JP3176349B2 - UV processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing contaminants on a substrate such as a semiconductor wafer using UV light.
It relates to a processing device.

[0002]

2. Description of the Related Art Conventionally, when a resist coating process or a cleaning process is performed on a substrate such as a semiconductor wafer, it is necessary to remove organic substances that contaminate the substrate surface. As a device for removing the contaminants, UV (Ultra Vio
let) UV that decomposes and desorbs organic pollutants by the action of light
There is a processing unit.

In a conventional UV processing apparatus, a wavelength of 300 n
m or less (high energy component: 399 kJ / mol or more)
Irradiation of UV light decomposes (disconnects covalent bonds between molecules) trace gas components such as resist solvent and HMDS that flow in from the atmosphere outside the chamber, and produces a sublimate as a source of dust. To create the basis.

FIG . 4 shows an example of a conventional UV processing apparatus. As shown in FIG. 1, a substrate loading / unloading mechanism such as a transport roller 5 is provided inside the chamber 1 as a transport unit for transporting the substrate 4 to be processed. Further, the chamber 1 is provided with an entrance 2 for loading and unloading the substrate 4 and an exhaust port 3 for discharging gas inside the chamber to the outside.

A UV generating lamp 6 is mounted on the upper part of the chamber 1 so that the substrate 4 to be conveyed is irradiated with UV light. It is configured to discharge dry air to the air.

According to the above-described conventional apparatus, the dry air discharged into the chamber 1 is supplied from the UV generating lamp
By irradiating V light, oxygen in the dry air is changed to ozone, and the ozone oxidizes and removes contaminants on the substrate 4. In addition, organic substances on the surface are separated and decomposed by UV light applied to the substrate surface.

As a specific example of this type of prior art, there is, for example, an apparatus disclosed in Japanese Patent Application Laid-Open No. 03-83338. This apparatus excites an ashing gas (oxygen gas containing ozone O3) by irradiating UV light, and blows this onto a substrate to remove a resist film. Japanese Patent Application Laid-Open No. 57-88003 discloses an ozone generation tube made of a material such as quartz through which oxygen can flow, and a UV light source for irradiating UV light around the ozone generation tube. An ozone generator has been disclosed.

[0008]

However, according to the above-described conventional UV processing apparatus, the atmosphere that enters the chamber from the outside through the entrance of the substrate provided in the chamber causes the high-energy component of the UV light. , Which reacts again to generate a sublimate (12) and contaminate the inside of the chamber.

Further, according to the apparatus disclosed in Japanese Patent Application Laid-Open No. 03-83338, since the UV light is hardly radiated to the substrate, the use efficiency of the UV light is reduced in order to remove the contamination on the substrate surface. Is extremely low. In addition, since high-energy components of UV light leak from the gas ejection holes, there is also a problem that a considerable amount of deposits (sublimates) are generated in the chamber. Further, Japanese Unexamined Patent Publication No.
According to the device disclosed in Japanese Patent Application Laid-Open No. 7-88003, there is also a problem that the utilization efficiency of UV light is extremely low.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a UV processing apparatus capable of removing contaminants on a substrate without generating deposits in a chamber.

[0011]

In order to solve the above-mentioned problems, the present invention has the following arrangement. That is, according to the first aspect of the present invention, the substrate conveyed in the chamber is
A UV processing apparatus for decomposing and removing contaminants on the substrate by irradiating the substrate with V light, the substrate having a substantially columnar shape, and extending in a direction perpendicular to a transport direction of the substrate. A UV light generating lamp provided above the transport path of
A glass tube provided so as to surround the V light generation lamp and having a hole as an ozone discharge port at a position facing the substrate, and a dry air supply tube for supplying dry air to the inside of the glass tube And comprising the glass tube
Ozone is generated inside and directed from the discharge port to the substrate
At the same time as the reaction inside the glass tube.
The UV light not given passes through the glass tube and passes through the substrate.
It is characterized in that the plate is irradiated .

