JP3892579B2 - Substrate rotating processing equipment - Google Patents

Description

[0001]
The present invention, like a spin coater, spin developer, spin scrubber, etc., keeps a substrate such as a semiconductor wafer or glass substrate in a horizontal position and rotates a processing solution such as a coating solution, a developer, or a cleaning solution while rotating around a vertical axis. The present invention relates to a substrate rotating type processing apparatus that supplies a substrate surface to perform processing.
[0002]
[Prior art]
In a substrate rotating processing apparatus used as a semiconductor manufacturing apparatus, for example, a spin coater, a substrate such as a semiconductor wafer or a glass substrate is held in a horizontal position by a chuck, and a coating liquid is supplied to the substrate surface while rotating around a vertical axis. The cup disposed around the substrate collects the coating solution that scatters from the top of the substrate to the surroundings as the substrate rotates, exhausts the interior of the cup from the bottom of the cup, and passes through the top opening of the cup. Clean air is introduced into the cup. And, with the current plate arranged inside the cup, the air that has flowed into the cup is guided in the outer peripheral direction and then guided toward the center of the cup along the bottom surface of the cup, forming an air flow in the cup, It prevents the excessive coating liquid splashed from the substrate from reattaching to the substrate (see, for example, Japanese Utility Model Publication No. 6-28223, Japanese Patent Application Laid-Open No. 5-234874).
[0003]
[Problems to be solved by the invention]
However, a complex flow of airflow is generated in the rotating cup of the substrate, and the scattered coating liquid that collides with the inner peripheral wall surface of the cup partially stays in the cup in a mist form. Yes. Here, the cup is conventionally formed of a plastic material such as polypropylene or fluororesin from the viewpoint of corrosion resistance to chemicals used for processing the substrate. However, since the plastic material is an insulator, the cup is easily charged. When the cup is charged, an electrostatic field is formed between the cup and the substrate on the chuck. As a result, the coating liquid fine particles staying in the cup are caused to flow toward the substrate due to a change in the air flow during the process and reattach to the substrate. This is because, when the size of the fine particles becomes 10 μm or less, the fine particles in the air are almost not affected by gravity and inertial force and are carried in the airflow, and the diameter of the fine particles is less than 1 μm. Then, the adhesion of the fine particles to the substrate is mainly performed by the Coulomb force (electrostatic force) between the substrate and the fine particles. When the fine particles of the coating solution are reattached to the substrate, it causes uneven coating, resulting in a decrease in coating quality. In addition, the adhesion of the coating liquid to the back of the substrate can be a cause of defects in the exposure process.
[0004]
If the cup is formed of a metal material that is a conductor, the cup is not charged, and an electrostatic field is hardly formed between the cup and the substrate. Therefore, the coating liquid fine particles are reattached to the substrate. Can be suppressed. However, in that case, the corrosion resistance of the cup becomes a problem. Therefore, it is conceivable to coat the surface of the metal material with a plastic material having chemical resistance. In this case, however, the coating material may be peeled off. Furthermore, it is conceivable that the cup is formed of a plastic material mixed with carbon to increase the conductivity of the cup. In this case, however, contamination due to falling off of the contaminants is a concern. There is also a technology to make plastic materials conductive by kneading or applying antistatic agents such as surfactants to plastic materials. There is a problem that the effect disappears.
[0005]
The present invention has been made in view of the circumstances as described above. During the processing of the substrate, a part of the processing liquid scattered from the substrate is prevented from reattaching to the substrate as fine particles. Non-uniformity can be eliminated to prevent degradation of processing quality, such as corrosion of cups, peeling of part of cup materials, contamination due to falling off of contaminants in cup materials, reduction of antistatic effect of cup materials, etc. An object of the present invention is to provide a substrate rotation processing apparatus that does not cause any problems.
[0006]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a substrate holding / rotating means for holding a substrate in a horizontal posture and rotating it around a vertical axis, and a processing liquid for supplying a processing liquid to the surface of the substrate held by the substrate holding / rotating means. A container having a top surface opened with a supply means, and disposed so as to surround the side and the lower side of the substrate held by the substrate holding / rotating means, and for recovering the processing liquid scattered from the substrate to the periphery. The cup is formed of an antistatic plastic material in which a conductive polymer is blended in a polymer base material.
[0007]
The invention according to claim 2 is characterized in that, in the processing apparatus according to claim 1, an antistatic polypropylene in which a conductive polymer is blended in a polypropylene base material is used as the antistatic plastic material forming the cup. To do.
[0008]
In the substrate rotating type processing apparatus according to the first aspect of the present invention, the cup is formed of an antistatic plastic material in which a conductive polymer is blended in a polymer base material. An electrostatic field is hardly formed between the substrate and the re-adhesion of the coating liquid fine particles to the substrate is suppressed. And since the cup is formed of a plastic material, it has corrosion resistance against chemicals, and the antistatic plastic material forming the cup is obtained by blending a conductive polymer in a polymer base material. Therefore, there is no worry that a part of the cup material is peeled off, contaminants in the cup material drop off and cause contamination, or the antistatic effect of the cup material decreases with time.
[0009]
In the processing apparatus according to the second aspect of the present invention, since antistatic polypropylene is used as a material for forming a cup, the cup has good moldability and chemical resistance in the same manner as polypropylene that has been most commonly used as a cup material. Also excellent.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention will be described below with reference to FIG.
