JP2019071482A - Developing liquid managing method and device - Google Patents

Abstract

To provide developing liquid managing method and device that can maintain desired development performance and realize development processing capable of maintaining desired line width and residual film thickness.SOLUTION: A developer management device D includes control means 21 having a data storage unit 23 for storing conductivity data having conductivity values of developing liquid which is pre-confirmed to have predetermined development performance for each concentration area specified by using, as indexes, the dissolved photoresist concentration and the absorbed carbon dioxide concentration of repetitively used alkaline developing liquid, and a controller 31 for using, as a control target value, a conductivity value stored in the data storage unit 23 of the concentration area specified by the measurement value of the dissolved photoresist concentration and the measurement value of the absorbed carbon dioxide concentration of the developing liquid, and outputting a control signal to control valves 41 to 43 provided to a flow path for feeding supplemental liquid which is to be supplemented to the developing liquid so that the conductivity of the developing liquid is equal to the control target value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method and apparatus for managing a developer, and more particularly, to a method and apparatus for managing an alkaline developer which is repeatedly used to develop a photoresist film in a process of developing a circuit board in a semiconductor or liquid crystal panel. About.

  In the development step of photolithography to realize fine wiring processing in semiconductors, liquid crystal panels, etc., a developer exhibiting alkalinity (hereinafter referred to as “alkaline developer”) as a chemical solution for dissolving a photoresist formed on a substrate Is used.

  In the manufacturing process of semiconductors and liquid crystal panel substrates, in recent years, the enlargement of wafers and glass substrates and the miniaturization and high integration of wiring processing have been promoted. Under these circumstances, it is necessary to measure the concentration of the main components of the alkaline developer with even higher precision and maintain and manage the developer in order to realize miniaturization and high integration of wiring processing of a large substrate. It has become to.

  The measurement of the component concentration of the conventional alkaline developing solution utilizes the fact that a good linear relationship is obtained between the concentration of the alkaline component of the alkaline developing solution (hereinafter referred to as "alkali component concentration") and the conductivity. (E.g., Patent Document 1).

  However, in recent years, the developing treatment increases the chance of the alkaline developing solution coming into contact with the air, and the alkaline developing solution absorbs carbon dioxide in the air, so the amount of carbon dioxide absorbed by the alkaline developing solution increases. When the absorbed carbon dioxide concentration becomes high, there are problems such as the fact that predetermined line width processing can not be maintained in the developer management by the conventional method.

  This problem is caused by the fact that an alkaline component having development activity in an alkaline developer is consumed in a reaction to generate carbonate by absorption of carbon dioxide. In addition, an alkaline component having a development activity in an alkaline developer is consumed as a result of dissolution of the photoresist and a reaction for producing a photoresist salt.

  To cope with such problems, various attempts have been made to control the developing solution to compensate for the consumed and reduced alkali components. In these attempts, by measuring the carbonate concentration, the alkaline component consumed in the reaction for producing a carbonate is compensated by the replenisher to make the concentration of the alkaline component having developing activity constant. The same applies to the alkali component consumed by the dissolution of the photoresist. These stand from the viewpoint that the alkali component which has become a carbonate or a photoresist salt loses its developing activity and is inactivated (for example, Patent Document 2).

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

  However, even with such various developer management attempts, it has still been difficult to achieve satisfactory developer management.

  The inventors of the present invention conducted intensive studies on developer control, and it was found that carbonates and resist salts are also partially released in the developer to contribute to the developing action, and from these components thought to be inactivated. The developer management which also takes into consideration the contribution to the development action of the developer can be realized by managing the conductivity value of the developer, and further, the management value of such conductivity is the concentration of absorbed carbon dioxide and the concentration of dissolved photoresist We obtained the knowledge that they differed in various ways.

  This is because the alkali component which has become a carbonate or photoresist salt is not inactivated but is partly liberated to contribute to the developing action, and from the alkali component or carbonate and resist salt having developing activity. It is believed that any component which is liberated to contribute to the development action affects the conductivity. That is, the inventor has found that the whole of the components having a developing action can be optimally managed by controlling the conductivity value of the developer, and the present invention has been achieved.

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

  In order to achieve the above object, the method of managing a developer according to the present invention measures the conductivity, the concentration of a dissolved photoresist and the concentration of absorbed carbon dioxide of a developer exhibiting alkalinity, which is repeatedly used, and dissolves the developer. Among the conductivity data having the conductivity value of the developer, which is previously confirmed to have a predetermined development performance for each concentration range specified using the photoresist concentration and the absorbed carbon dioxide concentration as an index, the dissolved photo measured The conductivity value of the concentration range specified by the resist concentration and the measured absorbed carbon dioxide concentration is set as a control target value of the conductivity of the developer, and the conductivity of the developer becomes the control target value. As described above, the developer is replenished with a replenisher.

  According to the method of managing a developing solution of the present invention, no matter what dissolved photoresist concentration and absorbed carbon dioxide concentration are in the developing solution, the component having the activity of developing in the developing solution is maintained constant. A desired development performance can be maintained, and a development process capable of maintaining a desired line width and residual film thickness can be realized.

  In order to achieve the above object, the developing solution management apparatus of the present invention is configured to perform predetermined development for each concentration range specified using the dissolved photoresist concentration of the developing solution exhibiting alkalinity and the absorbed carbon dioxide concentration, which are repeatedly used. A data storage unit storing conductivity data having a conductivity value of the developing solution previously confirmed to be a performance, a measured value of a dissolved photoresist concentration of the developing solution, and a measured value of an absorbed carbon dioxide concentration Using the conductivity value stored in the data storage unit of the concentration region specified by the control target value as the control target value, and the replenishing solution supplied to the developer so that the conductivity of the developer becomes the control target value A control unit including: a control unit that generates a control signal to a control valve provided in a flow path for sending a liquid.

  According to the developer management apparatus of the present invention, the component having the activity of developing in the developer is maintained constant regardless of what the concentration of dissolved photoresist and absorbed carbon dioxide are in the developer. A desired development performance can be maintained, and a development process capable of maintaining a desired line width and residual film thickness can be realized.

  According to a preferred embodiment of the developer management apparatus of the present invention, the characteristic value of the developer having a correlation with the concentration of the dissolved photoresist of the developer and the characteristic of the developer having a correlation with the absorbed carbon dioxide concentration of the developer. And a plurality of measuring devices for measuring a plurality of characteristic values of the developer including the value, and the control means performs multivariate analysis from the plurality of characteristic values of the developer measured by the plurality of measuring devices. The method further includes a calculation unit that calculates the measured value of the dissolved photoresist concentration of the developer and the measured value of the absorbed carbon dioxide concentration using a method.

