JPH0871389A - Preparation of developing solution - Google Patents

Abstract

PURPOSE: To continuously prepare a developing soln. containing other component other than alkali, for example, an additive component such as a surfactant or the like with high accuracy. CONSTITUTION: A developing raw soln. (TMAH aq. soln.) and pure water are supplied to a preparation tank 2 to obtain a dilute developing soln. and an additive is added to the dilute developing soln. The amt. of the additive to be added is measured by a load cell 46 so as to bring the concn. of the additive to set concn. to prepare a developing soln. containing the additive in predetermined concn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention adjusts a developing stock solution containing a high-concentration alkaline component to a predetermined concentration and adds an additive so that the diluted developing stock solution has a predetermined concentration. Regarding the method.

[0002]

2. Description of the Related Art As a method for adjusting a developing solution for a photoresist used in the manufacture of semiconductor devices, etc., a developing stock solution and pure water which is a diluting solution are stirred and mixed to measure the conductivity of the mixed solution. A method of adding undiluted developing solution or pure water so as to obtain a predetermined concentration based on the measured value (Japanese Patent Laid-Open No. 64-276)
No. 24), a method of measuring the potential difference between the developing stock solution and pure water, and adding the developing stock solution or pure water to a predetermined concentration based on this potential difference (JP-A-5216241). A method of measuring the ultrasonic wave propagation velocity of a mixed solution of a developing stock solution and pure water, and adding the developing stock solution or pure water so that a predetermined concentration is obtained based on the ultrasonic propagation speed (Japanese Patent Laid-Open No. 6-6113).
No. 6), or a method of controlling the addition amount of the developing stock solution or pure water to be added based on the above various measured values by a load cell (JP-A-5-216241, JP-A-6-61136, Kaihei 6-29207) is disclosed.

[0003]

However, in the above-mentioned prior art, the developer contains an alkaline component and other components, for example, an additive such as a surfactant which is added to enhance the developing performance. In this case, no special means is provided for controlling the addition amount of the additive and measuring the addition amount, and the concentration of the additive in the developing solution cannot be accurately measured.

In the recent ultra-fine processing in the manufacture of semiconductor devices, a change in the amount of the additive contained in the developing solution has a great influence on the pattern shape obtained by the developing treatment, so that the additive is added in the adjusting step of the developing solution. It is necessary to accurately mix the amounts, and there is a demand for a method for adjusting a developer that allows continuous and accurate adjustment of a developer containing an additive.

[0005]

In order to solve the above-mentioned problems, a method for preparing a developing solution according to the first aspect of the present invention is to dilute a developing stock solution containing an alkaline component so that the concentration of the alkaline component becomes a predetermined concentration, An additive is added to the diluted developing stock solution at a concentration lower than a predetermined concentration, the additive concentration in the diluted developing stock solution is measured, and the additive concentration in the diluted developing stock solution is measured based on the measurement result. The additive amount of the additive is controlled so as to obtain a predetermined concentration, and the controlled amount of the additive is added.

In the method for preparing a developing solution according to the second aspect of the invention, a developing stock solution containing an alkaline component is diluted so that the concentration of the alkaline component becomes a predetermined concentration, and a part of the diluted developing stock solution is extracted and stored. Add additive to the remaining diluted developing stock solution, measure the additive concentration in the diluted developing stock solution, and based on this measurement result, the additive concentration in the diluted developing stock solution becomes a predetermined concentration Thus, the additive amount of the additive or the stored diluted developing stock solution is controlled, and the controlled amount of the additive or the stored diluted developing stock solution is added.

Here, in order to dilute the stock developing solution containing the alkaline component so that the concentration of the alkaline component becomes a predetermined concentration, the stock developing solution and the diluting solution are supplied to a blending tank and mixed, and this blending is performed. The concentration of the alkaline component of the mixed solution in the tank is measured, and based on the measurement result, the addition amount of the developing stock solution or the diluent is adjusted so that the concentration of the alkaline component of the mixed solution in the preparation tank becomes a predetermined concentration. It may be controlled by a load cell arranged in the preparation tank, and the controlled addition amount of the developing stock solution or the diluent may be added to the preparation tank.

