Chemical liquid management method

Abstract

To provide a chemical liquid management method capable of managing whether or not a specified quantity of a chemical liquid has been accurately added to a fluid.SOLUTION: A chemical liquid management method for managing whether or not a specified quantity of a chemical liquid has been added to a fluid in a chemical liquid supply system including an addition unit that adds the specified quantity of the chemical liquid to a fluid supply line that supplies the fluid comprises: first conductivity measurement step 102 of measuring a first conductivity of the fluid with a first conductivity sensor disposed on the fluid supply line on an upstream side of the addition unit; second conductivity measurement step 103 of measuring a second conductivity of the fluid with a second conductivity sensor disposed on the fluid supply line on a downstream side of the addition unit; correction step of correcting the second conductivity based on the first conductivity; and determination step 105 of determining whether or not the specified quantity of the chemical liquid has been added to the fluid based on the corrected second conductivity.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a chemical solution management method. [Background technology]

[0002] Wafers, which have multiple devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration) formed on their surface, have their back surfaces ground to a specified thickness, and then are separated into individual devices using a cutting machine for use in electrical equipment such as mobile phones and personal computers.

[0003] The method of dividing the wafer into individual devices is generally to use a plating method on a base. An electrodeposited grinding wheel such as an electrodeposited hub blade is attached to a cutting device, and cutting is performed while supplying processing water to the blade and the surface of the wafer, thereby separating the wafer into individual devices (see, for example, Patent Document 1).

[0004] The processing water is supplied for the purposes of cooling the processing point between the wafer and the blade during cutting and removing cutting chips generated during cutting.

[0005] However, even if processing water is supplied, cutting debris cannot be completely removed, and there is a problem that cutting debris adheres to and remains on the wafer surface. Also, it is required to prevent corrosion of the metal parts on the wafer surface.

[0006] Therefore, the applicant developed and filed a patent application for an additive for dicing cutting water containing a predetermined concentration of surfactant or anticorrosive agent (hereinafter referred to as chemical solution) that prevents cutting debris from adhering and remaining on the wafer surface, and a processing method using the same (see, for example, Patent Document 2).

[0007] Currently, a chemical solution is supplied to a processing device as processing water by disposing an addition unit that adds a predetermined amount of chemical solution in a liquid supply path that supplies a fluid such as pure water or city water. In addition, to confirm whether the predetermined amount of chemical solution has been supplied to the fluid, a conductivity sensor is provided downstream of the addition unit, and the chemical solution concentration is measured by measuring the conductivity (see, for example, Patent Document 3).

[0008] There is also a processing method in which carbon dioxide is added to pure water to prevent electrostatic damage to the wafer, and the resulting water is supplied to a processing device as processing water for processing the wafer. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 10-242083 [Patent Document 2] Patent No. 5253765 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-165771 Summary of the Invention [Problem to be solved by the invention]

[0010] However, especially when the fluid is city water or pure water to which carbon dioxide has been added (hereafter referred to as CO2 water), the conductivity of city water or CO2 water is higher than that of pure water, so even if the chemical concentration is measured with a conductivity sensor downstream of the dosing unit, it is difficult to accurately determine whether the specified amount of chemical has been added. If the specified amount of chemical is not added, it can cause processing defects.

[0011] An object of the present invention is to provide a chemical liquid management method capable of managing whether a predetermined amount of chemical liquid has been accurately added to a fluid. [Means for solving the problem]

[0012] In order to solve the above-mentioned problems and achieve the object, the chemical liquid management method of the present invention is a chemical liquid management method for managing whether a predetermined amount of chemical liquid has been added to a fluid in a chemical liquid supply system equipped with an addition unit that adds a predetermined amount of chemical liquid to a fluid supply path that supplies a fluid, and is characterized by comprising at least a first conductivity measurement step of measuring a first conductivity of the fluid using a first conductivity sensor arranged in the fluid supply path upstream of the addition unit, a second conductivity measurement step of measuring a second conductivity of the fluid using a second conductivity sensor arranged in the fluid supply path downstream of the addition unit, a correction step of correcting the second conductivity based on the first conductivity, and a determination step of determining whether a predetermined amount of chemical liquid has been added to the fluid based on the corrected second conductivity. [Effects of the Invention]

[0013] The present invention has an effect of being able to manage whether or not a predetermined amount of chemical solution has been accurately added to a fluid. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a chemical liquid supply system that implements a chemical liquid management method according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing an example of conductivity data stored in the storage unit of the control unit of the chemical liquid supply system shown in FIG. [Figure 3] FIG. 3 is a flowchart showing the flow of the chemical liquid management method according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Modes (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made within the scope of the gist of the present invention.

