JPH04320954A - Automatic liquid control device - Google Patents

Abstract

PURPOSE:To enable a constitution for supplying a reagent to be simplified by supplying at least two types of reagents selectively to a reaction cell. CONSTITUTION:A three-way electromagnetic valve 30 for selectively enabling a channel 27 which communicates with a flask 25 and a channel 28 which communicates with a flask 26 to a channel 29 which communicates with a reaction cell 22 is provided. thus allowing a reagent for analyzing an effective constituent of a resist release liquid which is stored within the flasks 25 and 26 to be supplied to the reaction cell 22 selectively.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic liquid management device for determining whether or not a processing liquid has deteriorated.

0002

2. Description of the Related Art Conventionally, resist stripping solutions (processing solutions) used, for example, in semiconductor manufacturing processes, have been analyzed and managed by various methods, both automatic and manual. in particular,
When analyzing the resist stripping solution, perform neutralization titration or redox titration of sulfuric acid and hydrogen peroxide, which are the active ingredients of the resist stripping solution, or measure the absorbance of the resist stripping solution and its change using an absorbance meter. The degree of deterioration of the resist stripping solution was measured.

0003

[Problems to be Solved by the Invention] By the way, in the resist stripping solution analyzer as described above, when determining the deterioration of the resist stripping solution, it is necessary to titrate the concentrations of both sulfuric acid and hydrogen peroxide, respectively. As a result, at least two reagent supply systems are required for titrating the sulfuric acid and hydrogen peroxide, resulting in a problem that the configuration becomes complicated. That is, the reagent supply includes a storage section that stores a reagent for analyzing the sulfuric acid or hydrogen peroxide, a titration pump that transfers the reagent in the storage section, and a flow path that guides the reagent to the reaction cell by the titration pump. It is necessary to provide at least two systems in total, one system each for sulfuric acid and hydrogen peroxide, which has the problem of complicating the overall configuration. The present invention has been made in view of the above circumstances, and is an automatic system that selectively supplies at least two types of reagents to a reaction cell, thereby simplifying the configuration of the reagent supply system. The purpose is to provide liquid management equipment.

0004

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a sampling means for sampling a treatment liquid, and a titration means for determining the concentration of an active ingredient in the sampled treatment liquid by titration. , the titration means is a reaction cell that stores the sampled treatment liquid;
The reagent supply system is composed of a reagent supply system that drips and supplies a reagent for analyzing the active ingredient in the treatment liquid, and an electrode that detects the potential within the reaction cell, and the reagent supply system is
a first storage section in which a reagent for analyzing a first active ingredient in the processing liquid is stored; a second storage section in which a reagent for analyzing a second active ingredient in the processing liquid is stored; a switching valve that selectively connects a flow path leading to the first storage section and a flow path leading to the second storage section to a flow path leading to the reaction cell; The system is composed of a titration pump that transfers the liquid to the reaction cell through a passageway and drips the liquid.

[0005]

[Operation] According to the present invention, a switching valve is provided that selectively connects the flow path leading to the first storage section and the flow path leading to the second storage section to the flow path leading to the reaction cell. By the switching operation of the switching valve, the reagent (potassium permanganate) for analyzing the first active ingredient (hydrogen peroxide) in the processing liquid stored in the first storage part is transferred to the second storage part. The stored reagent (sodium hydroxide) for analyzing the second active ingredient (sulfuric acid) in the processing solution can be selectively supplied to the reaction cell, thereby creating two reagent supply systems. The configuration is simplified compared to conventional automatic liquid management devices that require

[0006]

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. An embodiment of the present invention will be described with reference to the overall schematic configuration diagram of FIG. 1 and the flowchart of FIG. 2. First, in FIG. 1, the reference numeral 1 indicates a processing liquid supply path through which a resist stripping liquid (processing liquid) is supplied. In addition,
The resist stripping solution contains components such as hydrogen peroxide (first active ingredient) and sulfuric acid (second active ingredient) that remove and dissolve resist (novolak resin, etc.) on semiconductor silicon wafers. ing. In the middle of the processing liquid supply path 1, along the flow direction X of the resist stripping solution, there are a cooler 2 for cooling the resist stripping solution, a filter 3 for removing impurities such as undissolved substances, a photocell 4, and a hexagonal solenoid valve. 5 are provided in sequence. The photocell 4 guides the resist stripping solution sent through the path 1 into a cell (not shown), and measures the absorbance of the resist stripping solution by irradiating the resist stripping solution with a light beam of a certain wavelength. It is something to do. Then, based on the change in absorbance detected by this photocell 4, the degree of deterioration of the processing liquid is measured.

