Substrate processing apparatus and processing liquid replenishing method

Abstract

The invention provides a substrate processing apparatus and a processing liquid replenishing method for preventing a processing liquid containing contaminants such as particles from being replenished into a container. The substrate processing apparatus includes: a processing unit that performs liquid processing on a substrate using a processing liquid; a container for storing the processing liquid before being supplied to the processing unit; a replenishment line that supplies the processing liquid from a processing liquid supply source to the container; a replenishment on-off valve for opening and closing the replenishment line; a first drain line branched from the replenishment line on the upstream side of the replenishment on-off valve; a first drain opening and closing valve for opening and closing the first drain line; and a control unit that controls the operation of the replenishment on-off valve and the operation of the first liquid discharge on-off valve before the replenishment of the processing liquid from the processing liquid supply source to the container via the replenishment line is started. A pre-discarding operation for discharging the processing liquid flowing from the processing liquid supply source into the replenishment line through the first liquid discharge line is performed.

Description

Technical Field

[0001] The invention relates to a substrate processing device and a processing liquid replenishing method. Background Art

[0002] The manufacturing process of semiconductor devices includes a liquid treatment step in which a chemical solution (processing solution) is supplied to a substrate for cleaning or wet etching. In a substrate processing system that implements such a liquid treatment step, a processing liquid supply system for supplying processing liquid to multiple liquid processing units includes a container for storing the processing liquid and a circulation line connected to the container at both ends for circulating the processing liquid. The processing liquid is supplied to the multiple liquid processing units via multiple branch lines connected to the circulation line. When the processing liquid in the container decreases due to repeated substrate processing, the container is replenished with new processing liquid.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-175552 Summary of the Invention

[0006] Technical problem to be solved by the invention

[0007] The present invention provides a technology for preventing a container from being replenished with a treatment liquid containing pollutants such as particles.

[0008] Technical solutions to technical problems

[0009] According to one embodiment of the present invention, there is provided a substrate processing device, which includes: a processing unit that uses a processing liquid to perform liquid processing on a substrate; a container for storing the processing liquid before it is supplied to the processing unit; a replenishing pipeline that supplies the processing liquid from a processing liquid supply source to the above-mentioned container; a replenishing on-off valve that opens and closes the above-mentioned replenishing pipeline; a first drain pipeline that branches from the above-mentioned replenishing pipeline on the upstream side of the above-mentioned replenishing on-off valve; a first drain on-off valve that opens and closes the above-mentioned first drain pipeline; and a control unit, which controls the operation of the above-mentioned replenishing on-off valve and the above-mentioned first drain on-off valve, and performs a pre-discarding operation of discharging the processing liquid that flows from the above-mentioned processing liquid supply source into the above-mentioned replenishing pipeline through the above-mentioned first drain pipeline before starting to replenish the processing liquid from the above-mentioned processing liquid supply source via the above-mentioned replenishing pipeline.

[0010] Effects of the Invention

[0011] According to the above embodiment, it is possible to prevent the container from being replenished with the processing liquid containing contaminants such as particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1It is a schematic cross-sectional view of a substrate processing system as one embodiment of a substrate processing apparatus.

[0013] Figure 2 This is a piping system diagram showing a configuration example of a sulfuric acid supply mechanism in a processing liquid supply mechanism included in a substrate processing system, and is a piping system diagram showing a first embodiment of a sulfuric acid replenishment mechanism included in the sulfuric acid supply mechanism.

[0014] Figure 3 This is a flowchart showing an example of a process related to a pre-discard operation.

[0015] Figure 4 This is a flowchart showing another example of the process related to the pre-discarding operation.

[0016] Figure 5 This is a piping system diagram showing a second embodiment of the sulfuric acid replenishing mechanism.

[0017] Figure 6 This is a piping system diagram showing a third embodiment of the sulfuric acid replenishing mechanism.

[0018] Figure 7 This is a flowchart showing another example of the process related to the pre-discarding operation.

[0019] Figure 8 It is a piping system diagram showing a fourth embodiment of the sulfuric acid replenishing mechanism.

[0020] Figure 9 It is a piping system diagram showing a fifth embodiment of the sulfuric acid replenishing mechanism.

[0021] Description of Reference Numerals

[0022] W substrate

[0023] 4. Control unit (control device)

[0024] 16 processing units

[0025] 102 Container

[0026] 202 Treatment liquid supply source

[0027] 204 Supplementary pipeline

[0028] 212 Supplementary on-off valve

[0029] 216 First drain line

[0030] 218 On-off valve for the first discharge. DETAILED DESCRIPTION

[0031] Reference Figure 1, a schematic configuration of a substrate processing system 1 (an example of a liquid processing apparatus) according to an embodiment will be described. Figure 1 1 is a diagram showing a schematic configuration of a substrate processing system 1 according to an embodiment. Hereinafter, to clarify positional relationships, mutually orthogonal X-axis, Y-axis, and Z-axis are defined, with the positive Z-axis direction being the vertically upward direction.

[0032] like Figure 1 As shown, the substrate processing system 1 includes an inlet and outlet station 2 and a processing station 3.

[0033] The loading and unloading station 2 includes a carrier placement unit 11 and a conveying unit 12. A plurality of carriers C for storing a plurality of substrates W (semiconductor wafers in this embodiment) to be processed in a horizontal posture are placed on the carrier placement unit 11.

