JPH08296564A - Liquid feeding method by bellows pump and device therefor - Google Patents

Abstract

PURPOSE: To provide a pump low in the pulsation of liquid such as a chemical to be fed. CONSTITUTION: In a liquid feeder 1 by bellows pump, a pair of air supply devices 10A, 10B are connected in parallel to an air supply source 138, and bellows pumps 20A, 20B are connected to the respective air supply devices 10A, 10B. These bellows pumps 20A, 20B are actuated with specified time difference to discharge liquid, and the liquid discharged from each bellows pump is fed to an object such as a washing device through a common feed pipe 50C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a liquid supply method by a bellows pump suitable for supplying a chemical liquid to a cleaning tank for cleaning a liquid, especially a semiconductor wafer, and an apparatus therefor.

[0002]

2. Description of the Related Art First, a conventional liquid supply device using a bellows pump will be described with reference to the drawings. FIG. 4 is a schematic view showing a semiconductor wafer cleaning apparatus using a conventional liquid supply apparatus using a bellows pump, and FIG. 5 is a bellows for supplying and circulating a chemical solution to the semiconductor wafer cleaning apparatus shown in FIG. FIG. 6 is a schematic diagram of a flow meter that is a liquid supply device using a pump (hereinafter, simply referred to as “liquid supply device”), and FIG. 6 is attached to the liquid supply device of the semiconductor wafer cleaning device of FIG.

In FIG. 4, reference numeral 100 generally indicates
A semiconductor wafer cleaning device (hereinafter simply referred to as "cleaning device"). The cleaning device 100 includes a cleaning tank 110 and a cleaning chemical liquid as a liquid (hereinafter, simply referred to as “chemical liquid”).
And a cleaning chemical liquid supply device 120 for supplying. The cleaning tank 110 is composed of a double tank including an inner tank 111 and an outer tank 112, and is provided with a supply port 113 and a discharge port 114 for the chemical liquid LM, although not specifically shown. The chemical liquid LM supplied from the supply port 113 to the inner tank 111 overflows and flows into the outer tank 112, and the chemical liquid LM that has flowed out is discharged from the discharge port 114 to the cleaning liquid supply device 12.
It is configured to be discharged to zero.

A plurality of semiconductor wafers S are placed in a carrier K in an inner tank 111 of the cleaning tank 110 and are cleaned by a high-purity chemical liquid LM supplied from a cleaning liquid supply device 120.

The cleaning liquid supply device 120 supplies a liquid LM to the cleaning bath 110 and circulates it, and a filter 121 for filtering out impurities contained in the liquid chemical supplied from the liquid supply device 130. And a flow meter 1 for displaying the flow rate of the chemical liquid flowing in the chemical liquid pipe 122C.
And 40.

As shown in FIG. 5, the liquid supply device 130 comprises a bellows pump 131 as a main constituent element, and two bellows 13 in a cylinder 132.
3A and 133B are connected in cascade. The bellows 133A and 133B are provided with a chemical solution intake port 134 and a chemical discharge port 135 at an intermediate portion thereof.
A chemical liquid pipe 122A for supplying the chemical liquid LM discharged from the cleaning tank 110 is connected to 34, and a chemical liquid pipe 122B for supplying the chemical liquid LM to the filter 121 is connected to the outlet 135. An air pipe 137A derived from an air supply device 136 composed of a pair of solenoid valves 136A and 136B is connected to the upper end of the cylinder 132, and the air supply device is connected to the lower end of the cylinder 132. Other air piping 137B derived from 136
Is connected. A compressed air supply source 138 is connected to the input side of the air supply device 136 via an air pipe 137C. Further, the air supply device 136 is configured to be controlled by the controller 139.

The bellows pump 131 having such a configuration
Is the air supply device 1 under the control of the controller 139.
36 solenoid valves 136A, 136B are alternately opened and closed to supply compressed air supplied from a compressed air supply source 138 through an air pipe 137C to the air pipes 137A and 137B.
Through the chemical liquid existing in the bellows 133B when compressed air compresses the bellows 133B to the filter 121 through the chemical liquid pipe 122B, and one of the bellows 133A is stretched to wash the washing tank 110. The chemical liquid discharged from the suction pipe is sucked into the stretched bellows 133A from the intake port 134 through the chemical liquid pipe 122A. In this way, the compressed air is applied to the bellows 133A and 133B to reciprocate, thereby creating a flow of the chemical liquid. By repeating this operation, the chemical liquid LM can be continuously circulated and supplied into the cleaning tank 110.

