JPH0917722A - Coating equipment - Google Patents

Abstract

PURPOSE: To discharge mist during high speed rotation by uniformalizing film thickness distribution of a coated film. CONSTITUTION: In a photoresist coating equipment for forming a coated film by dripping a photoresist solution 18 while holding and rotating a wafer 1 with a spin chuck 7 arranged within a treatment container 2, a sub-hood unit 20 exhausting air from a space at the upper side of a main hood opening 11 at the upper side of a main hood 8 arranged so as to exhaust air from an area around the wafer 1 at the treatment container outside the treatment container 2, and a plurality of stages of air exhaust ducts 26, 36 and 46 are arranged in the sub-hood unit 20. By doing this, exhaust air volume of the main hood can be supplemented by the sub-hood unit, so that the exhaust air volume of the main hood can be restricted, and the amount of contact of the exhaust air to the wafer can be uniformed as a whole and the film thickness distribution can be uniformed. Since flying mist can be captured by an air exhaust force of the sub-hood unit and thus resticking of the mist to the wafer can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating technique, and more particularly, to a technique for accommodating an object to be coated in a processing container and applying a coating material while rotating it. For example, in a semiconductor device manufacturing process, a semiconductor wafer ( Hereinafter, it will be referred to as a wafer.) A technique effective for applying a photoresist onto a wafer.

[0002]

2. Description of the Related Art As a coating apparatus for coating a photoresist on a wafer in a semiconductor device manufacturing process, as shown in Japanese Patent Publication No. 53-37189, a rotatable spin provided inside a processing container. There is a configuration in which a wafer is placed and held on a chuck, and while the wafer is being rotated, a photoresist solution is supplied onto the surface of the wafer to apply the photoresist. In this photoresist coating device, the photoresist liquid becomes a mist (hereinafter referred to as a photoresist mist) at the time of high-speed rotation and scatters to the outside of the wafer, and then collides with the inner peripheral surface of the processing container and bounces off. There is a risk of redeposition on the wafer.

Therefore, in the conventional photoresist coating apparatus, an exhaust hood for exhausting the wafer is covered on the upper side of the processing container to form a downward exhaust flow in the outer space of the wafer to force the photoresist mist. The anti-reflective surface is provided on the inner peripheral surface of the exhaust hood so that the inner surface of the exhaust hood is inclined so as to rise as it goes inward, so that the repelled photoresist mist is prevented from reattaching to the wafer. It is prevented.

An example of the description of this type of photoresist coating apparatus is Japanese Patent Publication No. 3-60761.

[0005]

By the way, in order to reduce the production cost by increasing the number of pellets to be obtained per wafer, the diameter of the wafer is being increased. Since the dropping amount of the photoresist liquid increases as the diameter of the wafer increases, the amount of photoresist mist scattered from the dropping amount also increases. Further, since the rotation speed of the wafer is also increased, the grain size of the photoresist mist is reduced. Therefore, it is necessary to quickly discharge the photoresist mist to the outside of the processing container by increasing the exhaust flow rate from the processing container.

However, in the above-mentioned photoresist coating apparatus, when the exhaust gas flow rate from the processing container is increased, the flow velocity in the peripheral portion of the wafer increases, so that the photoresist is dried more in the peripheral portion than in the central portion of the wafer. As a result, the film thickness of the peripheral portion becomes thicker, and the thickness distribution of the photoresist varies between the central portion and the peripheral portion of the wafer. As a result, there arises a problem that the photosensitivity of the photoresist and the dimensional accuracy after development are reduced.

That is, in the process of forming a photoresist film, the air flow in the vicinity of the wafer is a combination of the rotational flow induced by the rotation of the wafer and the flow generated by the exhaust force. The amount of air contacting the photoresist decreases, and the amount of air contacting the photoresist around the wafer increases. As a result, the solvent evaporation of the photoresist solution in the peripheral portion of the wafer is promoted, and the photoresist film in the peripheral portion becomes thicker.

