JP2002100555A - Resist-peeling device and manufacturing method of device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for detecting the concentration of carbon dioxide that is dissolved into resist release liquid after use, replenishing amine solution into the resist release liquid based on the detection result, and reusing the resist release capacity of the resist release liquid while restoring it, and the manufacturing method of a device. SOLUTION: The resist-peeling capability of the resist-peeling liquid 3 is greatly deteriorated by dissolving carbon dioxide in the air into the resist-peeling liquid 3. In this case, the concentration of the carbon dioxide dissolved into the resist-peeling liquid 3 is detected based on a pH value measured by a pH meter 17 via a pH electrode 16, and an MEA(monoethanol amine) solution 14 is replenished based on the detection result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a resist stripping apparatus and a device manufacturing method using the same.

[0002]

2. Description of the Related Art In a process of manufacturing a semiconductor chip such as an LSI or a device such as a thin film transistor, a film to be processed is etched using a resist formed on a film to be processed formed on a device substrate as a mask, and then the resist is formed. Is often stripped using a resist stripper. In this case, a mixture of amine, glycol ether, water and the like is used as the resist stripper, and the used resist stripper is collected and reused. However, the resist is stripped (dissolved) after use
Since the used resist is mixed, when the use time is prolonged, the resist concentration in the resist stripping solution increases, the resist stripping ability is deteriorated, and the resist is not worthy of use.
In such a case, conventionally, the resist stripping solution that is no longer used is replaced with a new resist stripping solution. That is, the resist stripping solution that is no longer used is discarded.

[0003]

As described above, conventionally, all the resist stripping solutions that are no longer used are replaced with new resist stripping solutions, so that the usage time of the resist stripping solution is rather short. There is a problem that it is short, the frequency of replacement increases, the operation rate decreases, and the resist stripping solution is discarded at an early stage, resulting in an increase in cost. An object of the present invention is to extend the use time of a resist stripper.

[0004]

