JPH11201947A - Electromagnetic sensor, control apparatus for concentration of developer and inspection method for concentration of developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection method, for the concentration of a developer, in which the concentration of the developer can be detected automatically and in real time by using tetramethylammonium hydroxide(TMAH) and in which the concentration can be controlled automatically, to provide an electromagnetic sensor for concentration inspection and to provide a control apparatus for the concentration of the developer. SOLUTION: A transmitting coil 2 and a receiving coil 3 are constituted of a toroidal coil which uses Permalloy or the like as a core, and they are piled up longitudinally so as to form an electromagnetic sensor. A developer flows through the hollow part of the electromagnetic sensor. The intensity of the electromagnetic coupling of both coils is changed due to the concentration of ions in the flowing-through developer. When a current flows to the transmitting coil 2, an induced current corresponding to the concentration of the ions at this time flows to the receiving coil 3. On the basis of the induced current, the concentration of the developer is detected. As a result, the concentration can be detected in a noncontact manner, and it is possible to obtain the electromagnetic sensor whose life is long and which is maintenance free as compared with a case in which an electrode is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tetramethyl ammonium hydroxide (TMAH) for developing a fine resist pattern such as a liquid crystal display.
, A developer concentration control method, a developer concentration control device,
Also, the present invention relates to a probe for an electromagnetic sensor and an electromagnetic sensor used in this device and the like.

[0002]

2. Description of the Related Art When developing a photoresist at the time of producing a fine wiring pattern such as a transparent electrode of a liquid crystal matrix display, unless the development ability of a developing solution is strictly managed, a disconnection due to excessive development or a bridge due to insufficient development. The occurrence rate becomes high. Therefore, for the development of such a fine pattern, a high-resolution and stable TMA is used instead of a conventional sodium hydroxide developer.
H is frequently used.

[0003]

In order to strictly control the concentration of the developer, it is necessary to accurately detect the concentration in real time and to control the concentration to be constant according to the result of the detection. In addition, the continuity resistance sensor using an electrode has a long-term change due to corrosion of the electrode surface and the like, and the detection accuracy is poor.
There was a problem that maintenance was required, such as periodic replacement. On the other hand, an electromagnetic sensor that detects magnetic resistance (permeability) is maintenance-free because it is non-contact. However, since the TMAH developer has a milder composition than the sodium hydroxide developer, it uses a normal electromagnetic sensor. The sensor was greatly affected by error factors such as bubbles in the liquid, and could not accurately detect its concentration.

[0004] For this reason, conventionally, in order to inspect the concentration of a TMAH developer, it is necessary to use an inspection method such as liquid chromatography, titration (neutralization titration), and atomic absorption (flame color reaction). There is a problem that the inspection cannot be automatically performed in real time and the concentration control cannot be performed automatically.

For this reason, conventionally, without controlling the concentration of the developing solution, a new developing solution is always used, and the number of sheets (thousands of sheets) which does not greatly deteriorate the developing solution is developed, and then the developing solution is discarded. Had to do batch processing. However, such a method has a problem in that the waste liquid is increased, so that the treatment is expensive and has an adverse effect on the environment, and the expensive TMAH is costly because it is discarded without being regenerated. Furthermore, even if a new developing solution is used, the deterioration gradually progresses by using it in the developing process, so that the degree of development differs between the first developed substrate and the last developed substrate, resulting in quality variations. There was a problem.

According to the present invention, there is provided a method for inspecting the concentration of a developer which can automatically detect the concentration of the developer using TMAH in real time and which can be automatically controlled, a probe for an electromagnetic sensor, an electromagnetic sensor, and a developing method. It is an object to provide a liquid concentration control device.

[0007]

According to a first aspect of the present invention, a transmitting coil of a hollow iron core and a receiving coil of a hollow iron core are overlapped so that the hollow portions coincide with each other, and the hollow portions are vertically opened. As described above.

According to a second aspect of the present invention, there is provided an electromagnetic sensor using the electromagnetic sensor probe according to the first aspect, wherein a transmitting circuit for supplying a predetermined current to the transmitting coil, and a transmitting circuit for supplying a current to the receiving coil when the transmitting circuit supplies a current. And a receiving circuit for detecting a value of the induced current generated.

