JP6712415B2 - Developer management device - Google Patents

Description

The present invention relates to a developer management device, and more particularly to a developer management device exhibiting alkalinity that is repeatedly used for developing a photoresist film in a development process of a circuit board in a semiconductor or a liquid crystal panel.

In the development process of photolithography that realizes fine wiring processing in semiconductors, liquid crystal panels, etc., as a chemical solution that dissolves the photoresist formed on the substrate, a developing solution showing alkalinity (hereinafter, referred to as “alkaline developing solution”). .) is used.

2. Description of the Related Art In recent years, in the manufacturing process of semiconductors and liquid crystal panel substrates, the size of wafers and glass substrates and the miniaturization and high integration of wiring processing have been advanced. Under such circumstances, it is necessary to measure the concentrations of the main components of the alkaline developer with even higher accuracy and maintain the developer in order to realize finer wiring processing and higher integration of large-sized boards. It has become to.

The conventional measurement of the component concentration of an alkaline developer utilizes the fact that a good linear relationship can be obtained between the concentration of the alkaline component of the alkaline developer (hereinafter referred to as “alkali component concentration”) and the conductivity. (For example, Patent Document 1).

However, in recent years, due to the development process, the alkaline developer has more opportunities to come into contact with air, and since the alkaline developer absorbs carbon dioxide in the air, the amount of carbon dioxide absorbed by the alkaline developer is increasing. When the absorbed carbon dioxide concentration becomes high, there is a problem in that the predetermined line width processing cannot be maintained in the conventional developer management.

This problem occurs because the alkaline component having a developing activity in the alkaline developing solution is consumed in the reaction to generate a carbonate by absorbing carbon dioxide. This is also because the alkaline component having a developing activity in the alkaline developing solution is consumed by the reaction of forming a photoresist salt by dissolving the photoresist.

To solve such problems, various attempts have been made to manage the developing solution so as to compensate the consumed and reduced alkaline component. In these attempts, the concentration of the alkaline component having a developing activity is made constant by measuring the carbonate concentration to supplement the alkaline component consumed in the reaction for producing the carbonate with a replenishing solution. The same applies to the alkaline component consumed by the dissolution of the photoresist. These are based on the viewpoint that the alkaline component which has become a carbonate or a photoresist salt loses the developing activity and is deactivated (for example, Patent Document 2).

Japanese Patent No. 2561578 JP, 2008-283162, A

However, it is still difficult to realize satisfactory developer control even by such various attempts of developer control.

The present inventor has conducted diligent research on developing solution management. As a result, carbonates and resist salts are partially released in the developing solution to contribute to the developing action, and from these components which are considered to be deactivated. The developer management that also considers the contribution of the developer to the developing action can be realized by controlling the conductivity value of the developer, and further, such conductivity control value is the absorbed carbon dioxide concentration and the dissolved photoresist concentration. It was found that there are various differences.

This is because the alkali component that has become a carbonate or photoresist salt is not deactivated, but a part of it is released and contributes to the developing action. It is believed that this is based on the fact that all the components that are released and contribute to the developing action act on the conductivity. That is, the present inventors have found that the total amount of components having a developing action is optimally controlled by controlling the conductivity value of the developer, and the present invention has been completed.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a developing solution management apparatus capable of achieving a predetermined developing performance for a photoresist.

In order to achieve the above-mentioned object, the developing solution management apparatus of the present invention has a predetermined development for each concentration region specified repeatedly by using dissolved photoresist concentration and absorbed carbon dioxide concentration of a developer exhibiting alkalinity as an index. A data storage unit in which conductivity data having the conductivity value of the developer, which has been confirmed in advance as performance, is stored, and a measured value of the dissolved photoresist concentration of the developer and a measured value of the absorbed carbon dioxide concentration. A replenisher solution replenished to the developing solution so that the conductivity of the developing solution becomes the control target value, with the conductivity value stored in the data storage section of the concentration region specified by A control unit for issuing a control signal to a control valve provided in a conduit for feeding the liquid, conductivity value of the developer, alkali component concentration value, dissolved photoresist concentration value and absorbed carbon dioxide. A display unit for displaying at least one of the conductivity value and the alkali component concentration value among the concentration values.

It is preferable that the developing solution management apparatus of the present invention further includes display switching means for switching a display target displayed on the display means.

It is confirmed in advance that the developer management device of the present invention has a predetermined developing performance for each concentration range specified repeatedly by using the dissolved photoresist concentration and the absorbed carbon dioxide concentration of a developer exhibiting alkalinity as an index. And a data storage unit in which conductivity data having a conductivity value of the developer is stored, and a concentration region specified by the measured value of the dissolved photoresist concentration of the developer and the measured value of the absorbed carbon dioxide concentration. The conductivity value stored in the data storage unit is used as a control target value, and is provided in a conduit for feeding a replenisher solution to the developer so that the conductivity of the developer becomes the control target value. At least a conductivity value of the developer, a conductivity value of the developer, an alkali component concentration value, a dissolved photoresist concentration value, and an absorbed carbon dioxide concentration value. And a display unit for displaying one of the alkaline component concentration values as a graph using the measurement time or the elapsed time from the start of the measurement as an index.

It is preferable that the developing solution management apparatus of the present invention further includes display switching means for switching a display target displayed on the display means.

According to the developer management apparatus of the present invention, no matter what the dissolved photoresist concentration and absorbed carbon dioxide concentration of the developer is, the components active in the developing action in the developer are kept constant, A desired development performance can be maintained, and a development process capable of maintaining a desired line width and remaining film thickness can be realized. Also, various data and graphs can be displayed.

According to a preferred aspect of the developing solution management apparatus of the present invention, the characteristic value of the developing solution correlated with the dissolved photoresist concentration of the developing solution and the characteristic of the developing solution correlated with the absorbed carbon dioxide concentration of the developing solution. Further comprising a plurality of measuring devices for measuring a plurality of characteristic values of the developing solution including a value, the control means, further, from a plurality of characteristic values of the developing solution measured by the plurality of measuring devices, An arithmetic unit for calculating a measured value of the dissolved photoresist concentration of the developer and a measured value of the absorbed carbon dioxide concentration by a multivariate analysis method.

According to a preferred aspect of the developing solution management apparatus of the present invention, the characteristic value of the developing solution correlated with the dissolved photoresist concentration of the developing solution and the characteristic of the developing solution correlated with the absorbed carbon dioxide concentration of the developing solution. A plurality of measuring devices for measuring a plurality of characteristic values of the developing solution including a value and a plurality of characteristic values of the developing solution measured by the plurality of measuring devices, using a multivariate analysis method, the developing And a calculation means for calculating the measured value of the dissolved photoresist concentration of the liquid and the measured value of the absorbed carbon dioxide concentration.

According to a preferred aspect of the developer management apparatus of the present invention, a density meter is provided, and the control means further measures with the density meter based on the correspondence relationship between the absorbed carbon dioxide concentration of the developer and the density. An arithmetic unit for calculating an absorbed carbon dioxide concentration value of the developing solution from the density value of the developed solution.

According to a preferred embodiment of the developer management apparatus of the present invention, the density value of the developer measured by the density meter based on the correspondence between the density meter and the absorbed carbon dioxide concentration and density of the developer. And a calculating means for calculating the absorbed carbon dioxide concentration value of the developer.

According to the developer management apparatus of the present invention, the predetermined development performance is repeatedly used for each concentration region specified by the absorbance and the absorbed carbon dioxide concentration, which are correlated with the dissolved photoresist concentration of the alkaline developer. A data storage unit in which alkaline component concentration data having an alkaline component concentration value of the developer which has been confirmed to be stored is stored, and a concentration specified by the measured value of the absorbance and absorbed carbon dioxide concentration of the developer. Using the alkali component concentration value stored in the area data storage unit as a control target value, a replenisher solution to be replenished to the developer solution is fed so that the alkali component concentration of the developer solution reaches the control target value. A control unit that includes a control unit that issues a control signal to a control valve provided in the pipeline, an alkali component concentration value of the developer, an absorbance value that is correlated with the dissolved photoresist concentration, and an absorbed carbon dioxide concentration. Display means for displaying at least the alkali component concentration value among the values.

