JP2003086565A - Chemical monitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical monitor improved so as to enable the continuous measurement at a low cost and the instantaneous sending of data information in the event of abnormal liquid concentration or temperature. SOLUTION: The chemical monitor improved so as to continuously measure the concentration or the temperature of a chemical in one measuring system by switching a plurality of etching tanks 17, 18 and 19 one after another is of an in-line type which takes the centralized management of the concentrations or temperatures of the plurality of etching tanks in one measuring system to enable the continuous measurement at a low cost, thereby instantaneously sending data information in the event of abnormal liquid concentration or temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to an apparatus for monitoring the concentration or temperature of a chemical solution in an in-apparatus treatment bath used for etching treatment, and more specifically, to a plurality of etching baths. The present invention relates to a chemical liquid monitor device for measuring the liquid concentration or temperature of each etching tank in the etching device.

[0002]

2. Description of the Related Art The cause of a change in the concentration of an etching solution in an etching process is that the active element (active ion concentration) in the etching solution is processed by the reaction of the thin film laminated on the etching substrate Decrease due to the decrease in the number, the etching processing capacity has deteriorated, the concentration has changed due to the evaporation of water during the etching solution circulation or evacuation in the tank, etc., and the water wraps around during the transfer of the substrate to the shower tank. , Due to forgetting to drain water when cleaning the tank.

Such a change in the concentration of the etching liquid component sometimes causes defective etching, which causes a decrease in yield due to defective leakage between patterns and uneven etching. Conventionally, with respect to changes in the concentration of the etching liquid component, a part of each etching liquid is extracted from each of the plurality of etching tanks, taken to a measuring instrument, and the concentration of the extracted etching liquid is measured.

Regarding the mixing of water, a dummy substrate in which a thin film to be etched is laminated on a raw glass is used,
Dummy etching was performed and the line width was measured to confirm the etching activity.

Regarding the frequency of exchanging the etching liquid,
Conventionally, it has been performed by controlling the time elapsed from the time of preparing the etching solution or by controlling the number of processed substrates in the etching solution.

Regarding the detection of the etching solution concentration, Japanese Patent Laid-Open No. 8-306654 describes a method in which each sensor is attached to each tank and the data is centrally controlled by a computer. Since each sensor is attached, the installation cost is high, and since maintenance is performed by each, there is a problem in that the time and frequency required for maintenance increase.

Further, since the concentration sensor is always immersed in the etching solution, there is a defect that the life of the sensor is shortened. Further, also in measuring the temperature of the liquid, conventionally, a sensor is installed in each etching tank to control the liquid temperature. As a result, a large number of sensors were required, and there was measurement variation among the sensors.

[0008]

However, it depends on the number of etching treatments, when the etching solution is circulated or when the water in the tank is exhausted to evaporate water, and when the substrate is transferred to the shower tank, the water wraps around and the tank is cleaned. Since it is difficult to detect the change in the temperature of the etching solution component due to forgetting to drain water at the time of occurrence, it is highly possible that the number of defective substrates is increased by continuing to flow the substrate even after the occurrence.

Further, after the discovery, a part of the etching solution is taken out, brought to a measuring instrument, and in the means for measuring the concentration, there is a considerable time from the taking out to the measurement, and the change before and after is unknown. It is difficult to identify the cause, and the etching solution is separated from the tank into the container, so that the etching solution atmosphere leaks to the process.

In the means for measuring and confirming the line width by performing the dummy etching, the result cannot be known until the stage where the dummy substrate passes through the processing steps and the inspection is completed.
It will take a considerable amount of time to start production.

In addition, since liquid exchange by time management causes a difference in the number of processed substrates to be etched within a specified time, and management of the number of processed substrates causes a difference in the specified substrate processing time. The etching solution concentration will vary. For this reason, there is a possibility that the liquid will not be replaced when it needs to be replaced, or that the liquid will be replaced when the liquid has not yet been replaced.

The liquid temperature also needs to be controlled for each bath, and the temperature sensor for each etching bath must be calibrated, so that maintenance is troublesome.

The present invention has been made to solve the above problems, and provides an improved chemical liquid monitor device capable of measuring and controlling the concentration or temperature of an etching liquid at low cost. Especially.

[0014]

A monitor device according to a first aspect of the present invention sequentially switches a plurality of in-line type etching tanks and continuously measures the concentration or temperature of a liquid with one measuring system. , Is characterized by managing.