According to a third aspect of the present invention, there is provided the electromagnetic sensor according to the second aspect, wherein the probe is provided in a developer.
A control unit for supplying TMAH or pure water in accordance with a detection value of the electromagnetic sensor.

[0010] The invention of claim 4 of the present application is a method in which TM is added to pure water.
A method for inspecting the concentration of a developer prepared by dissolving AH, comprising: installing an electromagnetic sensor including a transmission coil and a reception coil in the developer; applying an AC signal to the transmission coil; The concentration of the developer is detected based on an induced current generated in the coil.

[0011]

FIG. 1 is a diagram showing a configuration of an electromagnetic sensor according to an embodiment of the present invention. The electromagnetic sensor probe 1 is composed of a transmission coil 2 and a reception coil 3 which are vertically stacked.
Consists of The transmitting coil 2 and the receiving coil 3 are both formed of toroidal coils wound around a toroidal core. This toroidal coil has an outer diameter of about 6 cm and an inner diameter of the hollow part of about 3 cm. The transmitting coil 2 and the receiving coil 3 are housed in a cylindrical resin case 4.
On the upper and lower surfaces of the resin case 4, the transmitting coils 2 and
Openings 4 a and 4 b are formed in accordance with the hollow portion of the receiving coil 3. This resin case 4 is vertically oriented (opening 4
a, 4b are opened by a cable (so that they open up and down), and are installed so as to be immersed in the developer.

Further, lead wires (not shown) are drawn out of the case from the transmitting coil 2 and the receiving coil 3 and are connected to the oscillating circuit 6 and the receiving circuit 7 shown in FIG. The oscillation circuit 6 to which the transmitting coil 2 is connected
Oscillates a low-frequency signal of about 1 kHz to 5 kHz and applies it to the transmitting coil 2. The receiving circuit 7 to which the receiving coil 3 is connected detects an induced current flowing through the receiving coil 3 in a range of about 0.01 to 30 mA.

The coupling coefficient between the transmitting coil 2 and the receiving coil 3 is determined by their positional relationship and distance, as well as the magnetic permeability of the atmosphere. Since the positional relationship and the distance are fixed as shown in FIG. 2A, the coupling coefficient is determined exclusively by the atmosphere, that is, the magnetic permeability of the developer. Since the magnetic permeability of the developing solution is determined by the ion concentration in the solution, when a constant current is applied to the transmitting coil 2, the magnitude of the induced current flowing through the receiving coil 3 according to the coupling coefficient causes the developing solution to have a high permeability. The ion concentration can be detected.
This ion concentration is proportional to the concentration of TMAH in the liquid. Therefore, by detecting the value of the induced current flowing through the receiving coil 3 when the current flows through the transmitting coil 2, the concentration of the developer at that time can be determined.

The developer flows in a complicated manner by spraying or stirring, and tends to contain air bubbles. However, since the hollow portion is open up and down, no air bubbles accumulate in the hollow portion. Does not affect the coupling coefficient. In addition, by increasing the inner diameter to 3 cm, even if bubbles are formed, the magnetic permeability of the atmosphere as a whole is hardly affected. Thus, the concentration of the TMAH developer can be accurately detected by using this electromagnetic sensor. Further, since it is a non-contact sensor and has a high resistance to a developing solution (alkali), it can perform stable maintenance-free long-term concentration detection.

When a TMAH solution is used as a developer,
The concentration does not exceed 5 percent, and is usually used at a concentration of about 3 to 3.5 percent. When an exciting current is applied to the transmitting coil 2 under this condition, an induced current flows through the receiving coil 3 according to the concentration of the solution. The receiving circuit 7 scales and amplifies this current, then A / D converts it, and inputs it to the controller 8. The controller 8 incorporates a microcomputer (microcomputer), detects the value of the induced current with high accuracy, and calculates the concentration of the TMAH developer based on the detection result regarding the resolution. When the controller 8 also functions as the density management device 9 shown in FIG. 2, processing such as replenishment of the developer is performed in accordance with the detected density.

FIG. 2 shows claims 3 and 4 of the present invention.
It is a figure which shows the structure of the pattern development line of the transparent electrode for LCD displays which is embodiment of this invention. The developing line includes a main tank 10 for storing a developing solution currently used in the developing process, a conveyor 11 for conveying a transparent electrode sheet having an exposed electrode pattern, and a developing solution for the transparent electrode sheet conveyed on the conveyor. And a pump 13 for supplying the developing solution in the main tank 10 to the nozzle 12. The transported transparent electrode sheet is sprayed with a developing solution on the conveyor 11, and while transported, the resist other than the electrode pattern is melted and removed.