  According to a preferred embodiment of the developer management apparatus of the present invention, the characteristic value of the developer having a correlation with the concentration of the dissolved photoresist of the developer and the characteristic of the developer having a correlation with the absorbed carbon dioxide concentration of the developer. And a plurality of measurement devices for measuring a plurality of characteristic values of the developer including the values, and the plurality of characteristic values of the developer measured by the plurality of measurement devices using the multivariate analysis method, the development And calculating means for calculating a measured value of the dissolved photoresist concentration of the liquid and a measured value of the absorbed carbon dioxide concentration.

  According to a preferred aspect of the developer management device of the present invention, the developer management apparatus further comprises a densitometer, and the control means measures the density by the densitometer based on the correspondence between the absorbed carbon dioxide concentration and the density of the developer. The computer further comprises an operation unit that calculates the absorbed carbon dioxide concentration of the developer from the density of the developer.

According to a preferred embodiment of the developer management device of the present invention, the density of the developer measured by the densitometer based on the correspondence between the density meter and the absorbed carbon dioxide concentration and density of the developer. And calculating means for calculating the absorbed carbon dioxide concentration of the developer.
According to the method of managing a developer according to the present invention, the alkali concentration is measured based on the conductivity of the developer exhibiting alkalinity, which is repeatedly used, and the absorbance which is correlated with the concentration of the dissolved photoresist of the developer is measured. The concentration of absorbed carbon dioxide in the developer and the absorbance of the developer and the concentration of absorbed carbon dioxide in the developer are identified in advance as a predetermined development performance for each concentration range specified as an index Of the alkali concentration data having alkali concentration values, the alkali concentration value of the concentration range specified by the measured absorbance and the measured absorbed carbon dioxide concentration is set as the control target value of the alkali concentration of the developer, The replenisher is replenished with the replenisher so that the alkali concentration of the developer becomes the control target value.

  According to the developing solution management apparatus of the present invention, predetermined development is performed for each concentration range specified using the absorbance and the absorbed carbon dioxide concentration that are correlated with the dissolved photoresist concentration of the developing solution showing alkalinity repeatedly used. Data storage unit in which alkali concentration data having alkali concentration value of the developing solution previously confirmed to be a performance is stored, and a concentration region specified by measured values of absorbance and absorbed carbon dioxide concentration of the developing solution In the flow path for feeding the replenishing solution to be replenished to the developer so that the alkali concentration of the developer becomes the control target value, using the alkali concentration value stored in the data storage unit as the control target value And a control unit including a control unit that issues a control signal to a control valve provided.

  According to the present invention, no matter what dissolved photoresist concentration and absorbed carbon dioxide concentration are in the developing solution, the component having the activity for developing action in the developing solution is kept constant, so the desired developing performance can be obtained. It is possible to realize a development process that can be maintained and can maintain a desired line width and residual film thickness.

It is a schematic diagram of the image development process for demonstrating the developing solution management apparatus of 1st embodiment. It is a schematic diagram of the image development process for demonstrating the developing solution management apparatus of 2nd embodiment. It is a schematic diagram of the image development process for demonstrating the developing solution management apparatus of 3rd embodiment. It is a schematic diagram of the image development process for demonstrating the developing solution management apparatus of 4th embodiment. It is a graph which shows the relationship between the carbon dioxide concentration of a developing solution, and the density. It is a schematic diagram of the image development process for demonstrating the developing solution management apparatus of 5th 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 and the like of the devices etc. described in these embodiments are limited to those illustrated within the scope of the present invention unless otherwise specified. It is not limited. It is only schematically illustrated as an illustrative example.

  In the following description, a 2.38% tetramethyl ammonium hydroxide aqueous solution (hereinafter, tetramethyl ammonium hydroxide is referred to as TMAH) which is mainly used in the process of manufacturing a semiconductor or liquid crystal panel substrate as a specific example of a developer. Will be described using as appropriate. However, the developing solution to which the present invention is applied is not limited to this. Examples of other developing solutions to which the method and apparatus for managing developing solutions 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 trimethyl monoethanol ammonium hydroxide An aqueous solution of an organic compound such as (choline) can be mentioned.

  In the following description, component concentrations such as alkali component concentration, dissolved photoresist concentration, absorbed carbon dioxide concentration, and the like are concentrations by weight percentage concentration (wt%). “Dissolved photoresist concentration” refers to the concentration when dissolved photoresist is converted as the amount of photoresist, and “absorbed carbon dioxide concentration” refers to when absorbed carbon dioxide is converted as the amount of carbon dioxide The concentration of

  In the development processing process, development is performed by the developer dissolving unnecessary portions of the photoresist film after exposure processing. The photoresist dissolved in the developer produces a photoresist salt with the alkali component of the developer. For this reason, if the developing solution is not properly managed, as the developing process proceeds, the alkaline component having developing activity is consumed and the developing solution is deteriorated, and the developing performance is deteriorated. At the same time, the dissolved photoresist is accumulated in the developer as a photoresist salt with an alkali component.

  The photoresist dissolved in the developer exhibits surfactant action in the developer. For this reason, the photoresist dissolved in the developer improves the wettability of the photoresist film to be developed to the developer, and improves the compatibility between the developer and the photoresist film. Therefore, in the developing solution appropriately containing the photoresist, the developing solution can be well spread in the minute depressions of the photoresist film, and the development process of the photoresist film having the fine unevenness can be performed well.

  Further, in recent development processing, a large amount of developing solution has been repeatedly used with the increase in size of the substrate, and therefore, the opportunity for the developing solution to be exposed to air is increasing. However, alkaline developers absorb carbon dioxide in the air when exposed to air. The absorbed carbon dioxide forms a carbonate with the alkali component of the developer. For this reason, if the developer is not properly managed, the developer is consumed and reduced by carbon dioxide in which the alkali component having development activity is absorbed. At the same time, absorbed carbon dioxide is accumulated as a carbonate with the alkali component in the developer.

  However, carbonates in the developer have a developing action because they are alkaline in the developer.

  Thus, unlike the conventional recognition that the photoresist dissolved in the developer or the absorbed carbon dioxide deactivates the development activity of the development processing, it actually contributes to the development performance of the developer. There is. Therefore, instead of managing the developing solution so as to completely remove the dissolved photoresist and absorbed carbon dioxide, it is possible to dissolve these dissolved photoresist and absorbed carbon dioxide in the developing solution while optimizing these concentrations. It is necessary to manage the developer to maintain.