Further, the six-way solenoid valve 5 is (1) usually arranged as shown by a solid line, and the resist stripping liquid is passed through a loop 10 and paths 6 and 7 to a processing tank (not shown).
(2) When measuring the concentration of sulfuric acid and hydrogen peroxide in the resist stripping solution, the resist stripper is switched to the position shown by the dotted line and placed at the position shown by the solid line. During this time, the resist stripping solution temporarily stored in the loop 10 is pushed out by pure water sent through a pure water supply system 11 (described later) and guided to a reaction cell (described later). Note that the loop 10 has a preset amount of resist stripping liquid stored therein, that is, is used for quantitative determination. In addition, the route 6
A three-way solenoid valve 12 is installed in the path 6 to guide a particularly dirty resist stripping solution or a resist stripping solution mixed with pure water to the drain tank 9. What is provided is a pump 13, and what is provided in the middle of the path 8 is a PH electrode 14 that measures the pH of the resist stripping solution.

Further, the pure water supply system 11 includes a two-way solenoid valve 16, an intermediate trap 17, a pump 18, which are provided along the pure water supply path 15, and a branched path 19, to supply the pure water. The relief valve 20 maintains the water supply pressure below a certain value. Note that the pure water discharged by the relief valve 20 is guided to the drain tank 9. On the other hand, after being temporarily stored in the loop 10, the resist stripping liquid pushed out by the pure water is guided to the titration means 50 through the path 21. The titration means 50 includes a reaction cell 22 that stores the resist stripping solution sampled by the loop 10, and a reaction cell 22 that stores the resist stripping solution sampled by the loop 10.
In contrast, a reagent supply system 23 that drips a reagent for analyzing hydrogen peroxide or sulfuric acid in the resist stripping solution, and a reagent supply system 23 that drips a reagent for analyzing hydrogen peroxide or sulfuric acid in the resist stripping solution, and a reagent supply system 23 that drips a reagent for analyzing hydrogen peroxide or sulfuric acid in the resist stripping solution, and a reagent supply system 23 that drips a reagent for analyzing hydrogen peroxide or sulfuric acid in the resist stripping solution, and in the reaction cell 22, the degree of reactivity between the hydrogen peroxide or sulfuric acid and the reagent are determined. It is composed of an electrode 24 for measuring . The electrode 24 has a function of measuring the potential (oxidation-reduction potential, etc.) inside the reaction cell 22, and the measured data (a) is supplied to a data processing device (not shown). .

The reagent supply system 23 also includes a flask 25 (a first storage section) storing a potassium permanganate solution (reagent) that oxidizes hydrogen peroxide (first active ingredient) in the resist stripping solution. ) and sodium hydroxide (reagent) that neutralizes the sulfuric acid (second active ingredient) in the resist stripping solution.
A flask 26 (second storage part) in which is stored, a flow path 27 leading to the flask 25, and a flow path 2 leading to the flask 26.
A three-way solenoid valve (switching valve) 30 selectively connects the reagent in the flask 25 or 26 to the flow path 29 leading to the reaction cell 22, and In the titration pump 31, the amount of reagent dropped into the reaction cell 22 is supplied as measurement data (b) to a data processing device (not shown). It has become. And, the titration means 5 configured as described above.
From 0, measurement data (a) indicating the potential measured at the electrode 24 and measurement data (b) indicating the drip amount measured by a flowmeter (not shown) of the metering pump 27 are processed by the data processing device ( This data processing device calculates the concentration of hydrogen peroxide or sulfuric acid in the resist stripping solution. That is, in the data processing device, the point at which the potential jumps is taken as the end point of the reaction (based on the measured data (a)), and the amount of the reagent dropped at the end point of the reaction (based on the measured data (b)) is used to estimate the resist. The concentration of hydrogen peroxide or sulfuric acid in the stripping solution is calculated.