[0016] [Embodiment 1] A chemical liquid management method according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a diagram showing an example of the configuration of a chemical liquid supply system that implements the chemical liquid management method according to the first embodiment. Fig. 2 is a diagram showing an example of conductivity data stored in a storage unit of a control unit of the chemical liquid supply system shown in Fig. 1. Fig. 3 is a flowchart showing the flow of the chemical liquid management method according to the first embodiment.

[0017] (Chemical supply system) The chemical liquid management method according to the first embodiment is carried out by a chemical liquid supply system 1 shown in Fig. 1. As shown in Fig. 1, the chemical liquid supply system 1 includes a fluid supply path 10 that supplies a fluid 2, an addition unit 20 that adds a predetermined amount of chemical liquid 3 to the fluid supply path 10, and a control unit 30.

[0018] The fluid supply path 10 supplies a fluid 2 to a processing device, such as a cutting device or grinding device, that processes a workpiece such as a semiconductor wafer, to be used by the processing device during processing. City water is supplied as the fluid 2 from a city water supply source (not shown) through the fluid supply path 10, and the city water supplied from the city water supply source is supplied as the fluid 2 to the processing device.

[0019] 1 , the fluid supply path 10 includes a first conductivity sensor 11 disposed in the fluid supply path 10 upstream of the addition unit 20 in the direction of movement of the fluid 2, and a second conductivity sensor 12 disposed in the fluid supply path 10 downstream of the addition unit 20 in the direction of movement of the fluid 2. The first conductivity sensor 11 measures the conductivity of the fluid 2 in the fluid supply path 10 before the addition of the chemical solution 3 by the addition unit 20 after it has been supplied from the city water supply source, and outputs the measurement result to the control unit 30. The second conductivity sensor 12 measures the conductivity of the fluid 2 in the fluid supply path 10 after the addition of the chemical solution 3 by the addition unit 20 after it has been supplied from the city water supply source, and outputs the measurement result to the control unit 30.

[0020] The doping unit 20 adds a predetermined amount of chemical solution 3 to the fluid 2 in the fluid supply path 10. The chemical solution 3 supplied by the doping unit 20 changes the conductivity of the fluid 2 in the fluid supply path 10 depending on the amount supplied into the fluid 2, and is, for example, an additive such as the dicing cutting water described in Japanese Patent No. 5253765, a surfactant, or carbon dioxide. In the first embodiment, the chemical solution 3 supplied by the doping unit 20 increases the conductivity of the fluid 2 in the fluid supply path 10 as the amount supplied into the fluid 2 increases.

[0021] The addition unit 20 includes a tank 21 that stores the chemical solution 3, and a pump 22 that supplies the chemical solution 3 in the tank 21 into the fluid supply path 10. The pump 22 is a metering pump that supplies the chemical solution 3 in the tank 21 into the fluid supply path 10 at a flow rate set by the control unit 30.

[0022] The control unit 30 controls each component of the chemical solution supply system 1 to cause the chemical solution supply system 1 to add the chemical solution 3 to the fluid 2 in the fluid supply path 10. The control unit 30 is a computer having an arithmetic processing device with a microprocessor such as a CPU (central processing unit), a storage device with memory such as a ROM (read only memory) or RAM (random access memory), and an input / output interface device. The arithmetic processing device of the control unit 30 performs arithmetic processing in accordance with a computer program stored in the storage device, and outputs control signals for controlling the chemical solution supply system 1 to each component of the chemical solution supply system 1 via the input / output interface device.

[0023] The control unit 30 is also connected to a display unit configured with a liquid crystal display device or the like that displays various information and images, and an input unit that the operator uses to register processing content information, etc. The input unit is configured with at least one of a touch panel provided on the display unit and an external input device such as a keyboard.

[0024] The control unit 30 includes a storage unit 31 and an operation control unit 32. The storage unit 31 stores the conductivity data 33 shown in FIG. 2. The conductivity data 33 indicates the relationship between the concentration of the chemical solution 3 in the fluid 2 and the conductivity of the fluid 2. In the first embodiment, the concentration of the chemical solution 3 in the fluid 2 and the conductivity of the fluid 2 have a proportional relationship.

[0025] 2 indicates the concentration (wt %) of the chemical solution 3 in the fluid 2, and the vertical axis in FIG. 2 indicates the conductivity (mS / m) of the fluid 2. The conductivity data 33 shown in FIG. 2 indicates the relationship between the concentration of the chemical solution 3 added to the pure water and the conductivity of the pure water to which the chemical solution 3 has been added. The conductivity data 33 is determined for each type of chemical solution 3.

