JPH10281069A - Pumping unit - Google Patents

Abstract

[PROBLEMS] To combine a plurality of selectively driven pumps in a compact manner to reduce cost, and to combine with a filter unit by eliminating the need for a primary pump especially when applied to a photoresist coating apparatus. The present invention provides a pump unit that simplifies the system and enables constant discharge control of a photoresist liquid. SOLUTION: One actuator 32 is provided on a frame 51.
And a plurality of pumps 31 driven thereby are attached. The pump 31 has a flexible tube fram 608 separating the pump chamber 604 and the working fluid space 609, and the manifold 53 is used to connect the cylinder chamber 525 of the actuator 32 to the working fluid space 609 of each pump 31. ing. An air operated valve 54 is provided in each of the branch pipes 532 connected to each pump 31 of the manifold 53, and when the actuator 32 is driven, the working fluid is selectively supplied to the pump 31 via the open valve 54. Is done.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump unit in which a plurality of pumps are integrated, and more particularly to a photoresist coating apparatus for forming a photoresist film by dropping a photoresist solution onto a surface of a semiconductor wafer or the like. The present invention relates to a pump unit that is useful for the present invention.

[0002]

2. Description of the Related Art When a photoresist film is formed on a semiconductor wafer, a spin coating method is generally used in which a photoresist liquid is dropped onto a surface of the semiconductor wafer through a nozzle while rotating the semiconductor wafer. The main part of the photoresist coating device (resist dispensing system) used for the spin coating method is a pump that pumps up the photoresist liquid contained in the bottle and discharges it from the nozzle at a constant rate. And a filter for removing liquid dust, gel, and the like. In particular, the filter is an important factor that determines the performance of the resist dispensing system, and improvements have been made in filter performance, low pressure loss, large flow rate, and the like. Usually, for the purpose of reducing the size of the system, the filter is integrally incorporated in the pump housing.

[0003]

Generally, photoresist coating is performed in a resist coating room in a clean room. Bottles that require replacement of the photoresist solution may cause contamination if placed in a clean room. Therefore, it is desirable to place the bottle outside the clean room. However, if the length of the pipe from the bottle to the pump housing in the resist coating chamber becomes long, the inside of the pipe becomes negative pressure and bubbles are generated in the transferred photoresist liquid. When these bubbles enter the pump, not only the ejection amount from the nozzle becomes unstable, but also bubbles are generated in the resist film formed on the semiconductor wafer, making high-precision fine processing difficult.

In order to prevent the generation of such bubbles,
Separately from the pump in the pump housing (dispensing pump), a primary pumping pump near the bottle is required. For example, a method of extruding a photoresist liquid in a resist bottle using N ₂ gas or a method of transferring the liquid to a dispense pump by another primary pump is used. However, the use of such a pressure-feeding primary pump not only requires the resist bottle itself to withstand high pressure, but also complicates the system configuration. Especially,
A typical resist dispensing system is configured as a multiple type having a plurality of bottles each containing a different photoresist solution and a plurality of nozzles corresponding to these bottles. Therefore, if a primary pump is provided for each bottle, the system becomes very complicated.

On the other hand, if the pump housing containing the filter is arranged near the bottle outside the clean room, the piping from the filter to the nozzle becomes long, which also causes a great inconvenience. This is because the photoresist solution from which dust and the like have been removed by the filter is contaminated again along a long path to the nozzle, or is deteriorated. Furthermore, in the case of a multiple system, an actuator must be prepared for each of a plurality of pumps, which increases the size of the pump housing, requires a large space, and increases the cost of the system.

According to the present invention, a plurality of selectively driven pumps are compactly integrated to reduce the cost. In particular, when the present invention is applied to a photoresist coating apparatus, a primary pump is unnecessary and a system is combined with a filter unit. And to provide a pump unit capable of controlling the constant discharge of the photoresist liquid.

[0007]

In a pump unit according to the present invention, a plurality of pumps driven by a working fluid are unitized by sharing one actuator, and a working fluid space of each pump is connected via a manifold. A valve that is connected to the cylinder chamber of the actuator and that selectively turns on and off the supply of the working fluid driven by the actuator to the pumps at a branch portion of the manifold to the pumps. Features. In the present invention, for example, each of the pumps
A tube fram type in which a tubular flexible membrane is stretched between the pump chamber and the working fluid space. The valve is a normally open type air operated valve. Further, the actuator has a stepping motor and a bellows driven by the motor to expand and contract the cylinder chamber.

