JPH03151076A - Coating apparatus - Google Patents

Abstract

PURPOSE:To prevent the sticking of a fluid material to a substrate surface by providing a discharge fan which rotates in synchronization with a revolving shaft in a cap on this revolving shaft. CONSTITUTION:A proper amt. of resist 15 is dropped from a supply nozzle 13 onto a semiconductor wafer 10. A motor 11a is turned on to operate right thereafter to rotate a rotary disk 11 at a high speed, by which the semiconduc tor wafer 10 is rotated horizontally. The resist 15 on the semiconductor wafer 10 is then run over the entire surface of the semiconductor wafer 10 and the unnecessary resist 15 is removed from the surface of the semiconductor wafer 10 by centrifugal force. The velocity of flow of clean air 16 increases when the rotating speed of the semiconductor wafer 10 increases. The sticking of the resist 15 on the surface of the semiconductor wafer 10 does not arise. the yield of production is, therefore, improved.

Description

[Detailed Description of the Invention] [Summary] Regarding a coating device that horizontally rotates a substrate and applies a thin layer of a fluid substance to the surface of the substrate, the fluid substance that has been scattered from the surface of the substrate may adhere to the surface of the substrate again. The purpose of the present invention is to provide a coating device that can prevent this from occurring, and includes a rotating disk that is connected to a rotating shaft and horizontally rotates the mounted substrate, and a rotating disk that is housed inside and has upper openings at the top and bottom of the rotating disk. and a lower opening, and a supply nozzle disposed directly above a rotating disk for dripping a fluid substance onto a substrate, the coating device includes a rotating shaft in the cup that is synchronous with the rotating shaft. An exhaust fan is provided to rotate, and the exhaust fan is configured to exhaust gas within the cup from a side opening provided at a side of the cup.

[Industrial application field]

The present invention relates to a coating apparatus that rotates a substrate horizontally to apply a thin layer of a fluid substance to the surface of the substrate, and particularly relates to a coating apparatus that can prevent the fluid substance scattered from the substrate surface from adhering to the substrate surface.

To apply a resist to the surface of a substrate, for example a semiconductor wafer, the resist is dropped onto the semiconductor wafer, and then the semiconductor wafer is rotated horizontally at high speed to spread the resist over the entire surface of the semiconductor wafer, and the excess resist is removed by centrifugal force. This is done using a coating device (for example, a spin coater) that scatters and removes the coating from the surface of the semiconductor wafer.

[Conventional technology]

Next, a conventional coating device will be described in detail with reference to the drawings.

FIG. 2 is a diagram for explaining a conventional coating device, in which FIG. 2(a) is a schematic side sectional view of the main part of the first conventional example, and FIG. 2(b) is a schematic side sectional view of the main part of the first conventional example. A schematic side sectional view of the main parts is shown.

The first conventional coating device shown in FIG. 2 is composed of a rotating disk 21, a cup 22, a supply nozzle 23, and the like.

The rotating disk 21 is connected to the motor 2 via the rotating shaft 21b.
1a, and horizontally rotates a substrate 20 such as a semiconductor wafer placed on its surface.

The cup 22 houses the rotating disk 21 therein, and has an upper opening 22a just above the rotating disk 21 and a lower opening 22b diagonally below the rotating disk 21. ing.

The supply nozzle 23 is disposed directly above the rotating disk 21 and is configured to freely drop the resist 25 onto the surface of the substrate 20 temporarily fixed to the surface of the rotating disk 21.

Next, a method for coating the resist 25 on the surface of the substrate 20 using the conventional coating apparatus having such a configuration will be explained in the order of steps.

First, after placing the substrate 20 on the rotating disk 21, a vacuum suction mechanism (not shown) is activated to move the substrate 20 onto the rotating disk 21.
Hold it firmly on the surface of 1.

Next, an appropriate amount of resist 25 is dropped from the supply nozzle 23 onto the surface of the substrate 20 .

After that, the motor 21a is immediately turned on, and the rotating disk 2
1 at high speed in the direction shown by the arrow to horizontally rotate the substrate 20.

Then, the resist 25 on the substrate 20 flows over the entire surface of the substrate 20, and the unnecessary resist 25 becomes scattered resist 25' in the radial direction of the substrate due to centrifugal force, and is scattered onto the substrate 20.
removed from the surface of 0.

In this way, the resist 25 is thinly applied to the surface of the substrate 20, and the process of applying the resist 25 is completed.

It should be noted that during the coating operation, the cup 22 may be filled with the organic solvent that is the solvent for the resist 25 or the scattered resist 25'.
Clean air 26 is fed into the cup 22 from the upper opening 22a of the cup 22 to prevent it from leaking to the outside.

This clean air 26 flows through the cup 22 through a flow path as shown by arrow A, and then flows through a flow path as shown by arrow B, that is, an exhaust pipe 24a connected to the lower opening 22b of the cup 22.
It is discharged into the atmosphere via the recovery tank 24b and the exhaust pipe 24c in this order.

