit 10. For example, a flow meter 27, a flow controller 28, and a switching valve 29 are provided along the branch line 22. Furthermore, the configuration of these machines 27 to 29 is not limited to the configuration shown in FIG1.

[0028] When the switch valve 29 opens the branch line 22, the branch line 22 supplies the processing fluid L to the processing unit 10. The flow meter 27 measures the flow rate of the processing fluid L. The control unit 90 controls the flow controller 28 to set the flow meter 27's measurement value to the set value. On the other hand, when the switch valve 29 closes the branch line 22, the branch line 22 stops supplying the processing fluid L to the processing unit 10.

[0029] A return line 30 may also be provided along the branch line 22. The return line 30 branches off from the branch line 22, allowing the processed liquid to return to the liquid tank 20. The return line 30 is provided for each processing unit 10. For example, a switch valve 31 is provided along the return line 30.

[0030] When the switch valve 29 closes the branch pipe 22 and the switch valve 31 opens the return pipe 30, the processing liquid L is not supplied to the processing unit 10 and returns to the liquid tank 20. During the period when the processing unit 10 does not consume the processing liquid L, the processing liquid L heated by the heater 25 can continue to flow to a part of the branch pipe 22, thereby suppressing the temperature drop of the processing liquid L in the branch pipe 22.

[0031] On the other hand, when the switching valve 29 opens the branch pipe 22 and the switching valve 31 closes the return pipe 30, the processing liquid L is not returned to the liquid tank 20 but is supplied to the processing unit 10. The processing liquid L supplied to the processing unit 10 is consumed in the processing unit 10. That is, the processing liquid L supplied to the processing unit 10 is discharged to the outside of the substrate processing apparatus 1 and does not return to the liquid tank 20. As a result, the storage amount H of the processing liquid L stored in the liquid tank 20 is reduced.

[0032] The substrate processing apparatus 1 includes a discharge section 40 that reduces the storage amount H of the processing liquid L, separate from the processing section 10. The discharge section 40 reduces the storage amount H of the processing liquid L, for example, when the processing liquid L is replaced to suppress its deterioration. The discharge section 40 includes, for example, a first discharge section 41 and a second discharge section 42. Alternatively, the discharge section 40 may include only the first discharge section 41 or only the second discharge section 42.

[0033] The first discharge section 41 includes a first discharge pipe 43 connected to the liquid tank 20 and a first switch valve 44 for switching the first discharge pipe 43. When the first switch valve 44 opens the first discharge pipe 43, the first discharge pipe 43 discharges the processed liquid L from the liquid tank 20, thereby reducing the storage amount H of the processed liquid L. On the other hand, when the first switch valve 44 closes the first discharge pipe 43, the first discharge pipe 43 stops discharging the processed liquid L from the liquid tank 20.

[0034] The second discharge section 42 includes a second discharge pipe 45 connected to the circulation pipe 21 and a second switching valve 46 for switching the second discharge pipe 45. When the second switching valve 46 opens the second discharge pipe 45, the second discharge pipe 45 discharges the processed liquid L from the circulation pipe 21, thereby reducing the storage volume H of the processed liquid L. On the other hand, when the second switching valve 46 closes the second discharge pipe 45, the second discharge pipe 45 stops discharging the processed liquid L from the circulation pipe 21.

[0035] The substrate processing apparatus 1 includes a supply unit 50 for supplying new processing liquid L to the liquid tank 20. The supply unit 50 includes a supply line 51 connected to the liquid tank 20. New processing liquid L is supplied to the liquid tank 20 through the supply line 51. For example, a flow meter 52, a flow controller 53, and a switching valve 54 are provided along the supply line L1. Furthermore, the configuration of these devices 52 to 54 is not limited to the configuration shown in FIG1.

[0036] When the switch valve 54 opens the supply line 51, the supply line 51 supplies new processing liquid L to the liquid tank 20. The flow meter 52 measures the flow rate of the processing liquid L. The control unit 90 controls the flow controller 53 to set the flow meter 52's measurement value to the set value. On the other hand, when the switch valve 54 closes the supply line 51, the supply line 51 stops supplying new processing liquid L to the liquid tank 20.

[0037] The substrate processing apparatus 1 includes a plurality of detectors 61 to 64 for detecting the storage volume H of the processing liquid L in the liquid tank 20. The plurality of detectors 61 to 64 are set at different heights to detect whether there is processing liquid L at each setting position. In addition, although not shown in the figure, the substrate processing apparatus 1 may also have a floating detector, and the number of detectors may also be one.

[0038] The substrate processing apparatus 1 includes a control unit 90. The control unit 90 is, for example, a computer, and includes a CPU (Central Processing Unit) 91 and a memory medium 92 such as memory. The memory medium 92 stores programs that control various processes executed on the substrate processing apparatus 1. The control unit 90 controls the operation of the substrate processing apparatus 1 by having the CPU 91 execute the programs stored in the memory medium 92.