  In addition, a part of the photoresist salt and carbonate generated in the developing solution is dissociated to generate various free ions such as photoresist ion, carbonate ion and hydrogen carbonate ion. And these free ions affect the conductivity of the developer with various contributions.

  In these respects, the present inventors have intensively studied the developer management, and it is believed that carbonates and resist salts are also partially released in the developer to contribute to the developing action and to be inactivated. In addition, developing solution management taking into consideration the contribution of these components to the developing action can be realized by managing the conductivity value of the developing solution, and further, such managing value of conductivity is the concentration of absorbed carbon dioxide And, it was found that the concentration was different depending on the concentration of the dissolved photoresist.

  Therefore, assuming that the developer controls the aqueous solution of TMAH as the developer, the concentration of the dissolved photoresist and the concentration of absorbed carbon dioxide are variously changed to obtain the desired developing performance for the photoresist and the conductivity of the developer. I asked for the relationship with the value.

  The absorbed carbon dioxide concentration is changed between 0.0 and 1.3 (wt%), and the dissolved photoresist concentration is equivalent to 0.0 to 0.40 (wt%) (0.0 to 1.3 (abs) A sample of the developer of the aqueous TMAH solution, which was varied between) was prepared. The inventors measure the conductivity of the developer, the absorbed carbon dioxide concentration, and the dissolved photoresist concentration for these samples, and the development performance, the conductivity, the absorbed carbon dioxide concentration, and the dissolved photoresist concentration component are measured. An experiment was conducted to confirm the correlation. Absorbed carbon dioxide concentration was arranged in one item, vertically or horizontally, and dissolved photoresist concentration was set in another item, to form a matrix (combination table) arranged horizontally or vertically. For each combination of absorbed carbon dioxide concentration and dissolved photoresist concentration, the conductivity of the developing solution satisfying the desired developing performance for the photoresist was determined, and the columns were completed to complete the matrix.

  Here, the predetermined development performance means the development performance of the developer when the line width and residual film thickness to be realized in the development step are realized.

  The measurement results of absorbed carbon dioxide concentration, dissolved photoresist concentration, and 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 a predetermined development performance is 54 In the case of .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%) (equivalent to 0.0 (abs)) and the absorbed carbon dioxide concentration is 0.6 (wt%), the conductivity of the developer is 54.60. When it is (mS / cm) and the absorbed carbon dioxide concentration is 1.3 (wt%), the conductivity of the developer is 54.75 (mS / cm).

  In addition, when the absorbed carbon dioxide concentration is 0.6 (wt%) and the dissolved photoresist concentration is 0.22 (wt%) (equivalent to 0.7 abs), the conductivity of the developer is 54.60 (mS / m). The conductivity of the developer was 54.58 (mS / cm) when the concentration of the dissolved photoresist was 0.40 (wt%) (equivalent to 1.3 abs).

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

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

  In the above-mentioned experiment, the conductivity of the developer of each sample used the value measured by the conductivity meter. The absorbed carbon dioxide concentration used the value measured by titration analysis. The dissolved photoresist concentration used the weight adjustment 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., Ltd. was used.

  The conductivity, absorbed carbon dioxide concentration, and dissolved photoresist concentration described above are to find the relationship between the conductivity, absorbed carbon dioxide concentration, and dissolved photoresist concentration and development performance, and are not limited to the respective values. .

  As described above, it can be understood that the conductivity capable of exhibiting the developing performance varies depending on the absorbed carbon dioxide concentration and the dissolved photoresist concentration. Thus, in the management of the developer, in the developer containing absorbed carbon dioxide and the dissolved photoresist, the conductivity is taken as the control value, and the absorbed carbon dioxide concentration and the dissolved photoresist concentration are measured, and By varying the control value of conductivity based on the predetermined development performance can be exhibited.

  That is, the conductivity data having the conductivity value of the developer which is previously confirmed to be a predetermined development performance for each concentration region specified 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 developing solution which can exhibit predetermined development performance.

  In addition, when the inventor diligently studied the developer control, it is considered that carbonates and resist salts are also partially released in the developer to contribute to the developing action, and these components are considered to be inactivated. Management of the developing solution in consideration of the contribution to the developing action from the above can be realized by managing the alkali concentration value of the developing solution, and further, such a management value of the alkali concentration is the absorbed carbon dioxide concentration and the dissolved photoresist It was found that the absorbance was different depending on the concentration and was different.

  Therefore, assuming that the developer manages a TMAH aqueous solution as a developer, the inventor has a correlation between the alkali concentration measured based on the conductivity of the developer exhibiting alkalinity and the dissolved photoresist concentration of the developer. The absorbance and the absorbed carbon dioxide concentration of the developer were variously changed to determine the relationship between the desired developing performance for the photoresist and the alkali concentration of the developer.

  TMAH where the absorbed carbon dioxide concentration was varied between 0.0 and 1.3 (wt%) and the absorbance correlated with the dissolved photoresist concentration was varied between 0.0 and 1.3 (abs) A sample of the aqueous solution developer was prepared. The inventor measured the alkali concentration, absorbed carbon dioxide concentration, and absorbance of the developer for these samples, and conducted an experiment to confirm the correlation between the development performance, the alkali concentration, the absorbed carbon dioxide concentration, and the absorbance. . Absorbed carbon dioxide concentration was made into one item and arranged vertically or horizontally, absorbance was made another item, and the matrix (combination table) arranged horizontally or vertically was created. For each combination of absorbed carbon dioxide concentration and absorbance, the alkali concentration of the developing solution satisfying the desired development performance for the photoresist was determined, and each column was filled in to complete the matrix.

  Here, the predetermined development performance means the development performance of the developer when the line width and residual film thickness to be realized in the development step are realized.

  The measurement results of absorbed carbon dioxide concentration, absorbance, and alkali 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 solution), the alkali concentration of the developer capable of exhibiting a predetermined development performance is 2.380 wt% )Met.

  When the absorbed carbon dioxide concentration is 0.0 (wt%) and the absorbance is 0.8 abs, the alkali concentration of the developer capable of exhibiting a predetermined development performance is 2.479 (wt%), and the absorbance is 1. In the case of 3 abs, the alkali concentration of the developer was 2.378 (wt%).

  When the absorbance is 0.0 (abs) and the absorbed carbon dioxide concentration is 0.6 (wt%), the alkali concentration of the developer is 2.381 (wt%), and the absorbed carbon dioxide concentration is 1 In the case of .3 (wt%), the alkali 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 alkali concentration of the developer is 2.381 (wt%) and the absorbance is 1.3 abs, The alkali concentration of the developer was 2.380 (wt%).