According to the present invention, the dry air supplied from the dry air supply pipe is irradiated with UV light to generate ozone. This generation of ozone is limited to the inside of the glass tube. The generated ozone is ejected toward the substrate from a hole provided in the glass tube. At this time, the UV light that has not contributed to the generation of ozone passes through the glass tube and irradiates the substrate.

That is, in the vicinity of the UV generating lamp, ozone is generated from dry air (oxygen) using the high energy side of the UV light, and the ozone is sprayed on the substrate. Further, only the low energy side of the UV light is irradiated to the vicinity of the substrate brought into the atmosphere from the outside of the chamber. This suppresses the generation of dust such as sublimates based on the atmosphere components from the outside, and decomposes and removes the low binding energy components contaminating the substrate surface.

According to a second aspect of the present invention, there is provided a UV processing apparatus for irradiating a substrate conveyed in a chamber with UV light to decompose and remove contaminants on the substrate. A UV provided above the transport path of the substrate so as to extend in a direction orthogonal to the transport direction of the substrate.
A light generating lamps, the provided within the chamber to partition said substrate and said UV light generating lamp side, Oh
A glass plate on which a plurality of holes are formed as zon discharge ports ,
A said chamber interior which is partitioned by the glass plate and a dry air supply pipe for supplying oxygen to said UV light generating lamp side, the chamber inside of the Gala
Producing ozone in the upper region of the
While spraying from the discharge port toward the substrate, ozone
UV light on the long wavelength side that is not used for the generation of
And irradiates the substrate with light .

According to the present invention, the dry air supplied from the dry air supply pipe is irradiated with UV light to generate ozone. This generation of ozone is limited to the UV light generating lamp inside the chamber partitioned by the glass plate. The generated ozone is ejected toward the substrate from a hole provided in the glass plate. At this time, the UV light that has not contributed to the generation of ozone passes through the glass plate and irradiates the substrate.

That is, in the vicinity of the UV generating lamp, ozone is generated from dry air (oxygen) using the high energy side of the UV light, and the ozone is sprayed on the substrate. In addition, only the low energy side of the UV light is irradiated to the vicinity of the substrate brought into the atmosphere from outside the chamber. This suppresses the generation of dust such as sublimates based on the atmosphere components from the outside, and decomposes and removes the low binding energy components contaminating the substrate surface.

Further, the invention according to claim 3 is characterized in that:
A plurality of light generating lamps are provided along the direction of transport of the substrate, and the glass tube and the dry air supply tube are provided for each of the lamps.

The invention according to claim 4 is characterized in that the hole provided in the glass tube is formed in a slit shape along the longitudinal direction of the UV light generating lamp.

Further, the invention according to claim 5 is characterized in that:
A plurality of light-generating lamps are provided along the transport direction of the substrate.

The invention according to claim 6 is characterized in that the plurality of holes formed in the glass plate are formed so as to be dense near the UV light generating lamp.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. The UV processing apparatus according to the present invention aims at cleaning a substrate such as a semiconductor wafer, and divides the high energy side and the low energy side of UV light (ultraviolet light) to use the UV light efficiently. The purpose of the present invention is to prevent the generation of deposits inside the chamber due to proper use and side reactions. In each drawing, the same reference numerals are given to the same elements as those shown in FIG. 4 according to the above-described conventional technology.

Embodiment 1 FIG. 1 shows the first embodiment.
1 shows a configuration of a UV processing apparatus according to the embodiment. As shown in FIG. 1, a transport roller 5 as a transport unit for transporting a substrate 4 to be processed, an entrance 2 for loading and unloading the substrate 4, and a gas in the chamber are discharged to the outside in the chamber 1. Exhaust port 3 is provided.