[0039] As shown in FIG3, the control unit 90 includes, for example, a substrate processing unit 101, a first determination unit 102, a first supplementary control unit 103, a calculation unit 104, a second supplementary control unit 105, a second determination unit 106, a forced stop unit 107, a first fluid replacement control unit 108, and a second fluid replacement control unit 109. Furthermore, the functional blocks shown in FIG3 are conceptual and may not necessarily be physically configured as illustrated.

[0040] All or part of the functional blocks shown in Figure 3 can be distributed or integrated functionally or physically in any unit. All or any part of the processing functions performed in each functional block can be implemented by a program executed by the CPU, or by hardware implementation of wiring logic.

[0041] Next, referring to FIG4, an example of the processing of the substrate processing unit 101 will be described. Each step S101 to S106 shown in FIG4 is performed under the control of the substrate processing unit 101. The substrate processing unit 101 processes the substrate W by supplying processing liquid L to the substrate W.

[0042] First, a transport device (not shown) moves the substrate W into the processing container 11 (step S101). After placing the substrate W on the holding part 12, the transport device exits from the processing container 11. The holding part 12 holds the substrate W. Then, the rotating part 13 rotates the substrate W together with the holding part 12.

[0043] Next, the nozzle 16 supplies the liquid medicine to the center of the rotating substrate W (step S102). The liquid medicine spreads and wets the entire surface of the substrate W by centrifugal force, forming a liquid film.

[0044] Then, the nozzle 16 supplies cleaning fluid to the center of the rotating substrate W (step S103). The cleaning fluid expands and wets the entire surface of the substrate W by centrifugal force, rinsing off any residual cleaning fluid on the substrate W. As a result, a liquid film of cleaning fluid is formed on the surface of the substrate W.

[0045] Subsequently, nozzle 16 supplies drying liquid to the center of the rotating substrate W (step S104). The drying liquid expands and wets the entire surface of the substrate W by centrifugal force, rinsing off the cleaning liquid remaining on the substrate W. As a result, a liquid film of drying liquid is formed on the surface of the substrate W.

[0046] Next, the rotating part 13 rotates the substrate W to remove the drying liquid remaining on the substrate W, thereby drying the substrate W (step S105). After the substrate W is dried, the rotating part 13 stops rotating the substrate W.

[0047] Finally, the holding part 12 releases the substrate W from the holding part, and then the conveying device (not shown in the figure) takes the substrate W from the holding part 12 and moves the taken substrate W to the outside of the processing container 11 (step S106).

[0048] Next, referring to FIG5, an example of the processing of the first determination unit 102 and the first supplementary control unit 103 will be described. The processing after step S201 shown in FIG5 is performed periodically during the circulation of the processing liquid L.

[0049] First, the first determination unit 102 determines whether the storage amount H of the processing liquid L in the liquid tank 20 has not reached the lower limit value Hmin (step S201). This determination uses, for example, the detector 63 shown in FIG1.

[0050] When the detector 63 does not detect the presence of the processing liquid L, the first determination unit 102 determines that the storage amount H has not reached the lower limit value Hmin. On the other hand, when the detector 63 detects the presence of the processing liquid L, the first determination unit 102 determines that the storage amount H is above the lower limit value Hmin.

[0051] When the first determination unit 102 determines that the storage amount H has not reached the lower limit value Hmin (step S201, yes), the first replenishment control unit 103 replenishes the liquid tank 20 with new processing liquid L by the supply unit 50 (step S202). Thereby, the storage amount H is at or above the lower limit value Hmin.

[0052] The first replenishment control unit 103 can also replenish the new treatment fluid L to a storage volume H that is above the lower limit Hmin and below the upper limit Hmax. The detector 64 shown in Figure 1 detects that the storage volume H has reached the upper limit Hmax.

[0053] On the other hand, when the first determination unit 102 determines that the storage amount H is above the lower limit value Hmin (step S201, no), the first replenishment control unit 103 does not replenish new processing liquid L. After that, the current processing ends.

[0054] Even if the processing unit 10 consumes processing fluid L, the processing fluid L is replenished by the first replenishment control unit 103, and the storage level H of the liquid tank 20 remains at a certain level or above. The storage level H of the liquid tank 20 is maintained within the allowable range specified by the following limit value Hmin and the upper limit value Hmax.

[0055] Next, referring to FIG6, an example of the relationship between the number of particles attached to the substrate W, the cycle time, and the temperature of the processing solution will be explained. The cycle time is the elapsed time from step S404 in FIG11 (described later), which is the elapsed time since the completion of the liquid replacement process. Details of the liquid replacement process will be described later. In FIG6, the processing solution is IPA.