  When the absorbed carbon dioxide concentration is 1.3 (wt%) and the absorbance is 0.7 abs, the alkali concentration of the developer is 2.388 wt% and the absorbance is 1.3 abs, The alkali concentration of the developer was 2.388 (wt%).

  In the above experiment, when the absorbed carbon dioxide concentration increases in a certain concentration range, the control value of the alkali concentration tends to increase, and when the absorbance increases, the control value of the alkali concentration tends to decrease. The

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

  The absorbed carbon dioxide concentration used the value measured by titration analysis. 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., Ltd. was used. An absorptiometer was used to measure the absorbance.

  The above-mentioned alkali concentration, absorbed carbon dioxide concentration, and absorbance are to find the relationship between the alkali concentration, absorbed carbon dioxide concentration, and absorbance, and development performance, and are not limited to the respective values.

  As described above, it can be understood that the alkali concentration capable of exhibiting the development performance is variously different depending on the absorbed carbon dioxide concentration and the absorbance. Thus, in the management of the developing solution, in the developing solution containing absorbed carbon dioxide and the dissolved photoresist, the alkali concentration is taken as the control value of the developing solution, and the absorbed carbon dioxide concentration and absorbance are measured. By making the management value of the alkali concentration different based on the predetermined development performance can be exhibited.

  That is, the alkali concentration data (matrix) having the alkali concentration value of the developer which has been previously confirmed to be a predetermined development performance for each concentration range specified using the absorbance of the developer and the absorbed carbon dioxide concentration as an index By storing and using alkali concentration data (matrix), predetermined development performance can be exhibited.

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

First Embodiment
FIG. 1 is a schematic view of a developing process for describing the developing solution management device D of the present embodiment. The developing solution management apparatus D of the present invention is illustrated together with the developing process equipment A, the replenishing solution storage unit B, the circulating stirring mechanism C, and the like.

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

  The development process equipment A mainly includes a developer storage tank 61, an overflow tank 62, a development chamber hood 64, a roller conveyor 65, a developer shower nozzle 67, and the like. A developer is stored in the developer storage tank 61. The developer is replenished with a replenisher to control its composition. The developer storage tank 61 includes a liquid level meter 63 and an overflow tank 62, and manages an increase in the amount of liquid by replenishing the replenishment liquid. The developer storage tank 61 and the developer shower nozzle 67 are connected by a developer channel 80. The developer stored in the developer storage tank 61 is fed to the developer shower nozzle 67 through the filter 73 by the circulation pump 72 provided in the developer channel 80. The roller conveyor 65 is provided above the developing solution storage tank 61, and conveys the substrate 66 on which the photoresist film is formed. The developer is dropped from a developer shower nozzle 67. The substrate 66 transported by the roller conveyor 65 is immersed in the developer by passing through the developer to be dropped. Thereafter, the developer is collected in the developer storage tank 61 and stored again. Thus, the developer is repeatedly used repeatedly in the development step. In the developing chamber of a small glass substrate, processing may be performed such that carbon dioxide in the air is not absorbed by filling nitrogen gas or the like. The deteriorated developer is drained (drained) by operating the drain pump 71.

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

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

  In addition, when the replenishing solution flows into the circulation pipeline 85 via the merging pipeline 84, the replenishing solution that has flowed in is mixed with the developing solution circulating in the circulation pipeline 85 and is then introduced into the developing solution storage tank 61. Supplied.

  Next, the developer management apparatus D of the present embodiment will be described. The developing solution management apparatus D of the present embodiment is a developing solution in which it is confirmed in advance that predetermined developing performance is obtained for each concentration region specified using the dissolved photoresist concentration of the developing solution exhibiting alkalinity and the absorbed carbon dioxide concentration as an index. The conductivity data of the developer is used as the control target value for the conductivity of the concentration region specified by the measured value of the dissolved photoresist concentration and the measured value of the absorbed carbon dioxide concentration using the conductivity data having the conductivity value of This developer management apparatus is a system in which the developer is replenished with a replenisher so that the conductivity becomes a control target value.

  The developer management device D includes a measurement unit 1 and a control unit 21. The developer management device D is connected to the developer storage tank 61 by the sampling pipe 15 and the outlet pipe 16.

  The measurement unit 1 includes a sampling pump 14, a conductivity meter 11, a first concentration measurement means 12 for measuring a dissolved photoresist concentration, and a second concentration measurement means 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 in the rear stage of the sampling pump 14. It is desirable that the measuring unit 1 further includes a temperature control unit (not shown) for stabilizing the sampled developer at a predetermined temperature in order to enhance the measurement accuracy. At this time, it is preferable that the temperature control means be provided immediately before the measurement means. The sampling pipe 15 is connected to the sampling pump 14 of the measuring unit 1 of the developer management device D, and the outlet pipe 16 is connected to the pipe at the end of the measuring means.

  In FIG. 1, the conductivity meter 11, the first concentration measuring unit 12, and the second concentration measuring unit 13 are connected in series, but the conductivity meter 11, the first concentration measuring unit 12, The connection of the second concentration measuring means 13 is not limited to this. It may be connected in parallel, or each may be independently provided with a liquid flow path and measured. The order of the conductivity meter 11, the first concentration measuring means 12, and the second concentration measuring means 13 does not matter in particular. The measurement may be performed in an optimal order according to the characteristics of each measurement means.

  The control unit 21 includes a data storage unit 23 and a control unit 31. The data storage unit 23 is a developer used that has been previously confirmed to have a predetermined development performance for each concentration range specified using the dissolved photoresist concentration of the developer exhibiting alkalinity and the absorbed carbon dioxide concentration as an index. Conductivity data having a conductivity value is stored.

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

  The control unit 31 of the control means 21 is connected by signal lines to control valves 41 to 43 provided in the flow path for feeding the replenisher to the developer. In FIG. 1, the control valves 41 to 43 are illustrated as internal parts of the developer management device D, but the control valves 41 to 43 are not necessarily essential as components of the developer management device D of this embodiment. . The control unit 31 may be in communication with the control valves 41 to 43 so as to control the operation of the control valves 41 to 43 so that the developer can be replenished with the replenishment liquid. The control valves 41 to 43 may be present outside the developing solution management device D.

  Subsequently, the operation of the developing solution management device D of the present embodiment will be described.

