JPH03256320A - Liquid material coating device on semiconductor substrate - Google Patents

Abstract

PURPOSE:To allow a coating film amount to remain on a semiconductor substrate and to recover the residue by so mounting the substrate as to block the opening window of a vessel having the window formed in a vertical flat surface, and bringing the surface of the substrate into contact with liquid material. CONSTITUTION:A vessel 10 has an opening window 11 having a slightly smaller diameter in a wafer shape at its sidewall. A wafer 13 is mounted in the window 11, liquid material 12 is supplied from a supply/discharge port 15, and so controlled that the liquid level 15 becomes above the window 11 of the vessel 10. Then, the material 12 is discharged to lower the liquid level from the window 11, thereby forming a coating film on the water 13. Or, a pressure relief tube 28 and a gas supply tube 29 at the sidewall of the vessel are added through a valve 27 at the top of the vessel 20 having an opening window 21 similarly to the above. A wafer 23 is mounted in the window 21, liquid material 22 is supplied, and when the liquid level 26 reaches the tube 28, the supply of the liquid is stopped, and the valve 27 is closed. Then, the vessel 20 is tilted, the wafer 23 is disposed horizontally, the air 30 is, for example, supplied from the tube 29 to the center of the wafer 23, an air region is extended to the entirety, and a coating film is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an apparatus for applying liquid films such as resist and SOG to the surface of a semiconductor substrate. As a method of applying SOG, etc., the method shown in FIG. 2 is used for boat fishing.

That is, as shown in FIG. 2(a), a semiconductor substrate (wafer) 1 is vacuum-adsorbed onto a spin chuck 2, and a resist 4 is dropped from a dropping nozzle 3. The resist 4 dropped onto the surface of the wafer 1 tends to flow and spread over the entire surface of the wafer 1.

Then, as shown in FIG. 1(b), the resist 4 spreads over the entire surface of the wafer 1, and even in this state, a resist film is formed. However, if the viscosity of the material is high, it is difficult to form a thin film.
Although it is used in the range of m, it becomes extremely thick at about 50 to 11001 J. This method is known as the so-called dispensing method, and is often used in processes other than wafer processes (for example, component-mounted printed circuit boards).

Next, in order to thin the resist 4, a spin code method is generally used in which the wafer 1 is rotated and a part of the resist 4 is removed, as shown in FIG. 1(c).

(Problem to be Solved by the Invention) However, in the spin code method described above, the wafer is rotated in order to control the film thickness, and the rate at which part of the dropped material is discarded due to centrifugal force is 90% of the total amount of dropped material.
This is extremely uneconomical. For example, 1500c
When applying p resist to a thickness of 10 μm on a 6-inch wafer, a drop amount of approximately 3-30% is required to spread the resist over the entire wafer, and the proportion remaining as a coated film is 5.7 of the dropped amount. It is only %.

The present invention eliminates the above-mentioned problems and provides an apparatus for applying a liquid material to a semiconductor substrate, in which the amount remaining as a coating film on the wafer surface becomes the amount of material dripped in the coating process, and the amount of dropped material that is discarded is eliminated. The purpose is to provide.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an apparatus for applying a liquid material to the surface of a semiconductor substrate, which includes a container having an opening window with at least one surface formed in a vertical plane. , a semiconductor substrate mounted so as to close an opening window of the container; a liquid material is supplied into the container, the liquid level is raised above the opening window, and the surface of the semiconductor substrate is immersed; A liquid level control means for lowering the liquid level of the material through the opening window is provided.

Further, in an apparatus for applying a liquid material to a surface of a semiconductor substrate, a container having an opening window formed in a vertical plane on one side, a semiconductor substrate mounted so as to close the opening window of the container, and an inside of the container a liquid level control means for supplying a liquid material to the container and raising the liquid level from the opening window to immerse the surface of the semiconductor substrate; and the container is in a sealed state;
A means for rotating the container so that the surface of the semiconductor substrate is facing downward, and a means for bubbling gas toward the center of the semiconductor substrate so that only the applied film remains on the surface of the semiconductor substrate are provided. This is what I did.

(Function) As described above, the present invention is an apparatus for applying a liquid material such as a resist to the surface of a semiconductor substrate, in which the substrate surface of the semiconductor substrate is installed vertically, and the liquid material is applied to the surface of the semiconductor substrate by raising and lowering the liquid level. or in contact with a liquid material, place the surface face down and place it horizontally, and bubble the gas toward the center of the semiconductor substrate, leaving only the applied film on the semiconductor substrate surface, and recovering the rest. Can be reused.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram of the operation of a liquid material coating apparatus showing a first embodiment of the present invention.