[0034] The transport unit 12 is provided with a substrate transport device 13 and an interface 14 . The substrate transport device 13 can transport substrates W between the carrier C and the interface 14 .

[0035] The processing station 3 includes a conveying portion 15 and a plurality of processing units 16 arranged on both sides of the conveying portion 15 .

[0036] The transport unit 15 is provided with a substrate transport device 17 . The substrate transport device 17 can transport the substrate W between the interface 14 and any processing unit 16 .

[0037] The processing unit 16 supplies a processing fluid (processing liquid) to the substrate W to perform liquid processing on the substrate W.

[0038] The processing liquid may be any processing liquid used in the field of semiconductor device manufacturing. Specifically, examples include chemical solutions such as DHF, SC1, and SC2, rinse solutions such as DIW (pure water), and low-surface-tension organic replacement solutions such as IPA (isopropyl alcohol). In the exemplary embodiment described below, SPM (sulfuric acid peroxide), SC1, a two-fluid solution (DIW spray), and IPA are sequentially supplied to the substrate W in the processing unit 16.

[0039] The substrate processing system 1 includes a control device 4. The control device 4 is, for example, a computer and includes a control operation unit 18 and a storage unit 19. The storage unit 19 stores programs for controlling various processes performed in the substrate processing system 1. The control operation unit 18 controls the operation of the substrate processing system 1 by reading and executing the processing plans and control programs stored in the storage unit 19.

[0040] The above-mentioned processing scheme and control program may be recorded on a computer-readable storage medium and installed from the storage medium to the storage unit 19 of the control device 4. Examples of computer-readable storage media include a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), and a memory card.

[0041] In the above-described substrate processing system 1, the substrate transport device 13 of the transport station 2 first removes a substrate W from a carrier C placed on the carrier placement portion 11 and places the removed substrate W on the interface 14. The substrate W placed on the interface 14 is then removed from the interface 14 by the substrate transport device 17 of the processing station 3 and transported to the processing unit 16.

[0042] After being processed by the processing unit 16, the substrate W is transported from the processing unit 16 by the substrate transport device 17 and placed on the interface 14. The processed wafer W placed on the interface 14 is then returned to the original carrier C of the carrier placement unit 11 by the substrate transport device 13.

[0043] [Structure of the treatment liquid supply mechanism]

[0044] Next, refer to Figure 2 Next, a description will be given of a treatment liquid supply mechanism for supplying treatment liquid to each treatment unit 16. Treatment liquids include various treatment liquids, such as chemical liquids, rinse liquids such as DIW (pure water), and organic solvents such as IPA (isopropyl alcohol). Here, only the chemical liquid supply mechanism, specifically the sulfuric acid supply mechanism 100 of the SPM supply mechanism that supplies SPM (sulfuric acid-hydrogen peroxide solution, which is a mixture of sulfuric acid and hydrogen peroxide solution) as a chemical liquid, will be described. Other treatment liquid supply mechanisms can be appropriately selected from well-known mechanisms in the technical field of semiconductor manufacturing equipment, and their illustration and description will be omitted.

[0045] The sulfuric acid supply mechanism 100 includes a container 102 (storage container) for storing sulfuric acid and a circulation line 104. The container 102 is provided with a liquid level sensor 103 for detecting the height of the liquid surface, which will be described in detail later.

[0046] The circulation line 104 is provided with a pump 106 , a filter 108 , an on-off valve 110 , a heater (in-line heater) 112 , a flow meter 114 , an on-off valve 116 , and a back pressure valve 118 in order from the side close to the container 102 (upstream side).

[0047] A branch supply line connection area 120 is provided in the circulation line 104. In the branch supply line connection area 120, a plurality of branch supply lines 122 are branched from the circulation line 104. Figure 2In FIG. 1 , only one of the plurality of branch supply lines 122 is shown in its entirety, and only upstream ends of the other two branch supply lines 122 are indicated by arrows.

[0048] In the branch supply line 122, a flow meter 124, a flow control valve 126, and an opening and closing valve 128 are provided in sequence from the upstream side. A nozzle 130 is provided in the processing unit 16 at the downstream end of the branch supply line 122. The processing unit 16 is provided with a rotating chuck 161 (substrate holding rotating part) that holds the substrate W in a horizontal posture and rotates it around a vertical axis. The nozzle 130 is carried by a nozzle arm not shown in the figure, and can spray a chemical solution (in this embodiment, SPM mixed with sulfuric acid and hydrogen peroxide water) to any radial position of the substrate W held and rotated by the rotating chuck 161. In addition, the processing unit 16 has one or more nozzles for spraying other processing liquids (the aforementioned SC1, IPA, DIW, etc.), but the description of the nozzle is omitted. The structure of such a processing unit 16 is well known in the technical field of semiconductor manufacturing equipment, so a detailed description is omitted.

[0049] Between the flow control valve 126 and the on-off valve 128, a branch return line 132 branches off from the branch supply line 122. The same number of branch return lines 132 as the branch supply lines 122 (i.e., the same number as the processing units 16) is provided. An on-off valve 134 is provided on each branch return line 132. The plurality of branch return lines 132 merge with the main return line 136 at a branch return line merging area 138 provided on the main return line 136. The main return line 136 is connected to the container 102. Figure 2 In FIG. 1 , only one of the plurality of branch return lines 132 is shown as a whole, and only the downstream ends of the other two branch return lines 132 are shown by arrows.