The recovery tank 24b collects the resist 25 contained in the gas discharged from the cup 22 by settling it in the air.
This prevents the resist 25 from being released into the atmosphere.

[Problem to be solved by the invention]

As explained in connection with the first conventional coating apparatus, when the substrate 20 is rotated at high speed, the resist 25 dropped onto the surface of the substrate 20 becomes scattered resist 25 due to centrifugal force and spreads around the substrate 20. It scatters at high speed.

The scattered resist 25' collides with the inner wall of the cup 22 and at the same time bounces back toward the substrate 20.

However, as described above, the clean air 26 sent into the cup 22 flows from the center of the substrate 20 toward the outer circumference as shown by arrow A.

Therefore, when the rotational speed of the substrate 20 is low, the scattered resist 25' is discharged from the cup 22 to the outside together with the clean air 26, and does not adhere to the surface of the substrate 20 in the form of particles.

However, when the rotation speed of the substrate 20 is increased, the speed of the scattered resist 25' increases, and it becomes inevitable that the resist 25' will adhere to the surface of the substrate 20 against the flow of the clean air 26.

In order to prevent this scattered resist 25' from adhering to the surface of the substrate 20, it is effective to increase the amount of clean air 26 fed and to increase the flow velocity of the clean air 26 from the center to the outer circumference on the substrate 20. It is.

However, in the conventional coating apparatus, since a substantially constant amount of clean air 26 was fed, it was not possible to prevent the scattered resist 25' from adhering to the surface of the substrate 20.

Therefore, in order to eliminate the adhesion of the scattered resist 25' to the substrate 20, a second conventional coating apparatus shown in FIG. 2(b) was put into practical use.

This second conventional coating device is constructed by adding a rectifying plate 27 and an exhaust fan (not shown) to the atmospheric side terminal end of the exhaust pipe 24c in addition to the first conventional coating device shown in FIG. 2(a). It is added to.

That is, by taking such measures, the clean air 26 flowing in the cup 22 in the flow path shown by the arrows is made to flow from the center of the substrate 20 toward the outer circumference at a high speed.

However, due to constraints such as installation cost and occupied area, one exhaust fan is usually installed for each of a plurality of coating apparatuses.

As a result, the amount of exhaust air inside the cup 22 varies depending on the number of operating coating devices, and the flow rate of the clean air 26 from the center to the outer circumferential portion of the substrate 20 changes.

In order to avoid this change in the flow velocity of the clean air 26,
It was necessary to frequently adjust the current plate 27, which is a very troublesome task.

The present invention has been made in view of such problems, and its purpose is to provide a coating device that can prevent fluid substances scattered from the surface of a substrate from becoming granular and adhering to the surface of the substrate. It is in.

[Means to solve the problem]

The purpose is to attach the exhaust fan 14 to the rotary shaft 11b in the cup 12 so as to rotate in synchronization with the rotary shaft 11b.
This is achieved by a coating device characterized in that the exhaust fan 14 exhausts the gas inside the cup 12 from a side opening 12c provided on the side of the cup 12.

[For production]

The coating device of the present invention has a rotating shaft 11 in a cup 12.
b is provided with an exhaust fan 14 so as to rotate in synchronization with the rotating shaft 11b, and the exhaust fan 14 is configured to exhaust the gas in the cup 12 from a side opening 12c provided at the side of the cup 12. There is.

In this way, when the rotational speed of the substrate 10 is increased, the rotational speed of the exhaust fan 14 is also increased synchronously, and the flow rate of gas from the center of the surface of the substrate 10 toward the outer circumference increases in accordance with the rotational speed of the substrate 10. It gets faster.

Therefore, the fluid substance 1 scatters from the substrate 10, collides with the inner wall of the cup 12, and then rebounds toward the substrate 10.
The speed of No. 5 increases as the rotational speed of the substrate 10 increases, but as mentioned above, the gas flow rate from the center of the surface of the substrate 10 toward the outer periphery also increases with the rotational speed of the substrate 10. , the fluid substance 15 is pushed back by this fast gas flow and does not reach the surface of the substrate IO.

As a result, even if the rotational speed of the substrate 10 is increased, the fluid substance 15 will not adhere to the surface of the substrate 1o in the form of particles.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic side sectional view of essential parts of an embodiment of the coating apparatus of the present invention.

As shown in FIG. 1, an embodiment of the coating device of the present invention is constructed by adding an exhaust fan 14 and a side opening 12c to the coating device of the first conventional example shown in FIG. .

The structure and function of one embodiment of the coating apparatus of the present invention will be explained by describing the working procedure until the fluid substance 15, for example, resist is coated on the surface of the substrate 10.

First, a substrate 10, for example a semiconductor wafer, is placed on a rotating disk 11.
After placing the semiconductor wafer 10 on the rotating disk 11, a vacuum suction mechanism (not shown) is operated to firmly hold the semiconductor wafer 10 on the surface of the rotating disk 11.