In the figure, 10 is a container that temporarily stores liquid material 12. The side wall of this container 10 has a wafer-shaped opening window 11, which is slightly smaller than the diameter of the wafer 13 (for example, 2 to 3 windows on one side).
M).

Therefore, first, when the inside of the container 10 is empty, the wafer 13 is mounted using a mounting jig (vacuum chuck) 14 or the like as shown in FIG. 15
The liquid level 16 is controlled to be above the opening window 11 of the container 10.

Next, as shown in FIG. 1(b), when the liquid material 12 is discharged from the supply/discharge port 15 and the liquid level is lowered below the opening window 11 of the container 10, the coating film 17 is deposited on the surface of the wafer 13. It is formed. That is, by raising and lowering the liquid level 16 in the direction of the arrow, repeated coating becomes possible.

In this embodiment, it is preferable to press the wafer 13 with a mounting jig 14 that covers the entire wafer 13 due to the back surface force, since the pressure when pressed will not be uneven.

Next, FIG. 3 is an explanatory diagram of the operation of a liquid material coating apparatus showing a second embodiment of the present invention.

First, as shown in FIG. 3(a), similarly to the above embodiment, a wafer-shaped opening window 21 is provided on the side wall of the container 20, and the opening is slightly smaller than the diameter of the wafer 23. It has a structure in which a pressure relief pipe 28 via an 0N10FF valve 27 is added to the upper part of the container 20 and an air supply pipe 29 is added to the side wall of the container.
1, the liquid material 22 is supplied from the feed pipe 25, and when the liquid level 26 reaches the inside of the pressure release pipe 2B, the liquid supply is stopped and the 0N10FF pulp 27 is closed.

Next, as shown in FIG. 3(b), the container 20 is knocked down, the wafer 23 is made horizontal, and air 30, for example, is supplied to the center of the wafer 23 from the air supply pipe 29, so that the air area expands and spreads over the entire area. state.

At this stage, the formation of the coating film 40 on the surface of the wafer 23 is completed. To continue coating, discharge the liquid material from the supply/discharge pipe 25 while supplying air from the air supply pipe 29,
When the liquid level is sufficiently lowered, the wafer 23 is removed and the container 20 is placed upright to return to its original state.

Next, FIG. 4 is a schematic diagram of the liquid supply and drainage system of the liquid material coating device.

As shown in this figure, a container 2 for temporarily storing liquid material
Opening window 2 for bringing the wafer 23 into contact with the liquid material
1, the wafer 23 is supported by the mounting jig 24, and the arrow A
Attach it in the direction of A pressure relief pipe 28, an air supply pipe 29, and a supply/discharge pipe 25 are connected to the container 20 via valves 51, 61, and 41.

Therefore, to explain the process flow step by step, first, after mounting the wafer 23 in the container 20, liquid material is supplied from the supply/discharge pipe 25, but the valve 61 is closed, and the valve 51 (in the case of three-way pulp and 2-way (selectable) is opened in the direction of route BC.

Next, the liquid material is transferred from the storage tank 42 to the pressurized pulp 46
The valve 41 and the valve 51 are closed when the liquid level rises in the container 20 and reaches the pressure release pipe 28. In this state, the inside of the container 20 is filled with a liquid material. Next, with the wafer 23 attached, the container 20 is rotated and made horizontal. At this time, the wafer is located horizontally on the upper side, and by opening the valve 61 and introducing air, for example, from the air supply pipe 29, the liquid level is raised from the wafer surface as shown in FIG. 3(b). The film is separated, and only the film-forming portion remains on the wafer surface. At this time, as shown in FIG. 4, the valve 41 is set to EF.
At the same time as air is introduced from the air supply pipe 45, the liquid material passes through the discharge path EF from the drain pipe 25, operates the pump 43, suctions and pressurizes it, passes through the filter 44, and then, It is returned to the storage tank 42.

When the liquid level is sufficiently lower than the wafer surface, close the valve 61, stop the air supply from the air supply pipe 29, and turn the valve 51 to B.
By opening in the direction of the G line (atmospheric pressure side), the air force 5 is introduced by the suction pressure of the pump 43, and the liquid is drained from the supply pipe 25. In addition, in Fig. 4, 52
is a filter.

Then, when the liquid is almost completely drained from the container 20, the wafer 23 is removed and the container 20 is put back into its original state, thereby entering a standby state.

