JPS62211920A - Apparatus for supplying resist liquid - Google Patents

Abstract

PURPOSE:To sufficiently remove bubbles from liquid, by passing the liquid through a throttle valve before supplying it to a deaerating filter. CONSTITUTION:Resist liquid 2 fed to a deaerating filter 10 rapidly and temporally decreases its pressure immediately after passing through a throttle valve, whereby minute bubbles in the resist liquid 2 are expanded. The deaerating filter 10 utilizes the fact that the resist liquid 2 containing bubbles and the resist liquid not containing bubbles have different specific gravities, so that the filter allows only the resist liquid 2 without bubbles to pass through. Thus, the resist liquid without bubbles is filtered by a filter material 11 and is dropped down onto a semiconductor wafer 5 through a discharge valve 13. In this manner, the resist containing bubbles therein is deaerated sufficiently by rapidly decreasing its pressure and the deaerated resist is dropped to be applied on the wafer. Accordingly, the wafer coated in this manner has no residual bubbles in the resist film.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a resist solution supply device used for applying a photoresist solution onto a semiconductor tool in the manufacture of semiconductor devices. .

(Prior Art) In a photolithography process, which is an important process in the manufacture of semiconductor devices, a photoresist solution is applied onto a semiconductor wafer. In this resist coating, it is necessary not only to coat the substrate with a uniform film thickness, but also to ensure that the film coated on the semiconductor wafer does not contain any air bubbles. That is, if a film is applied to Regime 1 on a semiconductor wafer while the resist solution contains air bubbles, the remaining air bubbles will not interfere with uniform application within the resist film, but the air bubbles will remain within the resist film.
It may also reduce the yield of photolithography processing.

However, in general, the manufacturing process of resist solution includes a pressure filtration process, etc., and air and nitrogen easily dissolve into the resist solution.Furthermore, the viscosity of the solutions from Regime 1 to 1 is high, and it is difficult to handle them. has the property of easily taking in surrounding gas, and therefore tends to contain bubbles.

Here, FIG. 2 shows a conventional resist liquid supply device. In FIG. 2, the resist liquid 2 in the resist liquid container 1 is sucked from a supply path 3 by a pump 4, and then supplied from a discharge nozzle 5 to the semiconductor wafer in an upward direction. Further, the wafer 6 is fixed on a rotary table rotated by a motor 7, and on the other hand, a foreign matter removal filter 8 is provided in the middle of the supply path 3 for simply removing foreign matter from the resist solution 2.
is provided. Note that the resist liquid container 1 is provided with an exhaust pipe 9.

However, when using such conventional equipment,
Since the bubbles in the resist liquid 2 are not removed at all, it is extremely difficult to eliminate uneven coating and form and cover the resist S with a uniform film thickness.

Therefore, a resist liquid supply device having a function of removing air bubbles in the resist liquid 2 has already been proposed by the applicant (Japanese Patent Application No. 60-286469). The liquid supply device is shown. This device is equipped with a defoaming filter 10 in place of the foreign matter removal filter 8 of the device shown in FIG. 2 above.

A filter 11 is installed in the defoaming filter 10, and the resist liquid 2, which has a high specific gravity because it does not contain air bubbles, sinks to the lower layer and passes through this defoaming filter 10, but because it contains air bubbles, the resist liquid 2 has a high specific gravity. There are four resist liquids 2 so that small portions of the resist liquid 2 accumulate in the soil layer, cannot pass through the defoaming filter 10, and are returned to the resist liquid container 1 through the reflux path 12. 41 In Fig. 3, numerals 13.1/l are both flow rate adjustment valves, which control the droplet IZ flow rate and the reflux flow rate J.
”ru.

However, although this device can remove relatively large air bubbles, it cannot remove minute air bubbles because they pass through the defoaming filter 10, resulting in uneven coating. It is difficult to sufficiently prevent τ and form a Regime 1 film with an extremely uniform film thickness.

(Problems to be Solved by the Invention) The conventionally proposed resist liquid supply device d is unable to remove minute air bubbles, and therefore does not have good characteristics for Regimes 1 to 2 fabric thickness.

The present invention has been made in consideration of the above circumstances, and it is an object of the present invention to provide a resist liquid supply device that can sufficiently prevent uneven coating and form a resist film with an extremely uniform thickness.

