JPH0353690Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a chemical liquid filter used in a semiconductor manufacturing line, and more particularly to a residual pressure removal filter that prevents droplets from dropping from a chemical liquid supply nozzle.

2. Description of the Related Art In a semiconductor manufacturing line, there is a process in which a semiconductor wafer is subjected to chemical treatment such as chemical treatment or cleaning using a chemical treatment liquid or a chemical liquid such as pure water.

In the above process, chemical liquid treatment is performed using, for example, an apparatus as shown in FIG.

In FIG. 3, 1 is a turntable, 2 is a chemical supply pipe, and W is a semiconductor wafer.

The turntable 1 is equipped with a vacuum suction holding mechanism (not shown) and is driven to rotate in the horizontal direction.

The chemical liquid supply piping 2 extends from a chemical liquid pressure feeding means (not shown) via a gate valve 3 and a filter 4 to a chemical liquid dripping nozzle 5 arranged above the turntable 1.

The chemical processing by the above-mentioned apparatus will be explained in terms of the development processing of a positive resist, and is performed in the following manner.

First, a photoresist was applied on the turntable 1 in advance, and a latent image of a desired pattern was formed on the photoresist by exposure processing.
The semiconductor wafer W is positioned and placed, and in this state, the semiconductor wafer W is suctioned and held on the turntable 1 by the vacuum suction holding means.

Next, open the gate valve 3 of the chemical liquid supply pipe 2,
After a predetermined amount of the chemical developer is supplied from the dropping nozzle 5 to the surface of the semiconductor wafer W via the filter 4, the gate valve 3 is closed. In this state, the developer supplied onto the semiconductor wafer W is supplied so as to cover the entire surface of the semiconductor wafer W, and is raised to a predetermined thickness due to surface tension. ing.

Next, in order to uniformly perform the development process, the turntable 1 is rotated at an extremely low speed of about 0.1 to several times per second to stir the developer, and this state is maintained for a predetermined period of time.

After the predetermined time has elapsed, the turntable 1 is rotated at high speed to shake off the developer on the surface of the semiconductor wafer W by centrifugal force, and then pure water is supplied from a pure water supply nozzle (not shown) to complete the developer processing.

Problems to be solved by the invention Chemical liquid supply piping 2 in the above chemical liquid processing equipment
The following problems arose:

When the chemical liquid is supplied onto the semiconductor wafer W by the chemical liquid supply pipe 2, the chemical liquid is supplied under pressure by the pressure feeding means, and after a predetermined amount of the chemical liquid is supplied, the gate valve 3 is closed. However, the chemical liquid remaining in the filter 4 remains under pressure. That is, when the gate valve 3 is closed, pressure remains in the chemical liquid inside the filter 4.

Therefore, even if the gate valve 3 is closed after a predetermined amount of the chemical has been supplied onto the semiconductor wafer W, the residual pressure of the chemical in the filter 4 will cause the dropping nozzle 5 to
The above chemical solution may drip off.

Dropping of the chemical liquid as described above makes the amount of chemical liquid supplied to the semiconductor wafer W unstable, especially when the chemical liquid is supplied onto the semiconductor wafer W in a heaped state due to surface tension as described above. This causes problems such as not being able to hold the chemical liquid on the semiconductor wafer W due to the tension, and furthermore, the chemical liquid treatment not being performed uniformly.

In addition, in order to prevent droplets of the chemical liquid from dropping onto the semiconductor wafer W, the dropping nozzle 5 is moved above the semiconductor wafer W when the chemical liquid is being supplied, and is moved to a position further away from the top of the semiconductor wafer W at other times. Some have been moved, but
If this is done, a problem arises in that the device becomes dirty due to dripping of the chemical solution from the dropping nozzle 5 during movement.

Furthermore, since the purpose of the filter 4 is to remove dust by filtration, it must be connected downstream of the gate valve 4, etc., which is a source of dust generation, thus solving the problem of dripping of the chemical solution due to residual pressure as described above. There is a demand for filters with

Means for Solving the Problems The present invention has been made in view of the above-mentioned problems, and is a filter provided in a liquid supply pipe, which is partitioned by a partition wall having a through hole, and is provided upstream of the pipe. and a filter housing having two chambers each communicating with the downstream, a filter element disposed in one chamber of the filter housing, and a filter element disposed in the other chamber of the filter housing, which is connected to the piping. A flexible member that divides the flow path space into communication with the filter element through the through hole, and a space that communicates with the outside and is relatively depressurized when the liquid supply is stopped compared to when the liquid is supplied. This is a residual pressure removal filter.

