JP3378141B2 - Substrate rotation processing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate rotation processing apparatus for holding a substrate such as a semiconductor wafer and rotating the substrate to perform a predetermined process on the substrate.

[0002]

2. Description of the Related Art In a manufacturing process of a semiconductor device or a liquid crystal device, a substrate rotation processing apparatus is used to perform thin film coating processing and cleaning processing on a substrate. FIG. 3 is a cross-sectional view showing the configuration of a spin coating apparatus which is one of the substrate rotation processing apparatuses. The spin coating apparatus shown in FIG. 3 includes a substrate holding table 2 that holds the substrate 1 by suction, a rotation drive mechanism that rotates the substrate holding table 2, and a cup 20 that covers the periphery of the substrate 1.

The substrate holder 2 comprises a vacuum chuck for sucking and holding the substrate 1. The rotation drive mechanism includes a spin motor 3. The rotating shaft 4 of the spin motor 3 is rotatably supported by bearing bearings 6 arranged on the motor upper lid 5. The substrate support base 2 is fixed to the tip of the rotary shaft 4. The spin motor 3 has a motor fixing flange 27 that is put on the upper portion of the motor upper lid 5.
Is fixed to a fixed frame (not shown) in the spin coater.

In the spin coating apparatus as described above, it is necessary to prevent the mist (spray) of the coating liquid in the atmosphere from adhering to the surface of the substrate 1 and contaminating the surface of the substrate. Therefore, during the processing, a clean air flow 22 is supplied from the opening 21 of the cup 20 toward the upper surface of the substrate 1. The clean air flow 22 generates mist floating around the substrate 1
Of the cup 20 and is discharged to the outside through an exhaust pipe (not shown) provided on the lower surface of the cup 20. As a result, the spin coater always performs a spin coating process while keeping the periphery of the substrate 1 in a clean state.

However, if a part of the air flow 30 containing mist wraps around to the back surface side of the substrate 1 and enters the bearing bearing 6 side of the spin motor 3 along the rotating shaft 4, the bearing bearing 6 is deteriorated or spun. It may cause a failure of the motor 3.

For this reason, in the conventional spin coating apparatus, a method of filling the periphery of the rotary shaft 4 with nitrogen (N ₂ ) gas has been devised. In this method, the sleeve 1 is wrapped around the rotary shaft 4.
3 is provided, and a space 15 is formed between the inner surface of the sleeve 13 and the rotary shaft 4. Further, the sleeve 13 is provided with a gas introduction port 14, and nitrogen gas is introduced into the space 15 from the gas introduction port 14.

The introduced nitrogen gas fills the space 15,
It flows out from the upper end of the sleeve 13. For this,
It becomes difficult for the air flow 30 containing mist to enter the inside from the upper end of the sleeve 13. This prevents the mist from entering the bearing bearing 6 side of the spin motor 3.

[0008]

However, the sleeve 1
If a method of introducing nitrogen gas into the inside of the spin motor 3 is used, particles generated in the bearing 6 of the spin motor 3 are wound up and pollute the back surface of the substrate 1 this time. That is, in the bearing bearing 6 of the spin motor 3, fine particles are generated from the sliding portion.
The particles are carried on the flow of nitrogen gas in the sleeve 13 and are wound up in the sleeve 13 upward,
It is discharged outward from the upper end of the sleeve 13. If these particles adhere to the back surface of the substrate 1 and contaminate them, they will adversely affect the processing of the substrate 1 in a later process and cause a reduction in yield.

An object of the present invention is to provide a substrate rotation processing apparatus capable of preventing the substrate from being contaminated by particles generated from the rotation driving unit.

[0010]

A substrate rotation processing apparatus according to a first aspect of the present invention includes a motor having a rotary shaft supported by a rotary bearing portion and extending upward, and a substrate mounted on the tip of the rotary shaft of the motor and having a substrate. A substrate rotation processing device comprising a substrate holding unit for holding, a space forming member for forming a space surrounding the rotation shaft above the rotation bearing unit,
The space forming member includes a rotating member that is fixed to the rotating shaft inside the space formed by the space forming member, and that rotates with the rotating shaft to generate an airflow outward from the rotating shaft side in the space. Has an exhaust passage communicating with the space and for guiding the airflow generated by the rotating member to the outside.

A substrate rotation processing apparatus according to a second aspect of the present invention is the substrate rotation processing apparatus according to the first aspect of the present invention, which is formed between the rotation axis and the rotation axis above the space forming member. The cylindrical member is provided so that the gap between the space forming member and the space formed by the space forming member is communicated, and the inside of the cylindrical member is communicated with the gas supply means for supplying the inert gas.