An object of the present invention is to make the film thickness distribution of the coating film uniform over the entire area from the central portion to the peripheral portion of the object to be coated, and to promptly discharge mist generated during high speed rotation. It is to provide a coating technique that can be applied.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0010]

The outline of a typical invention among the inventions disclosed in the present application is as follows.

That is, the sub hood unit is arranged above the exhaust hood for exhausting the air around the object to be coated so as to exhaust the upper space of the hood opening.

[0012]

According to the above-mentioned means, since the exhaust air volume of the exhaust hood can be supplemented by the sub hood unit,
It is possible to suppress the exhaust air volume of the exhaust hood. As a result, it is possible to suppress the influence of the exhaust air flow around the object to be coated by the exhaust hood, so that the amount of exhaust air contacting the object to be coated can be made uniform throughout, and the film thickness distribution of the coating film can be reduced. It can be made uniform.

On the other hand, since the scattered mist is sucked and captured by the exhaust force of the sub-hood unit, it does not return to the object to be coated, and the mist is prevented from reattaching to the object to be coated.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front sectional view showing a photoresist coating apparatus which is an embodiment of the present invention. FIG. 2 is a front sectional view for explaining the operation.

In the present embodiment, the coating apparatus according to the present invention is configured as a photoresist coating apparatus for coating a photoresist on a wafer 1 as an object to be coated, and includes a processing container 2 arranged horizontally. I have it. The processing container 2 includes a cylindrical support portion 3 and a processing portion 4 which is formed in a substantially circular shallow dish shape and is horizontally supported on the upper end of the support portion 3. A rotary shaft 6 rotated by a driving device 5 such as a servomotor is arranged on the center line and inserted into a hollow portion on the upper surface of the processing unit 4 of the processing container 2. A spin chuck 7 is arranged and fixed to the upper end of a rotary shaft 6 in the recess of the processing unit 4 of the processing container 2 so as to be horizontally rotatable, and the spin chuck 7 vacuum-adsorbs a wafer 1 as an object to be coated. Is configured to be retained by.

An exhaust hood (hereinafter referred to as a main hood) 8 for exhausting the periphery of the wafer 1 held by the spin chuck 7 is installed above the outside of the processing container 2. The main hood 8 includes a support portion 9 formed in a cylindrical shape, and a hood portion 10 protruding radially inward from an upper end of the support portion 9. The hood portion 10 is formed in a circular ring shape, and the hood opening 11 is formed to have a diameter slightly larger than the outer diameter of the wafer 1 and is arranged concentrically with the rotating shaft 6. The cross-sectional shape of the hood portion 10 is formed into an isosceles triangle with an acute angle that becomes narrower toward the inner tip, and the tip thereof is arranged slightly above the upper surface of the wafer 1. A bottom surface of the hood portion 10 forms a bounce prevention surface 12 that is inclined so as to rise toward the inside. The bounce prevention surface 12 has a photoresist mist scattered from the wafer 1 in the direction of the wafer 1. It is inclined to reflect the photoresist mist downward so that it does not return.

The lower end of the supporting portion 9 of the main hood 8 is integrally connected to the supporting portion 3 of the processing container 2, and the supporting portion 9 of the main hood 8 and the processing container 2 which are arranged in an inner and outer double cylindrical shape. A space between the supporting portion 3 and the support portion 3 forms a circular ring-shaped main exhaust duct 13. The upper end of the main exhaust duct 13 communicates with the hood opening 11 of the main hood 8 and exhausts the outer peripheral space of the wafer 1 held by the spin chuck 7. A main exhaust pipe 15 connected to an exhaust device 14 such as a vacuum pump is connected to the main exhaust duct 13, and a main damper 16 as a variable flow rate adjusting valve is provided in the middle of the main exhaust pipe 15. .

Directly above the center of the spin chuck 7 is a photoresist liquid 1 in which the photoresist is diluted with a solvent.
A nozzle 17 for dropping 8 is installed so as to be vertically moved by an elevation drive device (not shown). The nozzle 17 may drop a small amount of the photoresist solution 18 onto the wafer 1. It is configured.