The chamber 1 has a size of, for example, about 600.times.500.times.200 mm. The transfer speed of the transfer roller 5 is, for example, 50 minutes per minute.
It is set to about 0 to 1500 mm. The substrate 4 is carried in from one of the entrances 2 by the carrying rollers 5 and is carried in the chamber, and is carried out of the chamber through the other entrance 2. Further, the exhaust port 3 provided in the chamber 1 has a diameter of, for example, 50 mm, and is formed such that the distribution pressure of each exhaust port is, for example, about 10 mmH2O.

Above the transfer path of the substrate 4 inside the chamber 1 (inside the chamber 10), a UV light generating lamp 6, a dry air supply pipe 11 (for example, a purge pipe with a diameter of about 10 mm), quartz, etc. A glass tube 7 (for example, about 100 mm in diameter) is provided above the substrate transport path so as to extend in a direction orthogonal to the transport direction of the substrate 4. UV light is applied.

Here, as shown in detail in FIG. 2, the UV generating lamp 6 and the dry air supply pipe 11 are connected to the glass tube 7.
The UV-generating lamp 6 is surrounded by a glass tube 7. This glass tube 7 is made of, for example, quartz glass. The glass tube 7 has an ozone outlet 9 at a position facing the substrate 4 along the longitudinal direction of the UV generating lamp 6.
(For example, a slit-shaped hole having a width of about 3 mm) is provided.

The UV generating lamp 6 has, for example, a diameter of 30.
mm, a low-pressure mercury lamp of, for example, about 300 watts is used, for example, having a wavelength of 184.9.
nm (646.8 kJ / mol) to 435.8 nm (
274.4 kJ / mol) of UV light.

The dry air supply pipe 11 is disposed above the inside of the glass tube 7 so as to be substantially parallel to the UV generation lamp 6, and a dry air discharge port (for example, A hole having a diameter of about 3 mm) is provided, and about 50 to 100 liters per minute of dry air is discharged from each discharge port. Although not shown, the dry air supply pipe 11 is provided so as to communicate with the outside of the glass tube 7, and dry air is supplied from the outside to the inside of the glass tube 7 via the dry air supply pipe 11. ing.

In this embodiment, the above-mentioned UV generating lamp 6 and the dry air supply pipe 1 are provided inside the chamber 1.
1 are built in the glass tube 7 and attached at three locations along the transport path of the substrate 4.

Hereinafter, the first embodiment configured as described above will be described.
Will be described. First, the substrate 4 loaded into the chamber 1 from one of the entrances 2 is transported by the transport rollers 5. Dry air is supplied from the dry air supply pipe 11 to the inside 8 of the glass tube so that the dry air is blown onto the UV generating lamp 6.

Inside the glass tube 7 (inside the glass tube 8), the oxygen (O2) in the dry air is changed to ozone (O3) by the UV light emitted from the UV generating lamp 6. That is, in this region (the inside of the glass tube 8), the reaction of “O2 → 2O (oxygen in an excited state)” and the “O2
A reaction of “2 + O → O3” is performed. At the same time, “O3 → O2 + O (the above-mentioned reverse reaction)” by UV light having a wavelength of 200 to 300 nm (599 to 399 kJ / mol) centered on a peak wavelength of 250 nm (479 kJ / mol).
And the reaction of “O2 + O → O3” occurs.

These reactions were carried out using a low-pressure mercury lamp as the UV generating lamp 6 at 185 nm and 254 nm, respectively.
m (647, 471 kJ / mol). Here, for example, light having a wavelength of 254 nm has an absorption coefficient of about 130 in the air and is completely absorbed by dry air inside the glass tube 7 (according to Hartley's absorption spectrum).

By such a reaction, ozone is generated inside the glass tube 7 and UV light having a wavelength of 300 nm or less (399 kJ / mol or more) is absorbed by dry air. As a result, ozone is ejected from the ozone discharge port 9 of the glass tube 7 toward the substrate 4, and UV light having a wavelength of 300 nm or more (399 kJ / mol or less) that has not contributed to the reaction inside the glass tube 7 is generated. The light is emitted through the glass tube 7.