According to a first aspect of the present invention, there is provided a resist stripping apparatus for stripping a resist using a resist stripper, collecting a used resist stripper, and reusing the resist. And an amine solution replenishing means for replenishing the resist stripping solution with an amine solution based on the detection result by the carbon dioxide concentration detecting means. The invention described in claim 2 is the first invention.
In the invention described in (1), a pH measuring means for measuring a pH of a resist stripping solution is used as the carbon dioxide concentration detecting means. The invention according to claim 3 is the invention according to claim 2.
Wherein the amine solution is supplied by the amine solution replenishing means when the pH value measured by the pH measuring means falls below a set value. According to a fourth aspect of the present invention, in the third aspect of the present invention, when the pH value measured by the pH measuring means is higher than the set value by a predetermined value, the amine solution is replenished by the amine solution replenishing means. Is to be stopped. According to a fifth aspect of the present invention, in the third aspect of the present invention, the amount of the amine solution supplied by the amine solution supply means is set to a predetermined amount. The invention according to claim 6 is the invention according to any one of claims 3 to 5, wherein the set value is 10.8 to 1
1.2. The invention according to claim 7 is the invention according to claim 6, wherein the set value is 11.0. According to an eighth aspect of the present invention, in the first aspect of the present invention, a conductivity measuring means for measuring the conductivity of the resist stripping solution is used as the carbon dioxide concentration detecting means. According to a ninth aspect of the present invention, in accordance with the eighth aspect of the present invention, there is provided a water supply means for measuring a water concentration of the resist stripping solution and supplying water to the resist stripping solution so that the water concentration becomes constant. The conductivity of the resist stripping solution is measured by the conductivity measuring means while the moisture concentration of the resist stripping solution is kept constant. The invention according to claim 10 is the invention according to claim 9
In the invention described in (1), when the conductivity measured by the conductivity measuring means is equal to or more than a set value, the amine solution replenishing means replenishes the amine solution. According to an eleventh aspect of the present invention, in the invention according to the tenth aspect, when the conductivity measured by the conductivity measuring unit falls below a predetermined value from the set value, the amine solution is replenished by the amine solution replenishing unit. The supply is stopped. According to a twelfth aspect of the present invention, in the tenth aspect of the present invention, the amount of the amine solution supplied by the amine solution replenishing means is a predetermined amount. According to a thirteenth aspect of the present invention, in the first aspect, the set value is set to 1300 to 600 μS / cm.
According to a fourteenth aspect, in the thirteenth aspect, the set value is 900 μS / cm. The invention according to claim 15, etching the film to be processed using a resist patterned on a film to be processed formed on a device substrate as a mask, then peeling the resist using a resist peeling solution, In a method of manufacturing a device for recovering and reusing a used resist stripping solution, the concentration of carbon dioxide dissolved in the resist stripping solution is detected, and based on the detection result, an amine solution is supplied to the resist stripping solution, and the resist is removed. The stripper is reused while restoring the resist stripping ability of the stripper. According to a sixteenth aspect, in the fifteenth aspect, the concentration of the carbon dioxide is detected based on a result of measuring a pH of the resist stripping solution. According to a seventeenth aspect, in the sixteenth aspect, the amine solution is replenished when the measured pH value falls below a set value. According to an eighteenth aspect of the present invention, in the invention according to the seventeenth aspect, when the measured pH value is higher than the set value by a predetermined value, the supply of the amine solution is stopped. The invention according to claim 19 is the invention according to claim 17.
In the invention described in (1), the replenishment amount of the amine solution is set to a predetermined amount. According to a twentieth aspect, in the invention according to any one of the seventeenth to nineteenth aspects, the set value is set to 10.8 to 11.2. According to a twenty-first aspect, in the twenty-second aspect, the set value is 11.0. According to a twenty-second aspect of the present invention, in the fifteenth aspect, the concentration of the carbon dioxide is detected based on a result of measuring the conductivity of the resist stripping solution. According to a twenty-third aspect of the present invention, in the invention of the twenty-second aspect, the electric conductivity of the resist stripping solution is measured by measuring the water concentration of the resist stripping solution, and supplying water so that the water concentration is constant. In this state, it is performed. According to a twenty-fourth aspect of the present invention, in the twenty-third aspect of the present invention, the amine solution is replenished when the measured conductivity is equal to or higher than a set value. The invention according to claim 25 is the invention according to claim 24.
The replenishment of the amine solution is stopped when the measured electric conductivity falls below the set value by a predetermined value. The invention according to claim 26 is
In the invention according to claim 24, the replenishment amount of the amine solution is set to a predetermined amount. The invention according to claim 27 is the invention according to any one of claims 24 to 26, wherein the set value is 1300 to 600 μm.
S / cm. The invention according to claim 28 is the invention according to claim 27, wherein the set value is 9
The value was set to 00 μS / cm. According to the present invention, focusing on the fact that the carbon dioxide in the atmosphere dissolves into the resist stripping solution, the factor that significantly deteriorates the resist stripping ability of the resist stripping solution is focused on, Since the concentration is detected and the amine solution is replenished based on the detection result, the replenishment of the amine solution reduces the concentration of carbon dioxide in the resist stripping solution and restores the resist stripping ability of the resist stripping solution. Therefore, the use time of the resist stripping solution can be extended.

[0005]

FIG. 1 is a schematic block diagram of a resist stripping apparatus according to an embodiment of the present invention. This resist stripping apparatus is a semiconductor film formed on a device substrate 21 in a process of manufacturing a semiconductor chip such as an LSI or a device such as a thin film transistor.
The apparatus main body 1 is provided after an etching apparatus (not shown) that etches the processing film 22 using a resist 23 patterned on the processing film 22 such as an insulating film or a metal film as a mask. Typically, the device substrate 21 is a glass substrate, and the processing target film 22 is an amorphous silicon semiconductor film or the amorphous silicon semiconductor film and an insulating film formed thereon, or formed on the insulating film. It is a metal film. A processing tank 2 is provided in a lower portion of the apparatus main body 1. The processing tank 2 contains a resist stripper 3. The resist stripping solution 3 is, for example, monoethanolamine (ME
A), butyl diglycol (BDG), water and the like are mixed.