  The developer sampled from the developer reservoir 61 is fed into the measuring unit 1 and temperature-controlled. Thereafter, the developer is sent to the conductivity meter 11, the first concentration measuring means 12, and the second concentration measuring means 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 is a conductivity having a conductivity value of the developer which is previously confirmed to be a predetermined development performance for each concentration region specified using the dissolved photoresist concentration of the developer and the absorbed carbon dioxide concentration as an index. A control value of conductivity corresponding to the conductivity value of data is set. The control unit 31 performs control as follows according to the measurement data received from the measurement unit 1.

  Control unit 31 measures the concentration of the dissolved photoresist measured in the conductivity data stored in data storage unit 23 based on the concentration of the dissolved photoresist and the concentration of absorbed carbon dioxide received from measurement unit 1. The conductivity value of the concentration range specified by the absorbed carbon dioxide concentration is determined. The determined conductivity value is set as a control target value of the developer conductivity.

  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, when the conductivity set as the control target value is the same as the measured conductivity, basically the replenisher is not added to the developer. In addition, when the conductivity set as the control target value is larger than the measured conductivity, the developer may be replenished with a replenishing solution which acts to increase the conductivity. In addition, 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 lower the conductivity.

  Here, as a replenishing solution to be replenished to the developing solution, there are, for example, an undiluted solution, a new solution, pure water and the like of the developing solution.

  The replenishing solution is stored in the replenishing solution reservoirs 91 and 92 of the replenishing solution reservoir C. A nitrogen gas pipe 86 provided with valves 46 and 47 is connected to the replenisher storage reservoirs 91 and 92, and is pressurized by nitrogen gas supplied via the pipe. Further, replenishing solution pipes 81 and 82 are connected to the replenishing solution storage tanks 91 and 92, respectively, and the replenishing solution is fed via the valves 44 and 45 which are normally open. Control valves 41 to 43 are provided in the replenishment solution pipelines 81 and 82 and the pure water pipeline 83, and the control valves 41 to 43 are controlled to open and close by the control unit 3. By operating the control valve, the replenishment liquid stored in the replenishment liquid storage tanks 91 and 92 is pressure-fed, and pure water is transported. Thereafter, the replenishing solution passes through the joining pipeline 84, joins with the circulating stirring mechanism D, is replenished to the developing solution storage tank 61, and is stirred.

  If the amount of replenished solution stored in the replenished solution storage tank 91, 92 decreases due to replenishment, the internal pressure drops and the supply amount becomes unstable. Therefore, according to the decreased amount of replenished solution, the valves 46, 47 are opened appropriately Gas is supplied and maintained so as to maintain the internal pressure of the replenisher reservoirs 91 and 92. When the replenisher reservoirs 91 and 92 became empty, the valves 44 and 45 were closed and replaced with a new replenisher reservoir filled with replenisher, or the separately supplied replenisher was exhausted. Refill the refill reservoir.

  Control of the control valves 41 to 43 is performed, for example, as follows. If the flow rate at the time of opening the control valve is adjusted, the replenishment liquid of the liquid amount to be replenished can be replenished by managing the time during which the control valve is open. The control unit 31 opens the control valve for a predetermined time so that the replenishment liquid of the liquid 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. And issue a control signal to the control valve.

  The control method may employ various control methods used to control the control amount to the target value. 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, the developer management apparatus D according to the present embodiment manages the developer by the conductivity in the developer regardless of the dissolved photoresist concentration and the absorbed carbon dioxide concentration regardless of the developer concentration. As a result, since the component having the activity of developing is maintained, desired development performance can be maintained, and development processing capable of maintaining desired line width and residual film thickness can be realized.

  Further, according to the developer management device D according to the present embodiment, the developer data is dissolved by using the conductivity data of the conductivity value of the developer whose development performance has been 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 desired development activity. That is, according to the developing solution management apparatus D according to this embodiment, the dissolved photoresist concentration of the developing solution is 0.25 (wt%) or more (equivalent 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 draining it, and the amount of developer drained can be reduced.

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

Second Embodiment
FIG. 2 is a schematic view of a developing process for describing the developing solution management device D of the present embodiment. The developing solution management apparatus D of the present invention is illustrated together with the developing process equipment A, the replenishing solution storage unit B, the circulating stirring mechanism C, and the like. In addition, the same code | symbol may be attached | subjected to the structure similar to the structure of 1st embodiment, and description may be abbreviate | omitted.

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

  Here, the characteristic value of the “correlated” developer means that the characteristic value is related to the concentration of the component, and the characteristic value changes in accordance with the change in the concentration of the component. For example, the characteristic value a of the developing solution having a correlation with at least the component concentration A of the component concentrations of the developing solution is at least one of the components when the characteristic value a is determined by a function using the component concentration as a variable. It means containing concentration A. The characteristic value a may be a function of only the component concentration A, but usually, when the multivariate function has component concentration B or C as a variable in addition to component concentration A, multivariate analysis The significance of using a method (eg, multiple regression analysis) is significant.

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

  In the present embodiment, the developer sampled from the developer reservoir 61 is fed into the measuring unit 1 and temperature-controlled. 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, absorbance, and density are measured. Each measurement data is sent to the control means 21.

  The calculating unit 32 calculates the measured value of the dissolved photoresist concentration of the developer and the measured value of the absorbed carbon dioxide concentration from the absorbance and the density measured by the measuring unit 1 by multivariate analysis. At this time, it is also possible to calculate the measurement value of the dissolved photoresist concentration and the measurement value of the absorbed carbon dioxide concentration by multivariate analysis from the conductivity, the absorbance, and the density.

  The control unit 31 measures the concentration of the dissolved photoresist measured in the conductivity data stored in the data storage unit 23 based on the dissolved photoresist concentration and the absorbed carbon dioxide concentration calculated by the computing unit 32. The conductivity value of the concentration range specified by the absorbed carbon dioxide concentration is determined. The determined conductivity value is set as a control target value of the developer conductivity.

  The other configurations, operations, and the like are the same as those of the first embodiment, and thus will not be described.

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

  If the inventor uses multivariate analysis (for example, multiple regression analysis) as the calculation method, the concentration of each component of the developer can be calculated more accurately than when the conventional method is used, and it is difficult. It has been found that the absorbed carbon dioxide concentration can be measured. Using the component concentration (dissolved photoresist and concentration absorbed carbon dioxide concentration) of the developer calculated by multivariate analysis (for example, multiple regression analysis), dissolved photoresist concentration and absorption in which developability was 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 that the 2.38% aqueous solution of TMAH is managed, an aqueous solution of TMAH in which the concentration of the alkaline component, the concentration of the dissolved photoresist, and the concentration of absorbed carbon dioxide were variously changed was prepared as a sample of the simulated developer. The inventor conducted an experiment to obtain the concentration of the component by multiple regression analysis from various characteristic values measured for these simulated developer solutions. Hereinafter, a general calculation method by the multiple regression analysis method will be described, and thereafter, a calculation method of the component concentration of the developer using the multiple regression analysis method will be described based on the experiments performed by the inventor.

