JPH01218664A - Rotary coating apparatus - Google Patents

Abstract

PURPOSE:To coating irregularity due to the dropping of a treatment liquid remaining on the mouth of a treatment liquid dripping nozzle, by transferring the dripping position of a treatment liquid from a treatment dripping nozzle between the end of a substrate and the rotation center of the substrate. CONSTITUTION:A substrate-supporting stand 2 supports and rotates a substrate 1 horizontally. A treatment liquid is supplied to a treatment liquid dripping nozzle 3 to drop the treatment liquid on the substrate 1 on the substrate- supporting stand 2 by a treatment liquid supplying apparatus 4. Then, the substrate 1 on which the treatment liquid is dripped is rotated to form a thin film of the treatment liquid on the substrate. At that time, the dripping position of the treatment liquid from the treatment liquid dripping nozzle 3 is transferred between the end and the rotation center of the substrate by a nozzle transferring apparatus 11. As a result, coating irregularity due to the dropping of the treatment liquid remaining on the mouth of the treatment liquid dripping nozzle is prevented.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention uses a so-called spin coating device, that is, uses centrifugal force due to rotation to coat a processing liquid such as a photoresist onto a semiconductor wafer, a photomask blank, etc. It relates to a device that uniformly coats the surface of a substrate.

[Prior Art] FIG. 7 shows a conventional example of the above-mentioned so-called spin coating device.

This rotary coating device includes a substrate mounting table 2 that supports a substrate 1 horizontally and can rotate the substrate 1 in a horizontal plane, and a device for dropping a processing liquid onto the surface of the substrate 1 on this mounting table 2. The structure is equipped with a processing liquid dropping nozzle 3 and a processing liquid supply device 4 that supplies processing liquid to the nozzle 3, and by rotating the substrate 1 onto which only the processing liquid has been dropped, a process liquid is applied to the surface of the substrate 1. This creates a thin film of processing liquid.

Each component is explained as follows.

The substrate 1 is a substrate that requires high accuracy in equalizing the thickness of the liquid applied to its surface, and specifically, as mentioned above, it is used for semiconductor wafers and photolithography. This applies to mask blanks, etc.

Furthermore, when the substrate 1 is, for example, a photomask blank, the processing liquid corresponds to a resist liquid for forming a resist film thereon.

The substrate mounting table 2 includes a disk 2a on which the substrate 1 is placed, and a drive mechanism (
(Illustrated path).

The disk 2a is provided with a fixing means (path shown) such as vacuum suction as a means for fixing the substrate 1 placed thereon.

The aforementioned nozzle 3 has a nozzle opening 3a through which the processing liquid is dropped.
is fixedly installed facing the rotation center of the substrate 1.

The processing liquid supply device 4 also includes a container 6 containing a processing liquid.
, a pipe 7 for sending the processing liquid from the container 6 to the nozzle 3, and a pressurizer 8 containing the container 6.

Here, the pressurizer 8 is a container body 8 that seals the periphery of the container 6.
a, and a gas supply/discharge port 8b for filling pressurizing scum (inert scum such as nitrogen) into the container body 8a. The processing liquid is sent to the nozzle 3 using gas pressure.

[Problems to be Solved by the Invention] Now, in the conventional spin coating apparatus described above, the processing liquid dropped from the nozzle 3 onto the center of rotation of the substrate 1 gradually spreads onto the substrate 1 due to the centrifugal force caused by the rotation of the substrate 1. This results in the formation of a thin film that spreads over the entire surface of the substrate 1 by diffusing toward the outer periphery of the substrate 1 .

However, the processing liquid remaining near the nozzle opening 3a of the nozzle 3 undergoes evaporation of volatile components (thinner, etc. in the case of resist liquid) due to contact with the atmosphere, and the processing liquid in the container 6 is have different viscosity etc.

Therefore, at the start of dripping, a processing liquid whose viscosity etc. deviate from the original set value is dropped, and due to the mixture of processing liquids with different viscosities, the processing liquid is not spread evenly due to rotation, resulting in uneven coating (unevenness in film thickness). ) could occur.