Function The residual pressure removal filter according to the present invention pressurizes the space defined by the flexible member in the filter housing when liquid is supplied, and depressurizes the space when liquid supply is finished. By returning the pressure, the flexible member is bent toward the flow path, and the two parts of the filter element when the liquid supply is stopped are
It is designed to absorb and remove the residual pressure of the liquid on the next side.

Embodiment FIG. 1 shows an embodiment of a filter for removing residual pressure according to the present invention.

In the drawings, 10 is a filter housing;
Reference numerals 20 and 21 denote a primary chamber and a secondary chamber formed by dividing the inside of the filter housing 10 into two in the axial direction by the partition wall 11; The housed filter element 40 indicates a flexible member housed in the secondary chamber 21 . The filter housing 10 is integrally formed with pipe portions 12a and 12b for connection to piping at the center of both axial ends, and each of the connection pipe portions 12a and 12b is
They communicate with the primary chamber 20 and the secondary chamber 21, respectively. Furthermore, a pipe portion 13 for connecting a pressure pipe 50 to the secondary chamber 21 is formed at the end of the filter housing 10 on the secondary chamber 21 side.

A hollow recess 31 is formed in the approximately central portion of the filter element 30 in the axial direction, and this hollow recess 31 is formed in the through hole 1 formed in the partition wall 11.
It communicates with the secondary chamber 21 via 4.

In this embodiment, the flexible member 40 is
There is a bellows. The bellows 40 has one end fixed to the partition wall 11 and the other end fixed to the inner surface of the filter housing 10 on the secondary chamber 21 side,
The inside of this bellows 40 is located in the through hole 1 of the partition wall 11.
4, it communicates with the hollow recess 31 of the filter element 30, and also communicates with the connecting pipe portion 12b of the filter housing 10.
Therefore, the bellows 40 divides the secondary chamber 21 into two and connects the filter element 30 to the connecting pipe portion 12b.
The bellows 40
Space 2 between the outside of the filter housing 10 and the filter housing 10
1'' is isolated from the flow path 21' and communicates with the pressure pipe 50.

The pressure pipe 50 has a bellows 4 in the secondary chamber 21.
This pipe line 51 is a pipe for pressurizing the space 21'' formed by
The control valve 52 is connected to the control valve 52. The control valve 52 is for increasing or decreasing the pressure of the pressure fluid supplied to the space 21'' within a predetermined range.

Now, the operation when the residual pressure removal filter according to the present invention is connected to the chemical liquid supply piping 2 of the chemical liquid processing apparatus shown in FIG. 3 will be explained below. The residual pressure removal filter is connected in place of the filter 4 of the chemical liquid supply pipe 2,
The connecting direction is such that the connecting pipe section 12a is connected to the downstream side of the gate valve 3 facing downward, and the connecting pipe line 12b is connected to the upstream side of the drip nozzle 5 facing upward. Further, in the initial state, an appropriate pressure fluid such as air is supplied from the pressure piping 50 to the space 21'' formed in the secondary chamber 21 of the residual pressure removal filter, and the pressure in this space 21'' is teeth,
The control valve 52 provides a predetermined positive pressure.

First, as described above, the semiconductor wafer W is positioned and placed on the turntable 1, and in this state, the semiconductor wafer W is held by the vacuum suction holding means.
is suctioned and held on the turntable 1.

Next, when the gate valve 3 of the chemical liquid supply pipe 2 is opened and the chemical liquid is supplied toward the residual pressure removal filter 4, the chemical liquid flows into the primary chamber 20 from the connecting pipe part 12a of the residual pressure removal filter. After entering and being filtered through the filter element 30,
From the hollow recess 31 to the flow path 21' and the connecting pipe section 12b
The chemical solution is then force-fed to the dropping nozzle 5, and the chemical solution is dripped onto the surface of the semiconductor wafer W. In this state, the bellows 40 is compressed from the outside by the pressure of the pressure fluid supplied to the space 21'', so that the bellows 40 is compressed compared to its natural state. The volume of the flow path 21' formed therein is also reduced.

