JP3082871B2 - Processing solution monitoring device - Google Patents

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.

[0002]

2. Description of the Related Art Generally, when processing is performed by immersing an object to be processed in a processing liquid tank, a processing liquid circulation pipe for circulating the processing liquid in the processing liquid tank and a processing liquid circulation pump are provided. 2. Description of the Related Art For example, a treatment liquid is cleaned by inserting a filter or the like for removing particles in the treatment liquid into a liquid circulation pipe.

For example, in a cleaning apparatus for cleaning a semiconductor wafer, such a processing liquid circulation pipe having a filter mechanism is provided in an HF processing liquid tank for removing an oxide film formed on the surface of the semiconductor wafer using hydrofluoric acid. To remove particles in the processing liquid. This is because particles easily adhere to the silicon surface of the semiconductor wafer from which the oxide film has been removed. However, in such an HF processing solution tank, the number of particles in the processing solution is kept at a predetermined level or less, and thus the , A processing liquid in the HF processing liquid tank is periodically collected to monitor the number of particles in the processing liquid.

[0004]

However, as described above, in the method of periodically collecting the processing liquid and monitoring the number of particles in the processing liquid, for example, the method suddenly occurs due to disturbances such as equipment troubles. In the case where the number of particles in the processing liquid increases, there is a danger that the detection is delayed, a large number of defective products are generated, and the yield is significantly reduced. Therefore, it is desirable to continuously monitor the state of the processing solution in real time.

On the other hand, if the number of particles in the processing liquid is to be continuously monitored by, for example, a flow-type particle counter, the amount of liquid that can flow through the particle counter is, for example, several milliliters to several tens of milliliters per minute. Due to the small amount, if the length of the pipe for collecting the processing liquid and introducing it to the particle counter becomes long, a time delay occurs in the measurement, and the real-time property is impaired.

In order to avoid such a problem,
It is necessary to provide a particle counter, for example, in the vicinity of the processing liquid collection part of the processing liquid tank. However, providing a monitoring device, such as a particle counter, in the vicinity of the processing liquid tank in this way is, for example, the structure of an existing processing apparatus. In many cases, it is practically impossible, or the maintenance performance of the monitoring device is significantly deteriorated.

Further, since a dedicated pump for sampling the processing liquid is required, there is a problem that the manufacturing cost of the apparatus is increased.

The present invention has been made in view of such a conventional situation, and is low in cost, excellent in maintainability and real-time performance, and continuously monitors the state of a processing solution in real time to realize processing. It is an object of the present invention to provide a processing liquid monitoring device capable of improving the reliability of the processing solution.

[0009]

That is, a processing liquid monitoring apparatus according to the present invention comprises a processing liquid tank, a processing liquid circulation pipe for returning a processing liquid derived from the processing liquid tank to the processing liquid tank, and a processing liquid circulation. A processing liquid monitoring apparatus for a processing system having a pump, wherein the processing liquid circulation pipe is communicated with the processing liquid tank near the processing liquid tank and a processing liquid circulation pipe on a more downstream side, and a part of the processing liquid flowing through the processing liquid circulation pipe is bypassed. A bypass pipe having a diameter smaller than that of the processing liquid circulation pipe, a desired position of the bypass pipe, and a bypass pipe on a more downstream side, and one of the processing liquid flowing through the bypass pipe. A sampling pipe having a smaller diameter than the bypass pipe, and a bypass pipe inserted through the sampling pipe to monitor a state of the processing liquid. Characterized by comprising a monitoring mechanism for grayed. Further, the processing liquid monitor according to claim 2 is provided.
The processing liquid is supplied from the lower part of the processing liquid tank.
Supplied from the overflow tank provided in the processing solution tank.
To be returned to the processing liquid circulation pipe.
Features. In addition, the processing solution monitoring device according to claim 3
The bypass pipe is provided in the processing liquid tank.
Between the bar flow tank and the processing liquid circulation pump.
It is characterized by having been done. Further, the processing liquid monitor according to claim 4 is provided.
The tarring device, wherein the processing liquid is circulating the processing liquid,
Characterized to be continuously monitored
And Further, the processing liquid monitoring device of claim 5 is
The monitoring mechanism is configured to control particles in the processing solution.
It is a particle counter that monitors the number of
Sign. Further, the processing liquid monitoring apparatus according to claim 6
Measures the flow rate of the processing liquid in the bypass pipe
A flow rate measuring mechanism and a buffer for adjusting the flow rate of the processing solution.
And a lube is provided.