On the other hand, a path 40 is provided at the bottom of the reaction cell 22 for discharging the resist stripping solution in the reaction cell 22 every time a measurement is completed, and a filter 41, a filter 41, A solenoid valve 42 and a drain pump 43 for discharging the solution from the reaction cell 22 are provided in this order. The solution discharged through the path 40 is sent into the drain tank 9 described above. In the above configuration, the components in the range shown by numeral 100 in FIG. 1 are used as sampling means, the components in the range shown by numeral 50 are used as titration means, and the components in the range shown by numeral 60 are used as discharge means.

Next, the control contents of the titration means 50 of the automatic liquid management device shown in FIG. 1 will be explained step by step with reference to the flowchart shown in FIG. Note that this control content is stored in a control device (not shown) and executed by the control device. <Step 1> The six-way solenoid valve 5 is switched from the position shown by the solid line to the position shown by the dotted line, and the resist stripping solution quantified in the loop 10 is pushed out by the pure water sent through the pure water supply system 11 and is then transferred to the reaction cell 22. invite. 《Step 2》 Determine whether or not the setting to analyze the hydrogen peroxide concentration in the resist stripping solution has been made. If YES, proceed to step 3; if NO, proceed to step 5.
Proceed to A. <<Step 3>><<Step4>> The solenoid valve 30 is operated to connect the flow path 27 and the flow path 29, thereby supplying the potassium permanganate solution in the flask 25 into the reaction cell 22.

<<Step 5A>> If settings have been made to analyze the concentration of sulfuric acid, which is an active ingredient in the resist stripping solution, the process proceeds to the next step 5B. Note that when analyzing the concentration of sulfuric acid after analyzing the concentration of hydrogen peroxide in the resist stripping solution, it is preferable to go through the following steps before introducing the resist stripping solution into the reaction cell 22. (Even when analyzing the concentration of hydrogen peroxide after analyzing the concentration of sulfuric acid in the resist stripping solution, it is preferable to go through the following steps). That is, with the solenoid valve 42 open and the flow path 28 and flow path 29 connected by the solenoid valve 30, the titration pump 31 and the drain pump 43 are operated for a certain period of time, and the inside of the path 29 is flushed with the flask. 26 is replaced with sodium hydroxide, which is a reagent for sulfuric acid concentration analysis. Thereafter, with the electromagnetic valve 42 closed and the titration pump 31 and drain pump 43 stopped, it is preferable to introduce the resist stripping liquid into the reaction cell 22 and perform the titration described below. <<Step 5B>><<Step5C>> With the flow path 28 and flow path 29 connected by the electromagnetic valve 30, the sodium hydroxide solution in the flask 26 is supplied to the reaction cell 22 by the titration pump 31. <Step 7> Measurement data (a) indicating the potential measured at the electrode 24 and measurement data (b) indicating the dripping amount measured at the metering pump 27 are supplied to the data processing device.

<<Step 8>> The data processing device is caused to calculate the concentration of hydrogen peroxide or sulfuric acid in the resist stripping solution based on the measured data (a) and (b). That is, in the data processing device, the point at which the potential jumps is taken as the end point of the reaction (based on the measured data (a)), and the amount of the reagent dropped at the end point of the reaction (based on the measured data (b)) is used to estimate the resist. Calculate the concentration of hydrogen peroxide or sulfuric acid in the stripping solution. <Step 9> Stop the titration pump 31 and close the solenoid valve 4.
2 is opened, and the drain pump 43 is operated to drain the resist stripping liquid from the reaction cell 22. Thereafter, the inside of the reaction cell 22 is washed with pure water supplied through the path 34, and the solenoid valve 42 is closed. <Step 10> Once again, it is determined whether or not to continue analyzing the concentration of the active ingredient in the resist stripping solution. If NO, proceed to the next original step 1. If YES, this flowchart is repeated as the step of the above flowchart. In step 2, the setting of whether to detect the hydrogen peroxide concentration or the sulfuric acid concentration may be set sequentially by the operator, or may be set to be set automatically, for example, alternately.

