JPH07275780A - Rotary cup type treating device - Google Patents

Abstract

PURPOSE:To keep uniform the pressure distribution in an inner cup and the coating film of a material to be treated by dividing an evacuating pass of an outer cup into a buffer space of large capacity connecting to an evacuating device and a communicative space connecting it and a space in the inner cup. CONSTITUTION:After a chuck 10 in which a material to be treated is set on the upper surface is lowered and engaged with an inner cup 3, liquid is dropped onto the upper surface of the material to be treated, and also an outer cup 2 and the inner cup 3 are closed by cover bodies 26, 27 respectively. Because at this time, an evacuating pass 20 is normally evacuated, the inner cup 3 is also evacuated through a liquid discharge and evacuating hole 22. Since the liquid discharge and evacuating hole 22 is not opened to a buffer space S1 to which an evacuating hole 23 is opened but opened to a communicative space S2 of small volume, however, the inner cup 3 is uniformly evacuated, not influenced by the evacuating hole 23. After that, the inner cup 3 and the chuck 10 each are rotated to uniformly diffuse liquid by centrifugal force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus used in a step of applying a film forming liquid to the surface of an object to be processed such as a wafer for a semiconductor element or a glass substrate for a liquid crystal panel.

[0002]

2. Description of the Related Art As a device for applying a coating liquid to a wafer for semiconductor devices or a glass substrate for liquid crystal panels, a spinner chuck is exposed in a fixed cup, and an object to be processed is fixed to the spinner chuck to form a spinner chuck. There is known a structure in which the object to be processed is rotated integrally and the liquid dropped on the surface of the object to be processed is uniformly diffused by the centrifugal force generated by this rotation.

However, in the above-mentioned processing apparatus, since the cup is fixed and the spinner chuck rotates, turbulent flow occurs in the cup, uniform coating is difficult, and fine dust adheres to lower the yield.

Therefore, as a device that does not cause a turbulent flow in the coating atmosphere, Japanese Patent Laid-Open No. 293056/1993 proposes a rotary cup type processing device. In this processing apparatus, the inner cup is arranged in the fixed outer cup, the object to be processed is set in the inner cup, and the inner cup is rotated by closing the upper opening of the inner cup with the lid, The inner cup is decompressed by centrifugal force to remove the gas dissolved in the coating liquid, and the coating liquid is uniformly dispersed on the surface of the object to be treated by centrifugal force.

Further, in order to help rotate the inner cup and reduce the pressure inside the inner cup, an annular exhaust passage is formed in the outer cup along the outer periphery of the inner cup, and a vacuum pump or the like is formed in the exhaust passage. The connected exhaust port is formed to constantly reduce the pressure in the exhaust passage.

[0006]

In the rotary cup type processing apparatus described above, the object to be processed is set in the inner cup, the coating liquid is dropped on the surface of the object to be processed, and then the inner cup is closed with the lid. Then, the upper opening of the outer cup is closed, and then the inner cup is rotated. On the other hand, the exhaust passage of the outer cup is always exhausted. As a result, when the lid closes the upper openings of the inner cup and the outer cup, the inside of the inner cup is depressurized through the drainage / exhaust hole formed in the inner cup.
Since there is only one exhaust port formed in the exhaust passage, the portion close to the exhaust port is strongly sucked, and the pressure distribution inside the inner cup becomes uneven at the start of processing such as coating, which adversely affects the uniformity of the film thickness. Exert. In particular, there is a significant difference in film thickness between the portion near the exhaust port and the other portion immediately before the start of rotation.

Further, when the rotation of the inner cup is stopped, the pressure in the exhaust passage of the outer cup is higher than the pressure in the inner cup, so that the gas in the exhaust passage instantaneously flows back into the inner cup, Pulsation occurs inside. The pulsation acts on the coating film on the surface of the object to be treated which still contains the solvent, and adversely affects the coating film as described above.

[0008]

In order to solve the above-mentioned problems, the present invention has an outer cup fixed to a base on the outside of an inner cup rotated by a motor, and the outer cup is provided on the outer circumference of the inner cup. In a rotary cup type processing device having an annular exhaust passage along
The exhaust passage is partitioned into a large-capacity buffer space connected to the exhaust device by a partition wall and a small-volume communication space that connects the buffer space and the inner cup inner space.
Here, it is possible to form exhaust ports at two opposing positions of the exhaust passage.

