JPH0616891Y2 - Ozone reaction processor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an ozone treatment for use in performing an ashing process or forming a film by reacting a solid surface such as a semiconductor wafer with an ozone-containing gas. Regarding the device.

(Prior Art and Problems Thereof) In the manufacture of integrated circuits, a wet process has conventionally been generally used to remove a photoresist from a semiconductor wafer.

The wet process is a method of removing a photoresist by washing a semiconductor wafer with a washing liquid such as caustic or organic solvent.

However, in this method, the photoresist cannot be completely removed, and the contamination of the wafer by the cleaning liquid is a problem that cannot be ignored.

In particular, these problems have come to be highlighted as the patterns of semiconductor wafers have become finer in recent years.

Therefore, an ashing process that uses oxygen plasma or an ozone-containing gas without using a cleaning liquid to remove the photoresist has attracted attention.

However, in the process using plasma, there is a problem that the integrated circuit formed on the semiconductor wafer is deteriorated by the electric charge from the ions contained in the plasma.

In the process using the ozone-containing gas, there is no problem that the integrated circuit formed on the semiconductor wafer is deteriorated by the electric charge from the plasma.

However, the apparatus used in this ozone ashing process has the following problems.

Since a metal ozonizer is generally used as an ozone generator, there is a problem that the metal inside the ozone generator is worn by ozone and is entrained in the reactor to contaminate the semiconductor wafer in the reactor.

Further, in the conventional ozone reaction treatment apparatus, usually only one ozone generator 1 is used and the voltage of the high-voltage power source of the ozone generator and / or the inflow rate of the mixed gas containing oxygen are changed to generate ozone. The amount of ozone generated and the ozone concentration were changed.

However, it was not possible to change the ozone concentration in a wide range by changing the voltage of the high-voltage power supply. Also,
With the method of changing the inflow rate of the mixed gas, the flow rate of the mixed gas must be reduced when producing an ozone-containing gas having a high ozone concentration.

Since ozone is highly active, it reacts with the semiconductor wafer and the like at the moment of contact with the surface of the semiconductor wafer and is consumed. Therefore, when the conventional ozone-containing gas disperser having a large number of concentric holes is used, the portion immediately below the opening such as a semiconductor wafer rapidly reacts with ozone and the bottom of the non-opening portion is used. There was a problem in that the part of was left unreacted and the state of the solid surface became non-uniform.

(Technical Means for Solving Problems) The present invention provides an ozone reaction treatment apparatus which does not have the above-mentioned drawbacks. That is, it is an ozone reaction treatment device for performing a reaction treatment by bringing a solid surface into contact with a gas containing ozone, wherein (a) the ozone generator is composed of a plurality of ozone generators at least the interior of which is made of ceramics. (B) these ozone generators are connected in series and / or in parallel, (c) at least one ozone generator high-voltage power supply circuit is independently openable and closable, and d) Concerning those having a configuration in which the outlet for ozone-containing gas is opened randomly.

The present invention will be described based on the embodiment shown in the drawings.

FIG. 1 shows an embodiment of the ozone reaction treatment apparatus of the present invention.

The cylinder 1 contains oxygen or a mixed gas containing oxygen (hereinafter, both are collectively referred to as an oxygen-containing gas).

The oxygen-containing gas in the cylinder 1 passes through the mass flow valve 2, and an ozone generator (hereinafter referred to as a ceramics ozonizer) 3a, at least the inside of which is made of ceramics,
It is led to 3b, 3c, and 3d.

The ceramics ozonizer may be made entirely of ceramics, or a ceramic coating layer may be provided only on the inner surface. Further, various oxides, nitrides, or carbides can be used for the ceramics. Of these, oxides are particularly preferable.

Ceramics ozonizer 3a, 3b, 3c, 3d
A part of the oxygen-containing gas from the cylinder 1 is ozonized.

The ceramics ozonizers 3a, 3b, 3c and 3d have high voltage power supplies 4a, 4b, 4c and 4d, respectively. Each high-voltage power supply can be opened and closed independently. Ceramics ozonizer 3a, 3b, 3c, 3d and high voltage power supply 4
Dotted lines between a, 4b, 4c and 4d indicate electrical connections.

Since the ceramics ozonizer 3 has excellent oxidation resistance, it is hardly worn by ozone contained in the ozone-containing gas.

Further, since a plurality of ceramics ozonizers 3 are connected, the ozone concentration of the ozone-containing gas can be adjusted depending on which of the ceramics ozonizers 3 is closed and the power supply voltage is applied.

For example, connect the ceramics ozonizer 3 in series,
By closing each high-voltage power supply circuit, the ozone concentration can be increased without reducing the flow rate of the ozone-containing gas.

On the other hand, by connecting the ceramics ozonizers 3 in parallel and closing each high-voltage power supply circuit, the flow rate can be increased without lowering the ozone concentration of the ozone-containing gas.

In the example shown in FIG. 1, four ceramics ozonizers 3a, 3b, 3c and 3d are connected in series two by two and are connected in parallel. However, the method of connecting a plurality of ceramics ozonizers is not limited to the example of FIG.

The ozone-containing gas discharged from the ozonizers 3a, 3b, 3c, 3d is guided to the reactor 6 through the filter 4.

Since the filter 4 is for preventing dust from the inside of the pipe from entering the reactor 6, it is desirable that the filter 4 is attached at this position. It is desirable that the filter material be made of an oxidation resistant material such as Teflon or ceramics.