The upper part of the apparatus main body 1 is a processing chamber 4. The processing chamber 4 has a carry-in port 5 and a carry-out port 6, and has a structure in which a transport roller 7 for transporting the device substrate 21 is provided therebetween. In this case, the floor of the processing chamber 4 serves as a funnel-shaped resist stripping liquid collecting unit 8, and the lower portion of the cylindrical opening of the resist stripping liquid collecting unit 8 is arranged in the upper part of the processing tank 2. A plurality of showers 9 are provided above the transport roller 7 in the processing chamber 4. Shower 9
Is connected to the lower part of the processing tank 2 via a pipe 10. A pump 11 is interposed in the pipe 10.

A supply tank 12 is provided outside the apparatus main body 1. 100% ME in the supply tank 12
A high-concentration MEA solution (amine solution) 13 appropriately diluted with A solution or water is accommodated. Supply tank 1
The MEA solution 13 in the processing tank 2 is supplied to the processing tank 2 through the pipe 16 by driving the pump 14. The drive control of the pump 14 will be described later in detail,
PH (pH) electrode 16 provided in the processing tank 2
The control unit 18 receives a pH signal from a pH meter 17 connected to the control unit 18.

Next, the case where the resist 23 on the device substrate 21 sent from the preceding etching apparatus is stripped by the resist stripping apparatus will be described. The resist stripping solution 3 in the processing tank 2 is supplied to the shower 9 via the pipe 10 by driving the pump 11. Then, the resist stripper 3 is sprayed from the shower 9 on the device substrate 21 on the transport roller 7, and the resist 23 on the device substrate 21 is dissolved and stripped. The resist stripping liquid 3 containing the stripped (dissolved) resist is collected in the processing tank 2 via the resist stripping liquid collecting unit 8,
Reused.

A factor that greatly deteriorates the resist stripping ability of the resist stripping solution 3 is that carbon dioxide in the atmosphere dissolves into the resist stripping solution 3. That is,
When the resist stripping solution 3 is exposed to the atmosphere in the processing chamber 4, carbon dioxide in the atmosphere dissolves in the resist stripping solution 3. When the concentration of carbon dioxide dissolved in the resist stripping solution 3 exceeds a certain value, the resist stripping ability of the resist stripping solution 3 is greatly deteriorated, and a resist residue is generated on the device substrate 21.

Here, the concentration of carbon dioxide dissolved in the resist stripper 3 is inversely proportional to the pH of the resist stripper 3. The pH of the resist stripping solution 3 is about 12 when the resist stripping solution 3 is a new solution, but gradually decreases as the use time elapses as shown in FIG. When the pH of the resist stripping solution 3 falls below 10.8 to 11.2 (hereinafter, as an example, 11.0), the resist stripping ability of the resist stripping solution 3 is greatly deteriorated, and the resist residue on the device substrate 21 is reduced. Will occur.

Therefore, the processing tank 2 (or the pipe 10)
The pH of the resist stripping solution 3 in the inside is adjusted through the pH electrode 16 to pH
The measurement is periodically performed by the H meter 17 and the measurement result (pH signal) is sent to the control unit 18. The control unit 18 determines whether or not the pH value according to the pH signal supplied from the pH meter 17 is equal to or less than a preset value 11.0.
If it is 0 or less, the pump 14 is driven. Here, the reason why it is 11.0 or less is that if it is less than 11.0,
This is because the pump 14 is driven before the resist residue is generated because the resist residue is generated.

When the pump 14 is driven, the supply tank 12
The MEA solution 13 is supplied to the processing tank 2 through the pipe 16. Then, the pH value of the resist stripping solution 3 in the processing tank 2 increases, and the concentration of carbon dioxide decreases.
As a result, the resist stripping ability of the resist stripping solution 3 in the processing tank 2 is restored, so that the use time of the resist stripping solution 3 can be extended, and the operation rate can be improved and the cost can be reduced.