  Multiple regression analysis consists of two steps: calibration and prediction. In the n-component multiple regression analysis method, it is assumed that m calibration standard solutions are prepared. The concentration of the j-th component present in the i-th solution is denoted as Cij. 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 or conductivity at a certain wavelength) Aik (k = 1 to p) are measured. The concentration data and the characteristic data can be collectively represented in the form of a matrix (C, A).

  A matrix relating these matrices is called a calibration matrix, and is represented by symbols S (Sk j; k = 1 to p, j = 1 to n) here.

  It is possible to calculate S by matrix operation from known C and A (the content of A may be not only homogeneous measurement values but also heterogeneous measurement values. For example, conductivity and absorbance and density). It is a calibration stage. At this time, p> = n and m> = np. Since all elements of S are unknowns, it is desirable that m> np, in which case the least squares operation is performed as follows.

  Here, superscript T means transposed matrix, superscript -1 means inverse matrix.

  If p characteristic values are measured for sample solutions of unknown concentrations and these are Au (Auk; k = 1 to p), then the concentration Cu (Cuj; j = 1 to n) to be determined by multiplying it by S You can get it.

  This is the prediction stage.

  The inventor regards the used alkaline developing solution (2.38% aqueous solution of TMAH) as a multicomponent system (n = 3) consisting of three components of an alkaline component, a dissolved photoresist, and absorbed carbon dioxide, and the developing solution Experiment to calculate each component concentration by the above-mentioned multiple regression analysis method from three characteristic values (p = 3), that is, conductivity value of developer, absorbance value at specific wavelength, and density value as characteristic values of The The inventor prepared 11 calibration standard solutions in which the alkaline component concentration (TMAH concentration), the dissolved photoresist concentration, and the absorbed carbon dioxide concentration were variously changed using the 2.38% aqueous solution of TMAH as the basic composition of the developer. (When m = 11, p> = n and m> np are satisfied).

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

The measurement was performed by adjusting the temperature of the calibration standard solution to 25.0 ° C. For temperature adjustment, keep the bottle containing the calibration standard solution for a long time in a thermostatic water bath whose temperature is controlled around 25 ° C, sample it from here, and make it 25.0 ° C again with the temperature controller just before measurement. It is a method called ,. The conductivity meter adopted its own conductivity meter. It measured using the conductivity flow cell made in-house which gave the platinum black processing. In the conductivity meter, the cell constant of the conductivity flow cell confirmed by the calibration operation separately is input. The absorptiometer also adopted one made in-house. It is an absorptiometer provided with the light source part of wavelength (lambda) = 560 nm, a photometry part, and a glass flow cell. For density measurement, a densitometer employing a natural vibration method to obtain a density from natural frequencies measured by exciting a U-shaped tube flow cell was used. The units of the measured conductivity value, absorbance value and density value are mS / cm and Abs. (Absorbance), g / cm ³ .

  The calculation is performed by assuming one of 11 calibration standard solutions as an unknown sample, determining the calibration matrix with the remaining 10 standards, calculating the concentration of the assumed unknown sample, and determining the known value (other accurate analysis methods It is based on the method (one piece omission cross confirmation method; Leave-One-Out method) and the density | concentration value and weight preparation value which were measured.

  Table 1 shows the results of the MLR-ILS calculation.

  In the calculation of MLR-ILS, in view of the fact that the aqueous solution of TMAH is strongly alkaline and absorbs carbon dioxide and is easily degraded, the concentration matrix used for the calculation can be accurately analyzed by the concentration of the alkaline component and the concentration of absorbed carbon dioxide. The value which measured separately the calibration standard solution by was used. However, for the dissolved photoresist concentration, the weight adjustment 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., Ltd. was used.

  Table 2 below shows the concentration matrix.

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

  The calibration matrix is shown in Table 4.

  Table 5 shows a comparison of the measured concentration values of Table 2 with the calculated MLR-ILS values of Table 1.

  As shown in Table 5, the concentration of TMAH, the concentration of dissolved photoresist, and the concentration of absorbed carbon dioxide determined by multiple regression analysis are all determined from the concentration of TMAH or absorbed carbon dioxide determined by titration analysis, and the adjusted weight. Both the photoresist concentration and the value are fairly similar.

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

  Multivariate analysis (for example, multiple regression analysis) is effective for calculating and determining the concentrations of a plurality of components. Measuring a plurality of characteristic values a, b, c, ... of the developer and determining component concentrations A, B, C, ... from the measured values by multivariate analysis (for example, multiple regression analysis) it can. At this time, it is necessary that at least one characteristic value correlated with at least one component concentration to be determined is measured and used for calculation.

  Component concentration is also a measure of the relative amount of that component relative to the whole. The component concentration of a mixed solution in which the component increases and decreases with time, such as a developer to be used repeatedly, is not determined by the component alone, and usually becomes a function of the concentration of other components. Therefore, it is often difficult to display the relationship between the characteristic value of the developer and the component concentration in a planar graph. In such a case, the component concentration can not be calculated from the characteristic value of the developer by an arithmetic method using a calibration curve or the like.

  However, according to multivariate analysis (for example, multiple regression analysis), if one set of measurement values of a plurality of characteristic values correlated with the component concentration to be calculated is used, this is used for the calculation, Is calculated. The remarkable effect of measuring component concentrations by measuring characteristic values even with component concentrations that are seemingly difficult to measure by conventional findings is that component concentrations by multivariate analysis (for example, multiple regression analysis) It can be obtained by measurement.

  As described above, according to the calculation method of the present invention, the alkali component concentration of the developer, the concentration of the dissolved photoresist, and the absorbed carbon dioxide concentration are determined as the characteristic values of the developer (for example, conductivity, absorbance at a specific wavelength, and , Density) can be calculated. According to the calculation method of the present invention, the concentration of each component can be calculated with high accuracy as compared with the conventional method.