The solid to be processed, such as a semiconductor wafer, is placed in the reactor 6
Inside, is contacted with ozone-containing gas and subjected to surface treatment such as ashing.

The ozone-containing gas leaving the reactor 6 is discharged through the ozone decomposer 8.

A vertical sectional view of the reactor 6 is shown in FIG. In the figure, reference numeral 12 is an ozone-containing gas disperser, and an outlet 10 is opened.

A solid 11 to be processed such as a semiconductor wafer faces the outlet 10. The solid 11 to be treated rests on a support 15. Normally, the rotating shaft 13 attached to the support base 15 is rotated by a motor (not shown) so that the solid 1
Rotate 1. However, the outlet 10 may be rotated if the solid 11 is too large to be rotated.

The air outlets 10 are opened randomly as shown in FIG. If the outlets 10 are opened in a regular shape such as concentric circles as shown in FIG.
A portion of the surface of No. 1 which is not exposed to the ozone-containing gas remains.

Further, it is preferable that the outlet 10 can be heated by a heating means (not shown). As such means, there is a heater embedded around the outlet 10. When the semiconductor wafer coated with the photoresist is ashed and the blow-out port 10 is soiled with the photoresist, the ozone-containing gas is blown out while heating the blow-out port 10 with a heater or the like embedded around it. By this method, the photoresist attached to the air outlet 10 is ashed and removed.

Reference numeral 14 is a means for heating the solid 11, and it is possible to use heater microwave heating, hot plate, lamp heating, or the like.

A bypass line 7 is provided in parallel with the reactor 6. The bypass line 7 is preferably adapted to be switched with the reactor 6 by switching valves 9a and 9b.

(Effect of the present invention) In the device of the present invention, the adjustment range of the ozone concentration of the ozone-containing gas is greatly expanded. Further, even when the ozone-containing gas having a high ozone concentration is generated, it is not necessary to reduce the flow rate of the mixed gas of the raw materials.

Further, by using the ceramics ozonizer for the ozone generator, the inner surface of the ozone generator is hardly worn by ozone, and the semiconductor and the like are not contaminated.

Further, when the holes of the ozone-containing gas blowout ports are arranged at random, it is possible to eliminate uneven treatment on the surface of the solid to be treated.

Further, when the bypass line is provided, the ozone-containing gas does not have to be stopped when the semiconductor wafer or the like is subjected to the ozone reaction treatment and then taken out of the reactor, so that the safety of the ozone reaction treatment device is enhanced. .

(Example of use) An example of use is shown below.

Use Example 1 In the ozone reaction treatment apparatus shown in FIG.
It was supplied to the ceramic ozonizer 3 at a flow rate of 0 / min. At this time, the high voltage power supply circuits of all four ceramics ozonizers 3 were closed. At this time, the ozone concentration supplied to the reactor 6 was 50,000 ppm.

Next, without changing the flow rate of oxygen, only two high voltage power supply circuits 3a and 3c out of the four ozonizers were closed. At this time, the ozone concentration was 27,000 ppm.

Further, when only the high voltage power supply circuit 3a of the four ozonizers was closed, the ozone concentration became 13000 ppm.

USE EXAMPLE 2 Using the ozone reaction treatment apparatus of FIG. 1, it was attempted to ash and remove the photoresist applied to the glass plate 11 having a side of 30 cm. Oxygen gas containing 50,000 ppm of ozone was supplied to the ozone distributor at a flow rate of 10 / min. As the ozone-containing gas disperser 12, one having a diameter of 43 cm and 400 outlets of 0.5 mm diameter opened randomly was used. The disperser 12 faces the glass plate 11 and is rotated at 6 rpm during the ozone reaction treatment.

It was found that the ashing at 250 ° C. for 60 seconds completely removed the photoresist on the glass plate and made the surface of the glass plate uniform.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of the ozone reaction treatment apparatus of the present invention. FIG. 2 is a schematic view showing an example of the arrangement of the ozone mixed gas outlets of the ozone reaction treatment apparatus of the present invention. FIG. 3 is a vertical sectional view of the reactor 6. 1: Oxygen or mixed gas cylinders containing oxygen 3a, 3b, 3c, 3d: Ceramics ozonizers 4a, 4b, 4c, 4d: High-voltage power supply 5: Filter 6: Reactor 7: Bypass line 9a, 9b: Switching valve 10: Outlet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication H01L 21/304 341 D 8831-4M

Claims (3)

[Scope of utility model registration request] 1. In an ozone reaction processing apparatus for carrying out a reaction process by bringing a solid surface into contact with a gas containing ozone, (a) at least the inside of the ozone generators 3a, 3b, 3c ... Is made of ceramics. (B) These ozone generators 3a, 3b, 3c ... Are connected in series and / or in parallel, and (c) Ozone generators 3a, 3b, 3c. ··· At least one of the high-voltage power supply circuits 4a, 4b, 4c, ... Is independently openable and closable, and (d) at least one of the support base 15 and the ozone outlet 10 is rotated. And (e), and the ozone reaction processing device, wherein the ozone outlet 10 is randomly provided. 2. The ozone reaction treatment apparatus according to claim 1, wherein a filter 5 is provided between the ozone generators 3a, 3b, 3c ... And the reactor 6. 3. The ozone reaction treatment apparatus according to claim 2, wherein a bypass line and a switching valve are installed in parallel with the reactor 6.