The amount of the additive added is controlled by a load cell, and the concentration of the alkaline component of the mixed solution in the preparation tank or the additive concentration in the diluted developing solution is measured by a conductivity meter or an ultrasonic densitometer. It is possible to measure with.

[0009]

In the first aspect of the present invention, a developing stock solution diluted so that the concentration of the alkaline component becomes a predetermined concentration is prepared, and the additive is added thereto in an amount less than the predetermined concentration, and the concentration of the additive is measured. By adding the additive so that the additive concentration becomes a predetermined concentration based on the result, it is possible to continuously adjust the developing solution containing the additive.

In the second aspect of the present invention, if a portion of the diluted developing stock solution in which the concentration of the alkaline component is a predetermined concentration is stored before adding the additive, the amount of the additive added is excessive. In some cases, the additive concentration can be compensated by adding a portion of the diluted stock solution stored.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a schematic configuration diagram of a developing solution adjusting apparatus for carrying out the method of the present invention, in which 1 is a developing solution tank, 2 is a preparation tank, 3 is a storage tank, 4 is a conductivity meter or ultrasonic concentration. A total of 5 is a pure water (diluting liquid) supply source, 6 is a nitrogen gas supply source, 33 is a reserve tank, 36 is an additive supply tank, and 45 is an additive tank.

The stock developing solution tank 1 contains a stock developing solution having a high concentration of an alkaline component, and can be connected to a pipe 8 from a nitrogen gas supply source 6 at a joint 7 and at a joint 9. It can be connected to the pipe 10 to the mixing tank 2. Here, the nitrogen gas supplied from the nitrogen gas supply source 6 passes through another pipe 11 and is guided to the bubbling tank 12 in which a predetermined amount of pure water is held, where it is bubbled to prepare the mixing tank 2 and the storage tank 3. The upper space of is made to be a nitrogen gas atmosphere containing water.

A sub-tank 26, a filter device 13, and an air valve 27 are sequentially provided in the middle of the pipe 10 to the mixing tank 2, and a liquid level sensor is attached to the sub-tank 26. By using the sub tank 26 provided with the liquid level sensor, it is possible to detect that one developing stock solution tank has become empty, so that the developing stock solution tank can be transferred to the other developing stock solution tank without delay and the developing stock solution can be continuously supplied. Can be supplied. Conventionally, it was not possible to maintain a sufficient concentration of alkali components simply by purging with an inert gas such as nitrogen gas, but by using a nitrogen gas atmosphere containing water in this way, it is possible to stabilize the alkali components. Became sustainable. The bubbling tank is supplied with pure water from the pure water supply source 5 so as to hold a predetermined amount of pure water, but prevents the pure water in the bubbling tank 12 from being deteriorated due to generation of bacteria or the like. Therefore, it is necessary to frequently exchange the pure water in the tank, or to provide a discharge pipe near the liquid surface so that the pure water is always kept flowing.

The air valve 27 is a large flow rate air valve,
A fine adjustment air valve 28 is provided in the bypass thereof. By doing so, when the developing stock solution is charged, the air valve 27 is used up to a predetermined amount, and thereafter the air valve 28 is used, whereby the developing stock solution can be accurately and easily charged into the mixing tank 2.

This means that, even when pure water is introduced into the mixing tank 2, a large flow rate air valve 29 is provided in the middle of the pipe 14 to the mixing tank 2 and a fine adjustment air valve 3 is used as a bypass thereof.
0 is provided and the air valve 29 and the air valve 30 are selectively used in the same operation as the introduction of the developing solution, whereby the concentration of the developing solution can be easily adjusted and the accuracy can be increased.

The additive supply tank 36 contains an additive added for the purpose of removing scum at the time of development, and can be connected to a pipe 39 from the nitrogen gas supply source 6 by means of a joint 37. At 38, it can be connected to the pipe 40 to the additive tank 45. Also, the additive tank 4
A sub-tank 41, a filter device 42, and an air valve 44 are sequentially provided in the middle of the pipe 40 to the liquid tank 5, and a liquid level sensor is attached to the sub-tank 41. As in the case of the developing stock solution tank, since a liquid level sensor is attached, even if one additive supply tank becomes empty, it moves to the other additive supply tank without delay, and the additive is continuously added. Can be supplied.

