JPH0737857A - Treating liquid monitor - Google Patents

Abstract

PURPOSE:To automatize control of the concentration of a treating liquid, such as an etching treating liquid, and the like and to contrive to improve the efficiency of the manufacturing operation of a semiconductor integrated circuit. CONSTITUTION:An etching liquid 2 for treating a semiconductor wafer is housed in a treating tank 3, the concentration of this etching liquid 2 is detected by a concentration measuring device 11 and the number of foreign substances in the etching liquid 2 is detected by a number-of-foreign-substances measuring device 12. The detection results are respectively displayed on a concentration display part and a number-of-foreign-substances display part. Pure water and a chemical are fed in the tank 3 on the basis of the detection results of the respective measuring devices 11 and 12 and the etching liquid 2 is always maintained in a prescribed concentration range. In the case where the number of the foreign substances and the concentration are respectively brought in an abnormal state, alarms are respectively operated and the abnormal states are informed to operators.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing liquid monitoring device for monitoring whether a processing liquid such as an etching liquid used for manufacturing a semiconductor integrated circuit is in an appropriate state.

[0002]

2. Description of the Related Art In the process of manufacturing a semiconductor integrated circuit, contaminants are removed before the steps of oxidation, vapor phase growth, ion implantation, etc. so that the contaminants do not remain on the surface of a semiconductor wafer. . In order to remove organic contaminants and inorganic contaminants, the surface of the semiconductor wafer is usually subjected to acid cleaning treatment.

Treatment solutions for acid cleaning include sulfuric acid, nitric acid, hydrofluoric acid, hydrochloric acid and the like, and hydrofluoric acid is used for removing the oxidized Si film. Contamination is removed by this acid cleaning, and in order to remove the oxide Si film formed on the surface of the semiconductor wafer at that time, etching treatment is performed as a surface treatment. As the etching treatment liquid at this time, hydrofluoric acid, an ammonium fluoride aqueous solution, or the like is used.

Through these steps, the semiconductor wafer is coated with a photoresist film in order to form a circuit pattern on the surface thereof, a pattern is formed on the photoresist film, and an etching process is performed.

In the etching treatment used as the surface treatment, the concentration of the HF (hydrofluoric acid) solution is maintained at a predetermined value so that a predetermined etching rate can be obtained for a predetermined processing time, and It is necessary to manage the processing liquid so that foreign matter is not contained in the solution.

[0006]

Conventionally, in addition to a semiconductor wafer to be manufactured, a semiconductor wafer for sample is immersed in a processing liquid, that is, an HF solution, and these are processed at the same time.
By measuring the film thickness difference between before and after the etching process on the sample semiconductor wafer, the etch rate to determine whether the processing liquid has a predetermined concentration or not is measured. I try to measure the number of.

In such a treatment liquid monitoring system, an operator monitors the treatment liquid off-line to determine whether or not the concentration of the treatment liquid is out of a predetermined specified value.
When foreign matter such as particles brought in together with the semiconductor wafer exceeds a predetermined number per unit volume of the processing liquid, the filter is replaced. As described above, conventionally, since the state of the processing liquid is monitored off-line, not only the work efficiency is not good, but also the production efficiency is reduced. Further, when the etch rate was out of the standard value, the etching solution had to be drained and mixed again.

An object of the present invention is to automate the management of the concentration of a processing solution such as an etching processing solution and improve the manufacturing work efficiency of a semiconductor integrated circuit.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0010]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, the treatment tank containing the treatment liquid is provided with concentration measuring means for detecting the concentration of the treatment liquid, and the concentration value detected by this concentration measuring means is displayed on the concentration display section. . The number of foreign matters contained in the treatment liquid is detected by the foreign matter number measuring means, and the number of foreign matters detected by the foreign matter number measuring means is displayed on the foreign matter number display section. Further, when the concentration of the treatment liquid deviates from a predetermined standard value, it is automatically adjusted to an appropriate concentration by the pure water from the pure water supply pipe and the chemical liquid from the chemical liquid supply means.