A sub hood unit 20 is installed above the outer side of the main hood 8 and the sub hood unit 2 is provided.
0 has a lower sub-hood, a middle sub-hood, and an upper sub-hood. The lower sub hood 21 includes a support portion 22 formed in a cylindrical shape having a diameter larger than that of the support portion 9 of the main hood 8, and a hood portion 23 projecting radially inward from the upper end of the support portion 22. . The hood portion 23 is formed in a circular ring shape, and the hood opening 24 of the hood portion 23 has a main hood opening 11 of the hood portion 10 of the main hood 8.
And is coaxially arranged. The hood portion 23 is formed in a thin plate shape, and is entirely bent from the base end portion of the support portion 22 at a bending angle θ ₁ so as to be inclined downward as it goes inward. Therefore, the bottom surface of the hood portion 23 forms a bounce prevention surface 25 that is inclined so as to descend toward the inside. The bounce prevention surface 25 is formed on the wafer 1 by the photoresist mist scattered from the wafer 1. It is inclined so as to reflect the photoresist mist outward so as not to return in the direction.

The lower end of the support portion 22 of the lower sub hood 21 is integrally connected to the support portion 9 of the main hood 8,
The space between the support portion 22 of the lower sub hood 21 and the support portion 9 of the main hood 8 arranged in the inner and outer double cylindrical shape forms a circular ring-shaped lower exhaust duct 26. The upper end of the lower exhaust duct 26 is communicated with the hood opening 24 of the lower sub hood 21, and the lowermost space of the space above the wafer 1 held by the spin chuck 7 is exhausted. A lower exhaust pipe 28 connected to an exhaust device 27 such as a vacuum pump is connected to the lower exhaust duct 26, and a lower damper 29 as a variable flow rate adjusting valve is provided in the middle of the lower exhaust pipe 28. .

The middle sub-hood 31 disposed above the outer side of the lower sub-hood 21 is a support portion 2 of the lower sub-hood 21.
The support part 32 is formed in a cylindrical shape having a diameter larger than 2, and the hood part 33 is provided so as to project radially inward from the upper end of the support part 32. The hood portion 33 is formed in a circular ring shape, and the hood opening 34 is formed to be the same as the hood opening 11 of the hood portion 10 of the main hood 8 and arranged coaxially. The hood portion 33 is formed in a thin plate shape, and is generally bent from the base end portion of the support portion 32 at a bending angle θ ₂ so as to incline downward as it goes inward. Therefore, the bottom surface of the hood portion 33 forms a bounce prevention surface 35 that is inclined so as to descend toward the inside. The bounce prevention surface 35 is formed on the wafer 1 by the photoresist mist scattered from the wafer 1. It is inclined so as to reflect the photoresist mist outward so as not to return in the direction.

The lower end of the support portion 32 of the middle sub hood 31 is integrally connected to the support portion 22 of the lower sub hood 21, and the middle sub hood 3 arranged in an inner and outer double cylindrical shape.
The space between the first support portion 32 and the support portion 22 of the lower sub hood 21 forms a circular ring-shaped middle stage exhaust duct 36. The upper end of the middle-stage exhaust duct 36 communicates with the hood opening 34 of the middle-stage sub-hood 31, and exhausts the middle-stage space located above the lowest-stage space of the upper space of the wafer 1 held by the spin chuck 7. ing. A middle exhaust pipe 38 connected to an exhaust device 37 such as a vacuum pump is connected to the middle exhaust duct 36,
In the middle of the middle exhaust pipe 38, a middle damper 39 as a variable flow rate adjusting valve is provided.

The upper sub hood 41, which is disposed above the outer side of the middle sub hood 31, is the support portion 3 of the middle sub hood 31.
A support portion 42 formed in a cylindrical shape having a diameter larger than 2 and a hood portion 43 protruding inward in the radial direction from the upper end of the support portion 42 are provided. The hood portion 43 is formed in a circular ring shape, and the hood opening 44 is formed to be the same as the hood opening 11 of the hood portion 10 of the main hood 8 and arranged coaxially. The hood portion 43 is formed in a thin plate shape and is entirely bent from the base end portion of the support portion 42 at a bending angle θ ₃ (90 °) so as to project horizontally. Therefore, a horizontal bounce prevention surface 45 is formed by the lower surface of the hood portion 43, and the bounce prevention surface 45 prevents the photoresist mist scattered from the wafer 1 from returning toward the wafer 1. Is set to reflect the photoresist mist outward.