The air valve 44 is a large flow rate air valve,
A fine adjustment air valve 43 is provided in the bypass thereof. As in the case of charging the developing solution, by properly using the air valve 44 and the air valve 43, the additive can be charged into the additive tank 45 easily and accurately.

The additive tank 45 is supported by a load cell 46, and the total weight of the additive tank 45 containing the additive supplied therein is measured by the load cell 46. The additive tank 45 and the preparation tank 2 are connected by an additive supply pipe 50. A pump 51 and a valve 47 are provided in the middle of the pipe 50. If a large flow rate air valve is used instead of the valve 47 in this example, and a fine adjustment air valve is used for this bypass as in the above case, the amount of the additive added to the mixing tank 2 from these valves will be negative. Can be controlled from the reading of.

The preparation tank 2 has a supply pipe 1 for supplying a developing stock solution.
0, a pure water supply pipe 14 and an additive supply pipe 50 are connected, and a stirring device 15 for mixing the developing stock solution, pure water and the additive is attached. Then, the mixing tank 2 is supported by the load cell 16, and the total weight of the mixing tank 2 containing the undiluted developing solution, pure water, and the additives supplied inside by the load cell 16 is measured.

The mixing tank 2 and the spare tank 33 are provided with piping 3
1 and the pipe 34 are connected. A pump 32 and a valve 48, and a pump 35 and a valve 49 are provided in the middle of the pipe 31 and the pipe 34, respectively. Further, the conductivity meter or ultrasonic densitometer 4 and the mixing tank 2 are connected by a pipe 20 so that the adjusted developing solution circulates between the conductivity meter or ultrasonic density meter 4 and the mixing tank 2. . As an instrument for measuring the alkali concentration and the additive concentration, various analysis means such as a conductivity meter, an ultrasonic densitometer, a potentiometer, an ultraviolet absorber, a pH meter, an impedance meter, etc. can be applied. From the point that can be done continuously,
A conductivity meter or an ultrasonic densitometer is particularly preferred.

The preparation tank 2 and the storage tank 3 are connected by a supply pipe 17 for the adjusted developer. A pump 18 and a filter device 19 are provided in the middle of the pipe 17,
A return pipe 21 branches off from the downstream side of the filter device 19 and is connected to the mixing tank 2. This return pipe 21
By circulating the mixed solution in the blending tank 2 by using, the insoluble matter in the mixed solution can be removed by the filter device 19 and the stirring of the mixed solution in the blending tank 2 can be performed at the same time. In some cases (for example, when the capacity of the mixing tank is relatively small), the installation of the stirring device 15 can be omitted. It should be noted that opening / closing valves 22 and 23 are provided on the downstream side of the branch portion of the pipe 17 and at the portion connecting the pipe 17 and the pipe 21.

Further, the compounding tank 2 and the bubbling tank 1
2 and the upper space of the storage tank 3 are connected by a communication pipe 24,
The upper space of the mixing tank 2 and the storage tank 3 is made to be a nitrogen gas atmosphere containing water to prevent the deterioration of the developing solution. Also, from the bottom of the storage tank 3,
Piping 25 for supplying the developer whose concentration is adjusted to the place of use
Has been derived.

FIG. 2 is a schematic configuration diagram of another developing solution adjusting apparatus for carrying out the method of the present invention. The major difference from Fig. 1 is that
Adding one compounding tank to two (2a, 2b), removing the spare tank, connecting one conductivity meter or ultrasonic densitometer to the two compounding tanks 2a, 2b. The same members as those of the developing solution adjusting device shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The developing stock solution tank 1 is connected to a nitrogen gas supply source 6 and a mixing tank 2a, and the upper spaces of the mixing tanks 2a and 2b and the storage tank 3 are made to have a nitrogen gas atmosphere containing water.

A sub-tank 26 with a liquid level sensor, a large flow rate air valve 27, etc. are provided in the middle of the pipe 10 to the mixing tank 2a. By using the sub tank 26, even if one developing stock solution tank becomes empty, the developing stock solution tank can be transferred to the other developing stock solution tank without delay and the developing stock solution can be continuously supplied.

A fine adjustment air valve 28 is provided in the bypass of the air valve 27. By using the air valve 27 up to a predetermined amount when the developing stock solution is charged, and then using the air valve 28, the developing stock solution can be accurately charged into the mixing tank 2a.

