JPH09289156A - Substrate spin-processing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fine particles of processing liquid which fly away from a substrate from being attached again to the substrate, by a method wherein the substrate is made to spin on a vertical axis, and a straightening plate is provided under the substrate inside a cup which surrounds the side and lower part of the substrate, and the inner surface of the cup and/or the straightening plate is charged with electricity. SOLUTION: A substrate is made to spin on a vertical axis as held in a horizontal position, processing liquid is fed to the surface of the substrate, and processing liquid which fly away from the surface of the substrate is recovered by a cup 46 which is possessed of an open top and made to surround the side and lower part of the substrate. Furthermore, air which flows into the cup 46 through its open top is guided in a peripheral direction by a straightening plate 50 provided inside the cup 46 under the substrate, the inside of the cup 46 is exhausted, and the substrate is processed. At this point, the inside of the cup 46 and/or the straightening plate 50 is charged with electricity, and the substrate is processed. A friction jig 54 is used to charge the inside of the cup 46 and the straightening plate 50 with electricity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, like a spin coater, a spin developer, a spin scrubber, etc., holds a substrate such as a semiconductor wafer or a glass substrate in a horizontal posture and rotates it around a vertical axis to apply a coating solution or a developing solution. The present invention relates to a substrate rotary processing method and a substrate rotary processing apparatus for supplying a processing liquid such as a cleaning liquid to the surface of a substrate for processing.

[0002]

2. Description of the Related Art In a substrate rotary 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 horizontally by a chuck and is rotated around a vertical axis to reach the substrate surface. The cup that is supplied with the coating liquid and surrounds the substrate collects the coating liquid that is scattered from the substrate to the surroundings as the substrate rotates, and the inside of the cup is exhausted from the bottom of the cup. Clean air is introduced into the cup through the top opening of the. Then, by the rectifying 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,
An air flow is formed in the cup to prevent the excess coating liquid scattered from the substrate from re-adhering to the substrate (for example, Japanese Utility Model Publication No. 6-28223 and JP-A 5-2).
34874, etc.). FIG. 3 shows an example of a schematic configuration of a conventional spin coater.

A spin coater, a partial portion of which is shown in a vertical cross section in FIG. 3, is a spin chuck 1 for holding a substrate W in a horizontal posture.
The substrate W having 0 and held by the spin chuck 10 is
It is rotated about a vertical axis by a spin motor 14 connected to a rotation support shaft 12 that supports the spin chuck 10. Around the substrate W, there is provided a container-shaped cup 16 having an opening 18 on the upper surface and surrounding the side and the lower side of the substrate W held by the spin chuck 10. A frustoconical flow plate 20 is fixed inside the cup 16 below the substrate W held by the spin chuck 10, and ventilation is provided between the lower surface side of the flow 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 below the straightening vane 20. The exhaust port 24 is connected to an exhaust means (not shown) via 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 through the drainage passage 28 toward a drainage port (not shown) to be drained. The liquid is discharged from the liquid port to the outside of the cup 16 through the drain pipe 30. Further, above the substrate W held by the spin chuck 10, a liquid supply nozzle 32 for supplying a coating liquid such as a photoresist liquid to the surface of the substrate W is arranged.

In the spin coater as shown in FIG. 3, the clean air supplied from above the cup 16 is the cup 16
Flowing down through the upper opening 18 and into the cup 16. The air that has flowed into the cup 16 flows downward along the upper surface of the straightening vane 20 in the outer peripheral direction while swirling as the substrate W rotates, and turns to the lower surface side of the straightening vane 20 by the exhaust pressure of the exhaust means. The gas flows into the vent passage 22 through the vent passage 22, flows from the exhaust port 24 into the exhaust passage 26, and passes through the exhaust passage 26 and is discharged to the outside of the cup 16.

[0005]

However, a complicated flow of air is generated in the cup 16 during the rotation of the substrate W, and the scattered coating liquid colliding with the inner peripheral wall surface of the cup 16 is
Part of it becomes a mist and remains in the cup 16.
The fine particles of the coating liquid staying in the cup 16 are caused to flow toward the substrate W due to a change in the air flow during the processing, and are reattached to the substrate. This is because when the size of fine particles in the air is 10 μm or less, they are not affected by gravity or inertial force and are carried in the air flow, and the diameter of fine particles is less than 1 μm. Then, the adhesion of the fine particles to the substrate is predominantly performed by the Coulomb force (electrostatic force) between the substrate and the fine particles. If the fine particles of the coating liquid reattach to the substrate W, uneven coating is caused and the coating quality is deteriorated. Further, the adhesion of the coating liquid to the back surface of the substrate W may cause a defect in the exposure process.