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

Also, according to the present invention, the preparation and preliminary measurement of a very large number of samples to enable high-precision measurement, which is required in the invention of Patent Document 2, is not necessary. (As in the above-mentioned experimental example, in the case of a developer having the number of components n = 3, the number p of samples satisfying m> = np (for example, p = 11 samples) is set as the number p = 3 of characteristic values to be measured Preparation and measurement is sufficient, if the number of components n = 2, the number of samples may be smaller.)
Furthermore, since the present invention uses multivariate analysis (for example, multiple regression analysis), it is possible to accurately calculate the absorbed carbon dioxide concentration of the developer which has been difficult to measure conventionally.

  In the present embodiment, the absorbance at λ = 560 nm is exemplified as a characteristic value of the developer having a correlation with the concentration of the dissolved photoresist in the developer, but the characteristic value is not limited to this. The absorbance at another specific wavelength, that is, the absorbance at a specific wavelength in the visible region, more preferably in the wavelength range of 360 to 600 nm, more preferably in the wavelength λ = 480 nm, can also be used as the characteristic value. It is because the absorbance at specific wavelengths included in these wavelength ranges has a relatively good correspondence with the dissolved resist concentration.

  Moreover, although the density was illustrated as a characteristic value of the developing solution which has a correlation with the absorbed carbon dioxide concentration of a developing solution, it is not limited to this. The characteristic value that can be adopted as the characteristic value to be measured in combination with the conductivity of the developing solution as the characteristic value of the developing solution having a correlation with the dissolved photoresist concentration of the developing solution or the absorbed carbon dioxide concentration is, for example, Besides the 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 view of a developing process for describing the developing solution management device D of the present embodiment. The developing solution management apparatus D of the present invention is illustrated together with the developing process equipment A, the replenishing solution storage unit B, the circulating stirring mechanism C, and the like. In addition, the same code | symbol may be attached | subjected to the structure similar to the structure of 1st embodiment and 2nd embodiment, and description may be abbreviate | omitted.

  The developing solution management device D of the present embodiment includes the measuring unit 1, the control unit 21, and the calculating unit 36. In the present embodiment, unlike the second embodiment, the control means 21 and the arithmetic means 36 for performing calculations are configured as separate devices.

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

  The control unit 31 measures the dissolved photoresist concentration and the measured concentration among the conductivity data stored in the data storage unit 23 based on the dissolved photoresist concentration and the absorbed carbon dioxide concentration calculated by the computing means. The conductivity value of the concentration range specified by the absorbed carbon dioxide concentration is determined. The determined conductivity value is set as a control target value of the developer conductivity.

  The other configurations, operations, and the like are the same as those in the second embodiment, and thus will not be described.

Fourth Embodiment
FIG. 4 is a schematic view of a developing process for describing the developing solution management device D of the present embodiment. The developing solution management apparatus D of the present invention is illustrated together with the developing process equipment A, the replenishing solution storage unit B, the circulating stirring mechanism C, and the like. In addition, the same code | symbol may be attached | subjected to the structure similar to the structure of 1st embodiment, 2nd embodiment, and 3rd embodiment, and description may be abbreviate | 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 an operation unit 33. The calculation unit 33 calculates the absorbed carbon dioxide concentration of the developer from the density of the developer measured by the density meter 13B based on the correspondence between the absorbed carbon dioxide concentration and the density of the developer.

  Control unit 31 measures the conductivity data stored in data storage unit 23 based on the dissolved photoresist concentration measured in measurement unit 1 and the absorbed carbon dioxide concentration calculated in operation unit 33. The conductivity value of the concentration region specified by the dissolved photoresist concentration and the measured absorbed carbon dioxide concentration is determined. The determined conductivity value is set as a control target value of the developer conductivity.

  The other configurations, operations, and the like are the same as those of the first embodiment, and thus will not be described.

  The relationship between the density value of the developer and the absorbed carbon dioxide concentration value will be described. The inventor obtained the following knowledge as a result of continuing earnest research. That is, a relatively good correspondence relationship (linear relationship) can be obtained between the density value of the developer and the absorbed carbon dioxide concentration value regardless of the concentration of the alkaline component and the concentration of the dissolved photoresist in the developer. . In addition, it is possible to measure the concentration of absorbed carbon dioxide which was conventionally difficult by measuring the density of the developer with a densitometer by using this correspondence relationship (linear relationship).

  The inventor uses the 11 calibration standard solutions used for calculating the component concentration of the developer using multivariate analysis as the simulated developer samples, and the alkali component concentration (TMAH concentration), the dissolved photoresist concentration, and the absorption for these are used as the simulated developer solutions. An experiment was conducted to measure the carbon dioxide concentration and the density, and to confirm the correlation between the component concentration and the density.

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

FIG. 5 shows a graph of absorbed carbon dioxide concentration and density of each sample shown in Table 6. This graph is a graph in which the carbon dioxide concentration (wt%) is taken on the horizontal axis and the density (g / cm ³ ) is taken on the vertical axis, and the values of each sample are plotted. From each plotted point, a regression line was determined by the least squares method.

  It can be understood from FIG. 5 that the absorbed carbon dioxide concentration of the developer has a good linear relationship with the density of the developer even though the concentration of the alkali component and the concentration of the dissolved photoresist are various. According to this experimental result, it is possible to calculate the absorbed carbon dioxide concentration of the developer by measuring the density of the developer if the correspondence relationship (linear relationship) between the carbon dioxide concentration and the density of the developer is used. The inventor has found that.

  Therefore, regardless of the alkali component concentration (TMAH concentration) and the dissolved resist concentration, it is possible to measure the absorbed carbon dioxide concentration of the developer by using the densitometer based on this correspondence relationship (linear relationship).

  By using the relationship between the density of the developer and the absorbed carbon dioxide concentration in the calculation unit 33, the absorbed carbon dioxide concentration of the developer can be easily measured.

Fifth Embodiment
FIG. 6 is a schematic view of a developing process for describing the developing solution management device D of the present embodiment. The developing solution management apparatus D of the present invention is illustrated together with the developing process equipment A, the replenishing solution storage unit B, the circulating stirring mechanism C, and the like. In addition, the same code | symbol may be attached | subjected to the structure similar to the structure of 1st embodiment and 2nd embodiment, and description may be abbreviate | omitted.

  The developing solution management apparatus D of the present embodiment includes the measuring unit 1, the control unit 21, and the calculating unit 37. In the present embodiment, unlike the fourth embodiment, the control means 21 and the arithmetic means 37 for performing calculations 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 developing solution from the density of the developing solution measured by the density meter 13B based on the correspondence between the absorbed carbon dioxide concentration and the density of the developing solution.