[0050] On the downstream side of the branch supply line connection area 120, an on-off valve 116 and a constant pressure valve 118 are provided in the circulation line 104. The constant pressure valve 118 maintains the pressure of the sulfuric acid in the branch supply line connection area 120 at a substantially constant level, thereby facilitating control of the flow rate of the sulfuric acid flowing through each branch supply line 122.

[0051] An on-off valve 144 and a constant pressure valve 146 are provided in the main return line 136 on the downstream side of the branch return line merging region 138 .

[0052] When SPM is not being supplied from nozzle 130 to substrate W, on-off valve 128 is closed and on-off valve 134 is opened, allowing high-temperature sulfuric acid to constantly flow through a portion of branch supply line 122 and branch return line 132. This prevents the sulfuric acid from cooling within branch supply line 122, and reduces the amount of liquid required for dummy dispenses to restore the temperature.

[0053] During normal operation of the substrate processing system, sulfuric acid in the container 102 circulates through the circulation line 104 and is heated by the heater 112 during the circulation. According to the processing arrangement of the substrate processing system, sulfuric acid is supplied to each processing unit 16 via the branch supply line 122. Figure 2 As schematically indicated by the arrow labeled H2O2 in the figure, hydrogen peroxide solution is supplied from the supply line of the hydrogen peroxide solution supply mechanism to the branch supply line 122 at a position near the nozzle 130. This hydrogen peroxide solution is mixed with sulfuric acid flowing in the branch supply line 122 to produce a mixture of sulfuric acid and hydrogen peroxide solution, namely SPM. The SPM is supplied from the nozzle 130 to the rotating substrate W, and the substrate W is subjected to SPM treatment (chemical liquid treatment).

[0054] During normal operation of the substrate processing system, substrates W are processed sequentially in each processing unit 16, thereby gradually reducing the amount of sulfuric acid in the container 102. When the liquid level sensor 103 detects that the liquid level of sulfuric acid in the container 102 has dropped to a predetermined lower limit, sulfuric acid is replenished into the container 102. The structure for replenishing sulfuric acid (sulfuric acid replenishing mechanism 200) will be described below. The sulfuric acid replenishing mechanism (processing liquid replenishing mechanism) 200 is also used to supply new sulfuric acid to an empty container.

[0055] The sulfuric acid replenishment mechanism 200 includes a sulfuric acid replenishment line 204 connecting a sulfuric acid supply source 202 to the container 102. The sulfuric acid supply source 202 is provided, for example, as a factory resource of a semiconductor device manufacturing plant in which the substrate processing system 1 is installed. In this case, the sulfuric acid supply source 202 is an auxiliary device of the semiconductor device manufacturing plant and is not part of the substrate processing system 1. The sulfuric acid supply source 202 may also be composed of a container containing a processing solution provided by a chemical solution manufacturer and a pressure delivery mechanism that supplies pressurized inert gas to the container to deliver sulfuric acid from the container.

[0056] The sulfuric acid replenishment line 204 is provided with an on-off valve 206, a filter 208, a flowmeter 210, and an on-off valve 212, in order from the upstream side. A drain line 216 branches off from the sulfuric acid replenishment line 204 at a branch point 214 on the secondary side of the filter 208, in other words, on the downstream side of the filter 208. A drain line 216 is provided with an on-off valve 218. The downstream end of the drain line 216 is connected to, for example, a plant wastewater line.

[0057] The operation of the sulfuric acid replenishment mechanism 200 will be described below. During normal operation of the substrate processing system, when the liquid level sensor 103 detects that the liquid level of sulfuric acid in the container 102 has dropped to a predetermined lower limit level, the on-off valves 206 and 212 of the processing liquid replenishment line 204 are opened while the on-off valve 218 of the discharge line 216 is closed. As a result, sulfuric acid is supplied (replenished) from the sulfuric acid supply source 202 via the sulfuric acid replenishment line 204 to the container 102. When the liquid level sensor 103 detects that the liquid level of sulfuric acid in the container 102 has reached a predetermined upper limit level, the on-off valves 206 and 212 are closed, and the replenishment of sulfuric acid to the container 102 is stopped.

[0058] When the substrate processing system is restarted after being stopped for a long period of time, the sulfuric acid remaining in the sulfuric acid replenishment line 204 during the shutdown is temporarily discarded via the drain line 216. Thereafter, sulfuric acid is replenished to the container 102 in response to a sulfuric acid replenishment request. In other words, the sulfuric acid remaining in the sulfuric acid replenishment line 204 for a long period of time is not supplied to the container 102 but discarded. This operation is referred to as a "pre-discarding operation."

[0059] When sulfuric acid is detained in the sulfuric acid replenishment line 204 for a long time, the pollutants such as the particles captured by the filter 208 (particularly due to the particle smaller than pores attached to the filter component surface without sieving (Non-sieving) mechanism) sometimes break away from the filter 208. In addition, the pollutants attached to the on-off valve 206 and the sulfuric acid replenishment line (piping) 204 sometimes break away from or dissolve in sulfuric acid. When the sulfuric acid containing such pollutants is supplied to container 102, the amount of the pollutants included in the sulfuric acid flowing in the circulation line 104 increases. Although pollutants such as particles can be removed by the filter 108 arranged at the circulation line 104, it is not possible to all remove. Therefore, the particle amount attached to the substrate W processed by the treatment unit 16 may increase. Therefore, it is preferred to maintain a higher cleanliness of the sulfuric acid supplied to container 102 via the sulfuric acid replenishment line 204, for this purpose, carry out pre-discarding operation.