On the other hand, a pump 16 for stirring the developing solution is provided in the main tank 10, and this pump 16 branches a part of the developing solution sucked for stirring and sends it to the sampling tank 14. Various sensors such as the electromagnetic sensor 15 shown in FIG. 1 are provided in the sampling tank 14.
The electromagnetic sensor 15 detects the concentration of the sampled developer. Since the developer in the main tank 10 is constantly fed into the sampling tank 14 by the pump 16, the concentration of the developer in the main tank 10 at that time can always be detected. This detected content is read into the density management device 9. The developing line is provided with a stock tank 20 for stocking a developing solution for replenishment, and is connected to the main tank 10 via a pump 22 for replenishing the developing solution.

When the detected value of the electromagnetic sensor 15 in the sampling tank 14 falls below an allowable range, the concentration management device 9 drives the replenishing pump 22 to supply an appropriate amount of developing solution to the main tank 1.
Replenish to zero.

When a new developer is supplied to the main tank 10 by the pump 22, a part of the old developer contained in the main tank 10 overflows and flows out to the recycling step 30. As a result, the old developing solution is replaced with a new developing solution, and the concentration and composition of the developing solution are maintained in appropriate ranges.

On the other hand, an electromagnetic sensor 21 is also provided in a stock tank 20 for supplying a new developing solution to the main tank 10.
The concentration of the developer in the stock tank 20 is detected. A chemical tank 23 and a pure water tank 25 are connected to the stock tank 20 via pumps 24 and 26. In the chemical tank 23, TM
A concentrated solution of AH is contained. The pure water tank 25 contains pure water for dilution. The TMAH in the chemical tank 23 and the pure water in the pure water tank 25 are supplied to the stock tank 20 by the pumps 24 and 26 under the control of the concentration control device 9.

When the amount of the developing solution in the stock tank 20 decreases,
The concentration management device 9 drives the pumps 24 and 26 to additionally prepare a new developer in the stock tank 20. The concentration of the developer in the stock tank 20 is detected by the electromagnetic sensor 21 and read by the concentration management device 9. The concentration management device 9 drives the pumps 24 and 26 based on the detection value of the electromagnetic sensor 21 to prepare a developer having an appropriate concentration.

The recycling step 30 for taking in the overflowed developer is divided into a separation step 31 and a concentration step 3.
It consists of two. The separation step 31 is a step of separating the resist resin dissolved in the developing solution.
Is a step of preparing a high-concentration TMAH solution by concentrating a developer prepared by diluting TMAH with pure water. The separation step 31 and the concentration step 32 may be performed sequentially or in parallel. When the processes are performed in parallel, for example, first, the resist component is roughly separated by filtration through a UF membrane, and then concentrated by an RO membrane (semi-permeable membrane) to thereby separate out the resist component and filter it. Such a procedure may be used.

The electromagnetic sensor 33 shown in FIG. 1 is also used in the concentration step 32. The electromagnetic sensor 33 detects the concentration of the TMAH solution concentrated in the concentration step 32 and inputs the detected concentration to the control 8. The concentration control device 9 performs the concentration step 3
When the TMAH solution in Step 2 is concentrated to a concentration of about 60%, it is recycled to the chemical tank 23 as a stock solution for developing solution preparation.

The set concentration of the developing solution in the stock tank 20, the allowable concentration of the developing solution in the main tank 10, and the concentration of the recycled solution in the concentration step 32 can be arbitrarily set from the operation panel of the concentration control device 9. Further, the drive timing and the drive amount of each pump can be arbitrarily set in the concentration management device 9.

According to the developing line of the above embodiment, the concentration of the developing solution being used in the main tank 10 is monitored by using the electromagnetic sensor 15, and the concentration of the developing solution is allowed by adding a new developing solution. By keeping the range, the total life of the developer can be extended. In addition, by separating the resist resin component from the used developer and concentrating and reusing the TMAH solution, almost no waste liquid is generated, which leads to environmental protection.