Furthermore, even if the dropping of a predetermined amount of processing liquid is completed and the processing liquid is well spread by rotation at that point,
After the regular processing liquid dropping operation is completed, there is a possibility that a small amount of the processing liquid remaining near the opening 3a of the nozzle 3 may drip onto the center of the substrate 1, resulting in uneven coating.

In addition, in the conventional apparatus described above, in order to properly diffuse the processing liquid to the periphery of the substrate 1 without causing uneven coating, it is necessary to over-drop (drop much more than necessary to obtain the original film thickness). (meaning), and most of it would be wasted, so consideration was also required to save the amount of dripping.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a spin coating device that can prevent the occurrence of uneven coating caused by dripping of processing liquid remaining at the nozzle opening of a processing liquid dripping nozzle. Another object of the present invention is to provide a spin coating device that can save processing liquid.

[Means for Solving the Problems] A spin coating apparatus according to the present invention includes a substrate mounting table that horizontally supports a substrate and rotates the substrate within a horizontal plane;
The processing liquid is dropped by using a processing liquid dropping nozzle for dropping the processing liquid onto the surface of the substrate on the substrate mounting table and a processing liquid supply device that supplies the processing liquid to the processing liquid dropping nozzle. This method creates a thin film of processing liquid on the surface of the substrate by rotating the substrate, but in order to achieve the purpose of preventing uneven coating, the position at which the processing liquid is dropped by the processing liquid dripping nozzle is adjusted. and a nozzle moving device for moving the substrate between an end of the substrate and a center of rotation of the substrate.

In addition, in order to achieve the purpose of saving processing liquid, the processing liquid supply device is provided with a supply amount that detects the amount of movement by the nozzle moving device and controls the supply amount of processing liquid according to the dropping position of the processing liquid. A control means is provided.

[Function] In the spin coating device according to the present invention, the nozzle for dropping the processing liquid can freely move the position of the nozzle opening for dropping the processing liquid relative to the substrate between the edge of the substrate and the center of rotation using the nozzle moving device. can be moved to Therefore, the nozzle opening is positioned at the edge of the substrate at the start and end of dropping.

When the nozzle opening is located at the edge of the substrate in this way, even if the processing liquid remaining near the nozzle opening drips onto the substrate, the dripping processing liquid will be scattered outside the substrate as the substrate rotates. The dripping processing liquid does not affect the central part of the substrate where a uniform film of processing liquid must be formed.

Then, after eliminating the influence of the processing liquid remaining in the nozzle port, the nozzle port is moved to the center of the substrate and a predetermined dropping operation is performed.

Therefore, a treatment liquid with stable properties can be accurately dropped, and uneven coating can be effectively prevented.

Additionally, in the past, the nozzle opening was fixed at the center of rotation of the substrate, and the entire amount of processing liquid required was dropped there.
In a configuration as in the present invention, in which the nozzle port is made movable and is further provided with a supply control means for controlling the amount of dropping (i.e., the amount of processing liquid supplied), dropping is performed while moving the nozzle,
However, in that case, it becomes possible to adjust the dropping amount to the most consistent amount corresponding to the position on the substrate.

As a result, it becomes possible to achieve uniform dispersion of the processing liquid with higher precision, and also to prevent excessive dripping and save on the amount of dripping.

[Example] The present invention will be described in detail below. In addition, in the example, the parts common to the conventional device shown in FIG. 7 are as follows.
The same reference numerals are used to omit the explanation.

1 to 3 show an embodiment of the invention according to claim 1. FIG.

As shown in FIG. 1, this spin coating device 10 includes a substrate 1
A substrate mounting table 2 for horizontally supporting the substrate 1 and rotating the substrate 1 in a horizontal plane, a processing liquid dripping nozzle 3 for dripping a processing liquid onto the surface of the substrate 1 on the substrate mounting table 2, It is equipped with a processing liquid supply device 4 for supplying processing liquid to a processing liquid dripping nozzle 3, and by rotating the substrate 1 onto which the processing liquid has been dropped, a thin film of the processing liquid is formed on the substrate surface. These points are the same as the conventional one.