As shown in FIG. 6, the flowmeter 140 includes a cylindrical transparent tube 141, a float 142 floated by a chemical solution flowing into the tube 141, and a pair of upper and lower floats 142 for detecting the vertical position. Optical sensor 143A,
143B, and a float 1 that moves up and down at the flow rate of the chemical liquid flowing from the chemical liquid pipe 122C into the pipe 141.
The vertical movement position of 42 is set to the optical sensors 143A and 143B.
In this way, the flow rate of the chemical liquid LM supplied to the cleaning tank 110 is monitored, and thus the operation of the liquid supply device 130 is indirectly known by the flow of the chemical liquid.

[0009]

However, as described above, the bellows is reciprocated by applying the compressed air, and thereby the flow of the chemical solution is produced. However, the bellows pump is applied in response to the application of the compressed air. 131
Does not move immediately, and the stroke of the bellows pump 131 cannot be taken sufficiently. Furthermore, the flow of the chemical liquid LM is not constant and pulsates.

The pulsation of this chemical causes the following problems. 1. Since the flow of the chemical liquid is not constant, the accurate flow rate cannot be measured. 2. In the method of detecting the flow rate in the liquid supply device 130, if the pulsation of the chemical liquid is large, only the on / off of the pump 130 can be detected, and if the particles adhere to the filter 121 and become clogged, the flow of the chemical liquid decreases. However, the width of the vertical movement of the chemical liquid in the tube 141 becomes narrow, and the chemical solution cannot be detected at the position between the optical sensors 143A and 143B. 3. Since the flow of the chemical liquid is not constant, convection of the chemical liquid is likely to occur in the dip cleaning machine, the etching rate becomes nonuniform, and particles are likely to be reattached to the semiconductor wafer which is the workpiece. The present invention is intended to solve such a problem, and an object thereof is to obtain a pump with a small pulsation of a chemical solution.

[0011]

Therefore, according to the liquid supply method by the bellows pump of the present invention, a plurality of air supply devices and a plurality of bellows pumps connected in parallel to the compressed air source are provided with a predetermined time difference from each other. To operate,
The problem was solved by adopting a method of supplying a desired liquid.

A liquid supply device using a bellows pump, which is an embodiment embodying the liquid supply method, is connected to an air supply source, a liquid supply source, and the air supply source in parallel, and then supplies the liquid. A plurality of bellows pumps having a liquid inlet and a liquid outlet connected to the source;
An air supply device connected between the air supply source and each bellows pump and connected to drive each bellows pump and provided with a valve, and a controller for driving each of these air supply devices with a specific time difference. And a pipe connected to the discharge port of each of the bellows pumps to solve the above problems.

[0013]

Therefore, according to the present invention, the bellows pump immediately responds to the supply of compressed air, and its stroke can be sufficiently taken, so that a sufficient amount of the chemical liquid can be supplied, and above all, the pulsation of the chemical liquid can be prevented. Can be suppressed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid supply method and apparatus using a bellows pump according to the present invention will be described below with reference to the drawings. 1 is a schematic view of a liquid supply device using a bellows pump according to an embodiment of the present invention, and FIG. 2 is a solenoid valve applied to an air supply device for explaining the operation of the liquid supply device using a bellows pump shown in FIG. FIG. 3 is a graph showing the pulsating state of the liquid by the liquid supply device by the bellows pump of the present invention.

First, a liquid supply device using a bellows pump according to an embodiment of the present invention (hereinafter simply referred to as "liquid supply device") will be described with reference to FIG. Reference numeral 1 generally indicates the liquid supply apparatus of the present invention. The liquid supply device 1 includes a pair of air supply devices 10A and 10B, a pair of bellows pumps 20A and 20B, and the air supply device 10.
It is composed of a controller 30 for controlling A and 10B.

The compressed air supply source 138 is connected in parallel with the pair of air supply devices 10A and 10B equipped with solenoid valves 11A and 11B through air pipes 12A and 12B, and these air supply devices 10A are connected. 10,
B will be described later with reference to FIG.
Controlled by.

Then, the bellows bellows pump 2 is connected to the air supply device 10A through air pipes 40A and 40B.
0A is connected to the bellows pump 20B via air pipes 40C and 40D. The bellows pumps 20A and 20B are cylindrical and airtight cylinders 21A and 21B.
In B, a pair of bellows 22A and 22B and a pair of bellows 22C and 22D are built in a state of being connected in series. The air pipes 40A and 40B are connected to the upper and lower ends of the cylinder 21A, and the air pipes 40C and 40D are connected to the upper and lower ends of the cylinder 21B.

Liquid inlets 23A, 23B and liquid outlets 24 are provided at the central connection portions of the pair of bellows 22A, 22B and bellows 22C, 22D, respectively.
A and 24B are provided. And these outlets 2
Liquid pipes 50A and 50B are connected to 4A and 24B, and the other ends of the liquid pipes 50A and 50B are connected to a common supply pipe 50C, for example, connected to a filter 121 shown in FIG. Cleaning tank 11 via 140
Connected to 0. On the other hand, the intake ports 23A, 23B
Is, for example, the outlet 114 of the cleaning tank 110 shown in FIG.
And the liquid such as the chemical liquid LM is flowed in.

