JP3751435B2 - Resist regeneration system and resist regeneration method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resist regeneration system and a regeneration method, and more particularly to a resist regeneration system and a regeneration method used in lithography or the like used for semiconductor manufacturing.
[0002]
[Prior art]
In lithography and the like used for semiconductor manufacturing, a coating operation for applying a resist to a base surface is performed. This coating operation is generally performed using a spin coat type resist coating apparatus. In a spin coat type resist coating apparatus, a substrate having a base surface is spin chucked, and then several cc of resist is dropped onto the center of the base surface. Furthermore, the substrate is rotated, and the resist dropped onto the center of the base surface is spread over the entire base surface by centrifugal force to form a resist film on the base surface.
[0003]
[Problems to be solved by the invention]
At this time, the resist remaining as a film on the base surface is a few percent of the dropped resist, and most of the resist jumps out of the substrate by centrifugal force. This jumped out (spun out) resist is recovered as a waste liquid and discarded as an industrial waste.
[0004]
For example, when a resist film having a thickness of about 1 μm is formed on the surface of a 6-inch diameter wafer as a substrate, the amount of resist used as the film is about 0.018 cubic cm. When the coating is a liquid film, the amount of resist used as the coating is several times this value. However, since the amount of the resist dropped onto the wafer surface, which is the base surface, is 2 to 3 cc, in any case, at least 97 to 98 percent of the dropped resist is spun out from the wafer surface and collected in the recovery container. It is collected and discarded as waste liquid.
[0005]
Such a situation in which most of the resist is discarded without being effectively used is not preferable from the viewpoint of cost saving, effective use of resources, and environmental pollution by waste liquid.
[0006]
For this reason, the appearance of a reproduction system capable of effectively using the resist is desired.
[0007]
In this invention, after forming a film with a resist, cleaning liquid such as edge rinse and back rinse used for cleaning the edge and back surface of the base is the same component as the solvent of the resist, and the resist recovered as waste liquid is: This is made by paying attention to the resist diluted with the cleaning liquid. Then, by removing a predetermined amount of cleaning liquid (solvent) from the resist recovered as waste liquid, it is intended to make the recovered resist reusable and effectively use the resist.
[0008]
[Means for Solving the Problems]
The resist regeneration system of the present invention includes a regeneration container that contains and regenerates the resist recovered from the resist coating apparatus, a solvent removal apparatus that evaporates the solvent component from the resist in the regeneration container and removes a part of the solvent component, and a solvent. And a control device for controlling the operation of the removing device. In this resist regeneration system, the controller operates the solvent removal device to remove the solvent component from the resist until the resist viscosity reaches a reusable target viscosity.
[0009]
According to such a configuration, a part of the solvent component is removed from the collected resist, and the viscosity of the collected resist increases to a reusable viscosity (target viscosity).
[0010]
In carrying out this invention, a weight measuring device for measuring the weight of the resist in the regeneration container is provided, and the control device operates the solvent removing device based on the measurement result of the weight measuring device; Do .
[0011]
According to such a configuration, the operation of the solvent removing device is controlled based on the weight of the resist.
[0012]
In carrying out the present invention, the control device calculates the target weight of the resist after removing the solvent component based on the viscosity and weight of the resist before removing the solvent component and the target viscosity of the resist. It is good also as a structure which operates a solvent removal apparatus so that it may become weight.
[0013]
According to such a configuration, if the viscosity of the resist before solvent component removal, that is, the recovered resist is input, the solvent is automatically removed until the resist reaches the target viscosity.
[0014]
In practicing the present invention, it is preferable that the solvent removing device includes a heating device for heating the resist in the regeneration container.
[0015]
According to such a configuration, the solvent is efficiently removed by heating the resist with the heating device.
[0016]
In carrying out the present invention, it is preferable that the solvent removing device includes a stirring device for stirring the resist in the regeneration container.
[0017]
According to such a configuration, the solvent is efficiently removed by stirring the resist with the stirring device.
[0018]
Furthermore, when carrying out the present invention, it is preferable that the regeneration container is accommodated in a sealed regeneration chamber and an exhaust device for exhausting the interior of the regeneration chamber is provided.
[0019]
According to such a configuration, the solvent is efficiently removed from the resist. Further, by appropriately processing the gas in the regeneration chamber exhausted by the exhaust device, the solvent gas does not fill the space where the resist regeneration system is installed.
[0020]
In carrying out the present invention, a nitrogen gas source for supplying nitrogen gas may be provided in the regeneration chamber.
[0021]
According to such a configuration, the inside of the regeneration chamber becomes a nitrogen atmosphere. As a result, the collected resist is regenerated in the regeneration chamber without coming into contact with air. For this reason, the mixing of moisture into the resist is suppressed.