According to the developer management apparatus of the present invention, the predetermined development performance is repeatedly used for each concentration region specified by the absorbance and the absorbed carbon dioxide concentration, which are correlated with the dissolved photoresist concentration of the alkaline developer. A data storage unit in which alkaline component concentration data having an alkaline component concentration value of the developer which has been confirmed to be stored is stored, and a concentration specified by the measured value of the absorbance and absorbed carbon dioxide concentration of the developer. Using the alkali component concentration value stored in the area data storage unit as a control target value, a replenisher solution to be replenished to the developer solution is fed so that the alkali component concentration of the developer solution reaches the control target value. A control unit that includes a control unit that issues a control signal to a control valve provided in the pipeline, an alkali component concentration value of the developer, an absorbance value that is correlated with the dissolved photoresist concentration, and an absorbed carbon dioxide concentration. At least the alkaline component concentration value among the values is displayed as a graph using the measurement time or the elapsed time from the start of measurement as an index.

According to the developing solution management apparatus of the present invention, it is preferable that the developer management apparatus further includes a display switching unit that switches a display target displayed on the display unit.

According to the present invention, no matter what the concentration of dissolved photoresist and the concentration of absorbed carbon dioxide in the developer, the components active in the developing action in the developer are maintained constant, so that the desired developing performance can be obtained. A development process that can maintain the desired line width and residual film thickness can be realized. Also, various data and graphs can be displayed.

It is a schematic diagram of the developing process for explaining the developing solution management apparatus of the first embodiment. It is a schematic diagram of the developing process for explaining the developing solution management apparatus of the second embodiment. It is a schematic diagram of the developing process for explaining the developing solution management apparatus of the third embodiment. It is a schematic diagram of the developing process for explaining the developing solution management apparatus of the fourth embodiment. 6 is a graph showing the relationship between the absorbed carbon dioxide concentration of a developer and the density. It is a schematic diagram of the developing process for explaining the developing solution management apparatus of the fifth embodiment. It is a schematic diagram of the developing process for explaining the developing solution management apparatus of the sixth embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as appropriate. However, the shapes, sizes, dimensional ratios, relative arrangements, etc. of the devices and the like described in these embodiments are limited to those shown in the scope of the present invention unless otherwise specified. It is not limited. It is only schematically shown as an example of explanation.

Further, in the following description, as a specific example of the developer, a 2.38% tetramethylammonium hydroxide aqueous solution (hereinafter, tetramethylammonium hydroxide is referred to as TMAH) mainly used in the manufacturing process of semiconductors and liquid crystal panel substrates. Will be described as appropriate. However, the developer to which the present invention is applied is not limited to this. Examples of other developing solutions to which the developing solution management method and apparatus of the present invention can be applied include aqueous solutions of inorganic compounds such as potassium hydroxide, sodium hydroxide, sodium phosphate, and sodium silicate, and trimethylmonoethanol ammonium hydroxide. Examples thereof include aqueous solutions of organic compounds such as (choline).

In the following description, the concentration of components such as the concentration of alkali components, the concentration of dissolved photoresist, the concentration of absorbed carbon dioxide, etc. is the concentration by weight percentage (wt %). "Dissolved photoresist concentration" means the concentration when the dissolved photoresist is converted as the amount of photoresist, and "absorbed carbon dioxide concentration" is when the absorbed carbon dioxide is converted as the amount of carbon dioxide. It means the concentration of.

In the development process, development is performed by the developer dissolving unnecessary portions of the photoresist film after the exposure process. The photoresist dissolved in the developing solution forms a photoresist salt with the alkaline component of the developing solution. For this reason, unless the developer is properly managed, as the development process proceeds, the alkaline component having a developing activity is consumed and deteriorates, and the developing performance deteriorates. At the same time, the dissolved photoresist is accumulated in the developer as a photoresist salt with an alkaline component.

The photoresist dissolved in the developing solution exhibits a surface-active effect in the developing solution. Therefore, the photoresist dissolved in the developing solution enhances the wettability of the photoresist film to be subjected to the developing treatment with respect to the developing solution, and improves the compatibility between the developing solution and the photoresist film. Therefore, with a developer containing an appropriate amount of photoresist, the developer is well distributed in the fine recesses of the photoresist film, and the photoresist film having fine irregularities can be well developed.

Further, in recent development processing, a large amount of developing solution has been repeatedly used with the increase in the size of the substrate, so that the developing solution is increasingly exposed to air. However, the alkaline developer absorbs carbon dioxide in the air when exposed to the air. The absorbed carbon dioxide forms a carbonate with the alkaline component of the developer. For this reason, unless the developer is properly managed, the developer is consumed by the carbon dioxide in which the alkaline component having the developing activity is absorbed and decreases. At the same time, the absorbed carbon dioxide accumulates in the developer as a carbonate with the alkaline component.

However, the carbonate in the developer has a developing action because it exhibits alkalinity in the developer.

Thus, unlike the conventional recognition that the photoresist dissolved in the developing solution and the absorbed carbon dioxide deactivate the developing activity of the developing process, actually, it contributes to the developing performance of the developing solution. There is. Therefore, instead of managing the developing solution to completely eliminate dissolved photoresist and absorbed carbon dioxide, allow the dissolved photoresist and absorbed carbon dioxide to be dissolved in the developing solution, while maintaining the optimum concentration of these. It is necessary to manage the developer to maintain it.

Further, a part of the photoresist salt or carbonate generated in the developing solution is dissociated to generate various free ions such as photoresist ion, carbonate ion, hydrogen carbonate ion. Then, these free ions influence the conductivity of the developer with various contribution rates.

With respect to these points, the present inventor has diligently studied the management of the developing solution, and it is considered that carbonate and resist salt are partially released in the developing solution to contribute to the developing action, and deactivate. In addition, it is possible to realize a developer control that also considers the contribution of these components to the developing action by controlling the conductivity value of the developer, and further, such a control value of the conductivity is the absorbed carbon dioxide concentration. And, it was found that there are various differences depending on the concentration of the dissolved photoresist.

Therefore, assuming that the TMAH aqueous solution is managed as the developing solution, the inventor changes the dissolved photoresist concentration and the absorbed carbon dioxide concentration variously to obtain a desired developing performance for the photoresist and the conductivity of the developing solution. The relationship with the value was calculated.

The absorbed carbon dioxide concentration is changed between 0.0 and 1.3 (wt%), and the dissolved photoresist concentration is 0.0 to 0.40 (wt%) (equivalent to 0.0 to 1.3 (abs)). Samples of the developing solution of the TMAH aqueous solution which was changed between the above steps were prepared. The inventors measured the conductivity of the developer, the absorbed carbon dioxide concentration, and the dissolved photoresist concentration for these samples, and evaluated the development performance, the conductivity, the absorbed carbon dioxide concentration, and the dissolved photoresist concentration component. An experiment was conducted to confirm the correlation. A matrix (combination table) was prepared in which the absorbed carbon dioxide concentration was set as one item and arranged vertically or horizontally and the dissolved photoresist concentration was set as another item and horizontally or vertically arranged. For each combination of the absorbed carbon dioxide concentration and the dissolved photoresist concentration, the conductivity of the developer that satisfies the desired developing performance for the photoresist was determined, filled in each column, and the matrix was completed.

Here, the predetermined developing performance means the developing performance of the developing solution when the line width and the remaining film thickness that are to be realized in the developing process are realized.

The measurement results of the absorbed carbon dioxide concentration, the dissolved photoresist concentration, and the conductivity of each representative sample are illustrated. When the absorbed carbon dioxide concentration is 0.0 (wt%) and the dissolved photoresist concentration is 0.0 (wt%) (equivalent to 0.0 (abs)) (so-called new solution), the predetermined development performance is exhibited. The conductivity of the resulting developer was 54.58 (mS/cm).

When the absorbed carbon dioxide concentration is 0.0 (wt%) and the dissolved photoresist concentration is 0.25 (wt%) (equivalent to 0.8 abs), the conductivity of the developer capable of exhibiting the predetermined developing performance is 54. When the dissolved photoresist concentration was 0.55 (mS/cm) and the dissolved photoresist concentration was 0.40 (wt%) (equivalent to 1.3 abs), the conductivity of the developer was 54.53 (mS/cm).

When the dissolved photoresist concentration is 0.0 (wt%) (corresponding to 0.0 (abs)) and the absorbed carbon dioxide concentration is 0.6 (wt%), the conductivity of the developer is 54.60. (MS/cm) and the absorbed carbon dioxide concentration was 1.3 (wt %), the conductivity of the developer was 54.75 (mS/cm).

When the absorbed carbon dioxide concentration is 0.6 (wt%) and the dissolved photoresist concentration is 0.22 (wt%) (corresponding to 0.7 abs), the conductivity of the developer is 54.60 (mS/mS/ cm) and the dissolved photoresist concentration was 0.40 (wt %) (corresponding to 1.3 abs), the conductivity of the developing solution was 54.58 (mS/cm).