[0060] Figure 3 An example of a specific process related to the pre-discard operation is shown.

[0061] The timer function attached to the control device 4 is used to measure the elapsed time ( Figure 3When the liquid level in container 102 is detected to have dropped to the lower limit level, control device 4 determines that sulfuric acid needs to be replenished (supplied) to container 102 (step S302). Next, control device 4 determines whether the elapsed time exceeds a predetermined threshold (step S303).

[0062] If it is determined that the threshold value is exceeded (yes in step S303), a pre-discard operation is performed (step S304). During the pre-discard operation, while the on-off valve 212 of the sulfuric acid replenishment line 204 is closed, the on-off valve 206 of the sulfuric acid replenishment line 204 and the on-off valve 218 of the drainage line 216 are opened. As a result, new sulfuric acid flows from the sulfuric acid supply source 202 into the sulfuric acid replenishment line 204, and the inflowing sulfuric acid is discharged from the drainage line 216. As a result, the sulfuric acid containing pollutants such as particulates that is retained in the sulfuric acid replenishment line 204 upstream of the branch point 214 is discharged via the drainage line 216.

[0063] The above-mentioned timer function is used to perform a pre-discarding operation for a predetermined time. Alternatively, the pre-discarding operation may be performed until the cumulative flow rate of sulfuric acid during the pre-discarding operation reaches a predetermined value. The cumulative flow rate of sulfuric acid can be obtained, for example, by integrating the time value detected by flow meter 210 installed in sulfuric acid replenishment line 204.

[0064] The predetermined time or the predetermined value of the accumulated flow rate can be determined based on the amount of retained sulfuric acid (which, for example, roughly corresponds to the internal volume of the sulfuric acid replenishment line 204 upstream of the branch point 214) and the discharge flow rate of sulfuric acid during the pre-discarding operation. For example, the conditions for the pre-discarding operation can be determined so that, for example, five times the amount of retained sulfuric acid (this amount is determined based on a safety margin based on preliminary experiments) is discarded via the drain line 216.

[0065] After the pre-disposal operation is completed, the on-off valve 218 of the drainage line 216 is closed, the on-off valve 212 of the sulfuric acid replenishment line 204 is opened, and sulfuric acid is replenished to the container 102 (step S305). When the required amount of sulfuric acid is replenished, the on-off valves 206 and 212 of the sulfuric acid replenishment line 204 are closed (S306), the timer is reset, and the elapsed time is measured again starting from the reset time (S301).

[0066] If it is determined in step S303 that the threshold value has not been exceeded (No), the above-described pre-discarding operation is not performed. With the on-off valve 218 of the drainage line 216 closed, the on-off valves 206 and 212 of the sulfuric acid replenishment line 204 are opened to replenish sulfuric acid into the container 102. In this case, when the replenishment of sulfuric acid is completed, the on-off valves 206 and 212 of the sulfuric acid replenishment line 204 are closed, the timer is reset, and the elapsed time is measured again starting from the reset time.

[0067] During the pre-disposal operation, the flow rate of sulfuric acid flowing through sulfuric acid replenishment line 204 can be varied. This can improve the removal of pollutants such as particulates during the pre-disposal operation. This flow rate variation can be achieved by installing a flow control valve upstream of branch point 214 in sulfuric acid replenishment line 204.

[0068] Figure 4 This process is similar to the process of determining whether a pre-discard operation is required based on the determination that a drug solution needs to be supplied. Figure 3 The process is different and pre-discarding is performed regularly.

[0069] The timer function attached to the control device 4 is used to measure the elapsed time (starting from the end time of the last sulfuric acid replenishment or the end time of the last pre-discarding operation) Figure 4 11). If it is determined that the elapsed time exceeds a predetermined threshold (yes in step S312), the on-off valve 206 of the sulfuric acid replenishment line 204 and the on-off valve 218 of the drainage line 216 are opened while the on-off valve 212 of the sulfuric acid replenishment line 204 is closed, and a pre-discarding operation is performed (step S313). At the end of the pre-discarding operation, the timer is reset, and the elapsed time is measured again starting from the reset time. Each time the elapsed time reaches the predetermined threshold, the pre-discarding operation is performed (a loop of steps S312 and S313).

[0070] If the elapsed time does not reach the preset threshold ("No" in step S312), and the liquid level sensor 103 detects that the liquid level in container 102 has dropped to the lower limit, the control device 4 determines that sulfuric acid needs to be replenished in container 102 (step S314). Then, with the on-off valve 218 of the discharge line 216 closed, the control device 4 opens the on-off valves 206 and 212 of the sulfuric acid replenishment line 204, thereby replenishing sulfuric acid in container 102 (step S315). When the required amount of sulfuric acid has been replenished, the on-off valves 206 and 212 of the sulfuric acid replenishment line 204 are closed (step S316), the timer is reset, and the elapsed time is measured again starting from the reset time (step S311).

[0071] Next, refer to Figure 5 , another embodiment of the sulfuric acid replenishing mechanism (hereinafter also referred to as the second embodiment) will be described. Figure 2 The embodiment shown (hereinafter also referred to as the first embodiment) is different in that an additional drain line 222 is provided. The other parts are the same as the first embodiment. The same reference numerals are given to the same components as the first embodiment, and repeated descriptions are omitted. When the sulfuric acid replenishing mechanism of the second embodiment is used, the structure of the sulfuric acid supply mechanism other than the sulfuric acid replenishing mechanism (omitted from the figure) is also the same as the first embodiment. Figure 2 The structures shown are the same.