The lower end of the support portion 42 of the upper sub-hood 41 is integrally connected to the support portion 32 of the middle sub-hood 31, and the upper sub-hood 4 arranged in an inner and outer double cylindrical shape.
A space between the first support portion 42 and the support portion 32 of the middle sub hood 31 forms a circular annular belt-shaped upper stage exhaust duct 46. The upper end of the upper exhaust duct 46 communicates with the hood opening 44 of the upper sub-hood 41, and exhausts the uppermost space of the space above the wafer 1 held by the spin chuck 7. An upper exhaust pipe 48 connected to an exhaust device 47 such as a vacuum pump is connected to the upper exhaust duct 46, and an upper damper 49 as a variable flow rate adjusting valve is provided in the middle of the upper exhaust pipe 48. . Each of the dampers 16, 29, 39, 49 is configured to be controlled by the controller 5 constructed by a computer or the like together with the drive device 5 for driving the spin chuck, with the operation described later.

[0025] The bending angle theta ₁ of the lower Sabufudo 21, a bending angle theta ₂ of the middle Sabufudo 31, the relationship between the bending angle theta ₃ of the upper Sabufudo 41, is set to satisfy the following equation (1) There is. θ ₁ > θ ₂ > θ ₃ ≧ 90 ° (1)

Further, the height interval H _{1 from} the opening 24 of the lower sub hood 21 to the opening 11 of the main hood 8 and the opening 2 of the lower sub hood 21 of the opening 34 of the middle sub hood 31.
4, the height interval H _{2 up} to 4 and the opening 4 of the upper sub hood 41
4 Height interval H ₃ to the opening 34 of the middle sub hood 31
The relationship with and is set so as to satisfy the following expression (2). H ₁ <H ₂ <H ₃ (2)

Next, the operation will be described. The wafer 1 as an object to be coated is placed on the spin chuck 7 and held by means such as vacuum adsorption. Then, the wafer 1 is rotated by the driving device 5 via the rotary shaft 6 to 4000-7000r.
It is rotated at pm. When this rotation is stable, a small amount (for example, 1.0 ml) of the photoresist liquid 18 having a predetermined viscosity (for example, 50 mPa · S) is dropped onto the center of the wafer 1 from the nozzle 17. Since the dropped photoresist liquid 18 is diffused in the direction of the outer periphery of the wafer 1 (direction tangential to the periphery of the wafer 1) by a centrifugal force, the surface of the wafer 1 is coated with a photoresist coating film (hereinafter, The coating film 19) is uniformly formed over the entire surface.

At this time, as shown in FIG. 2, part of the photoresist liquid 18 and the photoresist mist 18a scattered to the outside of the wafer 1 is sucked by the main exhaust duct 13 and discharged to the outside. The remaining portion is sucked by the exhaust ducts 26, 36, 46 of the sub hood unit 20 and discharged to the outside.

By the way, when the diameter of the wafer 1 becomes large (for example, 200 mm), the dropping amount of the photoresist liquid 18 increases and the rotation speed at the time of spinner coating also increases.
The amount of the photoresist mist 18a scattered from is also increased, and the particle size of the photoresist mist 18a is reduced. Therefore, in the spinner coating operation of the large-diameter wafer 1, the photoresist mist 18a is quickly removed by increasing the exhaust flow rate from the processing container 2.
Need to be discharged to the outside.

On the other hand, in the process of forming the coating film 19 after the dropping of the photoresist liquid 18, the air flow near the wafer 1 is a rotational flow induced by the rotation of the wafer 1 and the main exhaust duct 13 and the sub hood unit 20. Since the exhaust flow generated by the exhaust force of the exhaust duct is combined, the coating film 1 in the central portion of the wafer 1
The contact air volume of No. 9 is small, and the contact air volume of the coating film 19 on the peripheral portion of the wafer 1 is large. As a result, the evaporation of the solvent of the photoresist liquid 18 in the peripheral portion of the wafer 1 is promoted, and the film thickness in the peripheral portion becomes thick.