Next, an appropriate amount of resist 15 is dropped onto the semiconductor wafer 10 from the supply nozzle 13 .

After that, the motor 11a is immediately turned on and the rotating disk 1 is turned on.
Rotate the semiconductor wafer lO at high speed in the direction of the arrow.
Rotate horizontally.

Then, the resist 15 on the semiconductor wafer 10 flows over the entire surface of the semiconductor wafer 10, and the unnecessary resist 15 becomes scattered resist 15' in the radial direction of the semiconductor wafer 110 due to centrifugal force, and the semiconductor wafer 10
removed from the surface.

At this time, since the exhaust fan 14 is rotating in synchronization with the rotating shirt eye 1b, the exhaust speed of the exhaust fan 14 is approximately proportional to the rotation speed of the rotating shaft 11b, that is, the rotation speed of the semiconductor wafer 10. It has become.

Therefore, the flow rate of the clean air 16 from the center of the surface of the semiconductor wafer 10 toward the outer periphery of the semiconductor wafer 10 also increases.
It changes approximately in proportion to the rotation speed of 0.

In this way, when the rotational speed of the semiconductor wafer 1O becomes faster, the clean air 16 that is sent into the cup 12 from the upper opening 12a of the cup 12 and flows as shown by the arrow F flows from the center of the surface of the semiconductor wafer 10 to the outer periphery. It will flow quickly towards the area.

As a result, as the rotational speed of the semiconductor wafer IO increases, the speed of the resist 15 that scatters from the surface of the semiconductor wafer 10, collides with the inner wall of the cup 22, and bounces back toward the semiconductor wafer IO also increases. However, since the flow velocity of the clean air 16 from the center of the surface of the semiconductor wafer 10 toward the outer periphery is also increasing, the resist 1
5 is pushed back by the fast flow of clean air 16 and does not reach the surface of semiconductor wafer 10.

Therefore, even if the rotation speed of the semiconductor wafer 10 is increased, the resist 15 will not adhere to the surface of the semiconductor wafer 10 in the form of particles.

The exhaust pipe 17a1 recovery tank 17b1 exhaust pipe 17c connected to the lower opening 12b of the cup 12 collects organic solvent vapor that evaporates from the register 5 attached to the inner wall of the cup 12 when the exhaust fan 14 is not operating. , arrow G
This is to prevent the liquid from dissipating into the clean room where the coating equipment is installed.

In addition, in the recovery tank 17b, since a small amount of resist 15 is present in the air containing the organic solvent discharged through the flow path of arrow G, this resist 15 is allowed to sink in the tank and is recovered. This prevents it from being released into the environment.

In the embodiment described in detail above, the exhaust fan 14 is directly connected to the rotating shaft 11b, but the rotational speed of the rotating shaft 11b is detected electrically or optically, and the exhaust speed is determined by - An exhaust fan approximately proportional to the rotational speed of the cup 12 is connected to the side opening 12c of the cup 12.
Of course, it is also possible to configure it by connecting it to.

〔Effect of the invention〕

As is clear from the above description, according to the coating apparatus of the present invention, when a fluid substance such as a resist is applied to the surface of a substrate such as a semiconductor wafer, the fluid substance adheres to the substrate surface in the form of particles. is prevented.

Therefore, by using the coating apparatus of the present invention, it is possible to reduce defects in wiring patterns etc. formed on the surface of a substrate such as a semiconductor wafer, and it is possible to improve the manufacturing yield of semiconductor devices etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view of a main part of an embodiment of a coating device of the present invention, and FIG. 2 is a diagram for explaining a conventional coating device. In the figure, 10 is a substrate (semiconductor wafer), 11 is a rotating disk, 11a is a motor, 11b is a rotating shaft, 12 is a cup, 12a is an upper opening, 12b is a lower opening, 12c is a side opening, 13 14 is a supply nozzle, 14 is an exhaust fan, 15 is a fluid substance (resist), 16 is clean air, 17a is an exhaust pipe, 17b is a recovery tank, and 17c is an exhaust pipe. 4 Invention angle H1q - Strong rjf 已6 Shigoshi customer part I♂E1
1zuashisu Jkepu 6rij11 Figure

Claims (1)

[Claims] A board (1) connected to and mounted on a rotating shaft (11b).
A rotating disk (11) for horizontally rotating the rotating disk (11), and an upper opening (12a) and a lower opening (12b) in the upper and lower parts of the rotating disk (11). )
A coating device including a cup (12) having a cup (12) and a supply nozzle (13) disposed directly above a rotating disk (11) for dripping a fluid substance (15) onto a substrate (10), An exhaust fan (1
4), and the cup (12) is provided with the exhaust fan (14).
) from the side opening (12c) provided on the side of the cup (1
2) A coating device characterized by discharging the gas inside.