A substrate rotation processing apparatus according to a third aspect of the present invention is the substrate rotation processing apparatus according to the first or second aspect of the invention, in which the rotating member is a disk-shaped member. A substrate rotation processing apparatus according to a fourth aspect is the substrate rotation processing apparatus according to any one of the first to third aspects, wherein the space forming member has an inner peripheral surface that surrounds the periphery of the rotating member, An annular passage communicating with the exhaust passage is provided at a position below the rotating member on the inner peripheral surface.

In the substrate rotation processing apparatus according to the first to fourth aspects of the invention, the rotary member provided above the rotary bearing portion moves outward from the rotary shaft side of the motor and further through the exhaust passage to the outside. It creates an exhaust air stream. Therefore, when the particles generated from the sliding portion of the rotary bearing of the motor float upward, this air flow prevents the particles from moving upward, and the particles ride on the air flow and are discharged from the exhaust path to the outside. To be done. therefore,
The particles are prevented from being wound up along the rotation axis and contaminating the back surface of the substrate.

In particular, in the substrate rotation processing apparatus according to the second aspect of the present invention, when the inert gas is supplied to the inside of the cylindrical member provided above the space forming member, a part of the inert gas is generated inside the cylindrical member. And leaks from the top edge to near the back surface of the substrate. Therefore, the inert gas prevents the mist floating near the back surface of the substrate from entering the inside of the cylindrical member. Therefore, it is possible to prevent deterioration of the rotary bearing portion of the motor due to intrusion of mist.

Further, the other part of the inert gas forms an air flow that is sucked into the rotary member side, goes outward from the rotary shaft side, and is further discharged from the exhaust passage to the outside. Then, due to this air flow, particles generated from the rotating shaft of the motor are discharged to the outside. This prevents particles from being wound up along the rotation axis and contaminating the back surface of the substrate.

Particularly, in the substrate rotation processing apparatus according to the third aspect of the invention, the rotating member is formed of a disc-shaped member. The disk-shaped member not only generates an air flow that discharges the particles to the outside, but also serves as an obstacle to the upward movement of the particles. Also, it acts as a barrier when the waste liquid falls from above. As a result, it is possible to more reliably prevent the particles from being wound up and further prevent the mist and the waste liquid from entering the rotary bearing portion of the motor.

Particularly, in the substrate rotation processing apparatus according to the fourth aspect of the invention, the mist and waste liquid scattered around by the rotating member are guided to the annular passage and discharged to the outside through the exhaust passage. As a result, it is possible to prevent deterioration of the rotary bearing portion of the motor due to attachment of mist or waste liquid.

[0018]

1 is a sectional view of a spin coating apparatus according to a first embodiment of the present invention. In FIG. 1, the spin coating apparatus includes a substrate holder 2 that holds and rotates the substrate 1. The substrate holder 2 is composed of a vacuum chuck that holds the back surface of the substrate 1 by vacuum suction. The substrate holder 2 is attached to the tip of a rotary shaft 4 of a spin motor 3.

The spin motor 3 is fixed to a fixed frame (not shown) by a motor fixing flange 7 and a fixing member 8 which are placed on the motor upper lid 5. As a result, the spin motor 3 is fixed in a posture in which the rotating shaft 4 is oriented in the vertical direction.

The rotating shaft 4 is a motor upper lid 5 of the spin motor 3.
A bearing bearing 6 that supports the rotating shaft 4 is attached to a portion penetrating through. A disk storage space 10 is formed above the bearing 6. The disk storage space 10 is surrounded by the motor upper lid 5 of the spin motor 3 and the recess 9 formed on the lower surface side of the motor fixing flange 7. A rotary disk 12 is fixed to the rotary shaft 4 inside the disk storage space 10. Rotating disk 12
Are arranged close to the upper surface 9a of the recess of the motor fixing flange 7 and relatively far from the motor upper lid 5. This is because the pumping action occurs only on the upper surface side of the rotating disk 12. For example, the rotating disk 12
The distance between the motor fixing flange 7 and the upper surface 9a of the recess is 0.
It is adjusted to about 5 mm. In addition, this rotating disk 12
The pumping action of will be described later.

The motor fixing flange 7 is formed with an exhaust passage 11 communicating with the disk storage space 10. Exhaust path 1
The outlet side of 1 is connected to the exhaust means provided outside. Further, the lower end of the sleeve 13 is connected to the upper surface of the motor fixing flange 7. The sleeve 13 is formed in a cylindrical shape, and a space 15 is formed between the sleeve 13 and the rotary shaft 4. In addition, in the lower part of the sleeve 13, the space 1
A gas introduction port 14 communicating with 5 is formed. A gas supply section (not shown) as a gas supply means for supplying nitrogen gas as an inert gas is connected to the gas inlet 14 in communication therewith.