Even when adding pure water to the mixing tank 2a,
A large flow rate air valve 29 is provided in the middle of the pipe 14, and a fine adjustment air valve 30 is provided in the bypass thereof, and the air valve 29 and the air valve 30 are operated by the same operation as the introduction of the developing solution.
By properly using and, it is possible to easily adjust the concentration of the developing solution.

The additive tank 45 and the preparation tank 2b are connected by an additive supply pipe 50. This piping 50
A pump 51 and a valve 47 are provided midway. If a large flow rate air valve is used instead of the valve 47 in this example, and a fine adjustment air valve is used for this bypass as in the above case, the amount of the additive added to the mixing tank 2 from these valves will be negative. Can be controlled from the reading of.

In the mixing tank 2a, a supply pipe 1 for the developing solution is supplied.
0 and the pure water supply pipe 14 are connected, and an agitator 15 for mixing the developing stock solution and pure water is additionally provided. The blending tank 2a is supported by the load cell 16, and the total weight of the blending tank 2a containing the undiluted developing solution and pure water supplied therein is measured.

The mixing tank 2a and the mixing tank 2b are connected by a pipe 17. A pump 18, valves 23 and 59, and a filter device 19 are provided in the middle of the pipe 17. Further, the conductivity meter or ultrasonic densitometer 4 and the mixing tank 2a, and the conductivity meter or ultrasonic densitometer 4 and the mixing tank 2b are connected by pipes 20 and 55, respectively. A diluted developing stock solution and a diluted developing solution are circulated between the mixing tank 2a, the conductivity meter or the ultrasonic densitometer 4 and the mixing tank 2b.

The preparation tank 2b is connected to a diluted developing stock solution supply pipe 17 and an additive supply pipe 50, and is provided with a stirring device 57 for mixing the diluted developing stock solution and the additive.

The mixing tank 2b and the storage tank 3 are connected by supply pipes 54 and 56 for the adjusted developer. A pump 52 and a filter device 53 are provided in the middle of the pipe 54, and a return pipe branches from the downstream side of the filter device 53 and is connected to the mixing tank 2b. By using this return pipe to circulate the mixed solution in the mixing tank 2b, the insoluble matter in the mixed solution is removed by the filter device 53 and the mixing solution in the mixing tank 2b is stirred. In some cases (for example, when the capacity of the mixing tank is relatively small), the installation of the stirring device 57 can be omitted because it can be performed. The opening / closing valves 22, 5 are provided on the downstream side of the branch portion of the pipe 54 and on the return pipe.
8 are provided.

Further, the mixing tanks 2a and 2b, the bubbling tank 12 and the upper space of the storage tank 3 are connected by a communication pipe 24, and the upper spaces of the mixing tanks 2a and 2b and the storage tank 3 are filled with a nitrogen gas atmosphere containing water. By doing so, the deterioration of the developer is prevented.

In the above, in order to dilute the developing stock solution having a high concentration of the alkaline component to a predetermined concentration, first, the developing stock solution is supplied from the developing stock solution tank 1 into the mixing tank 2 or 2a, and the pure water supply source 5 is used. Deionized water is supplied from. The feed rate should be approximately equal to the desired dilution factor.

Then, the developing solution in the mixing tank 2 or 2a is uniformly mixed with pure water by the stirring device 15, and the pipe 17 provided with the filter device 19 is circulated to remove the insoluble matter. A part of the mixed liquid in the preparation tank 2 or 2a is sent to the conductivity meter or the ultrasonic densitometer 4. The electric conductivity meter or the ultrasonic densitometer 4 measures the concentration of the alkaline component of the diluted developer. Based on this measurement value, the weight of the undiluted developing solution or pure water that must be added to the preparation tank to obtain a predetermined concentration is calculated. Then, one of the undiluted developing solution and pure water, which must be added based on the calculated value, is again added to the mixing tank 2 or 2
supply in a. Whether or not a predetermined amount of undiluted developing solution or pure water has been added is determined by the load cell 16 in the mixing tank 2 or 2
This is done by measuring the weight of a.