[0072] like Figure 5 As shown, the additional drain line 222 is located on the primary side (upstream side) of the filter 208, specifically at a branch point 220 between the on-off valve 206 and the filter 208, and branches off from the sulfuric acid replenishment line 204. An on-off valve 224 is provided in the additional drain line 222. In the following description, the drain line 216 is also referred to as the first drain line 216, and the additional drain line 222 is also referred to as the second drain line 222.

[0073] The operation of the sulfuric acid replenishment mechanism 200 according to the second embodiment will be described below. During normal operation of the substrate processing system, when the liquid level sensor 103 detects that the liquid level of sulfuric acid in the container 102 has dropped to a predetermined lower limit, the on-off valves 206 and 212 of the sulfuric acid replenishment line 204 are opened while the on-off valves 218 of the first drain line 216 (first drain on-off valve) and the on-off valves 222 of the second drain line 222 (second drain on-off valve) are closed. This allows sulfuric acid to be supplied (replenished) from the sulfuric acid supply source 202 via the sulfuric acid replenishment line 204. When the liquid level sensor 103 detects that the liquid level of sulfuric acid in the container 102 has reached a predetermined upper limit, the on-off valves 206 and 212 of the sulfuric acid replenishment line 204 are closed, stopping the replenishment of sulfuric acid to the container 102.

[0074] When sulfuric acid stays in the sulfuric acid supply line 204 for a long time, a pre-discarding operation is performed similarly to the first embodiment. The pre-discarding operation in the second embodiment consists of a first pre-discarding operation performed initially and a second pre-discarding operation performed following the first pre-discarding operation.

[0075] During the first pre-discarding operation, while on-off valve 218 of first drain line 216 and on-off valve 212 of sulfuric acid replenishing line 204 are closed, on-off valve 224 of second drain line 222 is opened. New sulfuric acid then flows from sulfuric acid supply source 202 into sulfuric acid replenishing line 204, and the flowing sulfuric acid is discharged from second drain line 222. This discharges sulfuric acid containing contaminants such as particulate matter that have accumulated upstream of branch point 220 in sulfuric acid replenishing line 204 (on the primary side of filter 208).

[0076] For example, if sulfuric acid supply source 202 is a factory resource, even if sulfuric acid is retained at the connection with sulfuric acid replenishment line 204, which is a factory resource, and in the sulfuric acid flow path upstream thereof, contaminants such as particles may be detached or dissolved in the sulfuric acid. Furthermore, contaminants such as particles may be detached or dissolved in the sulfuric acid upstream of filter 208 in sulfuric acid replenishment line 204. Performing the first pre-disposal operation allows the discharge of sulfuric acid containing such contaminants.

[0077] The timer function is used to perform the first pre-discarding operation within a preset time. The first pre-discarding operation can also be performed until the cumulative flow of sulfuric acid during the pre-discarding operation reaches a preset value. Figure 5 In the structure, since the flow meter 210 cannot be used to measure the cumulative flow in the first pre-discarding operation, if it is desired to measure the cumulative flow, the position of the flow meter 210 can be changed to a position where the flow of sulfuric acid discharged through the second drainage pipeline 222 can be measured (for example, a position of the sulfuric acid replenishment pipeline 204 upstream of the branch point 220), or another flow meter can be set in the second drainage pipeline 222.

[0078] After the first pre-discarding operation is completed, the second pre-discarding operation begins. During the second pre-discarding operation, while the on-off valve 212 of the sulfuric acid replenishing line 204 is closed, the on-off valve 224 of the second drain line 222 is closed, and the on-off valve 218 of the first drain line 216 is opened. New sulfuric acid then flows from the sulfuric acid supply source 202 into the sulfuric acid replenishing line 204, and the flowing sulfuric acid is discharged from the first drain line 216. This discharges the sulfuric acid, which contains contaminants such as particulate matter that are trapped within the filter 208 of the sulfuric acid replenishing line 204 and downstream of the filter 208.

[0079] The timer function is used to perform a second pre-discarding operation for a predetermined time. The second pre-discarding operation may also be performed until the cumulative flow rate of sulfuric acid during the pre-discarding operation reaches a predetermined value.

[0080] In the case of performing the first pre-discarding operation and the second pre-discarding operation, it is also possible to perform Figure 3 and Figure 4 In this case, the “pre-discard (operation)” in the flowchart can be replaced with “first pre-discard (operation)) and second pre-discard (operation)”.

[0081] Next, refer to Figure 6 , another embodiment of the sulfuric acid replenishing mechanism (hereinafter also referred to as the third embodiment) will be described. Figure 2 The third embodiment differs from the first embodiment shown in FIG. 1 in that a liquid particle counter (particle detector) 240 (hereinafter referred to as "LPC") is provided in the sulfuric acid replenishment line 204. The other aspects are the same as those of the first embodiment. Components identical to those of the first embodiment are denoted by the same reference numerals and repeated descriptions are omitted. When the sulfuric acid replenishment mechanism of the third embodiment is used, the structure of the sulfuric acid supply mechanism other than the sulfuric acid replenishment mechanism (not shown) is also the same as that of the first embodiment. Figure 2 The structures shown are the same.