[0010]

In the processing liquid monitoring apparatus of the present invention having the above structure, a bypass line having a relatively large bypass pipe is provided, and the processing liquid is circulated in the bypass pipe at a relatively high flow rate and a relatively high flow rate. The processing liquid is led out to the vicinity of the monitoring device. Then, a small-diameter sampling pipe is connected to the bypass pipe, and the processing liquid is circulated to a monitoring device, for example, a particle counter.

Therefore, even when it is necessary to connect a small-diameter sampling pipe to the monitoring device and when the monitoring device must be installed at a place remote from the processing solution collection position, the collected processing solution can be monitored in a short time. And monitoring with excellent real-time performance can be performed while maintaining the maintenance of the monitoring device.

Therefore, the reliability of the processing can be improved by continuously monitoring the state of the processing liquid in real time.

Further, the processing liquid can be sampled by using the discharge and suction input of the processing liquid circulating pump in the processing liquid circulating pipe without using a dedicated pump for sampling the processing liquid. Can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to monitoring of a cleaning liquid in a cleaning apparatus for cleaning a semiconductor wafer will be described below with reference to the drawings.

As shown in FIG. 1, H formed in a container shape
The F processing liquid tank 1 is provided with an overflow recovery section 3 for collecting the HF processing liquid 2 overflowing from the HF processing liquid tank 1 so as to form a weir surrounding the F processing liquid tank 1. A rectifying plate 4 is provided at the bottom of the HF treatment liquid tank 1.

At the bottom of the overflow recovery section 3,
One end of the processing liquid circulation pipe 5 is connected, and the other end of the processing liquid circulation pipe 5 is connected to the bottom of the HF processing liquid tank 1. Further, a processing liquid circulation pump 6, a damper 7, a heat exchanger 8, and a filter 9 are inserted into the processing liquid circulation pipe 5 in this order from the overflow recovery unit 3 side (upstream side).
The HF treatment liquid 2 overflowing from the upper part of the HF treatment liquid tank 1 to the overflow recovery unit 3 is circulated by the treatment liquid circulation pipe 5 and the treatment liquid circulation pump 6,
The temperature is controlled by the heat exchanger 8 inserted in the processing liquid circulation pipe 5, the particles are removed by the filter 9 and returned into the HF processing liquid tank 1, and the semiconductor wafer is controlled by the HF processing liquid 2 whose temperature has been adjusted and cleaned. It is configured to perform ten cleaning processes.

The damper 7 serves to reduce the pulsating flow caused by the processing liquid circulation pump 6, and the HF processing liquid tank 1
A rectifying plate 4 provided at the bottom of the inside rectifies the HF processing liquid 2 flowing into the HF processing liquid tank 1 from the processing liquid circulation pipe 5 so that the HF processing liquid 2 is uniformly applied to the semiconductor wafer 10. Is what you do.

In the case of this embodiment, the processing liquid circulation pipe 5 and the processing liquid circulation pump 6 are, for example, 10 to 20 l / min.
The HF processing liquid 2 is circulated at a flow rate of, and the inner diameter of the processing liquid circulation pipe 5 is set to, for example, about 16 mm.

In contrast to the cleaning apparatus having the above configuration, the processing liquid monitoring apparatus is configured as follows.

That is, the bypass pipe 11 is provided so as to pass through the processing liquid circulation pipe 5 and open one end into the overflow recovery section 3. The other end of the bypass pipe 11 is connected to the processing liquid circulation pipe 5. The processing liquid circulation pump 6 is connected near the suction side. A flow meter 12 for measuring a flow rate and a valve 13 for adjusting a flow rate are inserted in the bypass pipe 11.