A monitor device according to a second aspect of the present invention is
The monitor device according to the first aspect is characterized in that the etching liquid switching unit chamber, the measurement unit chamber, and the data processing unit chamber are independently provided.

A monitor device according to a third aspect of the present invention is
The monitor device according to the first aspect is characterized in that the measuring section chamber and the data processing section chamber are separated from each other to prevent the chemical atmosphere from flowing into the data processing section chamber.

A monitor device according to a fourth aspect of the present invention is
One of the features of this system is that a single liquid leak sensor can handle liquid leaks by installing a switching valve and a manual valve in one unit.

A monitor device according to a fifth aspect of the present invention is
The monitoring device according to the first aspect is characterized in that the processing signal is fed back to the etching device sequence.

A monitor device according to a sixth aspect of the present invention is
The monitor device according to the first aspect is characterized in that the processed signal can be confirmed in real time even when not at the site by giving the processed signal to CIM (computer-integrated-manufacturing).

According to the monitor device according to the first aspect described above, since the number of sensors required is reduced by managing a plurality of etching tanks with one measurement system of the in-line type, continuous measurement can be performed at low cost. It will be possible and economical.

Further, since the same sensor is used, it is not necessary to worry about the data fluctuation due to the variation of each sensor.

In the monitor device according to the second aspect, there is an effect that data can be processed when a liquid concentration abnormality occurs.

With the monitor device according to the third aspect,
The monitor device itself can be protected by preventing the chemical atmosphere from entering the data processing unit.

With the monitor device according to the fourth aspect,
By putting the switching valve and the manual valve in one unit, one liquid leak sensor can handle the liquid leak, and the cost can be reduced.

With the monitor device according to the fifth aspect,
By prohibiting the introduction of the next lot substrate when the liquid concentration abnormality occurs, it becomes possible to prevent the subsequent substrate defect from occurring, and it becomes possible to replace the liquid by liquid concentration management.

With the monitor device according to the sixth aspect,
By giving the processing signal to CIM, it is possible to confirm in real time even when not at the site, so that the etching liquid can be easily managed. Further, since it is possible to promptly deal with the occurrence of an abnormality, it is possible to suppress a decrease in productivity due to the occurrence of a defect to a minimum, and it is possible to reduce the manufacturing cost as compared with the conventional case.

[0027]

Embodiments will be described in detail below with reference to the drawings.

FIG. 1 is a schematic view of an etching apparatus to which the monitor device according to the present invention is applied. The etching apparatus includes a transport unit 16, a plurality of etching tanks 17, 18, and 19 (here, three tanks), a washing tank 20, and the like. 22 in the figure
Is a glass substrate.

The size of the bath depends on the size of the etching substrate 22, and the material of the bath also differs depending on the type of etching solution. In the case of an acid or alkali type etching solution, or in the case of hydrofluoric acid type, a fluorinated material is used.

In the carrying section 16, the substrates are taken out one by one from the cassette containing a plurality of substrates (each-leaf processing) and carried to the etching tank 17. The substrate 22 is moved to the next etching tanks 18 and 19 after the lapse of the prescribed processing time, the same processing is performed, and after the etching is completed, it is moved to the water washing tank 20.

In each of the etching tanks, the etching liquid (the arrow represents the liquid) is in a shower state and evenly sprinkles on the upper surface of the substrate 22 to etch the thin film on the substrate 22.

Also in the water washing tank 20, water hits the substrate in a sheared state and the water washing treatment is performed. In the case of this embodiment, the chemicals in each etching tank may be of the same type or of different types. For substrates that are difficult to etch,
Since etching takes time, the chemicals in the etching bath are often set to the same type. When the type of chemical solution is different in each etching tank, an air knife is installed between the tanks to prevent the etching solution from being mixed between the tanks.

FIG. 2 is a configuration diagram of the etching solution switching section and the measuring section of the etching solution concentration or temperature monitoring device. The device includes manual valves 1 to 8, switching valves 9 to 14, a liquid leak sensor 15, and a measuring unit.

Further, the measuring unit is the etching liquid switching unit 9-1.
4 and the manual valves 7 and 8 are connected, and the manual valve 1 and the etching tank 1, the manual valve 2 and the etching tank 2, the manual valve 3 and the etching tank 3 are connected.
And are connected by piping. The manual valve 4 and the measuring part calibration liquid tank 21 are connected by a pipe, and the manual valves 5 and 6 are connected for drainage. The manual valve 5 is connected to the acid / alkali drainage valve of the etching apparatus to process the etching solution after measurement, and the manual valve 6 is used to process the calibration solution after calibration.
Connected to the dilute acid drain valve of the etcher, all valves 1-14 are contained within one unit.