[0082] like Figure 6 As shown, the LPC 240 is provided on the secondary side (downstream side) of the filter 208 in the sulfuric acid replenishment line 204 and upstream of the branch point 214 of the drain line 216 .

[0083] A specific application example related to the pre-discarding operation in the third embodiment is shown below.

[0084] (Application Example 1)

[0085] When the liquid level sensor 103 detects that the sulfuric acid level in container 102 has dropped to the lower limit, control device 4 determines that liquid chemical supply is necessary. Then, while keeping on / off valve 212 of sulfuric acid replenishment line 204 closed, control device 4 opens on / off valve 206 of sulfuric acid replenishment line 204 and on / off valve 218 of liquid discharge line 216, performing a pre-discharge operation to discharge the sulfuric acid remaining in sulfuric acid replenishment line 204. During this discharge process, LPC 240 detects the amount of particulate matter contained in the sulfuric acid passing through.

[0086] LPC 240 can also detect the particle count in real time, with control device 4 determining in real time whether the particle count exceeds a predetermined threshold. Alternatively, LPC 240 can sample data at predetermined intervals, with control device 4 determining whether the particle count exceeds the predetermined threshold based on the average of multiple samplings. Alternatively, LPC 240 can sample data at predetermined intervals, with control device 4 determining whether the particle count exceeds the predetermined threshold based on a moving average of the sampled data. Hereinafter, in this specification, the particle count compared with the threshold may be any of the aforementioned real-time measured values, average values, or values ​​based on a moving average.

[0087] When the amount of particles detected is less than a preset threshold, control device 4 stops the pre-discarding operation and begins replenishing sulfuric acid to container 102. Specifically, while opening valve 206 of sulfuric acid replenishment line 204, control device 4 closes valve 218 of drain line 216 and opens valve 212 of sulfuric acid replenishment line 204. When level sensor 103 detects that the sulfuric acid level in container 102 has reached a preset upper limit, valves 206 and 212 of sulfuric acid replenishment line 204 are closed, and replenishment of sulfuric acid to container 102 is stopped.

[0088] When sulfuric acid is being replenished in container 102, if the amount of particles detected by LPC 240 exceeds a preset threshold (due to some abnormality), control device 4 closes valve 212 of sulfuric acid replenishment line 204 and opens valve 218 of drain line 216. This stops replenishment of sulfuric acid in container 102 and resumes the pre-disposal operation.

[0089] (Application Example 2)

[0090] Reference Figure 7 The flowchart of the present invention will be used to illustrate the application example 2 related to the pre-discarding operation in the third embodiment.

[0091] After the last replenishment of sulfuric acid to container 102 is completed, and when the time for the next replenishment is approaching, the amount of particles in the sulfuric acid remaining in sulfuric acid replenishment line 204 is measured using LPC 240. During normal operation of the substrate processing system, the liquid in container 102 decreases at a substantially constant rate. Therefore, the aforementioned timer can be used to detect the approach of the next replenishment time based on the elapsed time since the sulfuric acid replenishment was completed. If the liquid level detection device attached to container 102 is configured to detect that the liquid level in container 102 is slightly above the lower limit level, the liquid level detection device can detect that the time for the next replenishment is approaching.

[0092] When sulfuric acid is stationary in the sulfuric acid supply line 204, the LPC 240 cannot measure the amount of particles meaningfully. This is because the particles that are causing the problem begin to move and diffuse in the sulfuric acid. Therefore, the measurement of the amount of particles in sulfuric acid ( Figure 7 Step S321) is carried out while sulfuric acid is being moved, and is carried out while pre-discarding. As in the first embodiment, pre-discarding is carried out by opening the on-off valve 206 and the on-off valve 218 while the on-off valve 212 is closed.

[0093] The amount of particles measured by the LPC 240 is compared with a predetermined threshold value (step S322 ).

[0094] If the particle amount exceeds the threshold ("Yes" in step S322), a pre-discarding operation is performed (step S323). If the moving average is measured as described above, the pre-discarding operation continues as is. After the timer detects that the pre-discarding operation has been performed for a predetermined time (or after the flow meter 210 detects that a predetermined amount of sulfuric acid has been discarded from the drain line 216), the particle amount measured by the LPC 240 is compared with a predetermined threshold (step S324).

[0095] If the amount of particles is less than the predetermined threshold value ("YES" in step S324), the control device 4 recognizes that there is no problem even if sulfuric acid is added to the container 102. If the result of the determination in step S322 is NO, the control device 4 also recognizes that there is no problem even if sulfuric acid is added to the container 102, and the process proceeds to step S325.

[0096] In this state, when the liquid level sensor 103 detects that the liquid level of sulfuric acid in the container 102 has dropped to the lower limit level, the control device 4 determines that sulfuric acid should be replenished to the container 102 (step S325). The control device 4 closes the on-off valve of the discharge line 216 and opens the on-off valves 206 and 212 of the sulfuric acid replenishment line 204 to start replenishing sulfuric acid to the container 102 (step S326). When the liquid level sensor 103 detects that the liquid level of sulfuric acid in the container 102 has reached the preset upper limit level, the control device 4 closes the on-off valves 206 and 212 of the sulfuric acid replenishment line 204 to stop replenishing sulfuric acid to the container 102 (step S327).