[0012]

In the processing liquid monitoring apparatus of the present invention described above,
Since the concentration of the processing liquid such as the etching processing liquid is automatically adjusted, the operator can always monitor the number of foreign substances in the processing liquid. Therefore, it is not necessary to frequently sample and measure the concentration of the processing liquid, and the filter for removing foreign matter can be replaced at an appropriate time, which significantly increases the work efficiency of the semiconductor integrated circuit manufacturing work. improves.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a case where the present invention is applied to an etching treatment for performing etching as a surface treatment before forming a circuit pattern on a semiconductor wafer, and FIG. 2 is an enlarged front view showing a part thereof. It is a figure.

The etching apparatus main body 1 is provided with a processing bath 3 containing an etching liquid 2 as a processing liquid therein, and a semiconductor wafer (not shown) is carried into the processing bath 3 and immersed therein. It is like this. A water washing tank 4 is arranged in the etching apparatus main body 1 adjacent to the treatment tank 3, and the semiconductor wafer after the etching treatment is washed in the water washing tank 4.

As shown in FIG. 2, pure water is supplied into the processing tank 3 through the pure water supply pipe 5 by the operation of the pure water supply pump 6, and the chemical liquid supply pump is supplied through the chemical liquid supply pipe 7. By the operation of 8, the chemical liquid such as hydrofluoric acid is supplied.

The etching apparatus main body 1 has a concentration measuring device 11 for detecting the concentration of the etching liquid 2 in the processing bath 3.
The etching solution 2 in the processing bath 3 is supplied to the measuring instrument 11 by a pipe 11a. Further, a foreign matter number measuring device 12 is arranged in the etching apparatus main body 1 in order to detect the number of foreign matter in the etching liquid 2, and the foreign matter number measuring device 12 is provided with a pipe 12a for removing the etching liquid 2 in the processing tank 3. Supplied.

The concentration value detected by the concentration measuring device 11 is lit up and displayed on the concentration display unit 13 shown in FIG. 3, and the number of foreign substances detected by the foreign substance number measuring unit 12 is lit up and displayed on the foreign substance number display unit 14. It is supposed to be done. These display portions 13 and 14 are the same as the etching processing apparatus main body 1 shown in FIG.
Is arranged in a predetermined portion of.

FIG. 4 is a block diagram showing the control circuit.
Concentration measuring device 11 and foreign matter number measuring device 12 are each CP
It is connected to the control unit 15 composed of U, etc., and the detection signals from the respective measuring instruments 11, 12 are sent to the control unit 15, and the respective detection values are displayed on the display unit via the control unit 15. The display is turned on in 13 and 14. Therefore, the operator can always monitor the state of the etching liquid 2 by visually observing the concentration of the etching liquid 2 and the number of foreign matters in the etching liquid 2.

Further, an operation signal is sent to each of the pure water supply pump 6 and the chemical solution supply pump 8 described above by a signal from the control section 15. Data of an appropriate concentration value is stored in a memory built in the control unit 15 or externally attached, and when the data is read out and the concentration of the treatment liquid in the treatment tank 3 deviates from the proper concentration, a pure concentration value is calculated. The water supply pump 6 and the chemical solution supply pump 8 are operated.

Therefore, since the concentration of the treatment liquid is automatically controlled so as to be a proper concentration set in advance, it is not necessary to perform the concentration inspection based on the sampling data and the inspection of the number of foreign matters as in the conventional case. The workability is greatly improved, the production efficiency is improved, and the manufacturing cost can be reduced. Further, since it is not necessary for the worker to collect sampling data, the safety of work is improved.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, by providing a concentration alarm 16 as shown in FIG. 4, when the concentration of the etching liquid 2 deviates from the standard value on the basis of the detection signal from the concentration measuring device 11, an abnormal state is given to the operator. You may also let us know.
Similarly, by providing the foreign substance alarm 17, the etching liquid 2 is detected based on the detection signal from the foreign substance number measuring device 12.
It is also possible to notify the operator of the abnormal state when the number of foreign matters in the inside has increased beyond a predetermined value.