[0022]
In carrying out the present invention, a solvent supply device for adding a solvent to the resist in the regeneration container may be provided, and the control device may control the operation of the solvent supply device. In this configuration, the control device operates the solvent supply device to add the solvent to the resist until the resist from which the solvent component has been removed by the solvent removing device has a predetermined viscosity.
[0023]
According to such a configuration, the viscosity of the resist is adjusted again by adding a solvent to the resist after the solvent is removed, so that the viscosity is adjusted with higher accuracy.
[0024]
In carrying out the present invention, the control device may be configured to control the operation of the solvent supply device based on the measurement result of the weight measuring device.
[0025]
In carrying out the present invention, the control device calculates the resist weight after the addition of the solvent based on the viscosity and weight of the resist from which a part of the solvent component has been removed and the target viscosity after the addition of the solvent. The solvent supply apparatus may be operated so that the weight of the solvent becomes the target weight after the addition of the solvent.
[0026]
According to such a configuration, when the viscosity of the resist from which a part of the solvent component is removed is input, the solvent is automatically added until the resist has a predetermined viscosity.
[0027]
Furthermore, according to another aspect of the invention of this application, the resist viscosity recovered from the resist coating apparatus is accommodated in a regeneration container, and the solvent viscosity is evaporated from the resist in the regeneration container so that the resist viscosity can be reused. There is provided a method for increasing the resist regeneration.
[0028]
According to such a configuration, a part of the solvent component is removed from the recovered resist by evaporation, and the viscosity of the recovered resist is increased to a reusable viscosity (target viscosity).
[0029]
In practicing the present invention, the solvent component may be evaporated until the resist in the regeneration container reaches the target weight.
[0030]
According to such a configuration, the operation of the solvent supply device is controlled based on the weight of the resist in the regeneration container.
[0031]
In practicing the present invention, the resist target weight may be calculated based on the resist viscosity and weight before solvent component removal and the resist target viscosity.
[0032]
In practicing the present invention, the solvent component may be evaporated while heating the resist in the regeneration container.
[0033]
According to such a configuration, the solvent is efficiently removed by heating the resist.
[0034]
In carrying out the present invention, the solvent component may be evaporated while stirring the resist in the regeneration container.
[0035]
According to such a configuration, the solvent is efficiently removed by stirring the resist.
[0036]
Further, in carrying out the present invention, the regeneration container may be housed in a sealed regeneration chamber, and the evaporation of the solvent component may be performed while exhausting the regeneration chamber while supplying nitrogen gas into the regeneration chamber. Good.
[0037]
According to such a configuration, the solvent is efficiently removed from the resist. Further, since the regeneration chamber has a nitrogen atmosphere, the recovered resist is regenerated in the regeneration chamber without coming into contact with air. For this reason, the mixing of moisture into the resist is suppressed. Furthermore, by appropriately processing the exhausted gas in the regeneration chamber, the solvent gas is not filled in the space where the resist regeneration is performed.
[0038]
In practicing the present invention, a solvent may be added to the resist with increased viscosity.
[0039]
According to such a configuration, the viscosity of the resist is adjusted again by adding a solvent to the resist after the solvent is removed, so that the viscosity is adjusted with higher accuracy.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, each figure has shown only the magnitude | size, shape, and arrangement | positioning relationship of each component roughly to such an extent that this invention can be understood. Therefore, the present invention is not limited to the embodiment shown in the drawings.
[0041]
<First Embodiment>
FIG. 1 is a drawing schematically showing a configuration of a resist regeneration system 100 according to a first embodiment of the present invention.
[0042]
The resist regeneration system 100 operates the solvent removing apparatus to evaporate a part of the solvent component from the resist recovered as a waste liquid, and removes this to increase (thicken) the viscosity of the resist. Is a system that makes it reusable. Therefore, the resist weight decreases during thickening. The resist regeneration system 100 increases the viscosity while monitoring the resist weight. When the resist weight decreases to the target value (target weight), it is determined that the resist has been increased to the desired viscosity (target viscosity). It is configured to end the thickening.
[0043]
First, the configuration of the resist reproduction system 100 will be described. The resist recycling system 100 includes a recovery container 10 for storing a resist recovered as a waste liquid, a recovery container 12 for recovering the recovered resist, and a recycled resist container 14 for storing the recovered resist. The collection container 10 contains the resist collected from a separate resist coating apparatus (not shown). The recovered resist is diluted with edge rinse, back rinse or the like, and its viscosity is smaller than the usable viscosity. The regeneration container 12 is disposed in a sealed regeneration chamber 16.
[0044]
The collection container 10 and the regeneration container 12 are connected by a pipe line 18. The pipe 18 is provided with a first pump 20 and a first filter 22 in order from the collection container 10 side. Therefore, the resist regeneration system 100 is configured such that the resist in the collection container 10 can be transferred to the regeneration container 12 by the first pump 20 while being filtered by the first filter 22.