[0056] As shown in Figure 6, after the liquid replacement process, the longer the circulation time, the more progress is made in filtration, and the number of particles attached to the substrate W decreases. Filtration refers to the use of filter 26 to capture the particles P contained in the treatment liquid L, as shown in Figure 7(A).

[0057] As shown in Figure 6, when the temperature of the processing solution L is room temperature or 60°C, the number of particles adhering to the substrate W gradually decreases and then stabilizes. On the other hand, when the temperature of the processing solution L is 70°C, the number of particles adhering to the substrate W gradually decreases and then increases. When the temperature of the processing solution L increases, as shown in Figure 7(B), the leached substance E dissolves from the filter 26 into the processing solution L, and is considered as leached substance E adhering to the substrate W as particles. The higher the temperature of the processing solution L, the easier it is for the leached substance E to dissolve, and the more particles adhering to the substrate W increases.

[0058] The leachate E, for example, dissolves in the processing solution L, passes through the filter 26, and precipitates as particulate matter on the substrate W. Alternatively, the leachate E may not dissolve in the processing solution L, but has a particle size sufficient to pass through the filter 26. In any case, as shown in Figure 7(C), the leachate E passes through the filter 26. The longer the circulation time, the more the leachate E accumulates, and the number of particulate matter considered to be attached to the substrate W increases.

[0059] Furthermore, the machine that generates the leachate E is not limited to the filter 26. Any machine installed in the circulation line 21 may generate the leachate E in the processing liquid L. The relationship between the number of particles adhering to the substrate W, the circulation time, and the temperature of the processing liquid L varies depending on the composition of the processing liquid L and the material of the machine.

[0060] In this embodiment, as shown in FIG7(D), the treatment liquid L contaminated by the leached substance E is discharged, and instead, a new treatment liquid L is added to the liquid tank 20. This suppresses the leached substance E from adhering to the substrate W as particulate matter, and suppresses the increase in particulate matter caused by the circulation of the treatment liquid L.

[0061] Next, referring to FIG8, an example of the processing of the calculation unit 104 and the second supplementary control unit 105 will be described. The processing after step S301 shown in FIG8 is performed in parallel with the processing after step S201 shown in FIG5, and is carried out during the circulation of the processing liquid L.

[0062] First, the calculation unit 104 calculates the replenishment amount R of the treatment liquid L replenished to the liquid tank 20 by the supply unit 50 at every set time t0 (step S301). The set time t0 is, for example, 1 hour, or it can be 10 minutes. The set time t0 can be appropriately changed. Hereinafter, the replenishment amount R at every set time t0 will also be referred to simply as the replenishment amount R.

[0063] The replenishment of the processing fluid L is shown in Figure 5. When the first determination unit 102 determines that the storage amount H has not reached the lower limit value Hmin (step S201, yes), the replenishment is performed. The more processing fluid L consumed in the processing unit 10, the easier it is for the storage amount H to decrease, and the more replenishment amount R is required. The replenishment amount R is equal to the consumption amount.

[0064] The processing unit 10 consumes processing liquid L when processing the substrate W. In addition, in order to prevent the processing liquid L from stagnating for a long time around the nozzle 16 during the period when the processing of the substrate W is interrupted, the nozzle 16 periodically sprays the processing liquid L. Therefore, the processing unit 10 still consumes processing liquid L during the period when the processing of the substrate W is interrupted.

[0065] However, during the period when the processing of substrate W is interrupted, the consumption of processing liquid L is less, and the replenishment amount R is also less than the period during which substrate W is processed. Furthermore, the fewer substrates W are processed per set time t0, the less processing liquid L is consumed, and the less replenishment amount R is replenished. The replenishment amount R and the consumption amount vary according to the operating status of the substrate processing apparatus 1.

[0066] The calculation unit 104 calculates the replenishment amount R, for example, from the measurement value of the flow meter 52 installed in the supply pipeline 51. At this time, the calculation unit 104 calculates the replenishment amount R by integrating the measurement value of the flow meter 52 over a set time t0.

[0067] The calculation unit 104 can also receive a processing plan including the processing time points of the substrate W from the main computer 200, and calculate the replenishment amount R from the processing plan. The calculation unit 104 calculates the number of substrate W processed per set time t0 from the processing time points of the substrate W, calculates the amount of processing liquid L consumed, and calculates the replenishment amount R.

[0068] The main computer 200 is located outside the substrate processing apparatus 1 and sends the processing plan to the substrate processing apparatus 1. The processing plan may include, in addition to the processing time of the substrate W, the supply time of the processing liquid L to the substrate W and the supply flow rate of the processing liquid L to the substrate W. Furthermore, the supply time and supply flow rate may also be read and used from the pre-memorized data in the control unit 90.