The present invention has been made in view of the above circumstances, and prevents a part of the processing liquid scattered from the substrate from becoming fine particles and reattaching to the substrate during the processing of the substrate. However, it is possible to provide a substrate rotary processing method capable of preventing the occurrence of processing unevenness and preventing the deterioration of processing quality, and to provide a substrate rotary processing apparatus capable of suitably implementing the method. To aim.

[0007]

The invention according to claim 1 is
While holding the substrate in a horizontal position and rotating it about the vertical axis, the processing liquid is supplied to the surface of the substrate, and a cup with an open top surface surrounds the sides and bottom of the substrate and scatters from the top of the substrate to the surroundings. And collect the processing liquid
Inside the cup, a current plate disposed below the substrate guides the air flowing down through the upper opening of the cup and flowing into the cup in the outer peripheral direction, and the exhaust means exhausts the inside of the cup, In the substrate rotary processing method for performing the processing, during the processing of the substrate, both or one of the inner surface of the cup and the rectifying plate is held in a charged state.

According to a second aspect of the present invention, in the substrate rotary processing method according to the first aspect, the inner surface of the cup and the rectifying plate are electrostatically charged.

According to a third aspect of the present invention, in the substrate rotary processing method according to the first aspect, a voltage is applied to the inner surface of the cup and the rectifying plate to charge the inner surface of the cup and the rectifying plate.

According to a fourth aspect of the invention, the substrate holding / rotating means for holding the substrate in a horizontal posture and rotating it about a vertical axis, and the processing liquid is supplied to the surface of the substrate held by the substrate holding / rotating means. Processing liquid supply means for forming a container having an opened upper surface, and is disposed so as to surround the side and the bottom of the substrate held by the substrate holding / rotating means, and the processing liquid is scattered from above the substrate to the surroundings. Is disposed below the substrate held by the substrate holding / rotating means inside the cup, and the air that flows down through the upper opening of the cup and flows into the cup is guided to the outer peripheral direction. In a substrate rotary processing apparatus including a rectifying plate for, and an exhaust passage that communicates the inside of the cup with an exhaust unit, a charging unit that charges both or one of the inner surface of the cup and the rectifying plate is provided. Establishment It is characterized in.

According to a fifth aspect of the present invention, in the substrate rotary processing apparatus according to the fourth aspect, the charging means is detachably mounted on the substrate holding / rotating means in a state where the substrate is not held. The tool is characterized in that the friction jig has a friction member that continuously slides in contact with the inner surface of the cup or the surface of the current plate when rotated by the substrate holding / rotating means.

According to a sixth aspect of the present invention, in the substrate rotary processing apparatus according to the fourth aspect, the cup and the rectifying plate are made of a conductive material, and the charging means applies a voltage to the cup and the rectifying plate. It is characterized in that the power supply device.

In the substrate rotary processing method according to the first aspect of the present invention, since the inner surface of the cup and / or the rectifying plate is held in a charged state during the processing of the substrate, the processing liquid is discharged from the rotating substrate. The particles of the processing liquid with a diameter of 1 μm or less, which are generated by scattering and colliding with the inner wall surface of the cup and staying in the cup, are attracted toward the inner surface of the cup and the current plate by the Coulomb force, and the inner surface of the cup and the air flow are rectified. Adheres to the surface of the plate. For this reason, the re-adhesion amount of the processing liquid particles on the substrate is reduced.

In the method of the second aspect of the present invention, the inner surface of the cup and / or the rectifying plate are electrostatically charged, so that the fine particles of the treatment liquid adhere to the inner surface of the cup and the surface of the rectifying plate.

In the method according to the third aspect of the present invention, the inner surface of the cup and / or the rectifying plate are charged by applying a voltage thereto, so that the fine particles of the treatment liquid adhere to the inner surface of the cup and the surface of the rectifying plate.

In the substrate rotary processing apparatus according to the fourth aspect of the present invention, since the inner surface of the cup and / or the rectifying plate is charged by the charging means, the inner surface of the cup and the rectifying plate are kept charged during the processing of the substrate. By holding the
The particles of the processing liquid having a diameter of 1 μm or less, which are generated by the processing liquid being scattered from the substrate being held by the rotating means and rotating and colliding with the inner peripheral wall surface of the cup, have Coulomb force. As a result, it is attracted toward the inner surface of the cup and the current plate, and adheres to the inner surface of the cup and the surface of the current plate. Therefore, the amount of redeposition of the fine particles of the processing liquid on the substrate is reduced.

In the apparatus according to the fifth aspect of the present invention, the friction jig is mounted on the substrate holding / rotating means while the substrate holding / rotating means is not holding the substrate when the substrate is not being processed. Then, by rotating the friction jig by the substrate holding / rotating means, the friction member of the friction jig continuously slides in contact with the inner surface of the cup or the surface of the straightening plate, and the friction member of the inner surface of the cup and / or the straightening plate The inner surface of the cup and the current plate are charged due to the friction with the surface. Thereafter, the friction jig is removed from the substrate holding / rotating means, the substrate is held by the substrate holding / rotating means, and the substrate is processed while the inner surface of the cup and the rectifying plate are charged.