[Structure of the invention]

(Means for Solving the Problems) The resist liquid supply device according to the present invention uses a pump to suck the resist liquid from a resist liquid container containing the resist liquid and drop it onto a wafer. It is equipped with a throttle valve that makes even small air bubbles larger by reducing the pressure, and a filter that removes micro air bubbles by passing them through a defoaming filter.

(Function) The throttle valve used in J3 of the present invention applies a rapid pressure change to the resist liquid passing through it.

As a result, the gas component dissolved in the resist liquid becomes large bubbles and is removed by the defoaming filter, so that only the resist liquid without bubbles is supplied to the semiconductor wafer.

(Example) The present invention will be described below based on illustrated embodiments.

FIG. 1 shows an embodiment of a liquid supply device to the register 1.

In the drawings, parts that are the same or similar to those of the conventional device are given the same reference numerals, and the explanation thereof will be simplified or omitted.

In this device, a throttle valve 20 is provided between the defoaming filter 10 and the pump 4. Immediately after the resist liquid 2 heading toward the defoaming filter 10 passes through the throttle valve 20, the pressure is suddenly temporarily reduced, and as a result, minute bubbles in the resist liquid 2 expand. In this state, the resist liquid 2 is supplied to the defoaming filter 10, but as described above, the specific gravity of the resist liquid 2 varies depending on whether it contains air bubbles or not. Since this is a device that uses different characteristics to avoid passing only Regime 1 to Liquid 2 that do not contain air bubbles, the resist liquid that contains air bubbles that are generated and expanded due to reduced pressure flows into the reflux path 12 and passes through the recovery valve 1/'.
The flow rate is adjusted through 1 and collected in the container 1. on the other hand,
The resist solution containing no air bubbles is filtered by the filter material 11 and dripped onto the semiconductor wafer via the outflow valve 13. Since the semiconductor wafer 6 is rotated at high speed by the spindle 7, a uniform resist film A1 is formed on the semiconductor wafer 6. As described above, according to this embodiment, the dissolved bubbles are sufficiently degassed by rapidly reducing the pressure of the saw resist, and then the coating is performed by dropping the resist onto the semiconductor wafer, resulting in zero coating. There will be no residual air bubbles inside. Especially when the applied film is subjected to a subsequent process such as baking, the effect is small.

In the description of the above embodiments, the coating means is shown as a spinner that rotates the base, but the present invention is not limited thereto. Furthermore, in the above embodiment, the regime liquid containing air bubbles is returned to the resist liquid container through the reflux path, but it may be transferred to another container and forced defoaming by vacuum, etc. .

For example, it is of course applicable to other organic resins, inorganic liquids, etc.1゜[Effects of the Invention] As described above, according to the present invention, when the regimen l~ is supplied to the defoaming filter, it is squeezed. It is supposed to pass through the valve,
The microbubbles contained in the liquid become large bubbles due to the sudden pressure reduction, and the liquid containing the bubbles is sufficiently removed.
It is possible to provide a resist liquid supply device capable of forming a uniform and high quality liquid coating film on a semiconductor substrate.

[Brief explanation of drawings]

FIG. 1 is a front view showing the configuration of a resist liquid supply device according to the present invention 1111, and FIGS. 2 and 3 are front views showing a conventional resist liquid supply device. 1... Resist liquid container, 2... Regime 1~liquid, 3...
... Supply path, 4... Pump, 5... Discharge 1.6.
...tsu■-ha, 7... spin motor, 10... filter section for removing air bubbles, 11... filter material, 12...
Reflux path, 13.1/I...flow adjustment valve, 20...throttle valve. Applicant's agent Sato -Yu = 8 - Mo l Figure color 2 Feri 3 Figure

Claims (1)

[Scope of Claims] 1. A resist liquid container that stores a resist liquid, and a pump that sucks the resist liquid from the resist liquid container and causes the resist liquid to drip from a discharge port and supply onto a semiconductor wafer;
A defoaming filter provided in front of the discharge port to remove air bubbles in the resist solution; and a throttle valve that enlarges minute air bubbles contained in the resist solution directed toward the defoaming filter by a depressurizing action. and a discharge pipe for discharging the resist solution containing large bubbles that could not pass through the defoaming filter. 2. The resist liquid supply device according to claim 1, wherein the discharge pipe is connected to the resist liquid container.