[0069] Next, the second replenishment control unit 105 checks whether the calculated value of the replenishment amount R calculated by the calculation unit 104 has not reached the set value R0 (step S302). The set value R0 is set to a value where the proportion of the dissolved substance E in the processing liquid is low and the number of particles attached to the substrate W is below a threshold.

[0070] When the set value R0 is large enough, even if the set value R0 is large, the number of particles attached to the substrate W will hardly decrease, and the amount of waste treatment liquid L will increase unnecessarily. Therefore, the set value R0 is also set with consideration of the discharge amount in step S304.

[0071] When the calculated value of the replenishment amount R is greater than or equal to the set value R0 (step S302, no), the replenishment amount R and the consumption amount are large, and the proportion of the dissolved substance E in the treatment liquid L is small. At this time, the second replenishment control unit 105 ends the current treatment.

[0072] On the other hand, when the calculated value of the replenishment amount R is less than the set value R0 (step S302, yes), the replenishment amount R and the consumption amount are low, and the proportion of dissolved substances E in the treatment liquid L is high. At this time, the second replenishment control unit 105 decides to reduce the discharge amount of the storage amount H in the liquid tank 20 (step S303). The discharge amount is, for example, the same as the difference between the set value R0 and the calculated value.

[0073] Next, the second replenishment control unit 105 reduces the storage amount H of the liquid tank 20 by the discharge unit 40 or the processing unit 10 (step S304). The second replenishment control unit 105 uses the first discharge unit 41 to reduce the storage amount H in a short time, or it can use the second discharge unit 42 or the processing unit 10.

[0074] The second replenishment control unit 105 can also prohibit the control performed by the first replenishment control unit 103 when the storage volume H of the liquid tank 20 is reduced to below the lower limit value Hmin. Since new treatment liquid L is replenished after the treatment liquid L contaminated by the leached substance E is discharged, the discharge and replenishment amounts can be reduced compared to the case where discharge and replenishment are performed simultaneously.

[0075] Next, the second replenishment control unit 105 replenishes the liquid tank 20 with new processing liquid L by the supply unit 50 (step S305). The replenishment amount is, for example, the same as the discharge amount and the same as the difference between the set value R0 and the calculated value. By replenishing in this way, the proportion of the dissolved substances E in the processing liquid L is reduced, and the number of particles adhering to the substrate W is reduced.

[0076] Next, referring to Figure 9, an example of the processing result of Figure 8 will be explained. In Figure 9, the horizontal axis displays time, and the vertical axis represents the integral value of the flow rate of the new processing liquid L replenished from the supply unit 50 to the liquid tank 20. The integral value is calculated every set time t0. The integral value can be calculated using the flow meter 52 or using the processing plan sent from the main computer 200.

[0077] When the replenishment amount R at each set time t0 does not reach the set value R0, steps S303 to S305 shown in FIG8 are performed, as shown by the dashed line in FIG9, to replenish the liquid tank 20 with new processing liquid L from the supply unit 50. On the other hand, when the replenishment amount R at each set time t0 is greater than or equal to the set value R0, steps S303 to S305 shown in FIG8 are not performed.

[0078] Next, referring to FIG10, an example of the relationship between the number of particles attached to the substrate W, the cycle time, and the replenishment amount R will be explained. The cycle time is the elapsed time from step S404 in FIG11 (described later), which is the elapsed time since the liquid replacement process was completed. Details of the liquid replacement process will be described later.

[0079] As shown in Figure 10, during the period when the actual value of the replenishment amount R is equal to the set value R, the longer the circulation time, the more progress is made in filtration, and the number of particles attached to the substrate W decreases. Subsequently, when the actual value of the replenishment amount R is 0, the longer the circulation time, the greater the proportion of dissolved substances E in the treatment liquid L, and the number of particles attached to the substrate W increases. From this, it can be seen that by managing the replenishment amount R above the set value R0, the increase in particles caused by the circulation of the treatment liquid L can be suppressed.

[0080] Next, referring to FIG11, an example of the processing of the second fluid replacement control unit 109 will be described. The processing after S401 shown in FIG11 begins when the second fluid replacement control unit 109 receives a fluid replacement command for the processing fluid L in the replacement cycle. The fluid replacement command is sent from, for example, the main computer 20.

[0081] The circulating treatment fluid L exists, for example, in the liquid tank 20, the circulation pipeline 21, the machines 23-26 installed in the circulation pipeline 21, the branch pipeline 22, the machines 27-28 installed in the branch pipeline 22, the return pipeline 30, and the machine 31 installed in the return pipeline 30. The volume of the treatment fluid L in the liquid tank 20 is not particularly limited to the proportion of the total volume of the circulating treatment fluid L, and is, for example, 30% to 50%.