In the apparatus according to the sixth aspect of the invention, by applying a voltage to the cup and / or the rectifying plate by the power supply device, the inner surface of the cup and the rectifying plate are charged, and the substrate is processed in this state.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below with reference to FIGS.

FIG. 1 is a longitudinal sectional view showing an example of the embodiment of the present invention and showing a schematic structure of a main part of a substrate rotary processing apparatus, here a spin coater, when a substrate is not processed. The basic structure itself of the spin coater is not different from the conventional one, and in FIG. 1, 40 is a spin chuck, 42 is a rotation support shaft, 44 is a spin motor, 4
6 is a cup, 48 is an upper surface opening of the cup 46, 50 is a straightening vane, and 52 is a ventilation path formed between the lower surface side of the straightening vane 50 and the inner bottom surface of the cup 46.

The substrate rotary processing method according to the present invention is carried out by using a spin coater as shown in FIG. 1. In this processing method, the inner surface of the cup 46, the straightening plate 50, or both of them are used. In the configuration, both the inner surface of the cup 46 and the rectifying plate 50 are held in a charged state, and the substrate is processed. A friction jig 54 as shown in FIG. 1 is used to charge the inner surface of the cup 46 and the rectifying plate 50.

The friction jig 54 has a bifurcated mounting rod 58 fixedly attached to the peripheral edge of a disk portion 56 having the same size as the base plate, and a friction brush 60 is attached to each end of the bifurcated mounting rod 58. 62 are attached to each other. The friction jig 54 is mounted on the spin chuck 40 by holding the disk portion 56 on the spin chuck 40 instead of the substrate when the substrate is not processed. When the friction jig 54 is mounted on the spin chuck 40, each friction brush 60, 62
Touches the inner surface of the cup 60 and the upper surface of the current plate 62. In this state, by driving the spin motor 44, the friction jig 54 is moved to the spin chuck 4
The friction brushes 60 and 62 are continuously brought into sliding contact with the inner surface of the cup 46 and the upper surface of the current plate 50, respectively. At this time, the friction between the friction brushes 60 and 62 and the inner surface of the cup 46 and the upper surface of the straightening plate 50 causes the inner surface of the cup 46 and the straightening plate 50 to be electrostatically charged. For example,
When the cup 46 and the rectifying plate 50 are made of polypropylene, the cup 46 and the rectifying plate 50 are negatively charged. The structure of the friction jig is not limited to the illustrated example, and various structures can be adopted.

When the inner surface of the cup 46 and the current plate 50 are charged, the drive of the spin motor 44 is stopped and the friction jig 54 is removed from the spin chuck 40. Then, the substrate is processed while the spin chuck 40 holds the substrate and the inner surface of the cup 46 and the rectifying plate 50 are held in a charged state by the same operation as a normal process. During the processing of the substrate, since the inner surface of the cup 46 and the rectifying plate 50 are held in a charged state, the processing liquid particles having a diameter of 1 μm or less retained in the cup 46 are rectified by the Coulomb force. It is less likely that the processing liquid fine particles are attracted toward the plate 50 and adhere to the inner surface of the cup 46 and the surface of the flow regulating plate 50, and the processing liquid particles re-adhere to the substrate. When the inside of the cup 46 is cleaned after the processing of the substrate is completed, the charged state is canceled or the opposite potential is charged.

The spin coater shown in FIG. 2 has substantially the same basic structure as the conventional spin coater shown in FIG. However, the cup 16 is configured by fitting the upper cup 16a and the lower cup 16b together, and the upper cup 16a is formed of a conductive material. The power supply device 64 is electrically connected to the upper cup 16a of the cup 16,
The upper cup 16a of the cup 16 can be electrically charged. When the substrate W is processed by this spin coater, a voltage is applied to the upper cup 16a by the power supply device 64 during the processing to process the substrate W while keeping the inner surface of the upper cup 16a charged. After the processing of W is completed, the application of the voltage to the upper cup 16a by the power supply device 64 is stopped. In the spin coater shown in FIG. 2, only the upper cup 16a is charged, but the lower cup 16b of the cup 16 is
The rectifying plate 20 and also the components other than the spin chuck 40 may be formed of a conductive material, and they may be electrically connected to the power supply device and charged during the process.

[0025]

According to the substrate rotary processing method of the first aspect of the present invention, it is possible to reduce the possibility that a part of the processing liquid scattered from the substrate becomes fine particles and reattaches to the substrate during the processing of the substrate. Therefore, it is possible to prevent the occurrence of processing unevenness and prevent deterioration of processing quality.