[0008] In the pump unit according to the present invention, a plurality of pumps selectively driven share one actuator, and the working fluid is branched and supplied by the manifold, thereby reducing the size and cost. It is planned. When the pump unit according to the present invention is applied to a photoresist coating apparatus or the like, a system can be configured as an external type in which a pump and a filter are separately arranged in combination with a separately configured filter unit. In particular, if the pump is a tube-flame type driven by a stepping motor and has a large discharge pressure, it is not necessary to use a primary pump, and the system can be simplified.

A photoresist coating apparatus according to the present invention comprises a bottle containing a photoresist solution, a pump for transferring the photoresist solution in the bottle and supplying the photoresist solution to a nozzle for dripping the photoresist solution, And a filter provided between the nozzle and the nozzle, wherein the filter is disposed in the photoresist coating chamber together with the nozzle, and the pump is disposed outside the photoresist coating chamber together with the bottle. It is characterized by having done.

The present invention also provides a plurality of bottles containing a photoresist solution, a plurality of pumps for selectively supplying the photoresist solution of these bottles to a plurality of different nozzles. In a photoresist coating apparatus including a plurality of filters provided between the respective nozzles, a filter unit is configured by combining the plurality of filters to form a filter unit together with the plurality of nozzles in a photoresist coating chamber. And disposing the plurality of pumps together to form a pump unit and disposing the pump unit together with the plurality of bottles outside the photoresist coating chamber.

In the system according to the present invention, the filter is not a type in which the filter is built in the pump housing.
The filter is arranged in the photoresist coating chamber together with the nozzle, and the pump is arranged outside the photoresist coating chamber together with the bottle, based on the external type installed outside the pump. Therefore, the piping from the filter to the nozzle can be made sufficiently short to prevent contamination and deterioration of the photoresist solution supplied to the nozzle. In addition, since the pump is disposed near the bottle and the pump is of a pressure-feed type from the pump to the photoresist coating chamber, it is possible to stably transfer the photoresist liquid without generating bubbles to the nozzle. Therefore, there is no need to use a primary pump, and the system can be simplified.

In particular, in the case of a multiple system, a plurality of pumps are collectively configured as a pump unit, and a plurality of filters are collectively configured as a filter unit, thereby making the resist dispensing system compact. In addition to this, the installation and replacement of each device, the layout change, and the like become easy, and an ideal system that can operate the system only by piping work to the resist bottle and the nozzle can be constructed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a resist dispensing system according to an embodiment of the present invention, and FIG. 2 shows a more specific system configuration in the case of a quadruple system. The resist bottles 1 (1a to 1d) containing different photoresist liquids are connected to the pump unit 3 via the chambers 2 (2a to 2d). The chamber 2 is for temporarily storing the photoresist liquid in the resist bottle 1 and replenishing the photoresist liquid from the resist bottle 1 every time the stored liquid is exhausted. A sensor for detecting the stored amount is provided.

The pump unit 3 is a unit of four pumps 31 (31a to 31d) corresponding to the resist bottles 1, respectively. In this embodiment, the four pumps 31 are driven by one actuator 32 controlled and driven by the driver 9.
Details of the pump unit 3 will be described later.

The photoresist liquid sucked up from the chamber 2 by the pump unit 3 is supplied to the filter unit 4. The filter unit 4 also has four filters 41 (41a) corresponding to the respective photoresist solutions.
To 41d) as a unit. In this embodiment, the filter 41 is of a disposable type. The photoresist liquid from each filter 41 is supplied to four nozzles 5 (5a to 5d) arranged on the semiconductor wafer 7 via an air operated valve (A / V) 42 and a suck-back valve (S / V) 43, respectively. ) And is discharged from the nozzle 5 in a fixed amount. Further, each filter 41 is connected to the exhaust port 6 via another air operated valve 44 in order to release air at a predetermined timing.