A sampling pipe 14 is provided so as to bypass and communicate with a part of the bypass pipe 11. The sampling pipe 14 is provided with a particle counter 15 and a flow rate measurement flow in order from the upstream side. A meter 16 and a valve 17 for adjusting the flow rate are interposed. The particle counter 15 is configured to be able to count the number of particles in the sample liquid while flowing the sample liquid in the flow cell, and to measure the flow rate in a range of, for example, about 5 to 50 ml / min. It is configured.

The bypass pipe 11 is constituted by a pipe having a smaller diameter than the processing liquid circulation pipe 5, and for example, in this embodiment, is constituted by a pipe having an inner diameter of about 7.5 mm. The sampling pipe 14 is formed of a pipe having a smaller diameter than that of the bypass pipe 11. For example, in this embodiment, the sampling pipe 14 is formed of a pipe having an inner diameter of 2 mm.

By using the discharge and suction input of the processing liquid circulation pump 6, a relatively large flow rate is returned from the overflow recovery section 3 to the processing liquid circulation pipe 5 through the vicinity of the particle counter 15 by the bypass pipe 11 (for example, , 15
0 to 300 ml / min) A HF treatment liquid is introduced into the particle counter 15 at a small flow rate (for example, about 10 ml / min) from the bypass pipe 11 to the particle counter 15 by the sampling pipe 14. It is configured so that the state of the liquid 2 can be monitored accurately, in real time, and continuously.

FIG. 2 shows the sampling pipe 1 from the sampling port of the bypass pipe 11 opening into the overflow recovery section 3.
The length of the bypass pipe 11 from the connection A to the particle counter 15 is set to 50 mm, and the length of the bypass pipe 11 from the connection A to the particle counter 15 is set to 50 mm.
Particles (polystyrene latex particles) are charged into the HF treatment liquid tank 1 at a flow rate of 185 ml / min and a flow rate of 10 ml / min inside the sampling pipe 14, and the particles are monitored by the treatment liquid monitoring apparatus of the present embodiment. This shows the result of performing. The measurement is
The measurement is performed once a minute for particles of 0.2 μm or more, and the lower part of the bar graph indicates the number of particles of 0.5 μm or more.

As shown in the figure, in the processing liquid monitoring apparatus of this embodiment, the particle counter 1
HF treatment liquid tank 1
Within 1 minute after the particles were injected, the injection of the particles could be detected.

Therefore, when particles are mixed in the HF processing liquid tank 1 due to disturbances such as equipment troubles, etc., this can be detected immediately. Does not occur, and the reliability of the processing can be improved. Further, since the particle counter 15 can be provided at an arbitrary place away from the HF processing liquid tank 1, the degree of freedom in the apparatus configuration is high, and the maintainability of the particle counter 15 can be ensured. Further, the HF treatment liquid 2 can be sampled by using the discharge and suction input of the treatment liquid circulation pump 6 of the treatment liquid circulation pipe 5 without using a dedicated pump for sampling the HF treatment liquid 2. Therefore, cost can be reduced.

FIG. 3 shows an example of the configuration of an automatic cleaning apparatus in which the HF processing liquid tank 1 is arranged.
Are three cleaning processing units 22 arranged in a straight line,
23 and 24, a loader 25 is provided in the cleaning processing unit 22 on the loading side, and an unloader 26 is provided in the cleaning processing unit 24 on the loading side. Further, between the cleaning processing unit 22 and the cleaning processing unit 23 and between the cleaning processing unit 23 and the cleaning processing unit 24, underwater loaders 27 and 28 included in any of these units are provided. .

In the cleaning unit 22 on the carry-in side, a rotary transfer arm 29 for transferring an object to be cleaned (semiconductor wafer) is provided at the center position.
(Upper and right sides in the figure) are provided with processing liquid tanks 30 and 31. The processing liquid tank 31 is used, for example, as a chemical processing liquid tank for performing an ammonia treatment, and the processing liquid tank 30 is used for, for example, a quick dump rinse (QD
R) Used as a treatment liquid tank.