Further, this spin coater is provided with a cup 20 which surrounds the periphery of the substrate 1. An opening 2 for introducing a clean air flow 22 is provided on the upper surface side of the cup 20.
1 is formed. Also, on the lower surface side of the cup 20,
A drain discharge port (not shown) for discharging the waste liquid of the coating liquid to the outside and an exhaust port (not shown) for discharging the air flow 30 containing mist to the outside are provided.

Here, in the above structure, the motor upper lid 5 and the motor fixing flange 7 constitute the space forming member of the present invention, the rotating disk 12 constitutes the rotating member of the present invention, and the sleeve 13 of the present invention. It constitutes a cylindrical member.

Next, the operation of the spin coater having the above structure will be described. First, nitrogen gas is introduced into the sleeve 13 through the gas inlet 14. The nitrogen gas fills the inside of the space 15, and a part of the nitrogen gas flows into the inside of the cup 20 from the upper end of the sleeve 13. Further, a part of the introduced nitrogen gas flows to the lower side of the sleeve 13 and fills the inside of the disk storage space 10.

When the spin motor 3 starts rotating, the rotary disk 12 fixed to the rotary shaft 4 rotates together with the rotary shaft 4. When the rotating disk 12 rotates, the nitrogen gas on the upper surface of the rotating disk 12 receives the centrifugal force from the surface of the rotating disk 12 and is forced out of the rotating disk 12. Therefore, when the external exhaust means is driven to exhaust the gas through the exhaust passage 11, the nitrogen gas pushed outward by the rotating disk 12 is exhausted to the outside through the exhaust passage 11.

When the nitrogen gas on the upper surface of the rotating disk 12 is discharged to the outside, the pressure on the upper surface of the rotating disk 12 drops.
For this reason, the nitrogen gas supplied into the sleeve 13 through the gas inlet 14 flows into the upper surface side of the rotating disk 12 whose pressure has decreased. Then, receiving the action of centrifugal force from the rotating disk 12, it is pushed out of the rotating disk 12 in the same manner as described above, and is discharged from the exhaust passage 11 to the outside.

Due to the pumping action of the rotating disc 12, the gas flows through the gas inlet 14 to the upper surface of the rotating disc 12,
Further, a flow of nitrogen gas discharged to the outside through the exhaust passage 11 is formed. Therefore, when the particles generated in the sliding portion of the bearing bearing 6 of the spin motor 3 are wound up inside the disk storage space 10, the particles are prevented from moving above the sleeve 13 by the flow of nitrogen gas. , Exhaust path 11 along the flow of nitrogen gas
It is discharged to the outside through.

The rotating disk 12 not only creates the flow of nitrogen gas, but also when the mist of the coating liquid enters from the upper end of the sleeve 13, the mist is generated by the spin motor 3.
The bearing has a function of preventing the bearing 6 from reaching the bearing 6.
That is, the rotating disk 12 is formed in a disk shape that spreads in the horizontal plane. Therefore, the mist that has entered the inside of the sleeve 13 is first prevented from entering below by the upper surface of the rotating disk 12. Then, by the rotation of the rotating disk 12, the particles are scattered to the inner peripheral surface side of the disk storage space 10. Then, it is discharged from the exhaust path 11 to the outside together with the nitrogen gas.

As described above, in the spin coater of the present embodiment, by utilizing the pumping action of the rotary disk 12 fixed to the rotary shaft 4, the rotary coater moves downward along the rotary shaft 4 and the bearing bearing 6 Since the flow of the inert gas to be discharged to the outside is formed slightly above, the particles generated from the bearing 6 can be discharged to the outside without being wound up above the rotating shaft 4.

FIG. 2 is a sectional view of a spin coater according to a second embodiment of the present invention. The spin coating apparatus according to the second embodiment differs from the spin coating apparatus according to the first embodiment shown in FIG. 1 only in the rotary disk 12 and the configuration related thereto. Therefore, the same parts as those in the configuration shown in FIG.