As explained above, according to the automatic liquid management device shown in this embodiment, the flow path 27 leading to the flask 25 and the flow path 28 leading to the flask 26 are selectively connected to the flow path 29 leading to the reaction cell 22. Since a three-way solenoid valve 30 is provided, the switching operation of the three-way solenoid valve 30 allows a reagent (potassium permanganate) for analyzing hydrogen peroxide stored in the flask 25 and a reagent (potassium permanganate) stored in the flask 26 to be used. A reagent for analyzing sulfuric acid (sodium hydroxide) can be alternatively supplied to the reaction cell 22, whereby 2
This has the effect of simplifying the configuration compared to conventional automatic liquid management devices that require a separate reagent supply system.

[0015] Normally, when hydrogen peroxide is reacted with the reagent potassium permanganate, sulfuric acid (potassium permanganate has different reactivity under acidic and neutral conditions, so However, according to the automatic liquid management device shown in this example, since it is assumed that a sulfuric acid-hydrogen peroxide-based resist stripping liquid will be analyzed, In particular, the step of adding sulfuric acid can be omitted when titrating hydrogen oxide. Furthermore, when quantifying hydrogen peroxide in a resist stripping solution that does not contain sulfuric acid, it is recommended to dissolve the reagent potassium permanganate in an aqueous sulfuric acid solution instead of in pure water. good. This makes it possible to perform quantitative analysis even when the sampled solution (processing liquid) does not contain sulfuric acid (for example, an aqueous solution containing only hydrogen peroxide). Further, the oxidizing agent is not limited to potassium permanganate, but potassium dichromate or the like may be used. Further, although sodium hydroxide was used as a neutralizing agent to neutralize sulfuric acid, the present invention is not limited thereto, and potassium hydroxide or the like may also be used. In this embodiment, the solenoid valve 30 is used to switch the reagents, and one titration pump 21 selectively supplies the two reagents, but the reagents may be supplied separately using the two pumps. good.

[0016]

Effects of the Invention As is clear from the above description, according to the present invention, the flow path leading to the first storage portion and the flow path leading to the second storage portion can be selectively replaced with the flow path leading to the reaction cell. Since a switching valve connected to the switching valve is provided, the switching operation of the switching valve causes the reagent (permanganese It is possible to selectively supply to the reaction cell a reagent (sodium hydroxide) for analyzing the second active ingredient (sulfuric acid) in the processing liquid stored in the second storage part. This has the effect of simplifying the configuration compared to conventional automatic liquid management devices that require two reagent supply systems.

[Brief explanation of drawings]

FIG. 1 is an overall schematic configuration diagram of an automatic liquid management device.

FIG. 2 is a flowchart showing control details of the control device of the automatic liquid management device.

[Explanation of symbols]

22 Reaction cell 23 Reagent supply system 24 Electrode 25 Flask (first storage part) 26 Flask (second storage part) 27 Flow path 28 Flow path 29 Flow path 30 Three-way solenoid valve (switching valve) 31 Titration pump 50 Titration means 100 Sampling means

Claims (1)

[Claims] 1. A method comprising: a sampling means for sampling a treatment liquid; and a titration means for determining the concentration of an active ingredient in the sampled treatment liquid by titration, the titration means comprising:
Consisting of a reaction cell that stores the sampled treatment liquid, a reagent supply system that drips and supplies a reagent for analyzing the active ingredient in the treatment liquid, and an electrode that detects the potential within the reaction cell. and the reagent supply system is
a first storage section in which a reagent for analyzing a first active ingredient in the processing liquid is stored; a second storage section in which a reagent for analyzing a second active ingredient in the processing liquid is stored; a switching valve that selectively connects a flow path leading to the first storage section and a flow path leading to the second storage section to a flow path leading to the reaction cell; An automatic liquid management device characterized by comprising a titration pump that transfers the liquid to a reaction cell through a channel and causes the liquid to drip.