For measuring the concentration of the acid and alkali etching solution,
In the quartz cell, near-infrared transmission spectroscopic measurement is performed with an interference filter at 8 wavelengths, and is performed regularly regardless of the presence or absence of substrate processing. When measuring the concentration of the etching solution in the etching tank 1, a switching valve is used. Open 9 and 13 and measure. Similarly, in the case of other tanks, the concentration is measured continuously and continuously.

After measuring the concentration of the etching solution in the etching tank 1, the switching valve 9 is closed, and the inner switching valve 10 is opened to measure the concentration of the etching solution in the etching tank 2. At this time, the etching solution in the etching tank 2 is piped. The etching liquid remaining in the etching tank 1 is flowed until it is discharged, and then the measurement is performed.

The replacement of the liquid in the pipe is performed when measuring any etching tank and when calibrating the concentration sensor in the measuring section.

For measuring the temperature of the acid or alkali etching solution, a temperature sensor is installed in the quartz cell of the measuring section, and the solution temperature is monitored every time the solution in each etching tank is switched.

Since the liquid temperature slightly affects the etching rate and the cross-sectional shape of the etching film, it is necessary to monitor it regularly.

FIG. 3 is an overall view of the etching liquid monitor device. By installing the measuring unit installed in the etching liquid switching unit room above the manual valve chamber, even if a liquid leak occurs in the manual valve chamber, the measuring unit is prevented from being affected and the data processing unit is set to the etching liquid. By using a unit separate from the switching unit chamber, it is possible to prevent the chemical liquid atmosphere from entering the data processing unit.

Further, by sending a signal from the data processing unit to the etching apparatus when a concentration abnormality or a temperature abnormality occurs, it is possible to prohibit the loading of the next lot substrate and prevent the subsequent substrate failure from occurring.

It should be considered that the embodiments disclosed herein are illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[0043]

As described above, according to the present invention, since the concentration or temperature of a plurality of etching tanks is centrally controlled by one measurement system of the in-line type, continuous measurement at low cost becomes possible, There is an effect that data information can be instantaneously transmitted when an abnormality in the liquid concentration or temperature occurs.

Further, by preventing the chemical liquid atmosphere from flowing into the data processing section, the monitor device itself can be protected. By inserting the switching valve and the manual valve into one unit, the liquid leakage sensor can detect the liquid. Corresponding to leaks, cost can be reduced, and by prohibiting the introduction of the next lot substrate when a liquid concentration abnormality occurs, it is possible to prevent subsequent substrate defects from occurring, and it is possible to perform liquid exchange by liquid concentration management. By giving a signal to CIM, it is possible to check in real time even when not at the site, so that the etching liquid can be easily managed.

Further, since it is possible to promptly respond to the occurrence of an abnormality, it is possible to minimize the reduction in productivity due to the occurrence of defects and to reduce the manufacturing cost as compared with the conventional case.

[Brief description of drawings]

FIG. 1 is a schematic view of an etching apparatus to which a monitor device according to the present invention is applied.

FIG. 2 is a configuration diagram of an etching liquid switching unit and a measuring unit of an etching liquid concentration or temperature monitoring device.

FIG. 3 is an overall view of an etching solution concentration or temperature monitoring device.

[Explanation of symbols]

1-8 Manual valve, 9-14 Switching valve, 15
Liquid leak sensor, 16 transfer unit, 17 to 19 etching bath, 20 water washing bath, 21 measuring unit calibration liquid bath, 22 glass substrate.

Claims (6)

[Claims] 1. A plurality of etching tanks are sequentially switched to one
A chemical solution monitor device that measures and controls the concentration or temperature of the chemical solution continuously with two measuring systems. 2. An etching solution switching chamber, a measuring chamber and a data processing chamber are independently provided.
The chemical solution monitoring device according to claim 1. 3. The chemical liquid monitor device according to claim 1, wherein the measurement chamber and the data processing chamber are separated from each other to prevent the etching solution atmosphere from flowing into the data processing chamber. 4. The chemical liquid monitor device according to claim 1, wherein one liquid leak sensor can handle liquid leaks by inserting a switching valve and a manual valve into one unit. 5. The chemical solution monitoring device according to claim 1, wherein the processing signal is fed back to the etching device sequence. 6. By raising the processed signal to CIM,
The chemical liquid monitoring device according to claim 1, wherein the chemical liquid monitoring device can be confirmed in real time even when not on site.