The air operated valve 42 is used for removing the residual pressure in order to prevent the resist solution from dripping from the tip of the nozzle 5 due to the residual pressure in the piping. The suck back valve 43 sucks the photoresist solution remaining at the tip of the nozzle 5 to prevent the excess photoresist solution from dripping, and to perform accurate discharge amount adjustment. It is used to prevent the deterioration of the characteristics of the photoresist liquid due to being kept exposed from the nozzle tip. From the SV controller 8 to the air operated valves 42 and 44 and the suck back valve 4
3 is controlled by speed controllers (SC) 46, 47, and 45, respectively, thereby controlling the opening and closing speeds of the valves 42 to 44. Each air operated valve 42, 44 and suck back valve 4
3 is also mounted in the unit 4 together with the filter 41.

It is important for the resist dispensing system to control the operation of pump-related air valves and suck-back valves. Particularly, in dispensing a low-viscosity photoresist solution, highly accurate timing control of the pump operation is indispensable, and the system controller 10 is used for this operation timing control.

As described above, in this embodiment, the pump 31
The pump unit 3 and the filter unit 4 are separately provided as a unit, so that the pump unit 3 and the filter unit 4 can be arranged in separate rooms. FIG.
This is a preferred arrangement example of the pump unit 3 and the filter unit 4. In this example, the filter unit 4 is disposed in a resist coating chamber 301 in a clean room, and the pump unit 3 is disposed together with the resist bottle 1 in a room 302 downstairs of the clean room. In this case, the distance from the pump unit 3 to the filter unit 4 is 3 to 15
[M], but in this embodiment, as will be described later, the pump 31 of the pump unit 3 is of a tube flam type capable of transferring about 15 [m], and without using a primary pump, it can reach the resist coating chamber. It is possible to transfer.

FIG. 4 shows another preferred arrangement of the pump unit 3 and the filter unit 4. In this example, the pump unit 3 and the filter unit 4 are on the same floor,
The filter unit 4 is arranged near the nozzle 5 in the resist coating chamber 301, and the pump unit 3 is arranged outside the resist coating chamber 301 together with the resist bottle 1.

In each of the arrangement examples shown in FIGS. 3 and 4, the pump unit 3 and the filter unit 4 are separately provided and the filter unit 4 is disposed in the resist coating chamber 301. The piping becomes short, and it becomes possible to prevent contamination or deterioration of the photoresist solution after passing through the filter. Further, the pump unit 3 and the resist bottle 1 together with the resist coating chamber 31
, The transfer of the photoresist solution is facilitated and the resist coating chamber 30
1 can be prevented. Further, the unitization of the pump and the filter facilitates installation and replacement of equipment and layout change.

Next, a specific configuration of the pump unit 3 of the embodiment will be described with reference to FIGS. FIG. 5 (a)
(B) is a front view and a side view showing the pump unit 3 partially cut away, and FIG. 6 is a rear view. The pump unit 3 includes the actuator 32 housed in the frame 51.
And the actuator 32 attached outside the frame 51
Pumps 31 (31a to 31d) driven by the pump
And

Each pump 31 is of a tube-fram type driven by a working fluid. As shown in a schematic sectional view of FIG.
It has a cylindrical pump chamber 604 whose upper end has an outlet 603. Inside the pump chamber 604, a Teflon cylindrical body 605 is integrally formed with the pump body 601 at the lower end thereof in order to prevent a large amount of photoresist solution from staying. The inflow port 602 is provided at the lower end of the cylindrical body 605. Hole 60 provided
6, 607 communicates with the pump chamber 604. A flexible tube frame 608 is stretched on the pump body 601 coaxially with the cylindrical body 605 so that the working fluid space 609 outside the tube frame 608 is supplied with fluorine oil 530 in this embodiment. Has become.

The lower inlet 602 of the pump body 601 is connected to the piping 611 from the chamber 2 via check valves 610a and 610b for suction, and the upper outlet 603 is connected via check valves 610c and 610d for discharge. Connected to a pipe 612 connected to the filter unit 4. When the fluorine oil 530 is driven by the actuator 32 to change the pressure in the working fluid space 609, the tube flam 608 bends in and out, thereby causing the lower end valves 610a and 610b or the upper end valves 610c and 610c.
Od is opened and the photoresist solution 630 is opened.
Is sucked and discharged. That is, the fluorine oil 53
0 is pushed out by the actuator 32, the tube fram 608 bends inward, and the suction side valve 61
0a and 610b are closed, and the photoresist solution 630 in the pump chamber 604 is opened and the discharge side valves 610c and 61 are opened.
Discharged via 0d. Conversely, when the fluorine oil 530 is sucked, the tube fram 608 bends outward, the discharge side valves 610c and 610d are closed, and the photoresist liquid 630 is pumped through the open suction side valves 610a and 610b. Sucked in 604.