The central cleaning processing unit 23 is provided with a rotary transfer arm 32 at the center position. Around the rotary transfer arm 32 (the right and left sides in the figure), the HF processing liquid tank 1 and the water overflow processing are performed. A tank 34 is provided.

In the cleaning unit 24 on the carry-out side, a rotary transfer arm 35 is provided at the center position.
A washing / drying mechanism 36 for washing / drying is provided, and a drying treatment tank 37 for performing a drying treatment with isopropyl alcohol (IPA drying) is provided on the lower side in the figure.

The underwater loaders 27 and 28, the processing liquid tank 1,
30, 31, 34, washing / drying mechanism 36, drying treatment tank 3
Reference numerals 7 are housed in cases each provided with a shutter mechanism for loading and unloading.

As shown in FIG. 4, the rotary transfer arm 29 has a wafer fork 51 for mounting a semiconductor wafer at the tip of a multi-joint arm 50 which can be rotated and extended horizontally. A plurality of, for example, 50, semiconductor wafers 10 can be placed without a wafer carrier. This wafer fork 51 has two parallel wafer support rods 52 in which support grooves are formed, and is configured to support 50 semiconductor wafers 10 on these wafer support rods 52 so as to be substantially parallel to each other. ing. The rotary transfer arms 32 and 35 are also connected to the rotary transfer arm 2.
It is configured similarly to 9.

On the other hand, the processing liquid tanks 30 and 31 and the underwater loader 27 are provided with a wafer boat 42 which can be moved up and down by a drive mechanism (not shown) as a wafer support mechanism dedicated to each tank. These wafer boats 42
Has three wafer support rods 53 configured in the same manner as the wafer support rods 52, and
It is configured to support 50 semiconductor wafers 10 so as to be substantially parallel to each other. The other processing liquid tanks 1 and the like have the same configuration.

Then, by the rotary transfer arm 29, 50
The semiconductor wafers 10 are supported and transported, and are positioned on the wafer boat 42. Thereafter, the wafer boat 42 is raised to transfer the semiconductor wafers 10 from the rotary transport arm 29 (wafer fork 51) to the wafer boat 42. It is configured as follows. Then, the rotary transfer arm 29 is retracted,
The wafer boat 42 is lowered and the semiconductor wafer 1 is placed in each tank.
0 is immersed. When the semiconductor wafer 10 is transferred from the wafer boat 42 to the rotary transfer arm 29 (wafer fork 51), a procedure reverse to the above procedure is performed.

In the cleaning device 21 having the above configuration, the loader 25
The loader 2 is arranged by an alignment mechanism (not shown)
5. Two wafer carriers 60 placed at predetermined positions on
The semiconductor wafers 10 are aligned using an orientation flat. Thereafter, the semiconductor wafers 10 in the wafer carrier 60 are pushed up, and these semiconductor wafers 10 are moved in the horizontal direction so as to approach each other, so that a total of 50 semiconductor wafers 10 in the two wafer carriers 60 are provided.
Are arranged in a line at a predetermined pitch.

Thereafter, the rotary transfer arm 29
These semiconductor wafers 10 are received. Then, these semiconductor wafers 10 are rotated by the rotary transfer arm 29.
The cleaning solution is transferred to the processing liquid tank 31, the processing liquid tank 30, and the underwater loader 27 sequentially, and the cleaning processing unit 22 performs a cleaning process.

Thereafter, the semiconductor wafer 10 is transferred to the cleaning unit 23 by the underwater loader 27, and the semiconductor wafer 10 is
The F treatment liquid tank 1, the washing overflow treatment tank 34, and the underwater loader 28 are sequentially transported to the tank, and the washing unit 23 performs the washing process.