[0026]

According to the first and second aspects of the present invention, the transmitting coil and the receiving coil are constituted by hollow iron core coils and are arranged vertically continuously, so that the influence of bubbles in the liquid is almost eliminated. Accurate concentration measurement becomes possible without receiving.

According to the present invention, as described above, the concentration of the developing solution is detected by using the electromagnetic sensor probe including the transmitting coil and the receiving coil. Also becomes possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an electromagnetic sensor according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a developing line of a transparent electrode of the LCD matrix display according to the embodiment of the present invention;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Probe for electromagnetic sensors, 2 ... Transmission coil, 3 ... Receiving coil, 4 ... Case, 4a, 4b ... Opening, 6 ... Oscillation circuit, 7 ... Receiving circuit, 8 ... Controller, 9 ... Concentration management device, 15, 21, 33: electromagnetic sensor, 10: main tank, 20
... stock tank, 23 ... chemical tank, 24 ... pure water tank, 30 ... recycling process, 32 ... concentration process

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[Procedure amendment]

[Submission date] February 15, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

Patent application title: Electromagnetic sensor, developer concentration control device and developer concentration inspection method

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction contents]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tetramethyl ammonium hydroxide (TMAH) for developing a fine resist pattern such as a liquid crystal display.
, A developer concentration control method, a developer concentration control device,
And relates to an electromagnetic sensor used for this device.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

SUMMARY OF THE INVENTION The present invention provides a developer concentration inspection method, an electromagnetic sensor , and a developer concentration control device capable of automatically detecting the concentration of a developer using TMAH in real time and automatically controlling the developer. The purpose is to provide.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

According to a first aspect of the present invention, there is provided a hollow core transmission coil having an inner diameter substantially half of the outer diameter, and a hollow core reception coil having the same outer diameter and inner diameter as the transmission coil. Are overlapped so that the hollow portions coincide .
The probe is always open so that the hollow part opens up and down.
It is installed in a flowing developing solution, and a predetermined voltage is applied to the transmitting coil.
A transmitting circuit for flowing a current, and when the transmitting circuit flows a current,
A receiving circuit for detecting a value of an induced current generated in the receiving coil;
And a road.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Deleted

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

According to a second aspect of the present invention, there is provided the electromagnetic sensor according to the first aspect , wherein the probe is provided in a developer.
Characterized by comprising a control means for introducing TMAH or pure water according to the detected value of the electromagnetic sensor.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010] The invention of claim 3 of the present application is a method in which TM is added to pure water.
A method for inspecting the concentration of a developer prepared by dissolving AH, comprising: a hollow iron core transmission coil having an inner diameter substantially half of an outer diameter; and a medium having the same outer diameter and inner diameter as the transmission coil.
Weight the receiving coil of the air core so that the hollow part matches.
Sprayed probe, so that the hollow part opens up and down,
It is installed in a constantly flowing developing solution, and when an AC signal is applied to the transmitting coil, the concentration of the developing solution is detected based on an induced current generated in the receiving coil.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction contents]

[0026]

According to the first aspect of the present invention, the transmitting coil and the receiving coil are each formed of a hollow iron core coil having an inner diameter of about half of the outer diameter, and are arranged vertically continuously in a flowing developer.
With this arrangement, accurate concentration measurement can be performed with little influence from bubbles in the liquid.

Claims (4)

[Claims] 1. A probe for an electromagnetic sensor, wherein a transmission coil of a hollow iron core and a reception coil of a hollow iron core are overlapped so that the hollow portions coincide with each other, and the probe is installed in a developer so that the hollow portions open up and down. 2. A transmission circuit for flowing a predetermined current through the transmission coil using the probe for an electromagnetic sensor according to claim 1, and detecting a value of an induced current generated in the reception coil when the transmission circuit flows a current. An electromagnetic sensor, comprising: a receiving circuit configured to: 3. The electromagnetic sensor according to claim 2, wherein the probe is provided in a developing solution, and control means for supplying tetramethylammonium hydroxide or pure water according to a detection value of the electromagnetic sensor. And a developer concentration control device. 4. Tetramethylammonium.pure water
A method for testing the concentration of a developer prepared by dissolving a hydroxide, comprising: installing an electromagnetic sensor including a transmission coil and a reception coil in the developer; applying an AC signal to the transmission coil; A developer concentration inspection method, comprising: detecting a concentration of the developer based on an induced current generated in a receiving coil.