[0009]

[Function] Even when the lids of the inner cup and the outer cup are closed, the inside of the inner cup is pulled into the buffer space through the small-volume communication space, and when the rotation of the inner cup is stopped, the buffer space is stopped. The gas gradually flows into the inner cup through the small-volume communication space.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a vertical sectional view of a rotary cup type processing apparatus according to the present invention, FIG. 2 is an enlarged sectional view of a main part of the rotary cup type processing apparatus, FIG. 3 is a plane sectional view showing an exhaust passage, and FIG. It is a plane sectional view showing another example of an exhaust passage.

In the rotary cup type processing apparatus, an annular outer cup 2 is fixed on a base 1, an inner cup 3 is arranged inside the outer cup 2, and the inner cup 3
The cylindrical shaft portion 4 is rotatably supported by the base 1 via the bearing 5, and the pulley 6 is fitted to the lower end of the cylindrical shaft portion 4, and the pulley 6 and the rotary shaft of the motor 7 are fitted to the pulley. The inner cup 3 is rotated by tensioning the timing belt 9 between the inner cup 3 and the timing belt 9.

A chuck 10 is arranged in an opening formed in the center of the inner cup 3. A shaft 11 hangs downward from the chuck 10 while penetrating through the tubular shaft portion 4, and a lower end portion of the shaft 11 is coupled to a vertically moving body 13 which is vertically moved by a cylinder unit 12.

When the lifting body 13 rises, the chuck 10 rises above the bottom surface of the inner cup 3, and the workpiece W such as a semiconductor wafer is set on the upper surface of the chuck 10 at this raised position. Is lowered, the chuck 10 is also lowered, and the upper surface of the chuck 10 and the bottom surface of the inner cup 3 are substantially flush with each other. In this flush state, the chuck 10 engages with the inner cup 3 in a concavo-convex manner, and the rotation of the inner cup 3 is transmitted to the chuck 10.

A horizontal cylinder unit 14 is attached to the elevating body 13 via a bracket, and a stopper 15 fixed to a rod of the cylinder unit 14 is provided.
Is inserted into the hole formed in the large-diameter portion 16 of the shaft 11, so that the chuck 10 is stopped at a predetermined rotation position.

On the other hand, the outer cup 2 is provided with an annular exhaust passage 20. The exhaust passage 20 is partitioned by a partition wall 21 into a large-capacity buffer space S1 and a small-volume communication space S2, and the communication space S2 has an inner cup 3 therein.
The drainage / exhaust hole 22 is opened, and an exhaust port 23 connected to a vacuum pump is opened in the buffer space S1. Here, the exhaust port 23 extends in the tangential direction of the exhaust passage 20, and the edge portion 23a of the exhaust port 23 has a rounded curved surface so that turbulent flow does not occur.

An arm 24 capable of arbitrary movement is arranged above the outer cup 2 and the inner cup 3, and an outer cup lid 26 is supported at the tip of the arm 24 via a block 25. The inner cup lid 27 is dropped onto the cup lid 26 to support the inner cup lid 27, and the rectifying plate 2 is provided on the lower surface of the inner cup lid 27.
8 is attached to the block 25, and the cleaning liquid supply passage 2 is attached to the block 25.
9 is formed, and a gap 30 is formed between the inner cup lid 27 and the current plate 28.

Here, for cleaning the inner cup 3, the inner cup 3 is rotated while supplying the cleaning liquid into the inner cup 3 through the cleaning liquid supply passage 29 and the gap 30 with the inner cup lid 27 closed. By doing.

In order to apply the coating liquid to the surface of the object W to be processed, the chuck 10 is raised above the inner cup 3 with the lids 26 and 27 of the outer cup 2 and the inner cup 3 removed. , The object to be processed W in this state
Is set on the upper surface of the chuck 10 and suction-fixed, and further the chuck 10 is lowered to engage the inner cup 3 with the concave and convex portions, and then the liquid is dripped on the center of the upper surface of the object W to be processed, and the outer cups 26 and 27 are used. 2 and the top openings of the inner cup 3 are closed.