[0097] If the result of step S324 is negative, it is determined whether the total execution time of the pre-discarding operation is less than a predetermined time (step S328). If the result of step S328 is positive, the pre-discarding operation is continued until the particle count becomes less than a predetermined threshold (a loop of steps S323, S324, and S328).

[0098] If the result of the determination in step S328 is "No," the control device 4 determines that there is some reason (e.g., an abnormality in the sulfuric acid supply source 202, which is a factory resource) that prevents the particle amount from being reduced to below the predetermined threshold value by the pre-discarding operation. The control device 4 then generates an alarm using the user interface of the substrate processing system 1, prompting the operator to conduct an inspection.

[0099] In addition, when using Figure 6 In the case of a configuration such as this, when sulfuric acid is replenished in container 102, if the amount of particles detected by LPC 240 exceeds a predetermined threshold, on-off valve 212 may be immediately closed and on-off valve 218 may be opened. This prevents contaminated sulfuric acid from being supplied to container 102 even when the amount of particles increases suddenly.

[0100] When the LPC 240 is configured to be able to detect the amount of particles for each particle size, a particle amount determination criterion (threshold value) may be determined for each particle size.

[0101] Next, refer to Figure 8 Another embodiment of the sulfuric acid replenishing mechanism (hereinafter also referred to as the fourth embodiment) will be described. The fourth embodiment differs from the first embodiment in that heated sulfuric acid is used for pre-disposal operation, and is otherwise the same as the first embodiment.

[0102] In the fourth embodiment, a bypass line 263 for heating is connected to connection points 261 and 262 provided between the on-off valve 206 and the filter 208 of the sulfuric acid replenishment line 204. The bypass line 263 is provided with an on-off valve 264 and a heater 265 in order from the upstream side. An on-off valve 267 is provided between the on-off valve 206 and the filter 208 of the sulfuric acid replenishment line 204 (hereinafter also referred to as the "main line portion 266" for ease of explanation). By switching between the on-off valves 264 and 267, the sulfuric acid supplied from the sulfuric acid supply source 202 can be directed to flow only through the main line portion 266 or the bypass line 263.

[0103] In the fourth embodiment, the determination of whether a pre-discarding operation is necessary is performed in the same manner as in the first embodiment. In the fourth embodiment, when a pre-discarding operation is performed, the on-off valves 206, 264, and 218 are opened while the on-off valves 267 and 212 are closed. Furthermore, the heater 265 is turned on (energized). At this point, sulfuric acid flowing from the sulfuric acid supply source 202 into the sulfuric acid replenishment line 204 flows into the bypass line 263, passes through the bypass line, then flows back into the sulfuric acid replenishment line 204, flows downstream in the sulfuric acid replenishment line 204, and is subsequently discharged through the drain line 216.

[0104] As the sulfuric acid passes through bypass line 263, it is heated by heater 265 and passes through filter 208. This allows particles adhering to the filter element surface due to the aforementioned non-sieving mechanism to detach from the filter element and flow out of filter 208. This allows filter 208 to be actively cleaned through the pre-discarding operation, thereby extending the life of the filter.

[0105] The pre-discarding operation, which accompanies cleaning of filter 208 with heated sulfuric acid, does not need to be performed every time a pre-discarding operation is performed. For example, it can be performed once every ten pre-discarding operations. Alternatively, it can be performed during maintenance of the treatment liquid supply mechanism. When performing a normal pre-discarding operation (not using heated sulfuric acid), it is sufficient to open on-off valves 206, 267, and 218 while on-off valves 264 and 212 are closed.

[0106] The flow resistance of bypass line 263 is preferably greater than that of main line portion 266. This is because reducing the flow rate of sulfuric acid through heater 265 improves heating efficiency. To achieve this, the diameter of bypass line 263 can be reduced, or an appropriate throttling portion can be provided in bypass line 263. Alternatively, on-off valve 264 can be replaced with a needle valve with a fully closing function.

[0107] Next, refer to Figure 9 Another embodiment of the sulfuric acid replenishing mechanism (hereinafter also referred to as the fifth embodiment) will be described. The fifth embodiment differs from the first embodiment in that heated sulfuric acid is used for pre-disposal operation, and is otherwise the same as the first embodiment.

[0108] In the fifth embodiment, a heater (heating device) for heating the filter 208 or an excitation device for applying vibration to the filter 208 is provided on the filter 208. The heating device or the excitation device is schematically represented by a dotted square box marked with the reference numeral 280. By heating the filter 208 or by applying vibration to the filter 208, the particles attached to the surface of the filter component are easily detached from the filter component due to the above-mentioned non-sieving mechanism. The heating of the filter 208 or the excitation of the filter 208 can be performed simultaneously with the pre-discarding operation, or can be started slightly before the pre-discarding operation. In the latter case, the pre-discarding operation can be performed more efficiently, and the time of the pre-discarding operation can be shortened. In this fifth embodiment, the life of the filter can also be extended by the cleaning effect of the filter.

[0109] According to the above embodiment, the processing liquid containing contaminants such as particles can be prevented from flowing into the container 102. As a result, the cleanliness of the processing liquid supplied to the substrate W in each processing unit 16 can be suppressed from decreasing, thereby preventing the particle contamination level of the substrate W from worsening.

[0110] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive, and the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the invention.

[0111] The substrate to be processed is not limited to semiconductor wafers, but may also be various substrates used in the field of semiconductor device manufacturing, such as glass substrates and ceramic substrates. The processing liquid is not limited to sulfuric acid, but may be any processing liquid used in semiconductor manufacturing, such as hydrogen peroxide solution and IPA.