[0082] By periodically replacing the treatment fluid L, the deterioration of the treatment fluid L can be suppressed. Although inert gases such as nitrogen are supplied to the space above the liquid tank 20, atmospheric air may intrude. As moisture in the atmosphere gradually dissolves into the treatment fluid L, the treatment fluid L deteriorates. The moisture concentration of the new treatment fluid L is lower than that of the treatment fluid L stored in the liquid tank 20, and can even be practically zero.

[0083] First, when the second liquid replacement control unit 109 receives a liquid replacement command, it stops the pump 23, thereby stopping the circulation of the processing liquid L (step S401). By stopping the pump 23, dry running of the pump 23 can be prevented during the emptying of the liquid tank 20. The second liquid replacement control unit 109 can also stop the pump 23 and the heater 25 at the same time. By stopping the circulation of the processing liquid L, concentrated overheating of a portion of the processing liquid L can be prevented.

[0084] Furthermore, the processing performed by the second fluid replacement control unit 109 and the processing performed by the first fluid replacement control unit 108, as described later, can be selectively executed. The second fluid replacement control unit 109 may also start the processing after step S401 when it receives a fluid replacement command and at the same time receives a command to prohibit the processing performed by the first fluid replacement control unit 108.

[0085] Next, while the pump 23 is stopped, the second fluid replacement control unit 109 reduces the storage volume H of the liquid tank 20 using the discharge unit 40 (step S402). Since the circulation of the processing fluid L has stopped, the second fluid replacement control unit 109 uses the first discharge unit 41 instead of the second discharge unit 42 to reduce the storage volume H. As a result, the liquid tank 20 is emptied.

[0086] Then, the second liquid replacement control unit 109 supplies the processing liquid L to the liquid tank 20 through the supply unit 50 (step S403).

[0087] Finally, the second fluid replacement control unit 109 restarts the pump 23, thereby restarting the circulation of the treatment fluid L (step S404). The second fluid replacement control unit 109 can also restart the pump 23 and the heater 25 at the same time.

[0088] Furthermore, in this embodiment, the time to restart the pump 23 is after step S403, as long as the storage amount H of the liquid tank 20 exceeds the first threshold H1 described later, or it can be during step S403. The time to restart the heater 25 is only required to be after the time to restart the pump 23, or it can be simultaneously.

[0089] The first threshold H1 is less than the lower limit Hmin (H1 < Hmin). The first threshold H1 is used for determination by the second determination unit 106. The second determination unit 106 determines whether the storage volume H of the liquid tank 20 in the processing liquid L circulation has not reached the first threshold H1. This determination uses, for example, the detector 61 shown in FIG1.

[0090] When the second determination unit 106 determines that the storage volume H has not reached the first threshold H1, the forced stop unit 107 stops the pump 23. In the circulation of the processing liquid L, if an abnormality occurs and the storage volume H decreases, the pump 23 can be prevented from running dry, thus preventing the pump 23 from malfunctioning.

[0091] However, when pump 23 is restarted, the number of particles P contained in the treatment fluid L increases. Particles P are generated due to friction between the parts that make up, for example, pump 23. Particles P are also generated due to detachment from the circulation line 21 or the machines 23-26 due to vibration. Furthermore, when heater 25 is restarted, filter 26 thermally expands, and particles P detach from filter 26. Therefore, the number of particles P increases immediately after the fluid replacement treatment.

[0092] On the other hand, the first liquid replacement control device 108, described later, differs from the second liquid replacement control unit 109. While the processing liquid L is circulated by the pump 23, it performs the operation of reducing the storage volume H of the liquid tank 20 by the discharge unit 40 and supplying new processing liquid L to the liquid tank 20 by the supply unit 50. Since the pump 23 is not stopped, it is not restarted. Furthermore, since the pump 23 is not stopped, the heater 25 is also not stopped. Therefore, the increase in the number of particles P immediately after liquid replacement processing can be suppressed.

[0093] Next, referring to FIG12, an example of the processing of the first fluid replacement control unit 108 will be described. The processing after S501 shown in FIG12 begins when the first fluid replacement control unit 108 receives a fluid replacement command. Furthermore, the processing performed by the first fluid replacement control unit 108 and the processing performed by the second fluid replacement control unit 109 can be selectively executed. The first fluid replacement control unit 108 may also begin the processing after step S501 when it receives a fluid replacement command and simultaneously receives a command to prohibit the processing performed by the second fluid replacement control unit 109.

[0094] When the first liquid replacement control unit 108 receives a liquid replacement command, it reduces the storage volume H of the liquid tank 20 by the discharge unit 40 while the processing liquid L is circulated by the pump 23 (step S501). Since the first liquid replacement control unit 108 continues to circulate the processing liquid L, the processing liquid L can also be continuously heated by the heater 25.