Mixing tank 2 measured by a load cell
Alternatively, when the weight of 2a is increased by the calculated weight, the supply of the developing stock solution or pure water to the mixing tank 2 or 2a is stopped, and then the developing stock solution and the pure water in the mixing tank 2 or 2a are mixed again. Mix uniformly and remove insolubles. A part of the mixed liquid in the mixing tank 2 or 2a is sent to the conductivity meter or the ultrasonic densitometer 4 to confirm that it is within the set concentration range. The developing stock solution diluted in this way so that the concentration of the alkaline component becomes a predetermined concentration is hereinafter abbreviated as "diluting stock solution".

At this point, the valve 23 is closed by the pump 18 and all the diluted stock solution in the mixing tank 2a is closed by the valve 59.
Is opened and transferred to the mixing tank 2b through the pipe 17. The diluted stock solution is adjusted and stored by repeating the above-described operation in the prepared mixing tank 2a.

Next, there are two methods for adding the additive to the diluted stock solution so that the concentration of the additive such as the surfactant in the diluted stock solution becomes a predetermined concentration. In the first method, first, the additive is added to the mixing tank 2 or 2b from the additive tank 45 in a smaller amount than a predetermined amount, for example, 60% to a predetermined amount.
90% supply. The supply amount is measured by measuring the weight of the additive tank 45 with the load cell 46.

Next, the diluting stock solution in the mixing tank 2 or 2b and the additive are uniformly mixed by the stirring device 15 or 57, and the pipe 17 provided with the filter device 19 or the pipe 54 provided with the filter device 53 is circulated. To remove insoluble matter. A part of the mixed liquid in the mixing tank 2 or 2b is used as a conductivity meter or an ultrasonic densitometer 4
Send to The conductivity meter or ultrasonic densitometer 4 measures the conductivity or ultrasonic wave propagation velocity of the mixed liquid. Based on this measured value, the weight of the additive that must be added to the preparation tank in order to obtain the predetermined concentration is calculated. Then, the additive that must be added based on this calculated value is supplied again into the mixing tank. The amount of the additive to be added is measured by the load cell 46, and is controlled and put in the added additive tank 45 to stand by. The additive amount of the additive can be easily calculated from this calibration curve if a relationship between the additive amount in the diluted stock solution and the conductivity or the ultrasonic wave propagation speed is prepared in advance as a calibration curve.

When the weight of the additive tank 45 measured by the load cell has decreased by the calculated weight, the supply of the additive to the mixing tank 2 or 2b is stopped, and then the dilution in the mixing tank 2 or 2b is performed again. The stock solution and additives are uniformly mixed and insoluble materials are removed. A part of the mixed liquid in the mixing tank 2 or 2b is sent to the conductivity meter or the ultrasonic densitometer 4 and it is confirmed that it is within the set concentration range. After that, the valve 22 is opened with the developer in the mixing tank 2 or 2b, and the pipe 17 or 54, 56 is opened.
Then, the toner is transferred to the storage tank 3 via and the adjustment of the developing solution is completed.

Next, the second method will be described. In the second method, first, a part of the diluted stock solution in the mixing tank 2 is
The valve 48 is opened, and the spare tank 33 is connected through the pipe 31.
Or the diluted stock solution is stored in the compounding tank 2a. The storage amount may be measured by measuring the weight of the mixing tank 2 or 2a with the load cell 16 or by attaching the load cell to 2b. The additive is supplied from the additive tank 45 into the compounding tank 2 or 2b. The supply amount is almost equal to the predetermined amount. The supply amount is measured by measuring the weight of the additive tank 45 with the load cell 46.

Then, as in the first method, the diluted stock solution in the preparation tank 2 or 2b is uniformly mixed with the additive, and the insoluble matter is removed. A part of the mixed liquid in the mixing tank 2 or 2b is used as a conductivity meter or an ultrasonic densitometer 4
And measure the concentration of the additive. Based on this measurement value, the weight of the additive or diluted stock solution that must be added to the preparation tank to obtain the predetermined concentration is calculated. Then, one of the additive and the undiluted stock solution that must be added based on this calculated value is supplied again into the mixing tank 2 or 2b. Whether or not a predetermined amount of the additive or the diluted stock solution has been added is determined by measuring the weight of the additive tank 45 by the load cell 46 or by measuring the weight of the blending tank 2 or 2a by the load cell 16. . A load cell may be attached to the mixing tank 2b to confirm whether or not a predetermined amount of the additive or the diluted actual solution has been added to the mixing tank 2b. In order to calculate the weight of the additive or diluted actual solution to be added, the relationship between the concentration of the alkaline component and additive in the mixed solution and the conductivity or ultrasonic wave propagation speed should be prepared in advance as a calibration curve. It is good to do based on this.