However, the apparatus of this embodiment is provided with a nozzle moving device 11 for moving the position at which the processing liquid droplet is dropped by the processing liquid dropping nozzle 3.

The nozzle moving device 11 will be described in detail in relation to the substrate 1 and the processing liquid as follows.

The substrate 1 has a square shape (for example, a 5 x 5 inch square)
It is supported on the mounting table 2 so that its center is the center of rotation. In this embodiment, the processing liquid is a resist liquid, and specifically, AZ1350 (trade name of Hoechst Co., Ltd.), which is a positive type resist liquid, is used.

The nozzle moving device 11 holds the nozzle 3 and
It comprises an actuator 12 for moving the nozzle 3, and a telescopic pipe 13 that communicates the nozzle 3 with a pipe 7 to allow movement of the nozzle 3.

The actuator 12 has a function of reciprocating the nozzle 3 within a certain range, and in this case, a so-called rodless cylinder (more specifically, the CY series manufactured by Chokera, etc.) is used. This actuator 12 includes a movable part 12a that holds the nozzle 3, and a rod 12b that sets the moving direction and range of the movable part 12a.A stopper 12c is fixed to the end of the rod 12b. A stand 1 that is not fixed to the floor etc.
It is supported by 4.

This actuator 12 allows the nozzle opening 3a of the nozzle 3 to reciprocate on a diagonal line of the substrate 1, that is, on a straight line from one end A of the substrate 1 through the rotation center C to the other end B. .

Next, a procedure for applying a treatment liquid in the spin coating apparatus 10 configured as described above will be described in detail.

First, with the nozzle port 3a of the nozzle 3 positioned on the end A of the substrate 1 on the mounting table 2, inert gas is supplied to the chamber body from the waste supply/discharge port 8b of the pressurizer 8 of the processing liquid supply device 4. 8a (at this time, the pressure inside the container body 8a is 0.5 kg/-
), and at the same time as starting dropping of the processing liquid, the nozzle 3 is moved linearly toward the other end B on the substrate 1 at a speed of 60 cm/sec by the moving device 11. This movement is performed while keeping the amount of drops from the nozzle 3 constant.

Then, when it reaches the nozzle opening 3a or the end B, the dropping of the processing liquid is finished. The amount of drops from the start of dropping to the end of dropping is set at 5 CC/sec (dotted line m in FIG. 6) to ensure a sufficient amount to form a film even in the center of the substrate 1.

Thereafter, the mounting table 2 is rotated to diffuse the dropped processing liquid L to form a film with a predetermined thickness.

In the above-described spin coating operation, the dropping of the processing liquid, which causes uneven coating, starts and ends at the edge of the substrate 1. Therefore, even if the processing liquid remaining in the vicinity of the nozzle opening 3a accidentally drips down, it can be easily scattered out of the substrate 1 and removed by rotating the substrate 1 at the edge of the substrate 1. is completed, and the nozzle opening 3a
It is possible to prevent uneven coating caused by dripping of the treatment liquid remaining on the surface of the substrate. Further, since the nozzle 3 is moved through the rotation center between an end at the beginning of dropping and an end at the end of dropping which are opposite to each other.

Furthermore, a thin film with a uniform thickness can be obtained.

FIG. 4 and FIG. 5 show an embodiment of the invention according to claim 2.

This spin coating device 16 has a supply amount control means 1 to the processing liquid supply device 4 of the spin coating device 10 shown in FIGS. 1 to 3.
7 is added.

This supply amount control means 17 detects the amount of movement of the nozzle 3 by the nozzle moving device 11 and controls the supply amount of the processing liquid according to the dropping position of the processing liquid. Specifically, This is a flow rate control device that sets the amount of gas to be supplied and discharged at the waste supply and discharge port 8b of the pressurizer 8. The supply amount control means 17 controls the amount of processing liquid by adjusting the inert scum pressure so that the amount of processing liquid dropped at the edge of the substrate 1 is reduced, as shown by the solid line n in FIG. Control the amount of supply.