As the respective alarms 16 and 17,
An alarm lamp or an alarm buzzer can be used, and an operator can be notified of an abnormal condition by operating one or both of them. As described above, when the alarms 16 and 17 are used, it is not necessary to use the chemical liquid supply pipe 7 or the pure water supply pipe 5 for automatically controlling the concentration of the processing liquid 2.

In the above description, the case where the invention made by the present inventor is mainly applied to the etching apparatus which is the field of application of the invention has been described, but the present invention is not limited to this. For example, an etching apparatus for wet etching, The present invention can be applied to the case where a semiconductor wafer is processed using a chemical solution such as a cleaning device.

[0026]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

(1). Since the concentration of the processing liquid such as the etching liquid is automatically set, the work of measuring the concentration of the processing liquid by an operator becomes unnecessary, and the manufacturing work efficiency and the production efficiency of the semiconductor integrated circuit are improved. Greatly improved.

(2) Since the number of foreign matters contained in the processing liquid is automatically measured, the work of measuring the number of foreign matters by an operator becomes unnecessary, and the manufacturing work efficiency and the production efficiency of the semiconductor integrated circuit are greatly increased. Improve to.

(3) Further, since the concentration of the processing liquid is automatically set, the work safety is improved.

(4) Further, the manufacturing cost of the semiconductor integrated circuit can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic front view showing a processing liquid monitoring apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged front view showing a main part of FIG.

FIG. 3 is a front view showing a display unit.

FIG. 4 is a block diagram showing a control circuit.

[Explanation of symbols]

 1 Etching apparatus main body 2 Etching liquid 3 Treatment tank 4 Rinsing tank 5 Pure water supply pipe 6 Pure water supply pump 7 Chemical liquid supply pipe 8 Chemical liquid supply pump 11 Concentration measuring instrument 11a Pipe 12 Foreign matter number measuring instrument 12a Pipe 13 Concentration display section 14 Foreign matter Number display unit 15 Control unit (concentration control means) 16 Concentration alarm 17 Foreign matter alarm

Front page continuation (72) Inventor Tokio Naito 5-22-1, Kamisuihonmachi, Kodaira-shi, Tokyo Inside Hitachi Microcomputer System Co., Ltd.

Claims (5)

[Claims] 1. A processing tank containing a processing liquid for processing a semiconductor wafer, a concentration measuring unit for detecting the concentration of the processing liquid, and a concentration display unit for displaying a value detected by the concentration measuring unit. A processing liquid monitoring device having. 2. The process according to claim 1, further comprising: a foreign matter number measuring means for detecting the number of foreign matter in the treatment liquid; and a foreign matter number display section for displaying the number of foreign matter detected by the foreign matter number measuring means. Liquid monitoring device. 3. A pure water supply means for supplying pure water into the processing tank, a chemical liquid supply means for supplying a chemical liquid such as an etching liquid into the processing tank, and the processing liquid detected by the concentration measuring means. 2. The processing liquid monitoring apparatus according to claim 1, further comprising: pure water supply means and concentration control means for controlling the chemical liquid supply means when the concentration of the liquid exceeds a standard value. 4. The processing liquid monitoring apparatus according to claim 1, further comprising a concentration alarm for notifying an operator of an abnormal state when the concentration of the processing liquid detected by the concentration measuring means deviates from a standard value. 5. The processing liquid monitor according to claim 2, further comprising a foreign material alarm for notifying an operator of an abnormal condition when the number of foreign materials in the processing liquid detected by the foreign material number measuring means exceeds a predetermined value. apparatus.