[0045]
The regeneration container 12 is placed on the weight sensor 24 in the regeneration chamber 16. That is, a weight measuring device Is arranged. The resist regeneration system 100 is configured to always monitor the weight of the resist R in the regeneration container 12 by the weight sensor 24.
[0046]
A heating device 26 is provided adjacent to the regeneration container 12. The resist regeneration system 100 is configured to heat the resist R in the regeneration container 12 to a predetermined temperature by the heating device 26. The predetermined temperature is, for example, a temperature of about 30 to 40 ° C. Examples of the preferable heating device 26 include a hot plate and a thermostatic bath. By heating the resist by the heating device 26, evaporation of the solvent component from the resist is promoted. The heating device 26 constitutes a part of the solvent removing device.
[0047]
Further, the resist regeneration system 100 is provided with a stirring device 28 for stirring the resist R in the regeneration container 12. The stirrer 28 includes a propeller-shaped or screw-shaped stirrer 28a that rotates within the resist R, and a drive unit 28b that rotationally drives the stirrer 28a. However, the stirring device may have other configurations. By the stirring of the resist by the stirring device 28, the evaporation of the solvent component from the resist is promoted. The stirring device 28 constitutes a part of the solvent removing device.
[0048]
The regeneration container 12 is provided with a temperature measuring device 30 that measures the temperature of the resist R in the regeneration container 12.
[0049]
The regeneration container 12 and the regeneration resist container 14 are connected by a pipe line 32. A second pump 34, a second filter 36, and a cooling device 38 are provided in the pipeline 32 in order from the regeneration container 12 side. As described above, the resist regeneration system 100 filters the resist regenerated in the regeneration container 12 by the second filter 36 and then cools the resist to the room temperature by the cooling device 38, and then the regeneration resist container 14 by the second pump 34. It can be transported to.
[0050]
An exhaust device 40 is attached to the regeneration chamber 16. The exhaust device 40 is a suction or decompression device such as an exhaust pump, and discharges a gas such as solvent vapor in the sealed regeneration chamber 16 to the outside of the regeneration chamber 16. By the operation of the exhaust device 40, the evaporation of the solvent from the resist R in the regeneration container 12 is promoted.
[0051]
Further, a nitrogen gas source 41 is connected to the regeneration chamber 16. The nitrogen gas source 41 is configured to supply nitrogen gas into the regeneration chamber 16. Therefore, by operating the exhaust device 40 while operating the nitrogen gas source 41, the inside of the regeneration chamber 16 is purged with nitrogen gas. As a result, the regeneration of the resist in the regeneration container 12 is performed in a nitrogen atmosphere.
[0052]
In addition, the resist regeneration system 100 is provided with a control device 42 that controls the operation of the entire system.
[0053]
Connected to the control device 42 is an input device 44 through which an operator inputs necessary numerical values to the control device 42. The control device 42 is connected to the first pump 20, the second pump 34, the heating device 26, the exhaust device 40, and the nitrogen gas source 41, and is configured to control these operations. Further, the control device 42 is configured so that the weight of the resist R in the regeneration container 12 monitored by the weight sensor 24 and the temperature of the resist R in the regeneration container 12 measured by the temperature measuring device 30 are input. Has been.
[0054]
The control device 42 calculates the target weight W2 of the resist based on the viscosity η1 and weight W1 of the resist R transferred to the regeneration container 12 and the viscosity (target viscosity) η2 of the resist desired to be obtained by the thickening process. The thickening step is executed, and when the resist weight W reaches the target weight W2, it is determined that the resist viscosity has reached the target viscosity η2, and the thickening step is stopped.
[0055]
FIG. 2 is a block diagram illustrating a configuration of a main part of the control device 42. The control device 42 is configured by a microcomputer and includes a target weight calculation unit 420, a memory 422, and a thickening control unit 424, as shown in FIG.
[0056]
The target weight calculation unit 420 receives the weight W1 of the resist R transferred to the regeneration container 12 from the weight sensor 24, the viscosity η1 of the resist R transferred to the regeneration container 12, and the resist desired to be obtained by the resist regeneration system 100. The viscosity (target viscosity) η2 is input via the input device 44. Furthermore, the target weight calculation unit 420 is configured to calculate the target weight W2 based on the weight W1 and viscosity η1 of the resist R and the target viscosity η2.
[0057]
The memory 422 stores data necessary for calculating the target weight W2.
[0058]
In response to the thickening execution command from the input device 44, the thickening control unit 424 issues a thickening execution signal for operating the solvent removal device such as the heating device 26 and the stirring device 28 to start the thickening process. It is configured as follows. Further, the thickening control unit 424 compares the current weight W of the resist R in the regeneration container 12 with the target weight W2, and when W and W2 become equal, the resist R in the regeneration container 12 It is determined that the viscosity η2 has been reached, the operation of the solvent removing device such as the heating device 26 and the stirring device 28 is stopped, and the thickening step is terminated.