When the absorbed carbon dioxide concentration is 1.3 (wt%) and the dissolved photoresist concentration is 0.22 (wt%) (corresponding to 0.7 abs), the conductivity of the developer is 54.75 (mS/mS/m). cm) and the dissolved photoresist concentration was 0.40 (wt %) (corresponding to 1.3 abs), the conductivity of the developer was 54.75 (mS/cm).

In the experiment described above, in a certain concentration range, when the absorbed carbon dioxide concentration increases, the control value of the conductivity tends to increase, and when the dissolved photoresist concentration increases, the control value of the conductivity tends to decrease. It was observed.

In the above experiment, the conductivity of the developer of each sample was a value measured by a conductivity meter. As the absorbed carbon dioxide concentration, the value measured by the titration analysis method was used. The dissolved photoresist concentration used was a weight adjusted value. The titration is a neutralization titration using hydrochloric acid as a titration reagent. As a titrator, an automatic titrator GT-200 manufactured by Mitsubishi Chemical Analytech Co. was used.

The conductivity, the absorbed carbon dioxide concentration, and the dissolved photoresist concentration are for finding the relationship between the conductivity, the absorbed carbon dioxide concentration, and the dissolved photoresist concentration and the developing performance, and are not limited to each numerical value. ..

As described above, it can be understood that the conductivity capable of exerting the developing performance varies variously depending on the absorbed carbon dioxide concentration and the dissolved photoresist concentration. Thus, in the management of the developer, in the developer containing the absorbed carbon dioxide and the dissolved photoresist, the conductivity is used as the control value, and the absorbed carbon dioxide concentration and the dissolved photoresist concentration are measured, and each measurement result is Based on the difference in the control value of the electric conductivity, a predetermined developing performance can be exhibited.

In other words, the conductivity data having the conductivity value of the developer, which has been confirmed in advance to have the predetermined developing performance, for each concentration region specified by using the dissolved photoresist concentration of the developer and the absorbed carbon dioxide concentration as an index ( By storing the matrix) and using the conductivity data (matrix), it is possible to manage the developer capable of exhibiting a predetermined developing performance.

In addition, when the inventor diligently studied the management of the developing solution, it was considered that carbonate and resist salt were partially released in the developing solution to contribute to the developing action, and that these components were considered to be deactivated. The developer management that also considers the contribution to the developing action from the developer can be realized by controlling the alkali component concentration value of the developer. It was found that there are various differences depending on the absorbance that is correlated with the photoresist concentration.

Therefore, assuming that a TMAH aqueous solution is managed as the developing solution, the inventor has a correlation between the concentration of the alkaline component measured based on the conductivity of the developing solution exhibiting alkalinity and the concentration of the dissolved photoresist of the developing solution. By varying the absorbance and the absorbed carbon dioxide concentration of the developer variously, the relationship between the desired developing performance for the photoresist and the concentration of the alkaline component of the developer was obtained.

Absorbed carbon dioxide concentration was changed between 0.0 and 1.3 (wt %), and absorbance that correlates with dissolved photoresist concentration was changed between 0.0 and 1.3 (abs). An aqueous developer solution sample was prepared. The inventors measured the alkali component concentration, the absorbed carbon dioxide concentration, and the absorbance of the developer for these samples, and conducted an experiment to confirm the correlation with the development performance, the alkali component concentration, the absorbed carbon dioxide concentration, and the absorbance. went. A matrix (combination table) was prepared in which the absorbed carbon dioxide concentration was set as one item and arranged vertically or horizontally, and the absorbance was set as another item and horizontally or vertically arranged. For each combination of the absorbed carbon dioxide concentration and the absorbance, the concentration of the alkaline component of the developing solution that satisfies the desired developing performance for the photoresist was determined, entered in each column, and the matrix was completed.

Here, the predetermined developing performance means the developing performance of the developing solution when the line width and the remaining film thickness that are to be realized in the developing process are realized.

The measurement results of the absorption carbon dioxide concentration, the absorbance, and the alkali component concentration of each representative sample are illustrated. When the absorbed carbon dioxide concentration is 0.0 (wt%) and the absorbance is 0.0 (abs) (so-called new liquid), the alkaline component concentration of the developer capable of exhibiting a predetermined developing performance is 2.380 (wt). %)Met.

When the absorbed carbon dioxide concentration is 0.0 (wt%) and the absorbance is 0.8 abs, the alkaline component concentration of the developer capable of exhibiting the predetermined developing performance is 2.379 (wt%) and the absorbance is 1 In the case of 0.3 abs, the alkaline component concentration of the developing solution was 2.378 (wt %).

When the absorbance is 0.0 (abs) and the absorbed carbon dioxide concentration is 0.6 (wt %), the alkaline component concentration of the developer is 2.381 (wt %) and the absorbed carbon dioxide concentration is When it was 1.3 (wt %), the alkaline component concentration of the developer was 2.388 (wt %).

When the absorbed carbon dioxide concentration is 0.6 (wt%) and the absorbance is 0.7 abs, the alkaline component concentration of the developer is 2.381 (wt%) and the absorbance is 1.3 abs. The concentration of the alkaline component of the developing solution was 2.380 (wt %).

When the absorbed carbon dioxide concentration is 1.3 (wt%) and the absorbance is 0.7 abs, the alkaline component concentration of the developer is 2.388 (wt%) and the absorbance is 1.3 abs. The concentration of the alkaline component in the developing solution was 2.388 (wt %).

In the above experiment, in a certain concentration range, when the absorbed carbon dioxide concentration is increased, the control value of the alkali component concentration tends to increase, and when the absorbance increases, the control value of the alkali component concentration tends to decrease. I was seen.

In the above experiment, the concentration of the alkaline component in the developer of each sample can be determined by measuring the conductivity with a conductivity meter. Specifically, a correlation (for example, a linear relationship) between the concentration of the alkali component of the new solution of the TMAH aqueous solution (TMAH aqueous solution before development) and the conductivity value is created as a calibration curve in advance. Based on this calibration curve, the alkali component concentration can be obtained from the conductivity value.

As the absorbed carbon dioxide concentration, the value measured by the titration analysis method was used. The titration is a neutralization titration using hydrochloric acid as a titration reagent. As a titrator, an automatic titrator GT-200 manufactured by Mitsubishi Chemical Analytech Co. was used. An absorptiometer was used for measuring the absorbance.

The above-mentioned alkali component concentration, absorbed carbon dioxide concentration, and absorbance are for finding the relationship between the alkali component concentration, absorbed carbon dioxide concentration, and absorbance and the developing performance, and are not limited to each numerical value.

As described above, it can be understood that the concentration of the alkaline component capable of exhibiting the developing performance varies depending on the concentration of absorbed carbon dioxide and the absorbance. Thus, in the management of the developer, in the developer containing the absorbed carbon dioxide and the dissolved photoresist, the alkali component concentration is used as the control value of the developer, and further the absorbed carbon dioxide concentration and the absorbance are measured, and the respective measurement results are obtained. By varying the control value of the concentration of the alkali component based on the above, a predetermined developing performance can be exhibited.

That is, the alkali component concentration data (matrix concentration data) having the alkali component concentration value of the developer which has been confirmed in advance to have a predetermined developing performance for each concentration region specified using the absorbance of the developer and the absorbed carbon dioxide concentration as an index. ) Is stored and the alkaline component concentration data (matrix) is used, a predetermined developing performance can be exhibited.

Next, specific examples will be described with reference to the drawings.

[First embodiment]
FIG. 1 is a schematic diagram of a developing process for explaining the developing solution management apparatus D of this embodiment. A developing solution management device D of the present invention is illustrated together with a developing process facility A, a replenisher storage part B, a circulation stirring mechanism C, and the like.

First, the developing process equipment A will be briefly described.