The actuator 32 is of a stepping motor drive type. Stepping motor 521
Is a type having a gear head 550 in order to cope with an increase in pump discharge pressure. Gear head 550
Of the pulley 522a attached to the belt 523
Is transmitted to a pulley 522b through the pulley 522b.
The nut 524b reciprocates along the shaft 524a of the ball screw 524 driven by the rotation of b. A rod 526 is attached to the nut 524b, and a bellows 527 made of Teflon is extended and contracted in the cylinder chamber 525 at the tip of the rod 526. FIG. 5
In the figure, the upper half of the center line of the shaft 524 shows the state where the bellows 527 is extended, and the lower half shows the state where the bellows 527 is compressed. The speed of the stretching movement of the bellows 527 is
Based on the output of the sensor 551, the speed controller 5
52 controls the stepping motor 521.

In the frame 51, an aluminum die-cast manifold 53 connected to the cylinder chamber 525 is provided. The manifold 53 has a main pipe 531 and four branch pipes 532 (532a to 532d) branched from the main pipe 531. Each of the branch pipes 532 is provided with an air operated valve 54 (54a to 54d) driven by compressed air. , Each valve 54 is connected to the corresponding pump 31. The air operated valve 54 is
It is a normally open type that is open in a steady state in which compressed air is not introduced. When compressed air is introduced, valves 541 (541a to 541) are connected via a rod (not shown).
d) is pressed downward to close the branch pipe 532.

Fluorine oil 530 as a working fluid is
From the cylinder chamber 525, the tube 53 of each pump 31 is connected via the manifold 53 and the branch pipe 532.
08 in a non-compressed state in a working fluid space 609 arranged outside. When the actuator 32 is driven, the manifold 53, the manifold 53,
Further, the fluorine oil 530 is pushed into the tube fram 608 of each pump 31 via each branch pipe 532. At this time, by closing unnecessary ones of the normally open type valves 54, the fluorine oil 530 can be supplied only to the pump 31 selected according to the required photoresist. A pressure sensor 5 is provided at the fluorine oil supply port of the cylinder chamber 525.
61 is attached, and controls the hydraulic pressure in the cylinder chamber 525 appropriately.

As described above, the pump unit 3 in this embodiment is a quadruple system in which one actuator 32 and four pumps 31 driven by the actuator 32 are integrated, so that compactness and cost reduction are achieved. It is planned. Also,
The pressure of the fluorine oil compressed and driven by the actuator 32 is controlled by the manifold 53 and the pressure of the manifold 4 attached thereto.
The air operated valves 54 selectively transmit the air to the pump 31. In addition, a gear head type stepping motor is used for the actuator 32, which makes it possible to cope with a high discharge pressure, thereby improving resolution and discharge accuracy.

Next, a specific configuration of the filter unit 4 will be described with reference to a front view of FIG. 8 and a side view of FIG. As shown, the filter unit 4 is configured by mounting four filters 41 on a support panel 401 together with respective air operated valves 42 and 44 and a suck back valve 43. Although the internal configuration of the filter 41 is not shown, it is a normal disposable type, and is arranged with the inlet 402 on the primary side (402a to 402d) down and the outlet 403 on the secondary side (403a to 403d) up. ing. That is, similarly to the case where the flow of the photoresist solution in the pump unit 3 is changed from “lower to upper”, the filter unit 4
However, the flow is “lower → upper”. As a result, the photoresist solution pumped up from the bottom by the pump unit 3 flows through the filter 41 from the bottom up as it is. Therefore, unnecessary retention of the photoresist liquid as in the case of passing through a U-shaped path, for example, is eliminated, and the liquid replacement property is excellent.

The filter 41 has a liquid discharge port 405 (405a to 405d) and an exhaust port 404 (404) adjacent to the photoresist liquid inlet 402 and outlet 403, respectively.
a to 404d). The exhaust port 404 is connected to the exhaust port 6 via the air operated valve 44 as described above. The air bleeding on the primary side of the filter 41 is performed by opening the valve 44 of the exhaust unit and introducing the liquid into the filter 41 with the valve 42 of the outlet 403 on the secondary side closed. Is automatically performed at an appropriate timing in response to a control signal from the system controller 10.