Check valves 51A and 51B are provided in the liquid pipes 50A and 50B, respectively, and as will be described later, the bellows 133A and 133B driven by compressed air from the air supply devices 10A and 10B.
It is intended to prevent the liquids discharged by the alternating operation of (1) and (2) from flowing back to the other pump side. The liquid supply apparatus 1 of the present invention is configured as described above.

Next, the operation of the liquid supply apparatus 1 will be described with reference to FIGS. The air supply device 10A is applied with the on / off cycle switching signal A shown in FIG.
For B, 3 / from switching signal A from controller 30
A switching signal B with a time difference delayed by four cycles is applied. Such switching signals A and B are supplied to the air supply device 10 respectively.
When applied to the solenoid valves 11A and 11B of A and 10B, the solenoid valves 11A and 11B are alternately opened and closed, and the compressed air from the respective air supply devices 10A and 10B drives the respective bellows pumps 20A and 20B, and the bellows 22A,
22B and the bellows 22C and 22D expand and contract. As a result, the bellows pump 20A discharges the liquid of the pulsating flow A shown by the dotted line in FIG. 3 to the liquid pipe 50A,
The bellows pump 20B discharges the liquid of the pulsating flow B shown by the alternate long and short dash line in FIG. 3 to the liquid pipe 50B, and the common supply pipe 50C is synergistically formed by the two pulsating flows A and B, so that the pulsating flow C shown in FIG. The liquid, that is, the liquid in which the pulsation is substantially suppressed can be generated.

The liquid is a cleaning chemical liquid, an etching liquid, etc.
Any chemical liquid may be used. Therefore, it goes without saying that the liquid supply apparatus 1 may be applied to supply the cleaning chemical solution to the cleaning chemical solution supply apparatus 120 and may be applied to supply the etching solution to the etching apparatus.

[0022]

As described above, according to the liquid supply device by the bellows pump of the present invention, the pulsation of the liquid discharged from both bellows pumps is suppressed by alternately operating the pair of bellows pumps. You can
Therefore, 1. The flow rate of the liquid can be accurately measured using the flow meter 140 shown in FIG. 2. Even if the operating capacity of the pump decreases, it can be easily monitored. Since the flow rate of the liquid is close to constant, in the dip cleaning device, the retention of the liquid chemical is reduced, it is easy to keep the chemical composition constant, and the etching rate is made uniform, and the particles become the object to be treated. A number of excellent effects are obtained, such as the degree of redeposition being reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a liquid supply device using a bellows pump according to an embodiment of the present invention.

FIG. 2 shows a solenoid valve switching signal applied to an air supply device for explaining the operation of the liquid supply device using the bellows pump shown in FIG.

FIG. 3 is a graph showing a pulsating state of liquid by the liquid supply device by the bellows pump of the present invention.

FIG. 4 is a schematic diagram showing a semiconductor wafer cleaning device using a liquid supply device using a bellows pump of the related art.

5 is a liquid supply device using a bellows pump for supplying and circulating a chemical liquid to the semiconductor wafer cleaning device shown in FIG.

6 is a schematic view of a flow meter mounted on the liquid supply device of the semiconductor wafer cleaning device of FIG.

[Explanation of symbols]

 1 Liquid Supply Device by Bellows Pump of the Invention 10A Air Supply Device 10B Air Supply Device 20A Bellows Pump 20B Bellows Pump 22A Bellows 22B Bellows 22C Bellows 22D Bellows 30 Controller 40A Air Piping 40B Air Piping 40C Air Piping 40D Air Piping 50A Liquid Piping 50B Liquid pipe 50C Common supply pipe

Claims (3)

[Claims] 1. A bellows pump for supplying a desired liquid by operating a plurality of air supply devices and a plurality of bellows pumps connected in parallel to an air supply source with a predetermined time difference from each other. Liquid supply method by. 2. A plurality of bellows including an air supply source, a liquid supply source, a liquid intake port connected in parallel to the air supply source, and a liquid intake port and a liquid discharge port connected to the liquid supply source. A pump, the air supply source, and each of the bellows pumps are connected to each other and are connected to drive each of the bellows pumps. The air supply device having a valve and each of the air supply devices are driven with a specific time difference. A liquid supply device by a bellows pump, comprising a control device and a pipe connected to a discharge port of each of the bellows pumps. 3. A check valve is attached to an intermediate portion of a pipe connected to a discharge port of each of the bellows pumps, and one check pipe is provided on a side opposite to the discharge port side of each check valve. The liquid supply device by the bellows pump according to claim 1, wherein the liquid supply device is connected to a common pipe.