In FIG. 2, the rotary disk 25 is formed in a shape like an umbrella which is inclined vertically downward as it goes from the center to the outer peripheral side. Further, the gap between the upper bottom surface of the recess 9 and the upper surface of the rotary disc 25 is smaller than the gap between the upper surface of the motor upper lid 5 and the lower surface of the rotary disc 25.
The upper bottom surface of the concave portion 9 of the motor fixing flange 7 is formed so as to be inclined in the vertical direction substantially parallel to the upper surface of the rotating disk as it goes from the center toward the outer peripheral side. This is the rotating disk 2
By making the pumping action on the upper surface of 5 larger than the pumping action on the lower surface of the disk 25, it is possible to prevent the particles generated in the sliding portion of the bearing bearing 6 from being rolled up, and to improve the lubricant of the bearing bearing 6. This is to prevent it from being removed.

A ring-shaped groove 26 is formed in the fitting portion between the recess 9 of the motor fixing flange 7 and the motor upper lid 5. The groove 26 communicates with the disc storage space 10. Further, the exhaust passage 11 formed in the motor fixing flange 7 communicates with the groove 26 and a part of the disk storage space 10.

The rotating disk 25 is the rotating disk 12 shown in FIG.
Similarly to the above, the rotary disc 4 rotates integrally with the rotary shaft 4 and
5 exerts a pumping action on the nitrogen gas (inert gas) on the upper surface. Therefore, the nitrogen gas introduced from the gas introduction port 14 descends inside the sleeve 13 along the rotating shaft 4, and passes through the upper surface of the rotating disc 25 to flow the nitrogen gas discharged from the exhaust passage 11 to the outside. Can be formed. As a result, the particles generated in the bearing bearing 6 of the spin motor 3 can be discharged to the outside along the flow of nitrogen gas.

When the mist of the coating solution enters from the upper end of the sleeve 13, the mist flows down to the outer peripheral side along the surface of the rotating disk 25 inclined downward, and is formed in the lower part of the disk storage space 10. The groove 26 is guided into the groove 26. Then, the mist introduced into the groove 26 is discharged to the outside through the exhaust passage 11. By such an action, the mist is prevented from reaching the bearing bearing 6 of the spin motor 3.

In FIG. 2, the upper surface of the motor upper lid 5 may be formed as an inclined surface which is inclined downward from the rotary shaft 4 toward the groove 26 side. In this case, the mist that has fallen onto the upper surface of the motor upper lid 5 is unlikely to move to the rotating shaft 4 side.
This can further prevent the mist from entering the bearing bearing 6.

In the first and second embodiments described above, the construction in which the flow of the inert gas is formed by using the rotating disks 12 and 25 has been described, but a pumping action is generated in the disk storage space 10. If it is possible, it is possible to use not only a disc shape but also another shape. For example, it is also possible to use a shape in which rod-shaped members are radially arranged, a shape in which blades are provided on the surface, or a shape in which an uneven surface is formed so as to increase the viscosity of air with the upper surface. It is possible.

The disk storage space may be formed only by the motor fixing flange 7, or may be formed by using another member.

[Brief description of drawings]

FIG. 1 is a sectional view of a spin coating apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a spin coater according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of a conventional spin coating device.

[Explanation of symbols]

1 substrate 2 substrate holder 3 spin motors 4 rotation axes 5 Motor top lid 6 bearings 7 Motor fixing flange 9 Motor fixing flange recess 9a Upper surface of recess of motor fixing flange 10 disk storage space 11 exhaust path 12,25 rotating disk 13 Sleeve 14 gas inlet 15 spaces 26 groove

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/027 B05C 11/08 H01L 21/304

Claims (4)

(57) [Claims] 1. A substrate rotation processing apparatus comprising: a motor having a rotary shaft that is supported by a rotary bearing unit and extends upward; and a substrate holding unit that is attached to a tip of the rotary shaft of the motor and holds a substrate. A space forming member for forming a space surrounding the rotary shaft above the rotary bearing portion, and fixed to the rotary shaft inside the space formed by the space forming member, together with the rotary shaft A rotating member for generating an airflow outward from the rotation shaft side in the space by rotating, the space forming member communicating with the space, and the airflow generated by the rotating member. A substrate rotation processing apparatus having an exhaust path for guiding the substrate to the outside. 2. A cylindrical member is provided above the space forming member so as to surround the rotating shaft and a gap formed between the rotating shaft and the rotating shaft communicates with the space formed by the space forming member. The substrate rotation processing apparatus according to claim 1, wherein the inside of the cylindrical member is communicated with a gas supply unit that supplies an inert gas. 3. The substrate rotation processing apparatus according to claim 1, wherein the rotating member is a disc-shaped member. 4. The space forming member has an inner peripheral surface surrounding the periphery of the rotating member, and has an annular passage communicating with the exhaust passage at a position below the rotating member on the inner peripheral surface. The substrate rotation processing apparatus according to any one of claims 1 to 3, which is characterized in that.