Thereafter, the semiconductor wafer 10 is transferred to the cleaning processing unit 24 by the underwater loader 28, and these semiconductor wafers 13 are
It is transported to the drying tank 37. Then, in the drying processing tank 37, a drying process (IPA drying) of the semiconductor wafer 10 with isopropyl alcohol is performed. At this time, the wafer fork 51 of the rotary transfer arm 35 is simultaneously inserted into the cleaning / drying mechanism 36 to perform cleaning / drying.

When the drying processing of the semiconductor wafer 10 in the drying processing tank 37 is completed, the semiconductor wafer 10 after the drying processing is received by the washed and dried wafer fork 51 and unloaded to the unloader 26. Thereafter, the semiconductor wafer 10 is accommodated in the wafer carrier 60 via the substrate support device 11 in a procedure opposite to the case of the loader 25.

In such a cleaning apparatus 21, the semiconductor wafer 10 can be cleaned and cleaned without using the wafer carrier 60.
Since the drying can be performed, it is possible to prevent the cleaning liquid and the like from being contaminated by the wafer carrier 60, and it is possible to perform a good cleaning process. Further, in the cleaning device 21, the entire device becomes very large, and it is difficult to provide the particle counter 15 and the like near the HF processing liquid tank 1. However, by using the processing liquid monitoring device of this embodiment, The particle counter 15 can be provided at a desired location where maintenance can be ensured without impairing the real-time property.

[0041]

As described above, according to the processing liquid monitoring apparatus of the present invention, the processing liquid state is continuously monitored in real time at low cost and excellent in maintainability and real-time performance. Thereby, the reliability of the processing can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a processing liquid monitoring apparatus according to one embodiment of the present invention.

FIG. 2 is a diagram showing a measurement example of the processing liquid monitoring device of FIG. 1;

FIG. 3 is a diagram showing a configuration of a cleaning device provided with the processing liquid monitoring device of FIG. 1;

FIG. 4 is a diagram showing a main configuration of the cleaning apparatus of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 HF processing liquid tank 2 HF processing liquid 3 Overflow recovery part 4 Rectifier plate 5 Processing liquid circulation pipe 6 Processing liquid circulation pump 7 Damper 8 Heat exchanger 9 Filter 10 Semiconductor wafer 11 Bypass pipe 12, 16 Flow meter 13, 17 Valve 14 Sampling piping 15 Particle counter

Claims (6)

(57) [Claims] 1. A processing liquid monitoring apparatus for a processing system comprising: a processing liquid tank; a processing liquid circulation pipe for returning a processing liquid derived from the processing liquid tank to the processing liquid tank; and a processing liquid circulation pump. A bypass pipe that communicates the vicinity of the liquid tank with the processing liquid circulation pipe on the more downstream side, and bypasses a part of the processing liquid flowing through the processing liquid circulation pipe, and has a smaller diameter than the processing liquid circulation pipe. A bypass pipe, which communicates with a desired position of the bypass pipe and a bypass pipe on a more downstream side, and bypasses a part of the processing liquid flowing through the bypass pipe, and has a smaller diameter than the bypass pipe. And a monitoring mechanism interposed in the sampling pipe and monitoring a state of the processing liquid. Monitoring device. 2. The processing liquid is supplied from a lower portion of the processing liquid tank, and is returned to the processing liquid circulation pipe from an overflow tank provided in the processing liquid tank. 2. The treatment liquid monitoring device according to claim 1. Wherein said bypass pipe, and an overflow tank provided in the processing solution tank, processing liquid monitoring device according to claim 1 or 2, wherein the provided between the treatment liquid circulation pump . Wherein said processing liquid, circulating in the treatment liquid, the treatment liquid monitoring device according to any one of claims 1 to 3, characterized in that it is configured to be continuously monitored . 5. The apparatus according to claim 1, wherein the monitoring mechanism is a particle counter that monitors the number of particles in the processing liquid .
2. The treatment liquid monitoring device according to claim 1. 6. The bypass pipe according to claim 1, further comprising: a flow rate measuring mechanism for measuring a flow rate of the processing liquid; and a valve for adjusting a flow rate of the processing liquid . The treatment liquid monitoring device according to any one of the preceding claims.