[0095] When the first liquid replacement control unit 108 receives a liquid replacement command, it can also reduce the storage amount H of the liquid tank 20 to a second threshold H2 by the discharge unit 40 while the processing liquid L is being circulated by the pump 23. The second threshold H2 is greater than the first threshold H1 and less than the lower limit Hmin (H1 < H2 < Hmin). The detector 62 shown in FIG1 detects that the storage amount H has reached the second threshold H2. Since the storage amount H remains above the first threshold H1, it is possible to prevent the pump 23 from being stopped by the forced stop unit 107.

[0096] The first fluid replacement control unit 108 may also differ from the second fluid replacement control unit 109 by using a second discharge unit 42 to reduce the storage capacity H of the fluid tank 20. Since the circulation of the treatment fluid L is not stopped, the second discharge unit 42 can be used. Furthermore, when using the second discharge unit 42, compared to using the first discharge unit 41, the treatment fluid L can reliably flow to the circulation pipeline 21.

[0097] Next, while the first liquid replacement control unit 108 is circulating the processing liquid L with the pump 23, the supply unit 50 supplies the processing liquid L to the liquid tank 20 (step S502). The storage amount H of the processing liquid L stored in the liquid tank 20 returns to the lower limit value Hmin or above.

[0098] Then, the first fluid replacement control unit 108 checks whether steps S501 and S502 (step S503) have been performed m times. m is a natural number of 1 or more, and is preset to a ratio of the new processing fluid L to the total volume of the circulating processing fluid L of 1 or more, which is at least the desired value. m can be changed appropriately. m is preferably a natural number of 2 or more, and the ratio of the new processing fluid L is the ratio of the new processing fluid L supplied after the start of step S501.

[0099] If the number of times steps S501 and S502 are performed has not reached m (step S503, No), the first fluid replacement control unit 108 performs steps S501 and S502 again. On the other hand, if the number of times steps S501 and S502 are performed reaches m (step S503, Yes), the first fluid replacement control unit 108 ends the current processing.

[0100] Next, referring to FIG13, an example of the relationship between the number of liquid replacements and the proportion of new liquid will be explained. The proportion of new liquid refers to the ratio of the new processed liquid L to the total volume of processed liquid L in the circulation. The number of liquid replacements refers to the number of times steps S401 to S404 in FIG11 are performed, or the number of times steps S501 to S502 in FIG12 are performed. The proportion of new processed liquid L is the proportion of new processed liquid L supplied after the start of step S401 or step S501.

[0101] The more times the liquid is replaced, the higher the proportion of new liquid becomes. Because during the processing shown in Figure 12, the old processing liquid L is discharged and the new processing liquid L is supplied without stopping the circulation of the processing liquid L, the old and new processing liquids L mix. Therefore, during the processing shown in Figure 12, the rate of increase in the proportion of new liquid is slower compared to the case shown in Figure 11. To ensure a very high proportion of new liquid, it is preferable for m in Figure 12 to be a natural number of 2 or higher, and even better if it is a natural number of 3 or higher.

[0102] Next, referring to FIG14, an example of the number of particles adhering to the substrate W after the liquid was replaced will be explained. The number of liquid replacements is set to be approximately the same as the proportion of new liquid. As can be clearly seen from FIG14, since the circulation of the processing liquid is not stopped when the liquid replacement is performed as in FIG12, the number of particles adhering to the substrate W can be suppressed to about 1 / 4 compared to the case of liquid replacement in FIG11.

[0103] Next, referring to FIG15, the modified substrate processing apparatus 1 will be described. Hereinafter, the main differences will be described. The modified substrate processing apparatus 1 includes a filter 26 provided downstream of the pump 23 of the circulation pipeline 21, a switch valve 71 provided downstream of the filter 26 of the circulation pipeline 21, and a processing liquid discharge section 72 that discharges processing liquid L from the filter 26 and the switch valve 71 of the circulation pipeline 21.

[0104] The treatment fluid discharge section 72 includes a discharge pipe 73 connected between the filter 26 and the switching valve 71 and the circulation pipe 21, and a switching valve 74 for switching the discharge pipe 73. When the switching valve 74 opens the discharge pipe 73, the discharge pipe 73 discharges the treatment fluid L from the circulation pipe 21. On the other hand, when the switching valve 74 closes the discharge pipe 73, the discharge pipe 73 stops discharging the treatment fluid L from the circulation pipe 21.

[0105] The second fluid replacement control unit 109 (see Figure 3) starts the pump 23 in step S404 after stopping the pump 23 in step S401 of Figure 11. Starting the pump 23 requires high driving force. High driving force will cause particulates to be generated from the filter 26, etc. The particulates will contaminate the circulation line 21. Once the circulation line 21 is contaminated by particulates, its purification requires a long time and a large amount of treatment fluid L.