[0059]
Next, a resist regeneration process performed by the resist regeneration system 100 will be described. First, the control device 42 operates the first pump 20 to transfer the resist in the collection container 10 to the regeneration container 12 through the pipe line 18. The resist in the collection container 10 is a resist whose viscosity is lowered by being diluted with a cleaning liquid such as back rinse or edge rinse.
[0060]
In the resist regeneration system 100, the control device 42 operates the exhaust device 40 and the nitrogen gas source 41 during the resist regeneration process, purges the interior of the regeneration chamber 16 with nitrogen gas, and makes the interior of the regeneration chamber 16 a nitrogen atmosphere. .
[0061]
The resist in the collection container 10 is filtered by the first filter 22 while being transferred to the regeneration container 12, and solid impurities are removed. In this embodiment, the resist is a positive resist. However, the present invention is also applicable to negative resists.
[0062]
Back rinse and edge rinse are the same components as the resist solvent. Examples of back rinse, edge rinse and resist solvents include ECA (ethylene glycol monoethyl ether acetate), EL (ethyl lactate), EEP (ethyl-3-ethoxypropionate), MMP (methyl-3-methoxypropioate). Nate), MAK (methyl amyl ketone (2-heptanone)), PGMEA (propylene glycol monomethyl ether acetate).
[0063]
Next, a thickening step is performed. In this thickening step, the resist R in the regeneration container 12 is heated while stirring under the control of the control device 42, thereby evaporating the solvent components such as back rinse and edge rinse that have diluted the resist from the recovered resist. And increase the viscosity of the resist to a reusable viscosity.
[0064]
As described above, in this thickening step, the weight W of the resist R in the regeneration container 12 decreases. In the resist regeneration system 100, when the controller 42 monitors the weight W of the resist R in the regeneration container 12, a thickening process is performed, and the resist R is desired when the weight W of the resist R decreases to the target value W2. It is determined that the viscosity has been increased to η2 (target viscosity) η2, and the thickening process ends.
[0065]
Next, the content of the thickening process performed by control of the control apparatus 42 is demonstrated along FIG. FIG. 3 is a flowchart showing the contents of control performed by the control device 42 in the thickening process.
[0066]
When the transfer of the resist to the regeneration container 12 is completed, the weight W1 of the resist R in the regeneration container 12 is input from the weight sensor 24 to the target weight calculation unit 420 of the control device 42 (S1). Next, the viscosity η1 (cp) of the resist R in the regeneration container 12 and the target viscosity η2 (cp) of the resist measured by the operator are input to the target weight calculation unit 420 via the input device 44 (S2). ).
[0067]
Next, the target weight calculation unit 420 calculates the target weight W2 based on W1, η1, and η2 and the data in the memory 422 (S3), and sends the target weight W2 to the thickening control unit 424. The target weight W2 is a value obtained when the solvent component such as back rinse is evaporated from the resist R in the regeneration container 12 during the thickening process, and the viscosity of the resist R in the regeneration container 12 becomes the target viscosity η2. This is the weight of the resist R. A method for calculating the target weight W2 will be described later. Since the resist R transferred to the regeneration container 12 includes back rinse and the like, the relationship of W1> W2 is established.
[0068]
When a thickening start command is input via the input device 44, the thickening control unit 424 issues a thickening execution signal (S4), and the solvent removing device configured by the heating device 26, the stirring device 28, and the like. Is activated to execute the thickening step (S5). The thickening step is performed while monitoring the weight W of the resist R with the target weight W2 as a target value.
[0069]
During the thickening step, the resist R in the regeneration container 12 is maintained at a constant temperature of, for example, 30 ° C. to 40 ° C. by the heating device 26 and the temperature measuring device 30 and is stirred by the stirring device 28. Further, nitrogen gas is supplied from the nitrogen gas source 41 into the regeneration chamber 16, and the gas in the regeneration chamber 16 is exhausted outside the regeneration chamber 16 by the exhaust device 40. The operations of the heating device 26, the stirring device 28, the exhaust device 40, the nitrogen gas source 41, and the like are also controlled by the control device 42.
[0070]
During the thickening process, the thickening control unit 424 compares the weight W of the resist R in the regeneration container 12 sent from the weight sensor 24 with W2 (S6). As described above, during the thickening step, the resist R in the regeneration container 12 is stirred while being maintained at a predetermined temperature. Therefore, during the thickening step, solvent components such as back rinse that diluted the resist are evaporated, and the viscosity η of the resist increases and the weight W decreases. While W is larger than W2, thickening is continued (S5). When the weight W of the resist R becomes equal to W2, the thickening control unit 424 determines that the resist R in the regeneration container 12 has been thickened to the target viscosity η2, and ends the thickening process (S7). That is, the operations of the heating device 26 and the stirring device 28 are stopped.