[0026] The operation control unit 32 controls each component of the chemical liquid supply system 1, causing the chemical liquid supply system 1 to add the chemical liquid 3 to the fluid 2 in the fluid supply path 10. The operation control unit 32 controls the flow rate of the chemical liquid 3 that the pump 22 supplies to the fluid 2 in the fluid supply path 10, based on the conductivity of the fluid 2 measured by the conductivity sensors 11 and 12 and the conductivity data 33 shown in Fig. 2, and causes the chemical liquid supply system 1 to supply the fluid 2 to which a predetermined amount of the chemical liquid 3 has been supplied to the processing device.

[0027] The functions of the storage unit 31 are realized by the above-mentioned storage device, and the functions of the operation control unit 32 are realized by the arithmetic processing unit performing arithmetic processing in accordance with the computer program stored in the storage device.

[0028] (Chemical solution management method) Next, a chemical liquid management method according to embodiment 1 will be described. The chemical liquid management method according to embodiment 1 is a method for managing whether a predetermined amount of chemical liquid 3 has been added to fluid 2, which is city water supplied from a city water supply source, in chemical liquid supply system 1 having the above-described configuration. The chemical liquid management method according to embodiment 1 is also a supply operation in which chemical liquid supply system 1 described above supplies fluid 2, to which a predetermined amount of chemical liquid 3 has been added, to a processing device.

[0029] In the chemical liquid management method, the chemical liquid supply system 1 receives and registers in the control unit 30 supply conditions under which the pump 22 supplies the chemical liquid 3 to the fluid 2 in the fluid supply path 10. The supply conditions include the flow rate of the chemical liquid 3 supplied by the pump 22 to the fluid 2 in the fluid supply path 10, the concentration of the chemical liquid 3 in the fluid 2 supplied to the processing device, etc. In the chemical liquid management method, when the control unit 30 of the chemical liquid supply system 1 receives an instruction to start supplying the fluid 2, the supply operation of the fluid 2 is started.

[0030] As shown in FIG. 3, the chemical liquid management method includes a chemical liquid addition step 101, a first conductivity measurement step 102, a second conductivity measurement step 103, a correction step 104, a determination step 105, and an adjustment step 106.

[0031] The chemical liquid adding step 101 is a step of supplying the chemical liquid 3 to the fluid 2 in the fluid supply path 10 based on the supply conditions. In the first embodiment, the chemical liquid adding step 101 is performed by the operation control section 32 of the control unit 30 causing the fluid supply path 10 to start supplying the fluid 2 to the processing device. In the first embodiment, the chemical liquid adding step 101 is performed by the operation control section 32 of the control unit 30 controlling the pump 22 to supply the chemical liquid 3 to the fluid 2 in the fluid supply path 10 at a flow rate determined by the supply conditions.

[0032] The first conductivity measurement step 102 is a step of measuring a first conductivity 34 (shown in FIG. 2 ) of the fluid by a first conductivity sensor 11 disposed in the fluid supply path 10 upstream of the addition unit 20. In the first embodiment, in the first conductivity measurement step 102, the first conductivity sensor 11 measures the conductivity of the fluid 2 in the fluid supply path 10 and outputs the measurement result, the first conductivity 34, to the control unit 30.

[0033] The second conductivity measurement step 103 is a step of measuring the second conductivity 35 (shown in FIG. 2 ) of the fluid by the second conductivity sensor 12 disposed in the fluid supply path 10 downstream of the addition unit 20. In the first embodiment, in the second conductivity measurement step 103, the second conductivity sensor 12 measures the conductivity of the fluid 2 in the fluid supply path 10 and outputs the measurement result, the second conductivity 35, to the control unit 30.

[0034] The correction step 104 is a step of correcting the second conductivity 35 based on the first conductivity 34. In the first embodiment, in the correction step 104, the operation control section 32 of the control unit 30 of the chemical solution supply system 1 subtracts the first conductivity 34 from the second conductivity 35 to calculate a conductivity difference 36 (shown in FIG. 2 and corresponding to the corrected second conductivity).

[0035] The determination step 105 is a step for determining whether a predetermined amount of the chemical solution 3 has been added to the fluid 2 based on the conductivity difference 36, which is the corrected second conductivity. In embodiment 1, in the determination step 105, the operation control unit 32 of the control unit 30 of the chemical solution supply system 1 calculates the concentration 37 (shown in Figure 2) of the chemical solution 3 corresponding to the conductivity difference 36 in the conductivity data 33 stored in the memory unit 31.

[0036] In embodiment 1, in judgment step 105, the chemical liquid supply system 1 calculates the difference between the concentration 37 of the chemical liquid 3 calculated by the operation control unit 32 of the control unit 30 and the concentration of the chemical liquid 3 in the fluid 2 determined by the supply conditions, and if the difference exceeds a predetermined value, it determines (No) that the predetermined amount of the chemical liquid 3 has not been added to the fluid 2, and proceeds to adjustment step 106.