[0106] Therefore, after stopping the pump 23, the second liquid replacement control unit 109 performs the action of closing the circulation pipeline 21 with the switch valve 71 and discharging the processing liquid L from the circulation pipeline 21 through the processing liquid discharge unit 72 when starting the pump 23. This can discharge the particles generated when the pump 23 starts to the discharge pipeline 73, thereby suppressing contamination of the circulation pipeline 21. Therefore, the time required for filtration before restarting the processing of the substrate W can be shortened, and the amount of processing liquid L used can be reduced.

[0107] When the elapsed time since, for example, pump 23 started reaches a set time, the second fluid replacement control unit 109 opens the circulation pipe 21 by switching valve 71. At the same time, the discharge of the processed fluid L by the processed fluid discharge unit 72 stops, and the circulation of the processed fluid L restarts (step S404 in FIG11). In addition, the set time is set taking into account the time until the particles generated when pump 23 starts reach the discharge pipe 73.

[0108] The switching valve 71 and the treated fluid discharge section 72 are preferably located upstream of the connection point between at least one branch pipe 22 and the circulation pipe 21. This prevents contamination not only in the circulation pipe 21 but also in the branch pipe 22. It is also preferable that the switching valve 71 and the treated fluid discharge section 72 are located upstream of the connection points between all branch pipes 22 and the circulation pipe 21.

[0109] The above describes embodiments of the substrate processing apparatus and substrate processing method of the present invention. The present invention is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations can be made within the scope of the claims. These naturally also fall within the technical scope of the present invention. [Simplified Explanation of the Diagram]

[0009] Figure 1 is a diagram showing an embodiment of a substrate processing apparatus. Figure 2 is a diagram showing an example of a processing unit. Figure 3 is a diagram showing an example of the components of a control unit using functional blocks. Figure 4 is a flowchart showing an example of the processing of the substrate processing unit. Figure 5 is a flowchart showing an example of the processing of the first determination unit and the first replenishment control unit. Figure 6 is a diagram showing an example of the relationship between the number of particles attached to the substrate, the circulation time, and the temperature of the processing liquid. Figure 7(A) is a diagram showing an example of the processing liquid at the start of the cycle; Figure 7(B) is a diagram showing an example of leaching from the filter; Figure 7(C) is a diagram showing an example of the leached components passing through; Figure 7(D) is a diagram showing an example of the replenishment and discharge of the processing liquid. Figure 8 is a flowchart showing an example of the processing of the calculation unit and the second replenishment control unit. Figure 9 is a diagram showing an example of the processing result of Figure 8. Figure 10 is a diagram showing an example of the relationship between the number of particles attached to the substrate, the circulation time, and the replenishment amount R. Figure 11 is a flowchart showing an example of the processing of the second liquid replacement control unit. Figure 12 is a flowchart showing an example of the processing of the first liquid replacement control unit. Figure 13 is a diagram showing an example of the relationship between the number of liquid replacements and the proportion of new liquid. Figure 14 is a diagram showing an example of the number of particles adhering to the substrate immediately after liquid replacement. Figure 15 is a diagram showing a modified example of the substrate processing apparatus.

Claims

1. A substrate processing apparatus comprising: a liquid tank for storing a processing liquid; a circulation pipeline for removing the processing liquid from the liquid tank and returning it to the liquid tank; a branch pipeline branching from the circulation pipeline; a processing unit for supplying the processing liquid to a substrate at the upstream end of the branch pipeline; a discharge unit for reducing the storage amount of the processing liquid stored in the liquid tank; a supply unit for supplying new processing liquid to the liquid tank; and a control unit for controlling the processing unit, the discharge unit, and the supply unit; the control unit comprising: a first determination unit for determining whether the storage amount of the processing liquid in the liquid tank has not reached a lower limit; a first replenishment control unit for replenishing the liquid tank with the processing liquid by the supply unit when the first determination unit determines that the storage amount has not reached the lower limit; and a calculation unit for calculating the amount of processing liquid replenished to the liquid tank by the supply unit at set intervals. The second replenishment control unit, when the calculated value of the replenishment amount by the calculation unit does not reach the set value, reduces the storage amount of the liquid tank by the discharge unit and replenishes the processing liquid to the liquid tank by the supply unit.

2. The substrate processing apparatus as described in claim 1, wherein, The supply unit includes a supply pipeline connected to the liquid tank and a flow meter that measures the flow rate of the processed liquid passing through the supply pipeline. The calculation unit calculates the replenishment amount from the measurement value of the flow meter.

3. The substrate processing apparatus as described in claim 2, wherein, The calculation unit receives a processing plan containing the processing time points of the substrate from an external main computer, and calculates the supplementary amount from the processing plan and the measurement value of the flow meter.