[0071]
Thereafter, the second pump 34 is operated, and the resist R in the regeneration container 12 is transferred to the regeneration resist container 14 via the pipe line 32. In the middle of this, the resist is filtered by the second filter 36 and further cooled to room temperature by the cooling device 38 to stop the thickening completely. When all the resist is transferred to the regenerated resist container 14, the regeneration process is completed.
[0072]
In the resist regeneration system 100, the target weight W2 of the resist is calculated in the target weight calculation unit 420 as follows. FIG. 4 is a graph showing the relationship between the viscosity (vertical axis) and weight (horizontal axis) of the resist used for this calculation. The unit of viscosity is cp and the unit of weight is Kg.
[0073]
This graph was created based on an experiment using the same type of resist and solvent as the resist to be reproduced. That is, this graph shows that resists having different viscosities, such as resists of 2 cp, 4 cp, 6 cp, 8 cp, 10 cp, and 12 cp, are prepared in a fixed amount (for example, 10 kg), and the viscosity and weight of each are heated and stirred. The calibration curves (a) to (f) are shown in which the viscosity and weight changes were plotted.
[0074]
In the resist reproduction system 100, data corresponding to this graph is stored as a map (or table) in the memory 422 of the control device. When the initial value η1, the target viscosity η2, and the initial weight value W1 of the resist are input, the target weight calculation unit 420 refers to the contents of this graph stored in the memory 422 and sets the target A weight W2 is calculated.
[0075]
For example, according to the calibration curve (a) of this graph, in order to thicken a resist having an initial weight value W1 of 10 kg and an initial viscosity value η1 of 2 cp to a target viscosity η2 of 6 cp, the weight W It can be seen that the resist thickening process may be continued until the amount reaches 6 kg. In this way, the target weight W2 is calculated based on the initial weight value W1, the initial viscosity value η1, and the target viscosity value η2. When the initial weight value W1 is not 10 kg, the target weight W2 is calculated by multiplying by an appropriate coefficient.
[0076]
According to the resist regeneration system 100 configured in this way, the viscosity η1 of the resist R accommodated in the regeneration container 12 is measured, and by inputting the η1 and the target viscosity η2, the resist recovered as waste liquid can be obtained in a desired manner. The viscosity can be increased automatically up to the viscosity.
[0077]
The present invention is not limited to a system that uses the above-described W2 calculation method, and other W2 calculation methods may be adopted. For example, the following W2 calculation method may be used.
[0078]
The relationship between the resist concentration x and the viscosity y (cp) is expressed by the following approximate expression.
[0079]
y = Aexp (Bx) (A and B are constants)
Therefore, the concentration (initial concentration) C1 of the resist R before the thickening step can be calculated from the viscosity (initial value) η1 of the resist in the regeneration container 12. Similarly, the resist concentration (target concentration) C2 when the resist reaches the target viscosity η2 (after the thickening step) can be calculated.
[0080]
The resist concentration C is a weight ratio indicating how much solid component is contained in the resist, so that C = W _solid / W (W _solid Is the solid component weight in the resist, and W is the total weight of the resist).
[0081]
Therefore, for the resist before the thickening step, C1 = W1 _solid / W1 is C2 = W2 for the resist after the thickening step _solid / W2 is established. Where W1 _solid Is the weight of the solid component in the resist before the thickening step, and W2 _solid Is the weight of the solid component in the resist after the thickening step. Since the thickening step is an operation of evaporating liquid components (solvent components) such as edge rinse from the resist, the weight of the solid component contained in the resist does not change before and after the thickening step. Therefore, W1 _solid Is W2 _solid Is equal to C1 and C2 are calculated from the approximate expression, and W1 can be measured by a weight sensor or the like.
[0082]
Therefore, the formula C1 = W1 for the resist before the thickening step _solid / W1 to W1 _solid To calculate W1 _solid For the resist after the thickening step C2 = W2 _solid / W2 W2 _solid By substituting into, the target weight W2 can be calculated.
[0083]
When this calculation method is employed, the approximate expression is stored in the memory 422 of the control device 42. Then, the target weight calculation unit 420 calculates the target weight W2 in the above-described process using the input W1, η1, and η2 and the approximate expression in the memory 422.
[0084]
According to this calculation method, even if the initial value η1 of the resist viscosity is a value including a fraction of 2.36, for example, the target weight W2 can be calculated accurately and quickly.
[0085]
<Second Embodiment>
FIG. 5 is a schematic diagram showing the configuration of a resist regeneration system 200 according to the second embodiment of the present invention.