When the weight of the additive tank 45 measured by the load cell is reduced by the calculated weight,
Alternatively, when the weight of the mixing tank 2 or 2b measured by the load cell increases by the calculated weight,
The supply of the additive or the diluted stock solution to the preparation tank 2 or 2b is stopped, and then the diluted stock solution and the additive in the preparation tank 2 or 2b are uniformly mixed and the insoluble matter is removed. A part of the mixed liquid in the mixing tank 2 or 2b is sent to the conductivity meter or the ultrasonic densitometer 4 and it is confirmed that it is within the set concentration range. After this mixing tank 2
Alternatively, the developer in 2b is transferred to the storage tank 3, and the adjustment of the developer is completed.

Next, specific examples of the method for adjusting the developing solution according to the present invention will be described with reference to numerical values. The stock solution for development is an aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH) having a concentration of about 20% by weight. Example 1 (first step): Two components [pure water-alkali (TMAH)]
Preparation of system developing solution The above developing stock solution and pure water were provided with a load cell 16 mechanism 1
Approximately 80 k in each of the m ³ compounding tanks 2 or 2 a
g, about 720 kg was supplied, the developing stock solution and pure water were uniformly mixed by the stirrer 15, and the insoluble matter was removed by circulating the pipe 17 provided with the filter device 19. Next, a part of this diluted developing stock solution was extracted from the preparation tank 2 or 2a, and the concentration of TMAH was determined using a calibration curve prepared in advance using the conductivity meter 4 to find that it was 2.444% by weight. . Therefore, the TMAH concentration is 2.380 wt% of the set concentration (permissible range ± 0.0
(2 wt%), 21.3 kg of pure water was added using the load cell 16, the developing stock solution and pure water were uniformly mixed again, and insoluble materials were removed to obtain a TMAH concentration of 2.382 wt%. Developer (hereinafter referred to as developer a)
Was adjusted. 5 kg of the developer a in the blending tank 2 thus adjusted is supplied to the auxiliary tank 3 through the pipe 31.
3 was stored in the preparation tank 2a, or 5 kg of the developer a in the preparation tank 2a was left in the preparation tank 2a, and all other amounts were transferred to the preparation tank 2b through the pipe 17.

Similarly, a developing solution having a TMAH concentration of 2.379% by weight (hereinafter referred to as developing solution b) and a developing solution having a TMAH concentration of 2.380% by weight (hereinafter referred to as developing solution c).
As described above, 5 kg of each of the developers b and c in the blending tank 2 is extracted and stored in the spare tank 33 or stored in the blending tank 2a.
In c, 5 kg was left in the compounding tank 2a, and all other amounts were transferred to the compounding tank 2b.

(Second step): 3 components [pure water-TMAH-
Additive] Preparation of system developing solution Acetynol EH (manufactured by Kawaken Fine Chemical Co., Ltd.), which is an acetylene alcohol-based nonionic surfactant, is added as an additive to the developing solution a remaining in the compounding tank 2 or 2b.
About 0.7 kg, and the developer a and the additive are uniformly mixed by a stirring device 15 or 57, and the pipe 17 provided with the filter device 19 or the pipe 54 provided with the filter device 53 is circulated. To remove insoluble matter. A part of this mixed solution was extracted and the conductivity was determined to be 51.6125 Ω ⁻¹ m ⁻¹ . The TMAH concentration of 2.382, which was prepared separately, was determined by the calibration curve at the time of addition, and the addition was found. The agent concentration was 870 ppm. Therefore, the set concentration of the additive is 1000ppm (allowable range ± 1
00ppm), the amount of the additive to be added is measured by the load cell 46 attached to the additive tank 45 (capacity 300 liters), and 0.12 kg of the additive is added to the mixing tank 2 or 2b, The developer a and the additive were uniformly mixed again, the insoluble matter was removed, a part of this mixture was extracted, and the conductivity was measured again. The concentration of the additive calculated from the value of conductivity was 1020 ppm. This value is set concentration 1000ppm (allowable range ± 10
(0 ppm) was satisfied, so adjustment was completed,
The adjusted developer (hereinafter, referred to as developer A) was transferred to the storage tank 3.