The developing process facility A mainly includes a developing solution storage tank 61, an overflow tank 62, a developing chamber hood 64, a roller conveyor 65, a developing solution shower nozzle 67, and the like. The developer is stored in the developer storage tank 61. The developer is replenished with a replenisher to control the composition. The developing solution storage tank 61 includes a liquid level gauge 63 and an overflow tank 62, and manages an increase in the amount of liquid due to replenishment of the replenisher. The developing solution storage tank 61 and the developing solution shower nozzle 67 are connected by a developing solution conduit 80. The developer stored in the developer storage tank 61 is sent to the developer shower nozzle 67 via the filter 73 by the circulation pump 72 provided in the developer conduit 80. The roller conveyor 65 is provided above the developer storage tank 61 and conveys the substrate 66 on which the photoresist film is formed. The developing solution is dropped from the developing solution shower nozzle 67. The substrate 66 conveyed by the roller conveyor 65 is immersed in the developing solution by passing through the dropped developing solution. Then, the developer is collected in the developer storage tank 61 and stored again. Thus, the developing solution is circulated and repeatedly used in the developing process. Incidentally, the developing chamber of a small glass substrate may be subjected to a treatment so as not to absorb carbon dioxide in the air, for example, by filling it with nitrogen gas. The deteriorated developer is drained by operating the waste pump 71.

The circulation stirring mechanism C will be described. The circulation stirring mechanism C is mainly for circulating and stirring the developer stored in the developer storage tank 61.

The bottom portion of the developing solution storage tank 61 and the side portion of the developing solution storage tank 61 are connected by a circulation line 85 in which a circulation pump 74 and a filter 75 are provided. When the circulation pump 74 is operated, the developer stored in the developer storage tank 61 circulates via the circulation pipe line 85. The developing solution is returned from the side portion of the developing solution storage tank 61 to the developing solution storage tank 61 through the circulation pipe line 85, and the stored developing solution is stirred.

Further, when the replenisher solution flows into the circulation line 85 via the confluence line 84, the inflowing replenisher solution is mixed with the developing solution circulating in the circulation line 85, and enters the developing solution storage tank 61. Supplied.

Next, the developing solution management apparatus D of this embodiment will be described. The developing solution management device D of the present embodiment is a developing solution that has been confirmed in advance to have a predetermined developing performance for each concentration region specified by using the dissolved photoresist concentration and the absorbed carbon dioxide concentration of the developer exhibiting alkalinity as an index. Using the conductivity data having the conductivity value of, the measured value of the dissolved photoresist concentration of the developer, and the conductivity of the concentration region specified by the measured value of the absorbed carbon dioxide concentration as the control target value, This is a developing solution management device of a type in which a replenishing solution is replenished to the developing solution so that the conductivity becomes a control target value.

The developing solution management device D includes a measuring unit 1 and a control unit 21. The developing solution management device D is connected to the developing solution storage tank 61 by a sampling pipe 15 and an outlet side pipe 16.

The measuring unit 1 includes a sampling pump 14, a conductivity meter 11, a first concentration measuring unit 12 for measuring a dissolved photoresist concentration, and a second concentration measuring unit 13 for measuring an absorbed carbon dioxide concentration. There is. The conductivity meter 11, the first concentration measuring means 12, and the second concentration measuring means 13 are connected in series after the sampling pump 14. It is desirable that the measuring unit 1 further includes a temperature adjusting unit (not shown) that stabilizes the sampled developer at a predetermined temperature in order to improve the measurement accuracy. At this time, it is preferable that the temperature adjusting means is provided immediately before the measuring means. The sampling pipe 15 is connected to the sampling pump 14 of the measuring section 1 of the developer management device D, and the outlet pipe 16 is connected to the pipe at the end of the measuring means.

Further, in FIG. 1, the conductivity meter 11, the first concentration measuring means 12, and the second concentration measuring means 13 are shown connected in series, but the conductivity meter 11, the first concentration measuring means 12, The connection of the second concentration measuring means 13 is not limited to this. They may be connected in parallel, or each may be independently provided with a liquid feeding path for measurement. The order of the conductivity meter 11, the first concentration measuring means 12, and the second concentration measuring means 13 is not particularly limited. The measurement may be performed in an optimal order according to the characteristics of each measuring means.

The control unit 21 includes a data storage unit 23 and a control unit 31. In the data storage unit 23, it is confirmed in advance that a predetermined developing performance is obtained in each concentration region specified by using the dissolved photoresist concentration and the absorbed carbon dioxide concentration of the developer exhibiting alkalinity as an index. Stored is electrical conductivity data having electrical conductivity values.

The control unit 21 is connected to the conductivity meter 11, the first concentration measuring unit 12, and the second concentration measuring unit 13 of the measuring unit 1 by a signal line. The conductivity value, the dissolved photoresist concentration value, and the absorbed carbon dioxide concentration value measured by the measuring unit 1 are sent to the control means 21.

The control unit 31 of the control unit 21 is connected by signal lines to the control valves 41 to 43 provided in the conduits that feed the replenisher to the developer. In FIG. 1, the control valves 41 to 43 are shown as internal parts of the developing solution management device D, but the control valves 41 to 43 are not essential as parts of the developing solution management device D of the present embodiment. .. The control unit 31 may communicate with the control valves 41 to 43 so as to control the operations of the control valves 41 to 43 and replenish the developer with the replenisher. The control valves 41 to 43 may be provided outside the developer management device D.

The developer management device D of the embodiment further includes a display unit 22. The display unit 22 may display at least one of the conductivity value, the alkali component concentration value, the dissolved photoresist concentration value, and the absorbed carbon dioxide concentration value of the developer. it can.

The display unit 22 may be a display monitor electrically connected to the developing solution management device D, or a touch panel type computer incorporated in the developing solution management device D. In the case of a touch panel computer, the control means and the display means (control section and data storage section) are integrally configured.

Next, the operation of the developing solution management device D of this embodiment will be described.

The developing solution sampled from the developing solution storage tank 61 is fed into the measuring section 1 and its temperature is adjusted. The developing solution is then sent to the conductivity meter 11, the first concentration measuring unit 12, and the second concentration measuring unit 13, and the conductivity, the dissolved photoresist concentration, and the absorbed carbon dioxide concentration are measured. Each measurement data is sent to the control means 21.

The control unit 31 has a conductivity having a conductivity value of the developer which has been confirmed in advance to have a predetermined developing performance for each concentration region specified by using the dissolved photoresist concentration and the absorbed carbon dioxide concentration of the developer as indexes. A conductivity control value corresponding to the conductivity value of the data is set. The control unit 31 controls according to the measurement data received from the measurement unit 1 as follows.

Based on the dissolved photoresist concentration and the absorbed carbon dioxide concentration received from the measurement unit 1, the control unit 31 determines the measured dissolved photoresist concentration and the measured dissolved photoresist concentration in the conductivity data stored in the data storage unit 23. Then, the conductivity value in the concentration region specified by the absorbed carbon dioxide concentration is obtained. The obtained conductivity value is set as a control target value for the conductivity of the developer.

The control unit 31 compares the measured conductivity received from the measurement unit 1 with the conductivity set as the control target value, and performs the following management according to the comparison result. That is, if the conductivity set as the control target value is the same as the measured conductivity, basically no replenisher is added to the developer. If the conductivity set as the control target value is higher than the measured conductivity, the developer may be replenished with a replenisher that acts to increase the conductivity. When the conductivity set as the control target value is smaller than the measured conductivity, the developer may be replenished with a replenisher that acts to reduce the conductivity.

Here, the replenisher to be replenished with the developer includes, for example, a stock solution of the developer, a new solution, and pure water.

The replenisher is stored in the replenisher reservoirs 91 and 92 of the replenisher reservoir C. The replenisher storage tanks 91 and 92 are connected to a nitrogen gas pipeline 86 having valves 46 and 47, and are pressurized by nitrogen gas supplied through the pipelines. The replenisher reservoirs 91 and 92 are connected to replenisher conduits 81 and 82, respectively, and the replenisher is delivered via the valves 44 and 45 that are normally open. Control valves 41 to 43 are provided in the replenisher liquid conduits 81 and 82 and the pure water conduit 83, and the control valves 41 to 43 are controlled to be opened and closed by the controller 31. By operating the control valve, the replenisher liquid stored in the replenisher liquid storage tanks 91 and 92 is pressure-fed, and pure water is also fed. After that, the replenisher is merged with the circulation stirring mechanism D through the merging pipe line 84, and is replenished and stirred in the developer storage tank 61.

When the amount of the replenisher stored in the replenisher reservoirs 91, 92 decreases due to the replenishment, the internal pressure decreases and the supply amount becomes unstable. Therefore, the valves 46, 47 are appropriately opened according to the decrease of the replenisher to open the nitrogen gas. A gas is supplied to maintain the internal pressure of the replenisher storage tanks 91 and 92. When the replenisher tanks 91 and 92 are empty, the valves 44 and 45 are closed to replace the replenisher tank with a new replenisher tank filled with replenisher, or the replenisher tank procured separately is emptied. Refill the replenisher reservoir.