[0086]
As shown in FIG. 5, the resist regeneration system 200 basically has the same configuration as the resist regeneration system 100. In addition to the configuration of the resist regeneration system 100, the resist regeneration system 200 includes a solvent supply device 50 for adding a solvent to the thickened resist. Then, the resist regeneration system 200 increases the resist viscosity to a viscosity higher than the desired viscosity by a thickening process similar to the thickening process performed in the resist regeneration system 100, and then adds a solvent to the resist. It is a resist regeneration system that performs an adjustment process for obtaining a resist having a desired viscosity. Hereinafter, the configuration and operation of the resist reproduction system 200 will be described focusing on this difference. In addition, about the component which is common in the resist reproduction | regeneration system 100, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
[0087]
The resist regeneration system 200 includes a solvent supply device 50 in addition to the configuration of the resist regeneration system 100. The solvent supply device 50 includes a solvent tank that stores an organic solvent having the same component as the solvent of the resist, and a pump that sends the organic solvent stored in the solvent tank to the resist R in the regeneration container 12 through the pipe line 52. Is included. The solvent supply device 50 is mechanically connected to the regeneration container 12 by a pipe line 52. Further, the solvent supply device 50 is electrically connected to a control device 242 that controls the operation of the entire system of the resist regeneration system 200. Under the control of the control device 242, the organic solvent in the solvent tank is removed from the resist in the regeneration container 12. It is configured to be added to R. The addition amount of the organic solvent is calculated by the control device 242.
[0088]
FIG. 6 is a block diagram illustrating a configuration of a main part of the control device 242. As shown in FIG. 6, the control device 242 has substantially the same configuration as the control device 42 of the resist regeneration system 100. The control device 242 is different from the control device 42 in configuration in that it includes a solvent supply control unit 244. In addition, the control device 242 is different from the control device 42 in operation in that the addition amount w of the organic solvent is calculated based on the resist weight W3, the viscosity η3, and the target viscosity η4 after the thickening step. The supply device 50 is operated, and the adjustment process for adding the organic solvent to the resist is performed until the weight of the resist reaches the target weight W3 + w (W4) after the addition of the solvent. Hereinafter, the configuration of the control device 242 will be described focusing on the differences.
[0089]
As shown in FIG. 6, the control device 242 includes a solvent supply control unit 244, a target weight calculation unit 246, a memory 248, and a viscosity increase control unit 424. The target weight calculation unit 246, the memory 248, and the thickening control unit 424 of the control device 242 function in the same manner as the target weight calculation unit 420, the memory 422, and the thickening control unit 424 of the control device 42 regarding the thickening process. It is configured.
[0090]
In addition to the function of the target weight calculation unit 420, the target weight calculation unit 246 calculates how much weight w of the organic solvent is added to the resist after the thickening step so that the resist has a desired viscosity η4. It has a mechanism. In addition to the contents of the memory 422, the memory 248 stores data necessary for calculating the addition amount w of the organic solvent. Further, the solvent supply control unit 244 issues a solvent supply signal in response to the adjustment start command from the input device 44, until the weight of the resist reaches the solvent supply device 50 to W3 + w, that is, the target weight W4 after the addition of the solvent. The organic solvent is added to the resist.
[0091]
Next, a resist regeneration process using the resist regeneration system 200 will be described. First, as in the resist regeneration system 100, a thickening process for resist collected as waste liquid is performed. However, in the resist regeneration system 200, the target viscosity η2 is set to be larger than the viscosity necessary for reusing the resist.
[0092]
After the thickening step is completed and the temperature of the resist is lowered to the same level as the room temperature, a resist adjustment step is performed. In the adjustment step, the resist is not heated. Therefore, the temperature of the resist is about room temperature during the adjustment process. The adjustment process is also controlled by the control device 242.
[0093]
The content of the adjustment process performed by control of the control apparatus 242 is demonstrated along FIG. FIG. 7 is a flowchart showing the contents of control performed by the control device 242 in the adjustment process.
[0094]
When the thickening process is completed and the temperature of the resist is lowered to about the room temperature, the weight W3 of the resist R in the regeneration container 12 is input from the weight sensor 24 to the target weight calculation unit 246 of the control device 242 ( S21). Next, the viscosity η3 (cp) of the resist R in the regeneration container 12 measured by the operator and the target viscosity η4 (cp) of the resist in the adjustment process are input to the target weight calculation unit 246 via the input device 44. (S22). Here, W3 and η3 should theoretically be equal to the target weight W2 and the target viscosity η2 of the thickening process, but in reality, W2 and η2 are affected by the effect of residual heat after the heating device 26 is stopped. Is different. Therefore, in the control in the adjustment step, the viscosity η3 and weight W3 of the resist whose temperature has been lowered to room temperature after the thickening step is completed are used as initial values of the viscosity and weight.
[0095]
Next, the target weight calculation unit 246 calculates W3, η3 and η4, and the target weight W4 after addition of the solvent based on the data in the memory 248 (S23), and sends it to the solvent supply control unit 244. The target weight W4 after the addition of the solvent is determined when the organic solvent having a weight w is added to the resist R in the regeneration container 12 during the adjustment process, and the viscosity of the resist R in the regeneration container 12 reaches the target viscosity η4. The weight of the resist R, that is, W3 + w. A method for calculating the target weight W4 after the addition of the solvent will be described later.