Similarly, the additive was added to the developer b remaining in the compounding tank 2 or 2b, mixed uniformly, and the concentration of the additive was measured using the conductivity meter 4.
It was 0 ppm. Based on this measurement result, a calculated amount of the developer b stored in the preliminary tank 33 or the mixing tank 2a in the first step was added, the mixture was uniformly mixed, the conductivity was measured again, and the calibration curve was obtained. The concentration of the additive was 990 ppm. This value is set density 1000p
Since the condition of pm (permissible range ± 100 ppm) was satisfied, the adjustment was completed, and the adjusted developer (hereinafter, referred to as developer B) was transferred to the storage tank 3.

Further, with respect to the developer c remaining in the compounding tank 2 or 2b, the additive is similarly added and mixed uniformly, and the conductivity is measured. The concentration was 960 ppm. Since this value satisfied the condition of the set concentration of 1000 ppm (allowable range ± 100 ppm), the adjustment was completed, and the adjusted developer (hereinafter, referred to as developer C) was transferred to the storage tank 3.

The above developing solutions A, B, and C were supplied to developing devices, respectively, and 200 positive resists on the selectively exposed wafer were developed, and none of them had a resist pattern comparable to the developing process. was gotten.

Example 2 (first step): Two components [pure water-alkali (TMAH)]
Preparation of system developing solution 1 m ^{3 of} developing stock solution and pure water equipped with load cell 16 mechanism
About 75 kg and about 725 kg are respectively supplied to the mixing tank 2 or 2a, and the developing stock solution and pure water are uniformly mixed by the stirring device 15, and the pipe 17 provided with the filter device 19 is circulated. The insoluble material was removed. Next, a part of this diluted developing stock solution was extracted from the preparation tank 2 or 2a, and the concentration of TMAH was determined using an ultrasonic densitometer 4 by a calibration curve prepared in advance. As a result, it was 2.274% by weight. It was Therefore, the TMAH concentration is 2.380 wt% of the set concentration (permissible range ± 0.0
1% by weight), 3.7 kg of the developing stock solution was added using the load cell 16, the developing stock solution and pure water were uniformly mixed again, and the insoluble matter was removed. The TMAH concentration was 2.375% by weight. Was prepared. 5 kg of the developer in the compounding tank 2 adjusted in this way is connected to the pipe 3
Either 1 was taken out and stored in the auxiliary tank 33 through 1 or stored, or 5 kg of the developer in the mixing tank 2a was left in the mixing tank 2a, and all other amounts were transferred to the mixing tank 2b through the pipe 17.

(Second step): 3 components [pure water-TMAH-
Additive] Preparation of System Developer A acetylene alcohol nonionic surfactant Surfynol 465 (manufactured by Air Products and Chemicals Co., Ltd.) was added to the developer remaining in the mixing tank 2 or 2b as an additive in about 1. 0 kg was added, and the developer and the additive were uniformly mixed by a stirring device 15 or 57, and insoluble matter was removed by circulating the pipe 17 attached with the filter device 19 or the pipe 54 attached with the filter device 53. . A part of this mixed solution was extracted, and the concentration of the additive contained in the developing solution was measured using an ultrasonic densitometer 4 by a calibration curve (not shown) at a TMAH concentration of 2.375% by weight. When determined in the same manner as in Example 1, the additive concentration was 1200 ppm. Therefore, the amount of the additive to be added should be adjusted so that the set concentration of the additive is 2000 ppm (allowable range ± 500 ppm).
(00 liter) 45 is measured by a load cell 46 attached to 45, and 0.90 kg of the additive is added to the mixing tank 2 or 2b.
Add to the inside, mix the developer and the additive evenly again, remove the insoluble matter, extract a part of this mixture, and use the ultrasonic densitometer 4 again to add it to the developer. The concentration of the additive contained was measured. Similarly to the above, the concentration of the additive determined from the calibration curve was 2300 ppm. This value is a set concentration of 2000 ppm (allowable range ± 50
(0 ppm) was satisfied, so adjustment was completed,
The adjusted developer was transferred to the storage tank 3.