With this configuration, materials other than the amount used for forming the applied film can be quickly recovered, filtered, and returned to the storage tank. In this case,
It is important to transport the liquid surface of the material without exposing it to the outside air as much as possible, to prevent contamination with dust and volatilization of solvent, and to maintain the properties of the material. In the case of conventional spin cords, the amount other than the amount applied to the coated film is scattered in the form of pine dew, so the solvent etc. evaporate and the quality deteriorates, making it impossible to recover and reuse.

Furthermore, in the case of the first embodiment, the coating is performed by raising and lowering the liquid level, and the thickness of the applied film is controlled by the solid component concentration of the liquid material, the viscosity, and the rate of drop of the liquid level. Depending on the material, "liquid dripping" tends to occur and the thickness tends to increase at the bottom of the wafer (due to the effect of gravity). In this case, as in the second embodiment, the wafer is held horizontally and the gas is pressed If the liquid surface is separated from the wafer by spreading it over the entire surface, the phenomenon of "liquid dripping" can be prevented.

Further, in the case of the second embodiment, unlike simply immersing the wafer in a liquid reservoir, when the wafer is set horizontally, the container is in a sealed state, and moreover, air is supplied from the air supply pipe 29. is supplied, so bubbles are first supplied from the center of the container, reach the center of the wafer, and then sequentially spread to the periphery. Therefore, the bubbles gradually spread the attached resist, forming a thin resist film. Here, since the bubble is sealed in a sealed container, the vapor pressure of the solvent is high, and the resist film on the wafer surface does not dry out during the process, making it possible to form a uniform thin film. can.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described above in detail, according to the present invention, the following effects can be achieved.

In the conventional spin code method, the amount of liquid material remaining as a film on the wafer surface is 5 to 10% of the dropped amount, and about 90% or more is currently wasted. Therefore,
According to the present invention, liquid materials other than the amount remaining on the wafer surface can be recovered so that the liquid materials that had to be discarded for film thickness control (El film formation) can be effectively used. By reusing and reusing the liquid material, the amount of liquid material used can be reduced compared to that of the traditional spin code method.
It can be suppressed to 710 or less.

Also, if you set the semiconductor substrate so that the surface is facing down,
Since the gas is bubbled toward the center of the semiconductor substrate, only the applied film remains on the surface of the semiconductor substrate.
A uniform thin film can be formed.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the operation of a liquid material coating apparatus showing a first embodiment of the present invention, FIG. 2 is a sectional view of a conventional liquid material coating process, and FIG. 3 is a diagram showing a second embodiment of the present invention. FIG. 4 is a diagram illustrating the operation of the liquid material applicator, and is a schematic diagram of the liquid supply and drainage system of the liquid material applicator. 10, 20... Container, 11.21... Opening window, 12
．． 22...Liquid material, 13.23...Wafer, 14
．． 24... Mounting jig (vacuum chuck), 15... Supply/discharge port, 16.26... Liquid level, 17.40... Coating film, 25... Supply/discharge pipe, 27... 0N10FF valve, 28...Pressure relief pipe, 29...Air supply pipe, 30...
Air, 41.51.61...Valve, 42...Storage tank, 43...Pump, 44...Filter, 45
...Air pipe, 46...Pulp for pressurization. (L:1)Cb)

Claims (2)

[Claims] (1) In an apparatus for applying a liquid material to the surface of a semiconductor substrate, (a) a container having an opening window formed in a vertical plane on at least one side; (b) a container mounted so as to close the opening window of the container; (c) After supplying a liquid material into the container and raising the liquid level through the opening window to immerse the surface of the semiconductor substrate, the liquid level of the liquid material is raised through the opening window. 1. An apparatus for applying a liquid material to a semiconductor substrate, comprising a liquid level control means for lowering the liquid material. (2) In an apparatus for applying a liquid material to the surface of a semiconductor substrate, (a) a container having an opening window formed in a vertical plane on one side, and (b) a device mounted so as to close the opening window of the container. a semiconductor substrate; (c) a liquid level control means for supplying a liquid material into the container and raising the liquid level from the opening window to immerse the surface of the semiconductor substrate; (d) the container. is in a sealed state, and the container is rotated,
A semiconductor substrate comprising means for setting the semiconductor substrate so that the surface thereof is facing downward; and (e) means for bubbling gas toward the center of the semiconductor substrate to leave only a portion of the applied film on the surface of the semiconductor substrate. liquid material application equipment.