[0011]
FIG. 1 shows an example of an embodiment of the present invention, and is a longitudinal sectional view showing a schematic configuration of a main part of a substrate rotating type processing apparatus, here a spin coater, when a substrate is not processed. This spin coater has a spin chuck 10 that holds a substrate W in a horizontal position, and the substrate W held on the spin chuck 10 is vertically aligned by a spin motor 14 that is connected to a rotation support shaft 12 that supports the spin chuck 10. Rotated around. Around the substrate W, there is disposed a cup 16 formed in a container shape having an opening 18 on the upper surface and surrounding the side and bottom of the substrate W held by the spin chuck 10. Inside the cup 16, a truncated cone-shaped rectifying plate 20 is fixed below the substrate W held by the spin chuck 10, and ventilation is provided between the lower surface side of the rectifying plate 20 and the inner bottom surface of the cup 16. A passage 22 is formed, and an exhaust port 24 communicating with the ventilation passage 22 is provided at a position below the rectifying plate 20. The exhaust port 24 is connected to an exhaust means which is factory equipment (not shown) through an exhaust path 26. Further, the inner bottom portion of the cup 16 forms a drainage passage 28, and the drain accumulated in the inner bottom portion of the cup 16 flows toward the drainage port (not shown) through the drainage passage 28 and is discharged. It is discharged from the liquid port through the drain pipe 30 to the outside of the cup 16. A coating solution supply nozzle 32 that supplies a coating solution such as a photoresist solution to the surface of the substrate W is disposed above the substrate W held by the spin chuck 10.
[0012]
In the spin coater as shown in FIG. 1, the clean air supplied from above the cup 16 flows down through the upper surface opening 18 of the cup 16 and flows into the cup 16. The air that has flowed into the cup 16 turns downward along the upper surface of the rectifying plate 20 and flows in the outer peripheral direction while turning as the substrate W rotates, and rotates toward the lower surface of the rectifying plate 20 by the exhaust pressure of the exhaust means. And flows into the ventilation path 22, flows into the exhaust path 26 from the exhaust port 24 through the ventilation path 22, and is discharged out of the cup 16 through the exhaust path 26.
[0013]
The basic configuration of the spin coater as described above is not different from the conventional one. In the device according to the present invention, the cup 16 is formed of an antistatic plastic material in which a conductive polymer is blended in a polymer base material. As the antistatic plastic material forming the cup 16, for example, an antistatic polypropylene in which a known conductive polymer is blended in a polypropylene base material is used. This antistatic polypropylene is produced by adding a conductive polymer to a monomer and polymerizing it when polymerizing propylene, and is commercially available, for example, under the trade name New-PP (61) from Nippon Valqua Industries, Ltd. ing.
[0014]
In this substrate rotating type processing apparatus, since the cup 16 is formed of antistatic polypropylene, the cup 16 is difficult to be charged, and therefore, an electrostatic field is almost between the cup 16 and the substrate W on the spin chuck 10. No longer formed. For this reason, during the rotation of the substrate W, the coating liquid fine particles that scatter from the substrate W to the surroundings and collide with the inner peripheral wall surface of the cup 16 and become mist are retained in the cup 16. The change prevents the liquid from flowing toward the substrate W and reattaching to the substrate W. Further, the antistatic polypropylene forming the cup 16 has chemical resistance similar to that of polypropylene, and has good moldability like polypropylene. The cup 16 made of antistatic polypropylene is formed of a plastic material in which the coating material is peeled off or carbon is mixed like a cup formed by coating a plastic material having chemical resistance on the surface of a metal material. Contamination is caused by falling off of contaminants such as cups that have been removed, and antistatic agents have fallen off, such as cups formed by kneading or applying antistatic agents such as surfactants to plastic materials. There is no problem that the antistatic effect gradually decreases.
[0015]
【The invention's effect】
When the substrate rotating processing apparatus of the invention according to claim 1 is used, it is possible to reduce part of the processing liquid scattered from the substrate as fine particles and re-adhere to the substrate during the processing of the substrate. Occurrence can be eliminated and deterioration of processing quality can be prevented. And in this processing apparatus, the corrosion resistance of the cup becomes a problem, a part of the cup is peeled off, contamination due to falling off of contaminants in the cup material occurs, or the antistatic effect of the cup material is increased with time. It does not cause a problem of lowering.
[0016]
In the processing apparatus according to the second aspect of the present invention, there is no difference from the case where the cup is formed of polypropylene, which has been most commonly used as a cup material, in terms of cup moldability and chemical resistance.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of a main part of a spin coater when a substrate is not processed, showing an example of an embodiment of the present invention.
[Explanation of symbols]
W substrate 10 Spin chuck 12 Rotating spindle 14 Spin motor 16 Cup 18 Cup upper surface opening 20 Rectifier plate 22 Ventilation path 24 Exhaust port 26 Exhaust path 28 Drain path 30 Drain pipe 32 Coating liquid supply nozzle

Claims (2)

A substrate holding and rotating means for holding the substrate in a horizontal position and rotating it around a vertical axis;
A processing liquid supply means for supplying a processing liquid to the surface of the substrate held by the substrate holding / rotating means;
A cup having an upper surface opened, and disposed so as to surround a side and a lower side of the substrate held by the substrate holding / rotating means, and a cup for collecting the processing liquid scattered from the substrate to the surroundings. In the substrate rotation processing apparatus provided,
A substrate rotation processing apparatus, wherein the cup is formed of an antistatic plastic material in which a conductive polymer is blended in a polymer base material. 2. The substrate rotating processing apparatus according to claim 1, wherein the antistatic plastic material forming the cup is an antistatic polypropylene in which a conductive polymer is blended in a polypropylene base material.

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