  The control unit 31 measures the conductivity data stored in the data storage unit 23 based on the dissolved photoresist concentration measured by the measurement unit 1 and the absorbed carbon dioxide concentration calculated by the calculation means 37. The conductivity value of the concentration region specified by the dissolved photoresist concentration and the measured absorbed carbon dioxide concentration is determined. The determined conductivity value is set as a control target value of the developer conductivity.

  Other configurations, operations, and the like are the same as those of the fourth embodiment, and thus the description thereof is omitted.

  As described above, according to the developing solution management apparatus D of this embodiment, the component having an activity for developing action in the developing solution is constant regardless of what dissolved photoresist concentration and carbon dioxide concentration the developing solution becomes. Since it is maintained, desired development performance can be maintained, and development processing which can maintain desired line width and residual film thickness can be realized.

  Next, a modification of the developing solution management device D of the present embodiment will be described.

  In FIGS. 1 to 4 and 6, the measurement unit 1 of the developer management device D depicts the developer management device D configured integrally with the control unit 21 and the arithmetic units 36 and 37, but the developer according to the present embodiment 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 optimum installation method according to the measurement principle adopted, so for example, the measurement unit 1 is connected inline to the developer channel 80 or the measurement probe is immersed in the developer storage tank 61. It may be installed as well. The measuring means of conductivity meter 11, first concentration measuring means 12, first characteristic value measuring means 12A, second concentration measuring means 13, second characteristic value measuring means 13A, and density meter 13B are separately installed. It may be The developing solution management device D of this embodiment can be realized as long as each measuring means communicates with each other so that measurement data can be exchanged with the control means 21 and the arithmetic means 36, 37.

  Depending on the measurement principle adopted by each measuring means, each reagent may be provided with a pipe if it is necessary to add a reagent, and if any waste liquid is required, each pipe may be a pipeline May be provided. The developer management apparatus D of the present embodiment can be realized even if the measurement units are not connected in series.

  In FIGS. 1 to 4 and 6, the developer management device D is provided so that the control valves 41 to 43 provided in the flow path for feeding the replenishment liquid to be replenished to the developer become internal components of the developer management device D. Although the aspect drawn in connection with the replenishment solution pipelines 81 and 82 and the pure water pipeline 83 was drawn, the developing solution management apparatus D of the present embodiment is not limited to this. The developer management apparatus may not have the control valves 41 to 43 as internal components, and may not be connected to the pipelines 81 to 83 for replenishing the developer with the replenishment liquid.

  The control means 21 in the developing solution management apparatus D of this embodiment and the control valves 41 to 43 provided in the pipeline for replenishing the replenishing solution have the control valves 41 to 43 as control means of the developing solution management apparatus D. It may be in the form of mutual communication so as to be received and controlled by the control signal emitted by 21. Even if the control valve is not an internal part of the developer management device D, the developer management device D of the present embodiment can be realized.

  Although the developing solution management apparatus of the present invention allows various modifications as described above, predetermined development is performed for each concentration region specified using the dissolved photoresist concentration and the carbon dioxide concentration as the indicators. Conductivity in 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, provided with the conductivity data having the conductivity value of the developer previously confirmed to be the performance With the conductivity value of the rate data as the control target value, the replenishing 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 method of managing a developer and the developer management device of the present invention, regardless of what dissolved photoresist concentration and carbon dioxide concentration the developer has, it is active in the developing action in the developer. Since the components possessed are maintained constant, desired development performance can be maintained, and development processing capable of maintaining desired line width and residual film thickness can be realized.

  In a preferred embodiment of the developer management apparatus, the dissolved photoresist concentration and the absorbed carbon dioxide concentration are calculated by multivariate analysis, so that the dissolved photoresist concentration and the absorbed carbon dioxide concentration can be determined with high accuracy. The target conductivity value can be determined from the conductivity data based on the dissolved photoresist concentration and the absorbed carbon dioxide concentration.

  Furthermore, as a preferred embodiment of the developer management apparatus, the absorbed carbon dioxide concentration of the developer is calculated from the density of the developer measured by the density meter based on the correspondence between the absorbed carbon dioxide concentration and the density of the developer. . Thus, the absorbed carbon dioxide concentration of the developer can be determined more simply. Based on the absorbed carbon dioxide concentration and the separately determined dissolved photoresist concentration, the target conductivity value can be determined from the conductivity data.

A: Development process equipment, B: Replenisher storage part, C: Circulating stirring mechanism, D: Developer control device 1: Measurement 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 piping, 16: outlet side piping 21: control means (for example, computer)
23: Data storage unit,
Reference Signs List 31 control unit 32, 33 calculation unit 36, 37 calculation unit 41 to 43 control valve 44 45 46 47 47 valve 61 developing solution storage tank 62 overflow tank 63 liquid surface Total, 64: development chamber hood, 65: roller conveyor, 66: substrate, 67: developer shower nozzle 71: waste liquid pump, 72, 74: circulation pump, 73, 75: filter 80: developer channel, 81, 82 ... pipeline for replenisher (developing solution and / or new solution), 83 ... pipeline for pure water, 84 ... merging pipeline, 85 ... circulation pipeline, 86 ... nitrogen gas pipeline 91, 92 ... replenishment fluid ( Developer stock solution and / or new solution) storage tank

Claims (2)

The alkali concentration is measured based on the conductivity of the developer exhibiting alkalinity, which is repeatedly used, and the absorbance which is correlated with the concentration of the dissolved photoresist of the developer is measured, and the absorbed carbon dioxide concentration of the developer is measured. And
Of the alkali concentration data having the alkali concentration value of the developer which has been previously confirmed to be a predetermined development performance for each concentration range specified using the absorbance of the developer and the absorbed carbon dioxide concentration as an index The alkali concentration value of the concentration range specified by the absorbance and the measured absorbed carbon dioxide concentration is set as a control target value of the alkali concentration of the developer,
A management method of a developer, wherein the developer is replenished with a replenishment liquid so that the alkali concentration of the developer becomes the control target value. The above-mentioned development in which it is confirmed in advance that predetermined development performance is obtained for each concentration range specified using the absorbance and the absorbed carbon dioxide concentration that are correlated with the dissolved photoresist concentration of the developer exhibiting alkalinity, which is repeatedly used. A data storage unit in which alkali concentration data having a solution alkali concentration value is stored;
With the alkali concentration value stored in the data storage unit of the concentration range specified by the measured value of the absorbance of the developer and the absorbed carbon dioxide concentration as a control target value, the alkali concentration of the developer is the control target value And a control unit which issues a control signal to a control valve provided in a flow path for feeding the replenishing solution to be replenished to the developing solution.
Control means comprising
Developer management apparatus comprising:

Images