[0037] The adjusting step 106 is a step of adjusting the flow rate of the chemical solution 3 that the addition unit 20 supplies to the fluid 2 in the fluid supply path 10. In the first embodiment, in the adjusting step 106, the operation control unit 32 of the control unit 30 adjusts the flow rate of the chemical solution 3 that the pump 22 supplies to the fluid 2 in the fluid supply path 10 based on the difference in concentration calculated in the determining step 105, and the process returns to the chemical solution adding step 101. Specifically, in the first embodiment, in the adjusting step 106, if the concentration 37 of the chemical solution 3 calculated by the operation control unit 32 of the control unit 30 from the conductivity data 33 and the like exceeds the concentration of the chemical solution 3 in the fluid 2 set in the supply conditions, the pump 22 decreases the flow rate of the chemical solution 3 that the pump 22 supplies to the fluid 2 in the fluid supply path 10 by a predetermined flow rate, and if the concentration 37 of the chemical solution 3 calculated from the conductivity data 33 and the like is lower than the concentration of the chemical solution 3 in the fluid 2 set in the supply conditions, the pump 22 increases the flow rate of the chemical solution 3 that the pump 22 supplies to the fluid 2 in the fluid supply path 10 by a predetermined flow rate.

[0038] In the chemical solution addition step 101 returning from the adjustment step 106, the operation control section 32 of the control unit 30 causes the pump 22 to supply the chemical solution 3 to the fluid 2 in the fluid supply path 10 at the flow rate adjusted in the adjustment step 106. Also, in the first embodiment, in the determination step 105, the chemical solution supply system 1 calculates the difference between the concentration 37 of the chemical solution 3 calculated by the operation control section 32 of the control unit 30 and the concentration of the chemical solution 3 in the fluid 2 determined by the supply conditions, and if the difference is equal to or less than a predetermined value, it determines (Yes) that a predetermined amount of the chemical solution 3 has been added to the fluid 2, and ends the chemical solution management method according to the first embodiment.

[0039] In the first embodiment, after the chemical liquid supply system 1 finishes the chemical liquid management method, the pump 22 supplies the chemical liquid 3 to the fluid 2 in the fluid supply path 10 at a flow rate determined by the supply conditions or a flow rate adjusted in the adjustment step 106 or the like. In the present invention, the chemical liquid supply system 1 may also perform the chemical liquid management method according to the first embodiment at predetermined time intervals while supplying the fluid 2 to the processing device.

[0040] As described above, the chemical liquid management method of embodiment 1 includes a first conductivity measurement step 102 in which a first conductivity 34 of the fluid 2 is measured using a first conductivity sensor 11 arranged in the fluid supply path 10 upstream of the addition unit 20, and a second conductivity measurement step 103 in which a second conductivity 35 of the fluid 2 is measured using a second conductivity sensor 12 arranged in the fluid supply path 10 downstream of the addition unit 20.Therefore, even if the conductivity of the fluid 2 before the chemical liquid 3 is added is unknown, the concentration 37 of the chemical liquid 3 in the fluid 2 to which the chemical liquid 3 has been added can be calculated in the determination step 105.

[0041] As a result, the chemical liquid management method according to embodiment 1 has the effect of being able to determine whether a predetermined amount of chemical liquid 3 has been accurately added to fluid 2 and to manage the fluid, even if the fluid 2 supplied to a processing device or the like is a liquid with unknown conductivity, such as city water or CO2 water.

[0042] The present invention is not limited to the above-described embodiment, and can be implemented in various modifications without departing from the gist of the present invention. [Explanation of symbols]

[0043] 1 Chemical supply system 2 fluid 3. Chemical Solution 10 Fluid supply path 11 First conductivity sensor 12 Second Conductivity Sensor 20 Addition Unit 34 First Conductivity 35 Second Conductivity 36 Conductivity difference (corrected second conductivity) 102 First Conductivity Measurement Step 103 Second Conductivity Measurement Step 104 correction steps 105 Judgment Step

Claims

[Claim 1] 1. A chemical liquid management method for managing whether a predetermined amount of chemical liquid has been added to a fluid in a chemical liquid supply system including an addition unit that adds a predetermined amount of chemical liquid to a fluid supply path that supplies the fluid, comprising: a first conductivity measuring step of measuring a first conductivity of the fluid with a first conductivity sensor disposed in the fluid supply path upstream of the dosing unit; a second conductivity measuring step of measuring a second conductivity of the fluid with a second conductivity sensor disposed in the fluid supply path downstream of the dosing unit; a correcting step of correcting the second conductivity based on the first conductivity; a determining step of determining whether a predetermined amount of chemical solution has been added to the fluid based on the corrected second conductivity; A chemical solution management method comprising at least the steps of:

Images