[0096]
When an adjustment start command is input via the input device 44, the solvent supply control unit 244 issues a solvent supply signal (S24), operates the solvent supply device 50, and executes the adjustment process (S25). ). The adjustment process is performed while monitoring the weight W of the resist R using the target weight W4 after the addition of the solvent as a target value.
[0097]
During the adjustment process, the solvent supply control unit 244 compares the weight W of the resist R in the regeneration container 12 sent from the weight sensor 24 with W4 (S26). As described above, since the organic solvent is added to the resist R in the regeneration container 12 by the solvent supply device 50 during the adjustment process, the viscosity R of the resist R in the regeneration container 12 gradually increases. As it decreases, its weight W increases. While W is smaller than W4, the solvent supply is continued (S25). When the weight W of the resist R becomes equal to W4, the solvent supply control unit 244 determines that the resist R in the regeneration container 12 has been diluted to the target viscosity η4, and ends the adjustment process. (S27). That is, the operation of the solvent supply device 50 is stopped.
[0098]
Thereafter, the second pump 34 is operated, and the resist R in the regeneration container 12 is transferred to the regeneration resist container 14 via the pipe line 32. In the middle of this, the resist is filtered by the second filter 36 and further completely cooled by the cooling device 38. When all the resist is transferred to the regenerated resist container 14, the regeneration process is completed. In the resist regeneration system 200, the cooling device 38 or its operation may be omitted.
[0099]
In the resist regeneration system 200, the target weight W4 after the solvent addition of the resist is calculated in the target weight calculation unit 246 as follows. FIG. 8 is a graph showing the relationship between the viscosity of the resist (vertical axis) and the weight of the added organic solvent (horizontal axis) used for this calculation. The unit for displaying viscosity is cp, and the unit for displaying weight is g.
[0100]
This graph is prepared in advance based on an experiment using the same type of resist and solvent as the resist to be regenerated. In this graph, resists having different viscosities, for example, 5 cp, 6 cp, 7 cp, 8 cp, 9 cp, and 10 cp resists are prepared in a certain amount (for example, 10 kg), and the viscosity is measured while adding an organic solvent to each. Calibration curves (g) to (l) are plotted in which the relationship between the weight of the added organic solvent and the viscosity of the resist is plotted.
[0101]
In the resist reproduction system 200, data corresponding to this graph is stored as a map (or table) in the memory 248 of the control device 242. Then, when the viscosity η3 and weight W3 of the resist after the thickening step and the target viscosity η4 are input, the target weight calculation unit 246 refers to the content of the graph of FIG. 8 stored in the memory 248. The weight w of the organic solvent to be added is calculated. Then, w is added to W3, and the resist target weight (target weight after addition of the solvent) W4 in the adjustment step is calculated.
[0102]
For example, according to the calibration curve (j) of this graph, 400 g of organic solvent is added to dilute a resist having a weight W3 of 10 kg and a viscosity η3 of 8 cp to a viscosity of 6 cp, which is the target viscosity η4 of the adjustment process. You can see that Therefore, the weight w of the organic solvent to be added is 400 g, and W4 is calculated as W3 + 400 g.
[0103]
In this manner, the target weight W4 after the addition of the solvent is calculated based on the initial weight value W3, the initial viscosity value η3, and the target viscosity value η4 in the adjustment step. If the initial weight value W3 is not 10 kg, the target weight W4 after the addition of the solvent is calculated by multiplying by an appropriate coefficient.
[0104]
According to the resist regeneration system 200 configured as described above, in the thickening step, the adjustment step of adding an organic solvent to the resist having a viscosity higher than the final target viscosity is performed at room temperature. Therefore, the viscosity of the resist can be adjusted with high accuracy.
[0105]
Also in the resist regeneration system 200, the calculation method of the target weight W4 after the addition of the solvent is not limited to the above calculation method, and may be another calculation method.
[0106]
The present invention is not limited to the above embodiment, and various changes and modifications can be made within the scope of the matters described in the claims. For example, in the first and second embodiments, the resist recycling system is separate from the resist coating apparatus. However, the resist recycling system of the present invention may be provided integrally with the resist coating apparatus.
[0107]
In the first and second embodiments, the solvent removal device of the resist regeneration system includes the heating device and the stirring device. However, the solvent removing apparatus of the present invention is not limited to this configuration, and may have any configuration as long as the solvent can be evaporated from the resist. For example, the structure provided with the heating apparatus and not provided with the stirring apparatus may be sufficient.
[0108]
【The invention's effect】
As described above, according to the present invention, the resist can be effectively used.
[Brief description of the drawings]
FIG. 1 is a drawing schematically showing a configuration of a resist regeneration system according to a first embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a main part of a control device of the resist regeneration system according to the first embodiment.