The pump 14 may be stopped automatically when the amount of the MEA solution 13 based on the experimental data is replenished. Further, when the pH value measured by the pH meter 17 rises by a predetermined value from the set value 11.0, for example, when it becomes 11.1, a stop signal is sent from the control unit 18 to the pump 14. Is also good.

By the way, when measuring pH, an operation of calibrating the pH electrode 16 is necessary, and there is a face that is not suitable for automatic measurement. In addition, there is a concern that potassium ions in the electrolyte may diffuse into the resist stripping solution 3 from the pH electrode 16. Therefore, next, another embodiment of the present invention which does not require such considerations will be described.

FIG. 3 is a schematic structural view of a resist stripping apparatus according to another embodiment of the present invention. In this figure, the same reference numerals are given to the same names as those in FIG. 1, and the description thereof will be omitted as appropriate. In this embodiment, the drive control of the pump 14 will be described in detail later.
Meter 3 connected to a conductivity electrode 31 provided therein
The control unit 18 receives the conductivity signal from the control unit 2. Further, the processing tank 2 is supplied with water via a pipe 34 having an electromagnetic valve 33 interposed. As will be described in detail later, the control of the solenoid valve 33 is performed by the control unit 18 that receives an absorbance signal from an absorptiometer 36 interposed in a branch pipe 35 connected in parallel to the pipe 10.

Here, the relationship between the pH and the electrical conductivity when carbon dioxide is absorbed in the new resist stripping solution 3 is as shown in FIG. As is clear from this figure, the conductivity of the resist stripping solution 3 is 16
It shows a value around 0 μS / cm, but gradually increases as the pH decreases. In this case, the pH is 10.8-11.
2 is approximately 1300-600 μS / cm
And the conductivity corresponding to pH 11.0 is approximately 900μ.
S / cm.

Incidentally, the relationship between the water concentration (wt%) of the resist stripping solution 3 and the electrical conductivity is as shown in FIG. In this case, in FIG. 5, the top line is the case where the pH of the resist stripping solution 3 is 10.77, the next line is the case where the pH is 11.05, and the next line is the case where the pH is 11.39.
And the next line is for pH 11.65,
The next line is for pH 11.85. As is clear from this figure, the conductivity of the resist stripping solution 3 gradually decreases as the water concentration decreases due to evaporation of the water in the resist stripping solution 3 irrespective of the pH value.

Accordingly, for example, as shown in FIG. 6, when the water concentration of the resist stripping solution 3 is constant, the conductivity of the resist stripping solution 3 is correlated with the pH. In this case, in FIG. 6, a black circle indicates a case where the water concentration is fixed at 43%, a black square indicates a case where the water concentration is fixed at 47.4%, and a black triangle indicates a case where the water concentration is 50.4%. It is a case where it is fixed. As a result, when the electrical conductivity was measured while keeping the moisture concentration of the resist stripping solution 3 constant,
The value of pH is known, and the concentration of carbon dioxide in the resist stripping solution 3 is known. Therefore, in this embodiment,
First, it is necessary to keep the water concentration of the resist stripping solution 3 constant. For this purpose, it is necessary to measure the water concentration of the resist stripping solution 3. The absorptiometer 36 shown in FIG. 3 is for that purpose.

Next, measurement of the water concentration of the resist stripping solution 3 by the absorptiometer 36 will be described. First, FIG. 7 shows the transmittance of the resist stripping solution 3 having a constant water concentration. In this case, in FIG. 7, the line indicated by the uppermost black diamond at a wavelength of about 980 nm is the resist stripper 5
In the case where the water amount in 0 ml is 0 ml, the next line indicated by a black square is the case in which the water amount in 5 ml of the resist stripping solution is 0.5 ml, and the next line indicated by a black triangle is the line in which the resist stripping solution is 5 m
1 shows the case where the water content is 1 ml, and the next black circle line shows the case where the water content in 5 ml of the resist stripping solution is 2 ml. As is clear from this figure, there is a peak at a wavelength of 980 nm, which is due to moisture. Therefore, when the absorbance at a wavelength of 980 nm of the resist stripping solution 3 is measured by the absorptiometer 36, the water concentration of the resist stripping solution 3 can be obtained.