Therefore, in order to promptly discharge the photoresist mist 18a to the outside of the processing container 2, the processing container 2
When the exhaust gas flow rate for the wafer 1 is simply increased, the contact air volume of the coating film 19 in the peripheral portion of the wafer 1 is further increased.
As the solvent evaporation of No. 8 is further promoted, the film thickness in the peripheral portion becomes more and more thick, and the phenomenon that the film thickness distribution in the wafer 1 becomes significantly more nonuniform occurs.

In order to avoid this phenomenon, in this embodiment, in order to increase the exhaust amount of the processing container 2 as a whole while suppressing the exhaust amount by the main exhaust duct 13, each exhaust duct 26 of the sub hood unit 20 is increased. , 36, 46
The exhaust control sequence by is executed. That is, since the amount of exhaust air from the main exhaust duct 13 is suppressed, an excessive increase in the amount of contact air of the coating film 19 on the outer peripheral portion of the wafer 1 is suppressed, so that the photoresist liquid 18 on the peripheral portion of the wafer 1 is suppressed. Evaporation of the solvent is suppressed, and as a result, increase in the film thickness of the coating film 19 on the peripheral portion of the wafer 1 is suppressed.

On the other hand, if the increase of the exhaust force of the main exhaust duct 13 is suppressed, the photoresist mist 18a easily scatters upward, so that the photoresist mist 18a is arranged above the hood opening 11 of the main exhaust duct 13. The exhaust ducts 26 of the sub hood unit 20
It will be aspirated and effectively captured by 36,46. Therefore, even if the exhaust force of the main exhaust duct 13 is suppressed, the photoresist mist 18a does not separate the wafer 1 from the wafer 1.
All are discharged to the outside of the processing container 2 without returning to the direction of.

When the photoresist solution 18 is dropped onto the large diameter wafer 1 while the wafer 1 is rotating at a high speed, a large amount of fine photoresist mist 18a is generated and the wafer 1
It was revealed by the present inventor that the particles are scattered above. This is considered for the following reasons. The photoresist liquid 18 dropped on the wafer 1 is coated with the coating film 1
The amount of excess photoresist liquid 18 is larger than that required for forming 9, and the excess photoresist liquid 18 is scattered by the rotation of the wafer 1 in the tangential direction of the outer periphery of the wafer with the kinetic energy E shown by the following equation. E = (1/2) × M × V ^{2 In the} equation, M is the mass of the photoresist mist 18a, and V is the speed of the photoresist mist 18a when leaving the outer periphery of the wafer. The detachment speed V increases in proportion to the radius r of the wafer 1 and the rotation speed N. Further, the grain size of the photoresist 18a is inversely proportional to the rotation speed N of the wafer 1,
The mass M is proportional to the cube of the particle size. Therefore, the wafer 1
As the number N of revolutions of N becomes larger and the radius r of the wafer 1 becomes larger, the particle size of the photoresist mist 18a becomes smaller,
The speed V at which the wafer is separated from the outer circumference increases. Since the photoresist mist 18a having a smaller particle size is more susceptible to lift than gravity, the photoresist mist 18a tends to rise and separate rather than horizontally separate, which is relatively high from the upper surface of the wafer 1. It will be scattered to the position.

The exhaust force of each exhaust duct 26, 36, 46 of the sub hood unit 20 is automatically adjusted by the controller in accordance with the extent to which the exhaust force of the main exhaust duct 13 is suppressed. The adjustment of the exhaust force of each exhaust duct 26, 36, 46 of the sub hood unit 20 is not only controlled by the relationship between the total exhaust force of the sub hood unit 20 and the exhaust force of the main exhaust duct 13. , The relationship between the exhaust ducts 26, 36, 46 is controlled. Then, the adjustment of these exhaust forces can be controlled by adjusting the opening degree (including fully closed and fully opened) of each damper 16, 29, 39, 49. Also, since the specific value of the exhaust amount varies depending on various conditions such as the diameter of the wafer, the rotation speed of the wafer, the type of photoresist, the viscosity of the photoresist liquid, and the dropping amount, an experiment or a simulated experiment using a computer, etc. It is desirable to obtain the optimum values in advance by an empirical method according to.