In the method according to the second aspect of the present invention, the inner surface of the cup and / or the rectifying plate is electrostatically charged, so that the fine particles of the treatment liquid adhere to the inner surface of the cup and the surface of the rectifying plate. The amount of re-adhesion of the fine particles of the treatment liquid on the surface of the substrate is reduced.

In the method according to the third aspect of the present invention, the inner surface of the cup and / or the rectifying plate are charged by applying a voltage thereto, whereby the fine particles of the treatment liquid adhere to the inner surface of the cup and the surface of the rectifying plate. Therefore, the amount of redeposition of the processing liquid particles on the substrate is reduced.

When the substrate rotary processing apparatus of the invention according to claim 4 is used, the method of the invention according to claim 1 can be preferably carried out, and during the processing of the substrate, the processing liquid scattered from the substrate is removed. It is possible to prevent a part of the particles from becoming fine particles and redepositing on the substrate, eliminate the occurrence of processing unevenness, and prevent deterioration of processing quality.

In the apparatus according to the fifth aspect of the present invention, the inner surface of the cup and / or the surface of the rectifying plate can be electrostatically charged by the friction jig when the substrate is not being processed. In addition, the fine particles of the treatment liquid can be adhered to the inner surface of the cup or the surface of the rectifying plate to reduce the re-adhesion amount of the treatment liquid fine particles to the substrate. Then, only the friction jig is prepared, and the conventional substrate rotary processing apparatus itself does not require any modification.

In the apparatus according to the sixth aspect of the present invention, the cup and / or the rectifying plate can be charged by applying a voltage from the power supply device, and during the processing of the substrate, the fine particles of the processing liquid are charged on the inner surface of the cup or the rectifying plate. It is possible to reduce the redeposition amount of the processing liquid fine particles on the substrate by adhering to the surface of the substrate.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an example of an embodiment of the present invention and showing a schematic configuration of a main part of a spin coater when a substrate is not processed.

FIG. 2 is a partial vertical cross-sectional view showing another example of the embodiment of the present invention and showing a schematic configuration of a main part of a spin coater.

FIG. 3 is a partial vertical cross-sectional view of a main part showing an example of a schematic configuration of a conventional spin coater.

[Explanation of symbols]

 10, 40 Spin chuck 12, 42 Rotating spindle 14, 44 Spin motor 16, 46 Cup 18, 48 Cup upper opening 20, 50 Straightening plate 26 Exhaust path 32 Liquid supply nozzle 54 Friction jig 56 Friction jig disk Parts 60, 62 Friction brush 64 Power supply device

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01L 21/30 564C

Claims (6)

[Claims] 1. A substrate is horizontally held and rotated about a vertical axis, a treatment liquid is supplied to the surface of the substrate, and a cup having an open upper surface surrounds the side and the lower side of the substrate. While collecting the processing liquid scattered from the top to the surroundings, inside the cup, by the rectifying plate disposed below the substrate, the air flowing down through the upper opening of the cup and leading into the cup in the outer peripheral direction, In a substrate rotating processing method, in which the inside of a cup is evacuated by an evacuation means to process a substrate, an inner surface of the cup and / or the rectifying plate is held in a charged state during processing of the substrate. A substrate rotating type processing method characterized by the above. 2. The substrate rotating processing method according to claim 1, wherein the inner surface of the cup and / or the current plate is charged by static electricity. 3. The substrate rotary processing method according to claim 1, wherein the inner surface of the cup and / or the rectifying plate is charged by applying a voltage thereto. 4. A substrate holding / rotating means for holding a substrate in a horizontal posture and rotating it about a vertical axis, and 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 a container shape with an open upper surface and disposed so as to surround the side and the lower side of the substrate held by the substrate holding / rotating means, and a cup for collecting the processing liquid scattered from above the substrate to the surroundings. A straightening plate disposed inside the cup, below the substrate held by the substrate holding / rotating means, for guiding the air flowing down through the upper opening of the cup and flowing into the cup in the outer peripheral direction, A substrate rotary processing apparatus having an exhaust path for communicating the inside of the cup with an exhaust means, characterized in that a charging means for charging the inner surface of the cup and / or the rectifying plate is provided. Dress . 5. The substrate holding / rotating means is detachably mounted on the substrate holding / rotating means in a state where the charging means does not hold the substrate.
The inner surface of the cup and / or when rotated by the rotating means
5. The substrate rotary processing apparatus according to claim 4, which is a friction jig having a friction member that continuously slides in contact with the surface of the current plate. 6. The substrate rotary processing apparatus according to claim 4, wherein the cup and / or the rectifying plate is made of a conductive material, and the charging means is a power supply device for applying a voltage to the cup and / or the rectifying plate.