The control of the control valves 41 to 43 is performed as follows, for example. If the flow rate flowing when the control valve is opened is adjusted, it is possible to replenish the replenisher liquid of the amount to be replenished by managing the time when the control valve is opened. The control unit 31 opens the control valve for a predetermined time so that the replenishment liquid of the amount to be replenished flows based on the measured conductivity received from the measurement unit 1 and the conductivity set as the control target value. To issue a control signal to the control valve.

As a control method, various control methods used for controlling the control amount to a target value can be adopted. In particular, proportional control (P control), integral control (I control), differential control (D control), and control (PI control etc.) combining these are preferable. More preferably, PID control is suitable.

As described above, according to the developing solution management device D according to the present embodiment, the developing solution is managed by the conductivity of the developing solution regardless of the dissolved photoresist concentration and the absorbed carbon dioxide concentration of the developing solution. As a result, the component having an activity in the developing action is maintained, so that the desired developing performance can be maintained, and the developing process capable of maintaining the desired line width and residual film thickness can be realized.

Further, according to the developing solution management device D according to the present embodiment, the dissolution of the developing solution is performed by using the conductivity data of the conductivity value of the developing solution whose developing performance is confirmed in advance as the control target management value. The photoresist concentration is 0.0 to 0.40 (wt%) (equivalent to 0.0 to 1.3 (abs)), and the absorbed carbon dioxide concentration is 0.0 to 1.3 (wt%). However, it can be used as a developer having a desired developing activity. That is, according to the developing solution management apparatus D of the present embodiment, the dissolved photoresist concentration of the developing solution is 0.25 (wt%) or more (corresponding to 0.8 (abs)), and the absorbed carbon dioxide concentration is 0. Even if it is 6 (wt%) or more, the developer can be used without being wasted, and the amount of the developer waste can be reduced.

In the above, an example using the conductivity, the absorbed carbon dioxide concentration, the dissolved photoresist concentration, and the conductivity data of the developer has been described. Without being limited to this, the developer can be managed using the alkali component concentration, the absorbed carbon dioxide concentration, and the absorbance of the developer and the alkali component concentration data.

[Second embodiment]
FIG. 2 is a schematic diagram of a developing process for explaining the developing solution management apparatus D of this embodiment. A developing solution management device D of the present invention is illustrated together with a developing process facility A, a replenisher storage part B, a circulation stirring mechanism C, and the like. The same components as those of the first embodiment may be designated by the same reference numerals and the description thereof may be omitted.

The measuring unit 1 of the developing solution management device D includes a conductivity meter 11, a characteristic value of the developing solution correlated with the dissolved photoresist concentration of the developing solution, and a characteristic value of the developing solution correlated with the absorbed carbon dioxide concentration of the developing solution. It has a plurality of measuring devices for measuring and. For example, an absorptiometer for measuring the absorbance at λ=560 nm is provided as the first characteristic value measuring means 12A for measuring the characteristic value of the developer having a correlation with the dissolved photoresist concentration. As the second characteristic value measuring means 13A for measuring the characteristic value of the developing solution having a correlation with the absorbed carbon dioxide concentration, a density meter for measuring the density of the developing solution is provided.

Here, the "correlated" characteristic value of the developer means that the characteristic value is related to the component concentration, and the characteristic value is changed according to the change of the component concentration. For example, among the component concentrations of the developer, the characteristic value a of the developer having a correlation with at least the component concentration A is at least one of the variables when the characteristic value a is obtained by a function having the component concentration as a variable. It is meant to include the concentration A. The characteristic value a may be a function of only the component concentration A, but normally, when the characteristic value a is a multivariable function having the component concentrations A, B, and C as variables, the multivariate analysis is performed. The significance of using the method (for example, multiple regression analysis method) is significant.

The control unit 21 includes a data storage unit 23, a control unit 31, and a calculation unit 32. The calculation unit 32 calculates the measured value of the dissolved photoresist concentration and the measured value of the absorbed carbon dioxide concentration of the developer by multivariate analysis from the plurality of characteristic values of the developer measured by the measurement unit 1.

In the present embodiment, the developing solution sampled from the developing solution storage tank 61 is fed into the measuring section 1 and the temperature thereof is adjusted. The developer is then sent to the conductivity meter 11, the first characteristic value measuring means 12A and the second characteristic value measuring means 13A, and the conductivity, the absorbance and the density are measured. Each measurement data is sent to the control means 21.

The calculation unit 32 calculates the measured value of the dissolved photoresist concentration of the developer and the measured value of the absorbed carbon dioxide concentration by multivariate analysis from the absorbance and the density measured by the measuring unit 1. At this time, the measured value of the dissolved photoresist concentration and the measured value of the absorbed carbon dioxide concentration can be calculated from the conductivity, the absorbance, and the density by multivariate analysis.

Based on the dissolved photoresist concentration and the absorbed carbon dioxide concentration calculated by the calculation unit 32, the control unit 31 measures the measured dissolved photoresist concentration and the measured dissolved photoresist concentration in the conductivity data stored in the data storage unit 23. The conductivity value in the concentration region specified by the absorbed carbon dioxide concentration is calculated. The obtained conductivity value is set as a control target value for the conductivity of the developer.

Other configurations, operations, etc. are similar to those of the first embodiment, and will be omitted.

Next, a method of calculating the measured value of the dissolved photoresist concentration and the absorbed carbon dioxide concentration from a plurality of characteristic values of the developing solution by multivariate analysis will be described.

The inventor can use the multivariate analysis method (for example, the multiple regression analysis method) as the calculation method to calculate the concentration of each component of the developer more accurately than in the case of using the conventional method. It was also found that the absorbed carbon dioxide concentration can be measured. If the developer component concentrations (dissolved photoresist concentration and absorbed carbon dioxide concentration) calculated by a multivariate analysis method (for example, multiple regression analysis method) are used, the dissolved photoresist concentration and absorption of which developability has been confirmed in advance It is possible to easily obtain the target conductivity value from the conductivity data having the carbon dioxide concentration and the conductivity value.

Assuming the case of controlling a 2.38% TMAH aqueous solution, TMAH aqueous solutions having various concentrations of alkali components, dissolved photoresist concentrations, and absorbed carbon dioxide concentrations were prepared as simulated developer samples. The inventor conducted an experiment to determine the component concentration of each of the simulated developer solutions by multiple regression analysis from various characteristic values measured. Hereinafter, a general calculation method by the multiple regression analysis method will be described, and then a calculation method of the component concentration of the developer using the multiple regression analysis method will be described based on an experiment conducted by the inventor.

Multiple regression analysis consists of two steps, calibration and prediction. It is assumed that m calibration standard solutions are prepared in the n-component multiple regression analysis. The concentration of the j-th component existing in the i-th solution is represented by C _ij . Here, i=1 to m and j=1 to n. For each of the m standard solutions, p characteristic values (for example, characteristic values such as absorbance at a certain wavelength or conductivity) A _ik (k=1 to p) are measured. The concentration data and the characteristic data can be collectively expressed in a matrix form (C, A).

A matrix that relates these matrices is called a calibration matrix, and is represented by a symbol S (S _kj ; k=1 to p, j=1 to n) here.

It is possible to calculate S from a known C and A (the content of A is not limited to the same measurement value but different measurement values may be mixed. For example, conductivity, absorbance, and density) by matrix calculation. It is a calibration stage. At this time, p>=n and m>=np must be satisfied. Since each element of S is an unknown number, it is desirable that m>np. In that case, the least squares operation is performed as follows.

Here, the superscript T means a transposed matrix, and the superscript -1 means an inverse matrix.

If p characteristic values are measured with respect to a sample solution of unknown concentration and these are Au(Au _k ; k=1 to p), the concentration Cu(Cu _j ; j=1 to n to be obtained by multiplying S by it is obtained. ) Can be obtained.

This is the prediction stage.

The inventor considers the used alkaline developer (2.38% TMAH aqueous solution) as a multi-component system (n=3) consisting of three components of an alkali component, a dissolved photoresist, and absorbed carbon dioxide, and considers the developer. From the three characteristic values (p=3), that is, the conductivity value of the developer, the absorbance value at a specific wavelength, and the density value, an experiment for calculating the concentration of each component by the above multiple regression analysis method was performed. It was The inventor prepared eleven calibration standard solutions in which the concentration of alkali components (TMAH concentration), the concentration of dissolved photoresist, and the concentration of absorbed carbon dioxide were variously changed using a 2.38% TMAH aqueous solution as a basic composition of the developer. (When m=11, p>=n and m>np are satisfied).