When the above developing solution was supplied to the developing device and 200 positive resists on the selectively exposed wafer were developed, a resist pattern comparable to that in the developing treatment was obtained.

[0053]

According to the first aspect of the present invention, a developing stock solution having a predetermined concentration of an alkaline component is prepared, an additive is added to the developing solution at a concentration lower than the predetermined concentration, and the concentration of the additive is measured. By controlling the additive amount of the additive so that the additive concentration becomes a predetermined concentration, and by adding the controlled additive amount of the additive, the developer containing the additive is continuously adjusted. Is possible.

In the second aspect of the present invention, if a part of the stock solution for development in which the concentration of the alkali component is a predetermined concentration is stored before the addition of the additive, if the additive amount of the additive is excessive, The additive concentration can be compensated by adding a part of the stock developing solution stored.

The addition amount of the developing stock solution or diluent and the additive is controlled by the load cell so that the concentration of the alkaline component and the concentration of the additive become the predetermined concentrations, and the controlled amount of the developing stock solution or the diluent and the addition are controlled. The developer can be adjusted with high accuracy by adding the agent.

Since the alkali concentration of the mixed solution in the preparation tank and the additive concentration in the diluted developing stock solution are measured by a conductivity meter or an ultrasonic densitometer, the measurement can be carried out continuously, which is convenient.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a developer adjusting device for carrying out the method of the present invention.

FIG. 2 is a schematic configuration diagram of another developer adjusting device for carrying out the method of the present invention.

FIG. 3 is a graph showing the relationship between the additive concentration and conductivity in TMAH aqueous solutions of various concentrations.

[Explanation of symbols]

1-development stock solution tank, 2, 2a, 2b-preparation tank, 3
... Storage tank, 4 ... Conductivity meter or ultrasonic densitometer, 5 ...
Pure water (diluting liquid) supply source, 33 ... Spare tank, 36 ... Additive supply tank, 45 ... Additive tank, 16, 46 ... Load cell.

Claims (6)

[Claims] 1. A diluted developing stock solution is prepared by diluting a developing stock solution containing an alkaline component so that the concentration of the alkaline component is a predetermined concentration, and adding an additive to the diluted developing stock solution at a concentration lower than the predetermined concentration. The additive concentration in the solution is measured, and the additive amount of the additive is controlled so that the additive concentration in the diluted developing stock solution becomes a predetermined concentration based on the measurement result. A method for preparing a developing solution, which comprises adding an additive to a diluted developing stock solution. 2. A developing stock solution containing an alkaline component is diluted so that the concentration of the alkaline component becomes a predetermined concentration, a part of the diluted developing stock solution is extracted and stored, and an additive is added to the remaining diluted developing stock solution. Is added to measure the additive concentration,
Based on this measurement result, the additive amount of the additive or the stored diluted developing stock solution is controlled so that the additive concentration in the diluted developing stock solution becomes a predetermined concentration, and the addition of the controlled addition amount is controlled. Agent or stored diluted developing stock solution,
A method for preparing a developing solution, which comprises adding the above-mentioned additive to a diluted developing stock solution. 3. The method for preparing a developing solution according to claim 1 or 2, wherein the developing stock solution containing the alkaline component is diluted with a developing stock solution so as to have a predetermined concentration of the alkaline component. The diluent is supplied to the mixing tank and mixed, the concentration of the alkaline component of the mixed solution in the mixing tank is measured, and the concentration of the alkaline component of the mixed solution in the mixing tank is determined based on the measurement result. It is characterized in that the addition amount of the developing stock solution or the diluting solution is controlled by a load cell arranged in the blending tank so that the controlled addition amount of the developing stock solution or the diluting solution is added to the blending tank. How to adjust the developer. 4. The method for adjusting a developing solution according to claim 1 or 2, wherein the additive amount of the additive is controlled by a load cell, and the additive is added in the controlled additive amount. How to adjust the developer. 5. The method of preparing a developing solution according to claim 3, wherein the concentration of the alkaline component of the mixed solution in the preparation tank is measured by a conductivity meter or an ultrasonic densitometer. Adjustment method. 6. The method for preparing a developing solution according to claim 1, wherein the additive concentration in the diluted developing stock solution is measured by a conductivity meter or an ultrasonic densitometer. How to adjust the developer.