4. The substrate processing apparatus as described in claim 1, wherein, The calculation unit receives a processing plan containing the processing time points of the substrate from an external main computer, and calculates the supplementary amount from the processing plan.

5. The substrate processing apparatus as described in any one of claims 1 to 4, wherein, When the second replenishment control unit reduces the storage volume of the liquid tank to below the lower limit, it prohibits the processing performed by the first replenishment control unit.

6. The substrate processing apparatus as described in any one of claims 1 to 4, wherein, The second replenishment control unit determines the amount by which the storage volume of the liquid tank is reduced based on the difference between the calculated value of the replenishment amount and the set value.

7. The substrate processing apparatus as described in any one of claims 1 to 4, wherein, When the calculated value of the replenishment amount is higher than the set value, the second replenishment control unit neither performs the action of reducing the storage amount of the liquid tank by the discharge unit nor the action of replenishing the processing liquid to the liquid tank by the supply unit.

8. The substrate processing apparatus as described in any one of claims 1 to 4, wherein, The discharge section includes at least one of the following: a first discharge section, including a first discharge pipe connected to the liquid tank and a first switch valve for switching the first discharge pipe; a second discharge section, including a second discharge pipe connected to the circulation pipe and a second switch valve for switching the second discharge pipe.

9. The substrate processing apparatus of claim 1 further comprises: a pump disposed in the circulation pipeline; the control unit further controls the pump; the control unit comprises: a first liquid replacement control unit, which, when receiving a liquid replacement command to replace the circulating processing liquid, performs an operation of reducing the storage amount in the liquid tank by the discharge unit and supplying the processing liquid to the liquid tank by the supply unit while the processing liquid is being circulated by the pump.

10. The substrate processing apparatus of claim 9 further comprises: a heater disposed in the circulation pipeline; and, when the first liquid replacement control unit receives the liquid replacement command, while the processing liquid is heated by the heater, performing an operation to reduce the storage amount in the liquid tank by the discharge unit and to supply the processing liquid to the liquid tank by the supply unit.

11. The substrate processing apparatus as claimed in claim 9 or 10, wherein, The control unit includes: a second determination unit that determines whether the storage level of the liquid tank has not reached a first threshold; and a forced stop unit that stops the pump when the second determination unit determines that the storage level has not reached the first threshold. When the first liquid replacement control unit receives the liquid replacement command, while the processing liquid is circulated by a pump, it performs the action of reducing the storage amount in the liquid tank to a second threshold greater than the first threshold by the discharge unit and the action of supplying the processing liquid to the liquid tank by the supply unit.

12. The substrate processing apparatus as claimed in claim 11, wherein, The first liquid replacement control unit, while circulating the processing liquid with a pump, repeatedly performs the actions of reducing the storage amount in the liquid tank to the second threshold with the discharge unit and supplying the processing liquid to the liquid tank with the supply unit.

13. The substrate processing apparatus as claimed in claim 9 or 10, wherein, The control unit includes: a second liquid replacement control unit, which, when receiving the liquid replacement command and receiving a command to prohibit the processing performed by the first liquid replacement control unit, performs the operation of reducing the storage amount in the liquid tank by the discharge unit and supplying the processing liquid to the liquid tank by the supply unit while the pump is stopped.

14. The substrate processing apparatus of claim 13 further comprises: a filter disposed downstream of the pump in the circulation pipeline; a switch valve disposed downstream of the filter in the circulation pipeline; and a processing liquid discharge section that discharges the processing liquid from the filter and the switch valve in the circulation pipeline; the second liquid replacement control unit, after stopping the pump, performs the operation of closing the circulation pipeline with the switch valve and simultaneously discharging the processing liquid from the circulation pipeline through the processing liquid discharge section when starting the pump.

15. A substrate processing method comprising the steps of circulating a processing liquid from a liquid tank through a circulation pipeline to the liquid tank, and supplying the processing liquid to a substrate at the front end of a branch pipeline branching from the circulation pipeline, and further comprising the following steps: determining whether the storage amount of the processing liquid in the liquid tank has not reached a lower limit; when it is determined that the storage amount has not reached the lower limit, replenishing the liquid tank with new processing liquid; calculating the amount of new processing liquid to be replenished to the liquid tank at a set time; and when the calculated value of the replenishment amount does not reach the set value, reducing the storage amount in the liquid tank and replenishing the liquid tank with new processing liquid.

16. The substrate processing method of claim 15 further comprises the following steps: when a liquid replacement instruction is received to replace the circulating processing liquid, while the processing liquid is being circulated, the storage amount of the processing liquid in the liquid tank is reduced, and new processing liquid is supplied to the liquid tank.

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