JPS6231622B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spin coating device used for coating a resist solution on a wafer, for example, in the manufacturing process of semiconductor devices.

Conventionally, this type of spin coating apparatus is constructed as shown in FIG. 1, for example. In the figure, reference numeral 1 denotes a tray with an open top surface, and a rotary table 3 for fixing and rotating a wafer 2 is provided inside the tray 1. This rotating table 3 is connected to a drive motor 5 via a rotating shaft 4.

That is, in this spin coating apparatus, the wafer 2 is fixed on the rotating table 3, and the resist liquid 6 is dropped onto the surface of the wafer 2 from above using, for example, a dropping nozzle (not shown). Next, the drive motor 5 is driven to rotate, and the wafer 2 is rotated together with the rotating table 3 via the rotating shaft 4. As a result, the resist liquid 6 is applied to the surface of the wafer 2.

However, in this spin coating device,
Since the upper surface of the tray 1 is open, the wafer 2 rotates in the outside air. Therefore, the state of application of the resist liquid 6 is easily affected by disturbances in the outside air flow. In other words, as shown in FIG. 2, the thickness of the applied resist liquid 6 is not uniform depending on the location away from the center of rotation of the wafer 2 (the uniform area is indicated by A, and the non-uniform area is indicated by B). show). Moreover, the resist liquid shaken off from the rotating wafer 2 and the solid matter separated from the liquid by evaporation of the resist liquid collide with the wafer 2 at high speed, causing unnecessary dust to adhere to the wafer 2. It is easy to cause consequences.

This invention was made in view of the above circumstances.
The purpose is to provide a spin coating device that can uniformly apply a liquid to an object to be coated without being affected by turbulence in the outside air during spin coating, and can improve the cleanliness of the coating surface. be.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A case in which an embodiment of the present invention is applied to a resist coating apparatus will be described below with reference to the drawings. FIGS. 3 and 4 show the basic structure thereof, and 11 is a rotary pot having a lid 12 on its upper surface that can be opened and closed. This rotary pot 11 is driven by a drive motor 1
5 is fixed to the rotating shaft 16 of the rotary pot 1.
1 is adapted to rotate integrally with a rotating shaft 16. Furthermore, a plurality of blade members 20 each having a notch 20a are arranged inside the rotary pot 11, and the wafer 13 is fixed to this notch 20a. The lid 12 is opened only when loading and unloading the wafer 13, and is kept closed during spin coating. Therefore, the air around the wafer 13 during spin coating is not affected by turbulence in the outside air. A plurality of discharge holes 1 are provided at the lower end of the side wall of the rotary pot 11.
7 and 17 are formed. Further, a saucer 18 is provided on the outer periphery of the rotary pot 11, and excess resist liquid accumulated at the bottom of the rotary pot 11 is drained through a drain hole 18.
7 and 17, and is discharged into this tray 18.

That is, in this rotary coating apparatus, first, the lid 12 of the rotary pot 11 is opened, the wafer 13 is fixed in the notch 20a, and the resist liquid 19 is dripped onto the surface of the wafer 13 from above using, for example, a dripping nozzle. After that, the lid 12 is closed, the drive motor 15 is driven to rotate, and the rotary pot 11 and the blade member 2 are rotated.
Rotate 0 as one unit. As a result, wafer 1
Resist liquid 19 is applied to the surface of 3, and the excess resist liquid passes through the discharge holes 17, 17 and drains into the tray 1.
It is discharged at 8.

As described above, the blade member 20 and the wafer (plate-shaped object) 13 rotate together in the closed space,
Since the air inside starts rotating within a very short time after the start of rotation, it is possible to create a state in which the air inside the rotary pot 11 is less turbulent. By the way, if there is no blade member 20, the rotary pot 11
Even if the wafer 13 starts to rotate, it is partially stopped for a while due to the inertia of the air, and the rotary pot 1
During the acceleration to the same rotational speed as 1, air turbulence occurs, creating a relative airflow around the wafer 13, resulting in uneven drying of the coating solution, and the resist solution on the wafer 13. This results in an inconvenience that the thickness of the layer 19 becomes non-uniform. That is, the blade member 2
0 constitutes a baffle plate for the rotation direction of the air in the rotary pot 11, thereby bringing the entire air inside the rotary pot 11 close to the rotation speed of the rotary pot 11, thereby reducing turbulence of the air in the rotary pot 11. I'm letting you do it.

That is, the airflow is regulated by the vane members 20, 20, and turbulence in the airflow when adjusting the rotational speed is reduced, thereby providing the following effects.

Increase in uniformly coated area: Since the lid 12 of the rotary pot 11 is closed during spin coating,
Coating unevenness around the wafer 13 caused by turbulence in the outside air is significantly reduced. Therefore, as shown in FIG. 5, the area A that is uniformly coated is increased compared to the conventional method, and the usable effective area of the wafer 13 is increased. This effect is particularly significant when the shape of the wafer 13 is rectangular.

Improved cleanliness of the coating surface: Since the entire interior of the rotary kettle 11 rotates, the resist liquid 1, which is heavier than air, is
9 and the solid matter are pressed against the side wall of the rotating pot 11, and collisions with the wafer 13 are reduced. Therefore,
Unnecessary dust adhesion to the surface of the wafer 13 is reduced,
The cleanliness of the coated surface is improved.

Since the evaporation rate of the resist liquid 19 during spin coating can be slowed down, the liquid state can be maintained for a long time, and it is easy to apply the resist liquid 19 thinly (a small amount of the resist liquid 19 is sufficient). Further, since the release time of the residual stress remaining in the resist liquid 19 on the surface of the wafer 13 after spin coating is completed can be controlled by changing the opening/closing time of the lid 12, minute irregularities on the surface of the applied resist liquid can be reduced.

In the above embodiments, a spin coating device for resist liquid used in the manufacturing process of semiconductor devices has been described, but the present invention is not limited to this. Of course, the present invention can also be applied to plate-like objects of other shapes.

As described above, according to the present invention, a rotary pot having a lid that can be opened and closed at the top is fixed to the rotating shaft of a drive motor, and is rotated together with the object to be coated inside. Since the air turbulence is reduced, the influence of outside air turbulence can be prevented during spin coating, and coating can be more uniform than before, and the cleanliness of the coated surface can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of a conventional spin coating device, FIG. 2 is a plan view of a wafer showing the coating state in the above device, and FIG. 3 is a configuration of a spin coating device according to an embodiment of the present invention. FIG. 4 is a plan view showing the attachment state of the blade member in the above device, and FIG. 5 is a plan view showing the application state in the above device. 11...Rotary pot, 12...Lid, 13...Wafer, 15
... Drive motor, 16... Rotating shaft, 17... Discharge hole, 1
8... Receiver, 19... Resist liquid, 20... Wing member, 20a... Notch.

Claims (1)

[Claims] 1. A rotary coating device for rotary coating of a liquid onto a plate-shaped object, which includes a drive motor, a rotary pot fixed to the rotating shaft of the drive motor, and having a lid that can be opened and closed at the top and a liquid discharge hole formed at the bottom. and a plurality of blade members having cutouts for fixing the plate-like object fixed inside the rotary pot, and a saucer for storing the liquid discharged from the discharge hole of the rotary pot. Rotary coating equipment.