Next, when a predetermined amount of the chemical solution has been supplied onto the semiconductor wafer W, the gate valve 3 is closed, and the control valve 52 is operated so that the pressure fluid supplied to the space 21'' in the secondary chamber 21 is The pressure is reduced to a predetermined value, for example, normal pressure.Then, the bellows 40 expands in the radial direction, and the volume of the flow path 21' formed in the bellows 40 increases.Therefore,
The residual pressure of the chemical liquid in the hollow recess 31 of the filter element 30 and the flow path 21' is absorbed by the expansion of the volume of the flow path 21', and the residual pressure of the chemical liquid causes the chemical liquid to flow out from the dropping nozzle 5. Dropping is prevented and the medicinal solution is accurately supplied in a predetermined amount. That is, by closing the gate valve 3, the chemical solution that is about to flow out toward the dripping nozzle 5 is sucked into the bellows 40 as the bellows 40 expands from the initial state.

In the following, as described above, the turntable 1 is rotated at an extremely low speed of about 0.1 to several revolutions per second to stir the chemical solution, and after maintaining this state for a predetermined period of time, the turntable 1 is rotated at high speed to The chemical solution on the surface of the wafer W may be shaken off by centrifugal force, and further cleaning with pure water may be performed to complete the chemical solution treatment.

In the above embodiment, the flexible member that partitions the secondary chamber 21 is a bellows 40 that is concentric with the filter housing 10. As in the other embodiment shown in , bellows 40', 40', etc. with closed tips may be formed radially in the middle of the straight pipe-shaped channel 21 from the partition wall 11 to the connecting pipe portion 12b. Furthermore, the flexible member may be a membrane-like member such as a diaphragm.

Furthermore, in the above embodiment, a case will be described in which the space 21'' partitioned by the flexible member 40 is connected to the pressure piping 50, pressurized when liquid is supplied, and returned to normal pressure when the liquid supply is stopped. However, the space 21'' may be connected to a pressure reduction pipe to maintain normal pressure when liquid is supplied and to reduce the pressure when liquid supply is stopped.In short, when liquid supply is stopped, liquid The pressure may be relatively reduced compared to the time of supply, and which format is more advantageous may be selected depending on the magnitude relationship between the liquid supply time and the liquid supply stop time.

Furthermore, by using the same chemical solution that is filtered by the residual pressure removal filter as the pressure fluid that pressurizes and depressurizes the flexible member, it is possible to avoid contamination of the chemical solution due to damage to the flexible member, or ignition and explosion. It may be possible to prevent this.

Furthermore, it goes without saying that the residual pressure removal filter according to the present invention can be used not only as a pipe for supplying a chemical liquid to a dropping nozzle of a chemical liquid processing apparatus as described above, but also as a pipe for supplying various liquids.

Effects of the Invention As explained above, the residual pressure removal filter according to the present invention has a space partitioned by a flexible member in the filter housing when the liquid is being supplied. By relatively reducing the pressure at the time, the flexible member is deformed in the radial direction, and the residual pressure of the liquid on the secondary side of the filter element when the liquid supply is stopped is removed. It is possible to completely prevent droplets from dripping from the dripping nozzle etc. when the supply of liquid is stopped, and therefore it is possible to accurately supply a predetermined amount of the liquid.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view showing one embodiment of the residual pressure removing filter according to the present invention, and FIG. 2 is a longitudinal sectional side view showing another embodiment of the residual pressure removing filter according to the present invention. FIG. 3 is a schematic structural diagram showing an example of a chemical liquid processing apparatus and chemical liquid supply piping according to the present invention. 10...Housing, 20...Primary room, 21...
...Secondary chamber, 21', 21...flow path (flow path space),
21″...Space, 30...Filter element,
40, 40'...Flexible member.

Claims (1)

[Claims for Utility Model Registration] A filter provided in a liquid supply pipe, comprising a filter housing that is partitioned by a partition wall having a through hole and has two chambers communicating with the upstream and downstream sides of the pipe. , a filter element disposed in one chamber of the filter housing, and a flow path disposed in the other chamber of the filter housing that communicates this chamber with the piping and the filter element via the through hole. 1. A residual pressure removal filter comprising a flexible member that defines a space and a space that communicates with the outside and whose pressure is relatively reduced when the supply of liquid is stopped compared to when the supply of liquid is stopped.