FIG. 3 is a flowchart showing the contents of control performed by the control device in the thickening process by the control device of the resist regeneration system according to the first embodiment;
FIG. 4 is a graph showing the relationship between the viscosity and weight of a resist used for calculating the target weight of the resist in the resist regeneration system according to the first embodiment.
FIG. 5 is a schematic diagram showing a configuration of a resist regeneration system according to a second embodiment of the present invention.
FIG. 6 is a block diagram illustrating a configuration of a main part of a control device of a resist regeneration system according to a second embodiment.
FIG. 7 is a flowchart showing the contents of control performed by the control device in the adjustment process by the control device of the resist regeneration system according to the second embodiment.
FIG. 8 is a graph showing the relationship between the viscosity of a resist and the amount of an organic solvent used for calculating the target weight of the resist in the adjustment step in the resist regeneration system of the second embodiment.
[Explanation of symbols]
10: Collection container
12: Recycle container
14: Recycled resist container
16: Regeneration chamber
18: Pipe line
20: First pump
22: First filter
24: Weight sensor
26: Heating device
28: Stirrer
28a: stirring member
28b: Drive device
30: Temperature measuring device
32: Pipe line
34: Second pump
36: Second filter
38: Cooling device
40: Exhaust device
41: Nitrogen gas source
42: Control device
44: Input device
100: Resist regeneration system
420: Target weight calculation unit
422: Memory
424: Thickening control unit

Claims (15)

A recycling container for storing and recycling the resist recovered from the resist coating apparatus;
A solvent removal device for removing a part of the solvent component by evaporating the solvent component from the resist in the regeneration container;
A weight measuring device for measuring the weight of the resist in the regeneration container;
A control device for controlling the operation of the solvent removal device,
Wherein the controller, the measurement results of the weight measuring apparatus is the target weight, the viscosity of the resist until the target viscosity reusable, Ru actuates the solvent remover to remove solvent component from the resist resist playback system which is characterized a call. The resist regeneration system according to claim 1 ,
The control device calculates the target weight of the resist after removal of the solvent component based on the viscosity and weight of the resist before removal of the solvent component and the target viscosity of the resist so that the weight of the resist becomes the target weight. A resist recycling system, wherein the solvent removing apparatus is operated. In the resist regeneration system according to claim 1 or 2 ,
The resist regeneration system, wherein the solvent removing device includes a heating device for heating the resist in the regeneration container. In the resist regeneration system according to claim 3 ,
The resist removal system, wherein the solvent removing device includes a stirring device for stirring the resist in the regeneration container. In the resist regeneration system according to any one of claims 1 to 4 ,
The regeneration container is housed in a sealed regeneration chamber;
A resist regeneration system comprising an exhaust device for exhausting the regeneration chamber. In the resist regeneration system according to claim 5 ,
A resist regeneration system comprising a nitrogen gas source for supplying nitrogen gas into the regeneration chamber. The resist regeneration system according to any one of claims 1 to 6 ,
A solvent supply device for adding a solvent to the resist in the regeneration container;
The control device controls the operation of the solvent supply device;
The resist regeneration system, wherein the control device operates the solvent supply device so as to add the solvent to the resist from which the solvent component has been removed by the solvent removing device until the resist has a predetermined viscosity. In the resist reproduction system according to claim 7 ,
The resist regeneration system, wherein the control device controls the operation of the solvent supply device based on a measurement result of the weight measuring device. In the resist regeneration system according to claim 8 ,
The control device calculates a target weight after addition of the solvent based on the viscosity and weight of the resist from which a part of the solvent component has been removed and the target viscosity after addition of the solvent, and the weight of the resist is calculated after the addition of the solvent. A resist regeneration system, wherein the solvent supply device is operated so as to achieve a target weight. The resist collected from the resist coating device is stored in a recycling container,
Evaporating the solvent component from the resist in the regeneration container to increase the viscosity of the resist to a reusable target viscosity ;
Resist reproducing method evaporate before Symbol solvent component, the resist of the reproduction vessel, based on the measurement results of the weighing device, characterized in that it is carried out until the target weight. The resist regeneration method according to claim 10 , wherein
The resist regeneration method characterized in that the target weight is calculated based on the viscosity and weight of the resist before removal of the solvent component and the target viscosity. The resist regeneration method according to claim 11 ,
2. A resist regeneration method, wherein the solvent component is evaporated while heating the resist in a regeneration container. The resist regeneration method according to claim 12 ,
A resist regeneration method, wherein the solvent component is evaporated while stirring the resist in a regeneration container. The resist regeneration method according to claim 12 or 13 ,
The regeneration container is housed in a sealed regeneration chamber;
The resist regeneration method characterized in that evaporation of the solvent component is performed while exhausting the regeneration chamber while supplying nitrogen gas into the regeneration chamber. The resist regeneration method according to any one of claims 10 to 14 ,
A method of regenerating a resist, comprising adding a solvent to the resist having an increased viscosity.

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