In the case of this embodiment, the suck back valve 4
3 is integrally formed with the air operated valve 42. It is conceivable that the pump itself has the function of the suck-back valve 43. However, the volume range required for the suck-back function is as small as 0 to 0.05 [ml], and is about 0.05 [ml]. Is controlled by the actuator 32 of this embodiment, 0.07
It must be controlled with a stroke length of 5 [mm], which is technically difficult. Therefore, by using a small suck-back valve-integrated air operated valve, a minute amount of suck-back can be achieved.

As described above, according to this embodiment,
A plurality of pumps and filters are unitized. Therefore, it is possible to construct a system photoresist dispensing system that enables the system to be operated only by piping work to the resist bottle and the nozzle, and also facilitates operations such as device replacement and layout change. In addition, the filter unit is placed in the resist coating chamber together with the nozzle, and the pump is placed outside the resist coating chamber together with the resist bottle to discharge the photoresist liquid without using a primary pump. Not only is it possible to prevent deterioration and contamination of the photoresist solution after passing through the filter, but also contamination of the resist coating chamber. Further, in this embodiment, both the pump unit and the filter unit are configured so that the photoresist liquid flows upward from below, thereby preventing the photoresist liquid from staying and improving the replaceability.

In particular, the pump unit according to this embodiment
Manifolds are combined and integrated so that a plurality of tube flam type pumps are selectively driven by an actuator using one stepping motor, so that the size and cost of the pump unit are reduced.

The present invention is not limited to the above embodiment. For example, in the embodiment, the pump and the filter are unitized by four each, but may be unitized by two or five or more. Further, in the embodiment, the pump is of the tube-flame type, but the present invention is also effective when another type of pump is used. Further, the pump unit according to the present invention can be applied not only to the photoresist coating apparatus described in the embodiment but also to an apparatus requiring the same fluid discharge control.

[0034]

As described above, according to the present invention, manifolds are combined and integrated so that a plurality of pumps are selectively driven by one actuator.
Provided is a pump unit capable of reducing the size and cost, and particularly simplifying the configuration of the entire system without using a primary pump separately from a filter when applied to a photoresist coating apparatus. be able to.

[Brief description of the drawings]

FIG. 1 shows a schematic configuration of a system according to an embodiment of the present invention.

FIG. 2 shows a specific configuration of the system of the embodiment.

FIG. 3 shows an example of arrangement of a pump unit and a filter unit according to the embodiment.

FIG. 4 shows another arrangement example of the pump unit and the filter unit of the embodiment.

FIG. 5 is a front view and a side view showing a specific configuration of the pump unit of the embodiment.

FIG. 6 is a rear view of the pump unit.

FIG. 7 is a sectional view schematically showing a pump structure of the pump unit.

FIG. 8 is a front view showing a specific configuration of the filter unit of the embodiment.

FIG. 9 is a side view of the filter unit.

[Explanation of symbols]

1 (1a to 1d): resist bottle, 2: chamber, 3
... Pump unit, 31a-31d ... Pump, 32 ... Actuator, 521 ... Stepping motor, 526 ...
Piston, 527: bellows, 525: fluorine oil,
53: Manifold, 532 (532a to 532d) ...
Branch pipe, 54 (54a to 54d): air operated valve, 601: pump body, 604: pump chamber, 608 ...
Tube flam, 610a to 610d ... check valve, 4
... Filter unit, 41 (41a-41d) ... Filter.

Claims (4)

[Claims] 1. A plurality of pumps driven by a working fluid are unitized by sharing one actuator, and a working fluid space of each pump is connected to a cylinder chamber of the actuator via a manifold. A pump unit provided with a valve for selectively turning on / off the supply of the working fluid driven by the actuator to each of the pumps at a branch portion to each of the pumps. 2. The pump unit according to claim 1, wherein each of the pumps is a tube flam type in which a tubular flexible membrane is stretched between a pump chamber and a working fluid space. 3. The pump unit according to claim 1, wherein the valve is a normally open type air operated valve. 4. The pump unit according to claim 1, wherein the actuator has a stepping motor and a bellows driven by the motor to extend and contract in a cylinder chamber.