In the experiment, the conductivity value, the absorbance value at the wavelength λ=560 nm, and the density value of the 11 calibration standard solutions were measured as the characteristic values of the developer, and the concentration of each component was analyzed by the multiple linear regression analysis (Multiple Linear Regression − Inverse Least Squares; MLR-ILS).

The measurement was performed by adjusting the temperature of the calibration standard solution to 25.0°C. To adjust the temperature, immerse the bottle containing the calibration standard solution in a constant temperature water bath whose temperature is controlled at around 25°C for a long time, sample it from here, and bring it back to 25.0°C again with a temperature controller immediately before measurement. , Is the method. As the conductivity meter, we used a self-made conductivity meter. It was measured using an in-house manufactured conductivity flow cell that had been subjected to platinum black treatment. The cell constant of the conductivity flow cell, which is separately confirmed by the calibration work, is input to the conductivity meter. The absorptiometer also used a self-made one. It is an absorptiometer including a light source unit having a wavelength λ=560 nm, a photometric unit, and a glass flow cell. For the density measurement, a density meter that employs a natural vibration method that obtains the density from the natural frequency measured by exciting a U-shaped flow cell is used. The units of the measured conductivity value, absorbance value and density value are mS/cm and Abs. (Absorbance), g/cm ³ .

For the calculation, one of the 11 calibration standard solutions is regarded as an unknown sample, the calibration matrix is calculated with the remaining 10 standards, and the concentration of the assumed unknown sample is calculated to obtain a known value (by another accurate analysis method). It is based on a method of comparing with measured concentration values and weight adjustment values (one-out crossing confirmation method; Leave-One-Out method).

The results of the MLR-ILS calculation are shown in Table 1.

In the MLR-ILS calculation, in view of the fact that the TMAH aqueous solution is strongly alkaline and absorbs carbon dioxide and is likely to deteriorate, the concentration matrix used for the calculation includes a titration analysis method capable of accurately analyzing the concentration of alkali components and the concentration of absorbed carbon dioxide. The value obtained by separately measuring the calibration standard solution was used. However, regarding the concentration of the dissolved photoresist, the weight adjusted value was used.

The titration is a neutralization titration using hydrochloric acid as a titration reagent. As a titrator, an automatic titrator GT-200 manufactured by Mitsubishi Chemical Analytech Co. was used.

The concentration matrix is shown in Table 2 below.

Table 3 shows the measurement results of the characteristic values of the calibration standard solution at this time. The column of absorbance is the absorbance value (optical path length d=10 mm) at the wavelength λ=560 nm.

The calibration matrix is shown in Table 4.

Table 5 shows a comparison between the measured concentration values in Table 2 and the calculated MLR-ILS values in Table 1.

As shown in Table 5, the TMAH concentration, the dissolved photoresist concentration, and the absorbed carbon dioxide concentration obtained by the multiple regression analysis method are all the TMAH concentration and the absorbed carbon dioxide concentration measured by the titration analysis, and the dissolution obtained from the adjusted weight. The values are very close to the photoresist concentration.

In this way, the conductivity of the alkaline developer, the absorbance at a specific wavelength, and the density are measured, and by using a multivariate analysis method (for example, multiple regression analysis method), the alkaline component concentration of the developer, the dissolution photo It is understood that the resist concentration and the absorbed carbon dioxide concentration can be measured.

The multivariate analysis method (for example, the multiple regression analysis method) is effective in calculating and obtaining the concentrations of a plurality of components. It is possible to measure a plurality of characteristic values a, b, c,... Of the developer and obtain the component concentrations A, B, C,... From the measured values by a multivariate analysis method (eg, multiple regression analysis method). it can. At this time, for the component concentration to be obtained, at least one characteristic value having a correlation with this component concentration needs to be measured and used in the calculation.

The component concentration is a scale showing the relative amount of the component with respect to the whole. The component concentration of a mixed solution in which the components increase and decrease over time, such as a repeatedly used developer, is not determined by the component alone, but is usually a function of the concentrations of other components. Therefore, it is often difficult to display the relationship between the characteristic value of the developing solution and the component concentration in a planar graph. In such a case, the component concentration cannot be calculated from the characteristic value of the developing solution by a calculation method using a calibration curve or the like.

However, according to the multivariate analysis method (for example, multiple regression analysis method), if one set of measured values of a plurality of characteristic values correlated with the component concentration to be calculated is prepared, this is used for calculation to calculate the component concentration. Is calculated. Even if it is difficult to measure the component concentration at first glance with conventional knowledge, the remarkable effect that the component concentration can be measured by measuring the characteristic value is obtained by the multivariate analysis method (for example, multiple regression analysis method). It can be obtained by measurement.

As described above, according to the calculation method of the present invention, the alkaline component concentration of the developing solution, the dissolved photoresist concentration, and the absorbed carbon dioxide concentration, the characteristic value of the developing solution (for example, conductivity, absorbance at a specific wavelength, and , Density) can be calculated based on the measured values. According to the calculation method of the present invention, it is possible to calculate the concentration of each component with higher accuracy than in the conventional method.

Further, in the present invention, since the multivariate analysis method (for example, multiple regression analysis method) is used, the characteristic of the developer which is not linearly related to the specific component concentration of the developer is used in the calculation for calculating the component concentration of the developer. Values can also be adopted.

Further, according to the present invention, preparation and preliminary measurement of a very large number of samples, which are required in the invention of Patent Document 2, for enabling highly accurate measurement are not necessary. (As in the experimental example described above, if the number of components is n=3, the number of characteristic values to be measured p=3, and the number of samples p satisfying m>=np (for example, p=11 samples) is set. It is sufficient to prepare and measure it. If the number of components n=2, the number of samples may be smaller.)
Furthermore, since the present invention uses a multivariate analysis method (for example, a multiple regression analysis method), it is possible to accurately calculate the absorbed carbon dioxide concentration of the developer, which was difficult to measure in the past.

In the present embodiment, the absorbance at λ=560 nm is exemplified as the characteristic value of the developing solution having a correlation with the dissolved photoresist concentration of the developing solution, but the characteristic value is not limited thereto. It is also possible to use the absorbance at another specific wavelength, that is, the absorbance at a specific wavelength in the visible region, more preferably in the wavelength region of 360 to 600 nm, more preferably at the wavelength λ=480 nm, as the characteristic value. This is because the absorbance at a specific wavelength included in these wavelength ranges has a relatively good correspondence with the dissolved resist concentration.

Further, although the density is exemplified as the characteristic value of the developer having a correlation with the absorbed carbon dioxide concentration of the developer, the density is not limited to this. As a characteristic value of the developing solution having a correlation with the dissolved photoresist concentration or absorbed carbon dioxide concentration of the developing solution, a characteristic value that can be adopted as a characteristic value to be measured in combination with the conductivity of the developing solution is, for example, at the specific wavelength. In addition to absorbance and density, ultrasonic wave propagation speed, refractive index, titration end point, pH and the like can be mentioned.

[Third embodiment]
FIG. 3 is a schematic diagram of a developing process for explaining the developing solution management apparatus D of this embodiment. A developing solution management device D of the present invention is illustrated together with a developing process facility A, a replenisher storage part B, a circulation stirring mechanism C, and the like. The same components as those of the first and second embodiments may be designated by the same reference numerals and the description thereof may be omitted.

The developing solution management device D of this embodiment includes a measuring unit 1, a control unit 21, and a calculation unit 36. In the present embodiment, unlike the second embodiment, the control unit 21 and the calculation unit 36 that performs calculation are configured as separate devices.

The measuring unit 1 includes a conductivity meter 11, a first characteristic value measuring unit 12A, and a second characteristic value measuring unit 13A. The calculation means 36 uses a multivariate analysis from the absorbance and density measured by the first characteristic value measuring means 12A and the second characteristic value measuring means 13A to measure the dissolved photoresist concentration of the developer and the absorbed carbon dioxide concentration. Calculate the measured value of. At this time, the measured value of the dissolved photoresist concentration and the absorbed carbon dioxide concentration can be calculated from the conductivity, the absorbance, and the density by multivariate analysis.

Based on the dissolved photoresist concentration and the absorbed carbon dioxide concentration calculated by the calculating means, the control unit 31 determines the measured dissolved photoresist concentration and the measured dissolved photoresist concentration in the conductivity data stored in the data storage unit 23. Then, the conductivity value in the concentration region specified by the absorbed carbon dioxide concentration is obtained. The obtained conductivity value is set as a control target value for the conductivity of the developer.