Now, the resist stripping solution 3 is measured by the absorptiometer 36.
The absorbance at a wavelength of 980 nm is periodically measured, and the measurement result (absorbance signal) is sent to the control unit 18. Control unit 1
8 judges whether or not the moisture concentration of the resist stripping solution 3 is less than a certain set value based on the absorbance signal supplied from the absorptiometer 36, and when it is less than a certain set value,
The electromagnetic valve 33 is opened, and moisture is supplied into the processing tank 2 via the pipe 34 so that the moisture concentration of the resist stripping solution 3 becomes a certain set value.

As described above, in a state where the water concentration of the resist stripping solution 3 is maintained at a certain set value, the conductivity of the resist stripping solution 3 in the processing tank 2 is periodically measured by the conductivity meter 32 through the conductivity electrode 31. And the measurement result (conductivity signal) is sent to the control unit 18. The control unit 18 controls the conductivity according to the conductivity signal supplied from the conductivity meter 32 so that the conductivity substantially corresponds to a preset value, for example, pH 11.0.
judge whether it is more than μS / cm, 900 μS / c
If it is not less than m, the pump 14 is driven.

When the pump 14 is driven, the supply tank 12
The MEA solution 13 is supplied to the processing tank 2 through the pipe 16. Then, the conductivity of the resist stripping solution 3 in the processing tank 2 decreases, the pH value increases, and the concentration of carbon dioxide decreases. As a result, the resist stripping ability of the resist stripping solution 3 in the processing tank 2 is restored, so that the use time of the resist stripping solution 3 can be extended, and the operation rate can be improved and the cost can be reduced.

The pump 14 may be stopped automatically after the MEA solution 13 is replenished in an amount based on the experimental data. When the conductivity measured by the conductivity meter 32 falls below a predetermined value of 900 μS / cm, for example, 800 μS / cm, a stop signal is sent from the control unit 18 to the pump 14. You may.

[0024]

As described above, according to the present invention, the concentration of carbon dioxide dissolved in the resist stripping solution is detected, and the amine solution is replenished based on the detection result. Thereby, the concentration of carbon dioxide in the resist stripping solution is reduced, the resist stripping ability of the resist stripping solution is restored, and therefore, the use time of the resist stripping solution can be extended, and thus the operation rate is improved and the cost is reduced. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a resist stripping apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a change over time in pH of a resist stripping solution.

FIG. 3 is a schematic configuration diagram of a resist stripping apparatus according to another embodiment of the present invention.

FIG. 4 is a diagram showing the relationship between pH and conductivity when carbon dioxide is absorbed in a new resist stripping solution.

FIG. 5 is a diagram showing the relationship between the water concentration of a resist stripper and the electrical conductivity.

FIG. 6 is a diagram showing the relationship between pH and conductivity of a resist stripper having a constant water concentration.

FIG. 7 is a view showing the transmittance of a resist stripper having a constant moisture concentration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Processing tank 3 Resist stripping liquid 4 Processing chamber 8 Resist stripping liquid collection part 9 Shower 11 Pump 12 Supply tank 13 MEA solution 14 Pump 16 pH electrode 17 pH meter 18 Control part 21 Device substrate 22 Film to be processed 23 Resist 31 Conductivity electrode 32 Conductivity meter 33 Solenoid valve 36 Absorbance meter

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H096 AA25 LA02 5F043 CC16 DD30 EE23 EE24 EE33 GG10 5F046 MA02 MA06 MA10

Claims (28)