According to the above embodiment, the following effects can be obtained. (1) Multi-stage exhaust duct 2 above the main hood 8
By disposing the sub hood unit 20 having 6, 36, 46, the exhaust amount by the main exhaust duct 13 can be suppressed by supplementing the exhaust amount of the sub hood unit 20, so that in the outer peripheral portion of the wafer 1. It is possible to suppress an excessive increase in the contact air volume of the coating film 19 by the main exhaust duct 13 and suppress the solvent evaporation of the photoresist liquid 18 in the peripheral portion of the wafer 1, and as a result,
It is possible to suppress an increase in the film thickness of the coating film 19 on the peripheral portion of the wafer 1.

(2) According to the above (1), since the evaporation of the excess solvent of the photoresist liquid 18 can be suppressed, the consumption amount of the photoresist liquid 18 can be reduced, and the cost of the lithography processing step, As a result, the production cost of the semiconductor device can be reduced.

(3) On the other hand, when the increase of the suction force of the main exhaust duct 13 is suppressed, the photoresist mist 18
a is easily scattered upward, and the sub hood unit 2 arranged above the hood opening 11 of the main exhaust duct 13
Therefore, even if the exhaust force of the main exhaust duct 13 is suppressed, the photoresist mist 1 is sucked and effectively captured by the exhaust ducts 26, 36, 46 of 0.
All of 8a can be discharged to the outside of the processing container 2 without returning to the direction of the wafer 1.

(4) By adjusting the exhaust flow rate of each exhaust duct 26, 36, 46 of the sub hood unit 20 in correspondence with the extent to which the exhaust force of the main exhaust duct 13 is suppressed, the photoresist Since it can be controlled to an optimum value in accordance with various conditions such as the type, the viscosity of the photoresist liquid, the dropping amount, the diameter of the wafer, the rotation speed of the wafer, etc., the above (1), (2) and (3) The effect can be reliably ensured and further enhanced.

(5) By reducing the gas flow rate acting on the coating film 19 on the wafer 1, even if the coating atmosphere temperature and the coating atmosphere humidity are slightly changed, it is possible to prevent the film thickness from changing, so that it is stable. It is possible to form a coating film having the above thickness.

(6) Since the quality and reliability of the coating film 19 can be improved by making the film thickness distribution of the coating film 19 uniform, it is possible to improve the quality and reliability of the coating film 19. It is possible to prevent the occurrence of overdeveloped portions and improve the accuracy of the entire lithography process.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, the sub hood unit is not limited to be constructed by three stages of exhaust air, but two stages of exhaust ducts or 4 stages.
It may be configured by an exhaust duct having more than one step.

The exhaust pipe and the exhaust device are not limited to being separately provided for each exhaust duct, but may be appropriately shared.

In the above description, the invention made by the present inventor was mainly described in the case of coating a photoresist on a wafer, which is the field of application of the background, but the present invention is not limited thereto. When applying a photoresist to a mask, when applying a photoresist to a liquid crystal panel, a compact disc, a circuit board, or the like, further, a coating material other than the photoresist such as an insulating material of glass or PIQ is applied to a wafer or a mask. In the case of coating, etc., it can be applied to all coating techniques for coating a material to be coated by rotation.

[0046]

The effects obtained by typical aspects of the invention disclosed in the present application will be briefly described as follows.

By disposing the sub hood unit on the upper side of the exhaust hood for exhausting the air around the object to be coated so as to exhaust the upper space of the hood opening, the exhaust air volume of the exhaust hood can be supplemented by the sub hood unit. The amount of exhaust air from the exhaust hood can be suppressed. As a result, it is possible to suppress the influence of the exhaust force around the object to be coated by the exhaust hood, so that the amount of contact of the exhaust air with the object to be coated can be made uniform throughout, and the film thickness distribution of the coating film can be reduced. It can be made uniform.