Other configurations and operations are the same as those in the second embodiment, and will not be described.

[Fourth Embodiment]
FIG. 4 is a schematic diagram of a developing process for explaining the developing solution management apparatus D of this embodiment. A developing solution management device D of the present invention is illustrated together with a developing process facility A, a replenisher storage part B, a circulation stirring mechanism C, and the like. The same components as those of the first embodiment, the second embodiment, and the third embodiment may be designated by the same reference numerals and the description thereof may be omitted.

The measuring unit 1 of the present embodiment includes a conductivity meter 11, a first concentration measuring unit 12, and a density meter 13B. The control unit 21 includes a data storage unit 23 and a calculation unit 33. The calculation unit 33 calculates the absorbed carbon dioxide concentration of the developing solution from the density of the developing solution measured by the density meter 13B based on the correspondence relationship between the absorbed carbon dioxide concentration of the developing solution and the density.

Based on the dissolved photoresist concentration measured by the measurement unit 1 and the absorbed carbon dioxide concentration calculated by the calculation unit 33, the control unit 31 measures the conductivity data stored in the data storage unit 23. A conductivity value in a concentration region specified by the dissolved photoresist concentration thus obtained and the measured absorbed carbon dioxide concentration is obtained. The obtained conductivity value is set as a control target value for the conductivity of the developer.

Other configurations, operations, etc. are similar to those of the first embodiment, and will be omitted.

The relationship between the density value of the developer and the absorbed carbon dioxide concentration value will be described. The inventor has obtained the following findings as a result of continuing diligent research. That is, it is possible to obtain a relatively good correspondence (linear relationship) between the density value of the developing solution and the absorbed carbon dioxide concentration value, irrespective of the alkaline component concentration of the developing solution or the dissolved photoresist concentration. .. Further, if this correspondence relationship (linear relationship) is used, it is possible to measure the absorbed carbon dioxide concentration, which has been difficult in the past, by measuring the density of the developer with a densitometer.

The inventor uses eleven calibration standard solutions used for the calculation of the component concentrations of the developing solution using the multivariate analysis method as simulated developing solution samples, and about these, alkali component concentration (TMAH concentration), dissolved photoresist concentration, absorption An experiment was carried out to measure the carbon dioxide concentration and the density and confirm the correlation between the component concentration and the density.

Table 6 below shows the measurement results of the component concentration and density of each sample. Table 6 is a table comparing the measured concentration values (wt %) of Table 5 with the densities (g/cm ³ ) of Table 3.

FIG. 5 shows a graph of the absorbed carbon dioxide concentration and the density of each sample shown in Table 6. This graph is a graph in which the abscissa represents the absorbed carbon dioxide concentration (wt %) and the ordinate represents the density (g/cm ³ ), and the values of the respective samples are plotted. From each of the plotted points, a regression line was obtained by the method of least squares.

From FIG. 5, it can be understood that the absorbed carbon dioxide concentration of the developing solution has a good linear relationship with the density of the developing solution in spite of various alkali component concentrations and dissolved photoresist concentrations. From this experimental result, it is possible to calculate the absorbed carbon dioxide concentration of the developing solution by measuring the density of the developing solution by using the correspondence relationship (linear relationship) between the absorbed carbon dioxide concentration of the developing solution and the density. The inventor has found that it is possible.

Therefore, regardless of the alkali component concentration (TMAH concentration) and the dissolved resist concentration, the absorbed carbon dioxide concentration of the developing solution can be measured by using the density meter by this correspondence relationship (linear relationship).

By using the relationship between the density of the developing solution and the absorbed carbon dioxide concentration, the calculation unit 33 can easily measure the absorbed carbon dioxide concentration of the developing solution.

[Fifth Embodiment]
FIG. 6 is a schematic diagram of a developing process for explaining the developing solution management apparatus D of this embodiment. A developing solution management device D of the present invention is illustrated together with a developing process facility A, a replenisher storage part B, a circulation stirring mechanism C, and the like. The same components as those of the first and second embodiments may be designated by the same reference numerals and the description thereof may be omitted.

The developing solution management apparatus D of this embodiment includes a measuring unit 1, a control unit 21, and a calculation unit 37. In the present embodiment, unlike the fourth embodiment, the control unit 21 and the calculation unit 37 that performs the calculation are configured as separate devices. The measuring unit 1 of the present embodiment includes a conductivity meter 11, a first concentration measuring unit 12, and a density meter 13B. The calculating means 37 calculates the absorbed carbon dioxide concentration of the developer from the density of the developer measured by the densitometer 13B based on the correspondence relationship between the absorbed carbon dioxide concentration of the developer and the density.

Based on the dissolved photoresist concentration measured by the measuring unit 1 and the absorbed carbon dioxide concentration calculated by the calculating unit 37, the control unit 31 measures the conductivity data stored in the data storage unit 23. A conductivity value in a concentration region specified by the dissolved photoresist concentration thus obtained and the measured absorbed carbon dioxide concentration is obtained. The obtained conductivity value is set as a control target value for the conductivity of the developer.

The other configurations and operations are the same as those in the fourth embodiment, and will be omitted.

As described above, according to the developing solution management apparatus D of the present embodiment, no matter what the dissolved photoresist concentration and the absorbed carbon dioxide concentration of the developing solution are, the components active in the developing action in the developing solution are constant. Therefore, it is possible to realize a developing process capable of maintaining desired developing performance and maintaining desired line width and residual film thickness.

Next, a modified example of the developing solution management device D of this embodiment will be described.

1 to 4 and 6, the measuring unit 1 of the developing solution management device D depicts the developing solution management device D integrally formed with the control means 21 and the computing means 36 and 37. The management device D is not limited to this. The measuring unit 1 can be configured separately.

In the measurement unit 1, there is an optimal installation method depending on the measurement principle adopted, and therefore, for example, the measurement unit 1 is connected in-line to the developer pipeline 80, or the measurement probe is immersed in the developer storage tank 61. It may be installed like this. The conductivity meter 11, the first concentration measuring unit 12, the first characteristic value measuring unit 12A, the second concentration measuring unit 13, the second characteristic value measuring unit 13A, and the density meter 13B are separately installed. May be The developing solution management apparatus D of the present embodiment can be realized as long as each measuring means communicates with the control means 21 and the calculation means 36, 37 so as to exchange measurement data with each other.

Depending on the measurement principle adopted by each measuring means, if reagent addition is required, each measuring means may be provided with a pipe for it, and if a waste liquid is required, each measuring means has a conduit for that purpose. May be provided. The developing solution management apparatus D of this embodiment can be realized even if the respective measuring means are not connected in series.

In FIGS. 1 to 4 and 6, the developing solution management device D is configured so that the control valves 41 to 43 provided in the pipeline for feeding the replenisher solution to be supplied to the developing solution become internal parts of the developing solution management device D. Is drawn to be connected to the replenisher pipe lines 81 and 82 and the pure water pipe line 83, but the developing solution management apparatus D of the present embodiment is not limited to this. The developing solution management device may not include the control valves 41 to 43 as internal parts, and may not be connected to the pipelines 81 to 83 for supplying the replenishing solution to the developing solution.

The control means 21 in the developing solution management device D of this embodiment and the control valves 41 to 43 provided in the pipeline for replenishing the replenishing solution are the control means of the developing solution management device D. It suffices that the control signals issued by 21 are communicated with each other so as to be controlled. Even if the control valve is not an internal component of the developing solution management apparatus D, the developing solution management apparatus D of this embodiment can be realized.

[Sixth embodiment]
FIG. 7 is a schematic diagram for explaining the developing solution management apparatus D of this embodiment. The developer management device D of this embodiment has the same configuration as that of the first embodiment. The same components as those of the first to fifth embodiments may be designated by the same reference numerals and the description thereof may be omitted.

As shown in FIG. 7, the display means 22 of the sixth embodiment uses at least the conductivity value and the alkali component of the developer conductivity value, the alkali component concentration value, the dissolved photoresist concentration value and the absorbed carbon dioxide concentration value. Either one of the concentration values can be displayed as a graph using the measurement time or the elapsed time from the start of measurement as an index.

Further, in the present embodiment, the display unit 22 can switch the graph display of the characteristic value and the component concentration by the switching button BT which is the display switching unit set on the screen of the display unit 22.