Note that in FIG. 4, reference numeral 18 is a signal line for detecting the amount of movement of the nozzle 3.

The procedure for applying the processing liquid using this rotary coating device 16 is to control the amount of the droplet while the nozzle port 3a moves from end A to B on the substrate 1 to the solid line n in FIG. 6 using the supply amount control means 17. This is the same as the spin coating apparatus 10 shown in FIG. 1, except that it is adjusted as shown.

However, according to the spin coating device 16, uneven coating can be prevented in the same way as the spin coating device 10 described above. and,
Furthermore, due to the nature of the spin coating method, it is possible to conserve the processing liquid by reducing the amount of the processing liquid dripped at the edges of the substrate 1, where excessive dropping is generally likely to occur. It is also possible to prevent unnecessary processing liquid from flowing around.

In this embodiment, the dripping amount of the processing liquid was controlled by controlling the inert gas pressure, but it is also possible to provide a supply amount control means in the pipe 7 itself connected to the nozzle 3. good.

Further, the processing liquid may be sent out using a pump or the like without relying on gas pressure.

Furthermore, even if the amount of drops from the nozzle 3 is kept constant and the amount of drops on the substrate 1 is adjusted by changing the moving speed of the nozzle 3, the amount of processing liquid can be similarly saved. can be achieved.

[Effects of the Invention] The spin coating apparatus according to the present invention is equipped with a nozzle moving device and the treatment liquid dropping nozzle can move freely on the substrate, so when starting and finishing dropping, the nozzle opening of the nozzle is It can be located at the edge of the board.

Therefore, even if the treatment liquid remaining near the nozzle drips onto the substrate, the dripped treatment liquid can be easily scattered off the substrate by rotating the substrate, effectively preventing uneven coating. I can do something.

In addition, by providing a supply amount control means that controls the amount of processing liquid dropped, the amount of processing liquid dropped can be adjusted to the optimal amount corresponding to the position on the substrate, and the uniform dispersion of the processing liquid can be achieved with higher precision. At the same time, it is also possible to prevent excessive dripping and save on the amount of dripping.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an embodiment of the first invention seen from the side, Fig. 2 is a plan view of the same, Fig. 3 is a view from the ■ arrow in Fig. 2, and Fig. 4 is a schematic diagram of the second invention. FIG. 5 is a schematic diagram of one embodiment seen from the side; FIG. 5 is a plan view of the same; FIG. 7
The figure is a schematic configuration diagram of a conventional spin coating device. 1... Board, 2... Board mounting stand, 3... Nozzle,
L...-15= Processing liquid, 4... Processing liquid supply device, 10... Rotary coating device, 11... Nozzle moving device, 12... Actuator, 16... Rotary coating device, 17 ...Supply amount control means.

Claims (2)

[Claims] (1) A substrate mounting table that horizontally supports a substrate and rotates the substrate in a horizontal plane, a processing liquid dripping nozzle for dropping a processing liquid onto the surface of the substrate on this substrate mounting table, and a processing liquid dripping nozzle for dropping a processing liquid onto the surface of the substrate on this substrate mounting table. a processing liquid supply device for supplying a processing liquid to a dropping nozzle, the spin coating device forming a thin film of the processing liquid on the surface of the substrate by rotating the substrate onto which the processing liquid has been dropped; 1. A spin coating apparatus comprising a nozzle moving device that moves a position at which a processing liquid is dropped by a processing liquid dropping nozzle between an end of the substrate and a center of rotation of the substrate. (2) The processing liquid supply device further comprises a supply amount control means for detecting the amount of movement by the nozzle moving device and controlling the supply amount of the processing liquid in accordance with the dropping position of the processing liquid. 1. The spin coating device according to 1.