On the other hand, since the scattered mist can be sucked by the exhaust force of the sub hood unit and reliably captured, it is possible to reliably prevent the mist from returning to the object to be coated and the mist to be coated. It is possible to prevent redeposition on the surface.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a photoresist coating apparatus according to an embodiment of the present invention.

FIG. 2 is a front cross-sectional view for explaining the operation.

[Explanation of symbols]

1 ... Wafer (object to be coated), 2 ... Processing container, 3 ... Support part,
4 ... Processing part, 5 ... Drive device, 6 ... Rotating shaft, 7 ... Spin chuck, 8 ... Main hood (exhaust hood), 9 ... Support part, 10 ... Hood part, 11 ... Hood opening, 12 ... Bounce prevention surface, 13 ... Main exhaust duct, 14 ... Exhaust device,
15 ... Main exhaust pipe, 16 ... Main damper, 17 ... Nozzle, 18 ... Photoresist liquid, 18a ... Photoresist mist, 19 ... Coating film (photoresist film), 20 ... Sub hood unit, 21 ... Lower sub hood, 22 ... Support part, 23 ... Hood part, 24 ... Hood opening, 25 ... Bounce prevention surface, 26 ... Lower exhaust duct, 27 ... Exhaust device, 2
8 ... Lower exhaust pipe, 29 ... Lower damper, 31 ... Middle sub hood, 32 ... Support part, 33 ... Hood part, 34 ... Hood opening, 35 ... Bounce prevention surface, 36 ... Middle stage exhaust duct, 3
7 ... Middle exhaust device, 38 ... Middle exhaust pipe, 39 ... Middle damper, 41 ... Upper sub hood, 42 ... Support part, 43 ... Hood part, 44 ... Hood opening, 45 ... Bounce prevention surface, 46
... upper exhaust duct, 47 ... upper exhaust device, 48 ... upper exhaust pipe, 49 ... upper damper, 50 ... controller, θ ₁ ...
Bending angle of lower sub hood, θ ₂ … Bending angle of middle sub hood, θ ₃ … Bending angle of upper sub hood, H ₁ … Height interval of lower sub hood opening to main hood opening, H ₂ … Lower sub hood opening of middle sub hood Height interval up to H _3, ... Height interval up to the middle sub-hood opening in the upper sub-hood opening.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Yamagami 3-3, Fujibashi 2-3, Ome-shi, Tokyo Within Hitachi Tokyo Electronics Co., Ltd. (72) Inventor Masayoshi Kanematsu 3-3-2 Fujibashi, Ome-shi, Tokyo Hitachi Higashi Kyo Electronics Co., Ltd. (72) Inventor Yoichiro Tamiya, 3-3 Fujitobashi, Ome-shi, Tokyo 2 Hitachi Tokyo Electronics Co., Ltd. (72) Shinya Ogane 3-3 Fujibashi, Ome-shi, Tokyo 2 Hitachi 2 Electronics Co., Ltd. (72) Inventor Masahiro Ishiuchi 3-3 Fujibashi, Ome City, Tokyo 2 Hitachi Hitachi Electronics Co., Ltd.

Claims (3)

[Claims] 1. A spin chuck provided inside a processing container is configured to hold an object to be coated and rotate it to supply a coating material onto the surface to coat the material to form a coating film. In a coating apparatus in which an exhaust hood is disposed outside the processing container so as to exhaust the periphery of an object to be coated in the processing container, a sub-hood unit that exhausts an upper space of the hood opening is disposed above the exhaust hood. The sub-hood unit is provided with a plurality of stages of exhaust ducts. 2. The coating apparatus according to claim 1, wherein the exhaust flow rate in the exhaust duct of each stage of the sub-hood unit is adjustable. 3. The exhaust flow rate in the exhaust duct of each stage of the sub-hood unit is configured to be adjustable respectively, and is also configured to be automatically adjusted according to the coating conditions. The coating device according to claim 2, which is characterized in that.