The display means 22 of the sixth embodiment can also be applied to the second to fifth embodiments. The developing solution management apparatus of the present invention, although various modifications as described above are allowed, a predetermined concentration area specified for each of the dissolved photoresist concentration and absorbed carbon dioxide concentration of the developing solution as an index. Provided with the conductivity data having the conductivity value of the developer previously confirmed to be the development performance, the concentration region of the concentration range specified by the measured value of the dissolved photoresist concentration of the developer and the measured value of the absorbed carbon dioxide concentration. Using the conductivity value of the conductivity data as a control target value, a replenisher solution to be replenished to the developer is fed so that the conductivity of the developer becomes the control target value.

As described above, according to the developing solution management method and the developing solution management apparatus of the present invention, no matter what the dissolved photoresist concentration and absorbed carbon dioxide concentration of the developing solution may be, it is active in the developing action in the developing solution. Since the component having a is maintained constant, it is possible to realize a development process capable of maintaining a desired developing performance and a desired line width and residual film thickness.

As a preferred embodiment of the developer management apparatus, the dissolved photoresist concentration and the absorbed carbon dioxide concentration are calculated by the multivariate analysis method, so that the dissolved photoresist concentration and the absorbed carbon dioxide concentration can be accurately obtained. A target conductivity value can be obtained from the conductivity data based on the dissolved photoresist concentration and the absorbed carbon dioxide concentration.

Further, as a preferred embodiment of the developer management device, the absorbed carbon dioxide concentration of the developer is calculated from the density of the developer measured by a density meter based on the correspondence relationship between the absorbed carbon dioxide concentration of the developer and the density. .. Thereby, the absorbed carbon dioxide concentration of the developer can be obtained more easily. Based on this absorbed carbon dioxide concentration and the separately determined dissolved photoresist concentration, a target conductivity value can be calculated from the conductivity data.

A... Development process equipment, B... Replenisher storage part, C... Circulating stirring mechanism, D... Developer management device 1... Measuring part 11... Conductivity meter, 12... First concentration measuring means, 12A... First characteristic value measurement Means, 13... Second concentration measuring means, 13A... Second characteristic value measuring means, 13B... Density meter 14... Sampling pump, 15... Sampling pipe, 16... Exit side pipe 21... Control means (for example, computer), 22... Display means 23... data storage unit,
31... Control part, 32, 33... Calculation part, 36, 37... Calculation means 41-43... Control valve, 44, 45, 46, 47... Valve 61... Developer storage tank, 62... Overflow tank, 63... Liquid level Total, 64... Developing chamber hood, 65... Roller conveyor, 66... Substrate, 67... Developer shower nozzle 71... Waste liquid pump, 72, 74... Circulation pump, 73, 75... Filter 80... Developer solution line, 81, 82 ... Replenisher (development stock solution and/or new solution) pipeline, 83... Pure water pipeline, 84... Combined pipeline, 85... Circulation pipeline, 86... Nitrogen gas pipelines 91, 92... Replenisher ( Stock solution for development and/or new solution)

Claims (11)

Predetermined development for each concentration region specified for each combination of the dissolved photoresist concentration and the absorbed carbon dioxide concentration, using the dissolved photoresist concentration and absorbed carbon dioxide concentration of a developer that is repeatedly used as an index A data storage unit that stores conductivity data having a conductivity value of the developer that has been previously confirmed to be performance;
Conductivity of the developer, with the conductivity value stored in the data storage unit of the concentration region specified by the measured value of the dissolved photoresist concentration of the developer and the measured value of the absorbed carbon dioxide concentration as the control target value. A control section for issuing a control signal to a control valve provided in a conduit for feeding a replenisher solution to be replenished with the developing solution,
With a control means,
Display means for displaying at least conductivity values of the conductivity values of the developer, dissolve the photoresist concentration values and absorption of carbon dioxide concentration values,
A developing solution management device. The developer management apparatus according to claim 1, further comprising a display switching unit that switches a display target displayed on the display unit. Predetermined development for each concentration region specified for each combination of the dissolved photoresist concentration and the absorbed carbon dioxide concentration, using the dissolved photoresist concentration and absorbed carbon dioxide concentration of a developer that is repeatedly used as an index A data storage unit that stores conductivity data having a conductivity value of the developer that has been previously confirmed to be performance;
Conductivity of the developer, with the conductivity value stored in the data storage unit of the concentration region specified by the measured value of the dissolved photoresist concentration of the developer and the measured value of the absorbed carbon dioxide concentration as the control target value. A control section for issuing a control signal to a control valve provided in a conduit for feeding a replenisher solution to be replenished with the developing solution,
With a control means,
Conductivity value of the developer, at least conductivity values among dissolve the photoresist concentration values and absorption carbon dioxide concentration values, display means for displaying the graph in the indicator the time elapsed from the measurement time or the measurement start,
A developing solution management device. The developer management apparatus according to claim 3, further comprising a display switching unit that switches a display target displayed on the display unit. Measuring a plurality of characteristic values of the developing solution including a characteristic value of the developing solution correlated with the dissolved photoresist concentration of the developing solution and a characteristic value of the developing solution correlated with the absorbed carbon dioxide concentration of the developing solution. Further comprising a plurality of measuring devices,
The control means further comprises
From a plurality of characteristic values of the developing solution measured by the plurality of measuring devices, by a multivariate analysis method, a calculation unit that calculates a measured value of a dissolved photoresist concentration of the developing solution and a measured value of an absorbed carbon dioxide concentration,
The developer management device according to claim 1, further comprising: Measuring a plurality of characteristic values of the developing solution including a characteristic value of the developing solution correlated with the dissolved photoresist concentration of the developing solution and a characteristic value of the developing solution correlated with the absorbed carbon dioxide concentration of the developing solution. Multiple measuring devices,
From a plurality of characteristic values of the developing solution measured by the plurality of measuring devices, using a multivariate analysis method, a calculation for calculating a measured value of dissolved photoresist concentration and a measured value of absorbed carbon dioxide concentration of the developing solution. Means and
The developer management apparatus according to claim 1, further comprising: Equipped with a density meter,
The control means further comprises
An arithmetic unit that calculates the absorbed carbon dioxide concentration value of the developer from the density value of the developer measured by the densitometer based on the correspondence relationship between the absorbed carbon dioxide concentration of the developer and the density,
The developer management device according to claim 1, further comprising: A densitometer,
Calculation means for calculating the absorbed carbon dioxide concentration value of the developer from the density value of the developer measured by the densitometer based on the correspondence between the absorbed carbon dioxide concentration of the developer and the density,
The developer management apparatus according to claim 1, further comprising: Repeatedly used, the absorbance and the absorbed carbon dioxide concentration correlated with the dissolved photoresist concentration of the developer exhibiting alkalinity is used as an index , and the concentration is specified for each concentration region specified for each combination of the absorbance and the absorbed carbon dioxide concentration. A data storage unit in which alkaline component concentration data having an alkaline component concentration value of the developer, which has been previously confirmed to be the developing performance of, is stored,
With the alkali component concentration value stored in the data storage unit in the concentration region specified by the measured values of the absorbance and absorbed carbon dioxide concentration of the developer as a control target value, the alkali component concentration of the developer is the control target. A control unit for issuing a control signal to a control valve provided in a pipe line for feeding a replenisher solution to be replenished to the developer so that the value becomes
With a control means,
Alkaline component concentration value of the developer, absorbance value correlated with the dissolved photoresist concentration, and a display means for displaying at least the alkaline component concentration value of the absorbed carbon dioxide concentration value,
A developing solution management device. Repeatedly used, the absorbance and the absorbed carbon dioxide concentration correlated with the dissolved photoresist concentration of the developer exhibiting alkalinity is used as an index , and the concentration is specified for each concentration region specified for each combination of the absorbance and the absorbed carbon dioxide concentration. A data storage unit in which alkaline component concentration data having an alkaline component concentration value of the developer, which has been previously confirmed to be the developing performance of, is stored,
With the alkali component concentration value stored in the data storage unit in the concentration region specified by the measured values of the absorbance and absorbed carbon dioxide concentration of the developer as a control target value, the alkali component concentration of the developer is the control target. A control unit for issuing a control signal to a control valve provided in a pipe line for feeding a replenisher solution to be replenished to the developer so that the value becomes
With a control means,
Alkali component concentration value of the developer, absorbance value correlated with the dissolved photoresist concentration, and at least the alkaline component concentration value of the absorbed carbon dioxide concentration value, a graph with the elapsed time from the measurement time or measurement start as an index Display means for displaying,
A developing solution management device. The developer management apparatus according to claim 9, further comprising a display switching unit that switches a display target displayed on the display unit.

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