Claims

1. A substrate processing device, characterized in that: include: a processing unit for liquid-treating the substrate using a processing liquid; a container for storing the treatment liquid before being supplied to the treatment unit; a replenishment line for supplying treatment fluid from a treatment fluid supply source to the container; a replenishment on-off valve for opening and closing the replenishment pipeline; a first drain line branching from the replenishment line on the upstream side of the replenishment on-off valve; a first liquid discharge on-off valve for opening and closing the first liquid discharge pipeline; and Control Department, The control unit controls the operation of the replenishment on-off valve and the first liquid discharge on-off valve, and performs a pre-discarding operation of discharging the treatment liquid flowing from the treatment liquid supply source into the replenishment pipeline through the first liquid discharge pipeline before starting to replenish the treatment liquid from the treatment liquid supply source to the container through the replenishment pipeline.

2. The substrate processing device according to claim 1, wherein: The replenishment line is provided with a filter, and the first drain line branches off from the replenishment line on a secondary side of the filter.

3. The substrate processing device according to claim 1, wherein: The control unit performs the preliminary discarding operation when the processing liquid is not continuously replenished into the container through the replenishment line for a predetermined time period.

4. The substrate processing device according to claim 3, wherein: The control unit performs the pre-discarding operation until a preset time has passed or a preset amount of the treated liquid is discharged from the first drain line.

5. The substrate processing device according to claim 2, wherein: further comprising a particle detector for detecting an amount of particles contained in the treatment fluid in the replenishment line, The control unit performs the pre-discarding operation when the amount of particles detected by the particle detector exceeds a predetermined threshold value.

6. The substrate processing device according to claim 5, wherein: The control unit performs the pre-discarding operation until the amount of particles detected by the particle detector becomes smaller than a predetermined threshold value.

7. The substrate processing device according to claim 2, wherein: Also includes: a second drain line branching from the make-up line on the primary side of the filter; and A second liquid discharge on-off valve for opening and closing the second liquid discharge pipeline, The control unit controls the operation of the replenishment on-off valve, the first drain on-off valve, and the second drain on-off valve. Before replenishment of the treatment liquid from the treatment liquid supply source to the container via the replenishment pipeline is started, a first pre-discarding operation of discharging the treatment liquid flowing from the treatment liquid supply source into the replenishment pipeline via the second drain pipeline is performed, and then a second pre-discarding operation of stopping the discharge via the second drain pipeline and discharging the liquid via the first drain pipeline is performed.

8. The substrate processing device according to claim 7, wherein: When the processing liquid is not continuously replenished into the container through the replenishment line for a predetermined time, the control unit performs the first pre-discarding operation and the second pre-discarding operation.

9. The substrate processing device according to claim 8, wherein: The control unit performs a first pre-discarding operation until a preset time has passed or a preset amount of treatment liquid is discharged from the second drainage pipeline, and then performs a second pre-discarding operation until a preset time has passed or a preset amount of treatment liquid is discharged from the first drainage pipeline.

10. The substrate processing device according to claim 7, wherein: further comprising a particle detector for detecting an amount of particles contained in the treatment fluid in the replenishment line, The control unit performs the first pre-discarding operation and the second pre-discarding operation when the amount of particles detected by the particle detector exceeds a predetermined threshold value.

11. The substrate processing device according to claim 10, wherein: The control unit performs the first pre-discarding operation until a predetermined time has passed or a predetermined amount of treatment liquid is discharged from the second drainage line, and then performs the second pre-discarding operation until the amount of particles detected by the particle detector is less than a predetermined threshold.

12. The substrate processing device according to claim 2, wherein: A heater is provided in the replenishment line on the upstream side of the filter, and the control unit uses the heater to heat the treatment liquid to pass through the filter when performing the pre-discarding operation.

13. The substrate processing device according to claim 2, wherein: A heater is provided for heating the filter. The control unit heats the filter using the heater when performing the pre-discarding operation.

14. The substrate processing device according to claim 2, wherein: A vibration device is provided to vibrate the filter. The control unit vibrates the filter using the vibration device when performing the pre-discarding operation.

15. A method for replenishing a treatment liquid, characterized in that: The processing liquid replenishing method replenishes the processing liquid to the container in the substrate processing device, The substrate processing device comprises: a processing unit for liquid-treating the substrate using a processing liquid; a container for storing the treatment liquid before being supplied to the treatment unit; a replenishment line for supplying treatment fluid from a treatment fluid supply source to the container; a replenishment on-off valve for opening and closing the replenishment pipeline; a first drain line branching from the replenishment line on the upstream side of the replenishment on-off valve; and a first liquid discharge on-off valve for opening and closing the first liquid discharge pipeline; In the treatment liquid replenishing method, before replenishing the treatment liquid from the treatment liquid supply source to the container via the replenishing line, a pre-discarding operation of discharging the treatment liquid flowing from the treatment liquid supply source into the replenishing line via the first drain line is performed.

16. The method for replenishing the treatment liquid according to claim 15, wherein: The replenishment line is provided with a filter, and the first drain line branches off from the replenishment line on a secondary side of the filter.

17. The method for replenishing the treatment liquid according to claim 15, wherein: The preliminary discarding operation is performed when the processing liquid is not continuously replenished into the container through the replenishing line for a predetermined period of time.

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