[Claims] 1. A resist stripper for stripping a resist using a resist stripper, collecting and reusing a used resist stripper, and detecting the concentration of carbon dioxide dissolved in the resist stripper. Detecting means;
An amine solution replenishing means for replenishing the resist removing solution with an amine solution based on the detection result by the carbon dioxide concentration detecting means. 2. The resist removing apparatus according to claim 1, wherein said carbon dioxide concentration detecting means comprises a pH measuring means for measuring a pH of a resist removing liquid. 3. The method according to claim 2, wherein said p
When the pH value measured by the H measuring means falls below a set value, the amine solution is replenished by the amine solution replenishing means. 4. The method according to claim 3, wherein said p
When the pH value measured by the H measuring means is higher than the set value by a predetermined value, the supply of the amine solution by the amine solution replenishing means is stopped. 5. The resist stripping apparatus according to claim 3, wherein the amount of the amine solution supplied by the amine solution supply means is a preset amount. 6. The resist stripping apparatus according to claim 3, wherein the set value is 10.8 to 11.2. 7. The resist stripping apparatus according to claim 6, wherein the set value is 11.0. 8. The resist stripping apparatus according to claim 1, wherein said carbon dioxide concentration detecting means comprises a conductivity measuring means for measuring the conductivity of a resist stripping solution. 9. The invention according to claim 8, further comprising a water supply means for measuring a water concentration of the resist stripping solution, and supplying water to the resist stripping solution so that the water concentration is constant. A resist stripping apparatus characterized in that the measurement of the electrical conductivity of the resist stripping solution by the measuring means is performed while keeping the water concentration of the resist stripping solution constant. 10. The invention according to claim 9, wherein the amine solution is replenished by the amine solution replenishing means when the conductivity measured by the conductivity measuring means becomes a set value or more. Resist stripper. 11. The invention according to claim 10, wherein the replenishment of the amine solution by the amine solution replenishing means is stopped when the conductivity measured by the conductivity measuring means falls below the predetermined value by a predetermined value. A resist stripping apparatus, characterized in that: 12. The resist stripping apparatus according to claim 10, wherein the amount of the amine solution supplied by the amine solution replenishing means is a preset amount. 13. The method according to claim 10, wherein the set value is 1300 to 600 μS / c.
m. 14. The resist stripping apparatus according to claim 13, wherein the set value is 900 μS / cm. 15. A method for etching a film to be processed using a resist patterned on a film to be processed formed on a device substrate as a mask, and then peeling off the resist using a resist stripping solution; In a method of manufacturing a device for recovering and reusing a stripping solution, the concentration of carbon dioxide dissolved in the resist stripping solution is detected, and based on the detection result, an amine solution is supplied to the resist stripping solution, and the resist in the resist stripping solution is removed. A method for manufacturing a device, wherein the device is reused while restoring the peeling ability. 16. The device manufacturing method according to claim 15, wherein the concentration of the carbon dioxide is detected based on a result of measuring a pH of a resist stripping solution. 17. The device manufacturing method according to claim 16, wherein the amine solution is replenished when the measured pH value falls below a set value. 18. The device manufacturing method according to claim 17, wherein the supply of the amine solution is stopped when the measured pH value is higher than the set value by a predetermined value. 19. The device manufacturing method according to claim 17, wherein the replenishment amount of the amine solution is a preset amount. 20. The device manufacturing method according to claim 17, wherein the set value is 10.8 to 11.2. 21. The device manufacturing method according to claim 20, wherein the set value is 11.0. 22. The device manufacturing method according to claim 15, wherein the concentration of the carbon dioxide is detected based on a result of measuring the conductivity of the resist stripping solution. 23. The method according to claim 22, wherein the measurement of the conductivity of the resist stripping solution is performed by measuring a water concentration of the resist stripping solution, and replenishing water so that the water concentration is constant. A method for manufacturing a device. 24. The device manufacturing method according to claim 23, wherein the amine solution is replenished when the measured conductivity is equal to or higher than a set value. 25. The device manufacturing method according to claim 24, wherein the replenishment of the amine solution is stopped when the measured electric conductivity falls below the set value by a predetermined value. 26. The device manufacturing method according to claim 24, wherein the replenishment amount of the amine solution is a preset amount. 27. The method according to claim 24, wherein the set value is 1300 to 600 μS / c.
m. A method for manufacturing a device, comprising: 28. The device manufacturing method according to claim 27, wherein the set value is 900 μS / cm.