At this time, since the inside of the exhaust passage 20 is constantly sucked, the inside of the inner cup 3 also serves as the drainage / exhaust hole 22.
However, since the drainage / exhaust hole 22 is not directly opened to the buffer space S1 where the exhaust port 23 is open but is opened to the communication space S2 having a small volume,
The inner cup 3 is uniformly depressurized without being affected by the exhaust port 23.

After that, the inner cup 3 is rotated.
Then, the inner cup 3 and the chuck 10 suction-fixing the workpiece W rotate integrally, and the liquid dropped by the centrifugal force is uniformly diffused on the upper surface of the workpiece W. Further, due to the centrifugal force, the gas in the inner cup 3 is discharged from the exhaust / exhaust hole 22 into the communication space S2 of the outer cup 2.
The inner space of the inner cup 3 is further decompressed by entering the buffer space S1 via.

After a lapse of a predetermined time, the rotation of the motor is stopped and the inner cup 3 is stopped. At this time, since the gas inside is exhausted by the centrifugal force, the inner cup 3 is in a reduced pressure state as described above. Therefore, the gas in the large-capacity buffer space S1 gradually flows into the inner cup 3 via the small-volume communication space S2. At this time, since it flows in via the small-volume communication space S2, it does not suddenly flow into the inner cup and pulsation is prevented.

FIG. 4 is a plan cross-sectional view showing another embodiment of the exhaust passage. In this embodiment, the exhaust direction is opposite to the exhaust passage 20 in the tangential direction and in the opposite direction at two opposing locations of the exhaust passage 20. The exhaust ports 23, 23 are formed so that the exhaust can be performed more uniformly.

[0023]

As described above, according to the present invention,
An exhaust passage having an exhaust port is formed in the outer cup of the rotary cup type processing apparatus, and the exhaust passage is partitioned by a partition into a large-capacity buffer space and a small-volume communication space. Since the drainage and exhaust hole is opened,
When the upper openings of the inner cup and the outer cup are closed by the lids, the pressure distribution in the inner cup does not become uneven when starting the process. Further, even when the rotation of the inner cup is stopped, the external gas temporarily returns from the buffer space to the inner cup through the small-volume communication space, so that pulsation is suppressed. Therefore, a coating film having a uniform thickness without waviness can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a rotary cup type processing apparatus according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of the rotary cup type processing device.

FIG. 3 is a plan sectional view showing an exhaust passage.

FIG. 4 is a plan sectional view showing another embodiment of an exhaust passage.

[Explanation of symbols]

1 ... Base, 2 ... Outer cup, 3 ... Inner cup, 10 ... Chuck, 20 ... Exhaust passage, 21 ... Partition wall, 2
2 ... Drainage / exhaust hole, 23 ... Exhaust port, 26 ... Outer cup lid, 27 ... Inner cup lid, S1 ... Buffer space, S2 ... Communication space, W ... Object to be treated.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical indication location H01L 21/306 21/68 N (72) Inventor Hideya Kodaira 150 Nakamaruko, Nakahara-ku, Kawasaki-shi, Kanagawa Tokyo Koka (72) Inventor Koji Ueda 150 Nakamaruko, Nakahara-ku, Kawasaki-shi, Kanagawa Tokyo Ohka Kogyo Co., Ltd. (72) Hidenori Miyamoto 150, Nakamaruko, Nakahara-ku, Kawasaki, Kanagawa Tokyokyoka Kogyo Co., Ltd. (72) Inventor Ryuzo Takatsuki 6186 Kinoko Town, Ihara City, Okayama Prefecture Tatsumo Co., Ltd.

Claims (2)

[Claims] 1. A rotary cup type processing apparatus in which an outer cup fixed to a base is arranged outside an inner cup rotated by a motor, and an annular exhaust passage is formed in the outer cup along the outer circumference of the inner cup. In the rotary cup type, the exhaust passage is divided into a large-capacity buffer space connected to the exhaust device by a partition wall and a small-volume communication space that connects the buffer space and the inner cup inner space. Processing equipment. 2. The rotary cup type processing apparatus according to claim 1, wherein exhaust ports are formed at two opposing locations in the exhaust passage.