The ozone discharged from the ozone discharge port 9 is
As a result of oxidizing organic contaminants on the surface of the substrate 4, the gas is changed into water and carbon dioxide gas, and is discharged from the exhaust port 3 to the outside of the chamber. The UV light having a wavelength of 300 nm or more transmitted through the glass tube 7 has a low binding energy component of contaminants on the surface of the substrate 4 (such as molecular bonding by van der Waals force).
Contributes to the separation and decomposition of water and promotes the removal of contaminants on the substrate surface.

According to the first embodiment, the columnar UV
Since the light generating lamp 6 is used to eject ozone from the slit-shaped holes, it is possible to uniformly spray ozone on the surface of the substrate 4 and to uniformly irradiate UV light.

Embodiment 2 FIG. 3 shows a configuration of a UV processing apparatus according to the second embodiment of the present invention. This apparatus replaces the glass tube 7 shown in FIG. 1 with a quartz tube having a thickness of, for example, about 1 mm in the chamber 1 so as to vertically separate (divide) the UV generating lamp 6 side and the substrate 4 side. A glass plate 7a made of glass is provided.
On the entire surface of a, an ozone discharge port 9a having a diameter of 3
Micropores of about millimeters are formed. FIG.
Instead of the dry air supply pipe 11 shown in FIG.
Near the entrance inside the chamber 1 partitioned by
A dry air supply pipe 11a for supplying dry air containing oxygen is provided on the side where the V generating lamp 6 is provided.

The hole formed in the glass plate 7a is U
It may be formed so as to be dense near the V light generating lamp 6, or may be formed so as to be localized near the UV light generating lamp 6. Thereby, measures can be taken to prevent unreacted gas from leaking to the substrate side, and ozone can be efficiently generated from dry air.

According to the second embodiment, the chamber 1
Inside, ozone is generated from oxygen in dry air by UV light in the upper region of the glass plate 7a,
The high energy side of the light is absorbed. And the glass plate 7
Ozone is blown toward the substrate 4 from the ozone discharge port 9a, thereby oxidizing and removing contaminants on the surface of the substrate 4. The low energy component of the UV light passes through the glass plate 7a and is irradiated on the substrate 4 to separate and decompose contaminants on the surface of the substrate 4.

The UV according to the first or second embodiment
According to the processing apparatus, the UV light on the long wavelength side that is not used for generating ozone is applied to the substrate 4 and used for separating and decomposing low binding energy components of contaminants on the substrate. As a result of comparison of the amount of deposits generated with the conventional apparatus, in the conventional apparatus, white deposits (sublimates) were generated in about one week after cleaning the inside of the chamber, and the amount of generated dust increased. In the UV processing apparatus according to the present invention, generation of deposits was not observed even after one month of operation. Further, the contact angle with water on the substrate surface is the same as the conventional one, and therefore, the effect of cleaning the substrate surface with water does not deteriorate.

[0039]

As described above, according to the present invention, the following effects can be obtained. That is, according to the present invention, a short-wavelength U having high energy in the chamber is provided.
Since the region where V acts is limited, unintended (unintended) side reactions due to UV light can be suppressed, and the generation of deposits (sublimates) that cause dust in the chamber can be reduced. I can do it. Moreover, the reaction of converting oxygen into ozone by short-wavelength UV light can be efficiently performed. Therefore, contaminants on the substrate can be removed without generating any deposits in the chamber.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a UV processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing details around a UV generating lamp according to the first embodiment of the present invention;

FIG. 3 is a diagram illustrating a configuration of a UV processing apparatus according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a UV processing apparatus according to a conventional technique.

[Explanation of symbols]

1 ... chamber, 2 ... doorway, 3 ... outlet, 4 ... substrate,
5: conveying roller, 6: UV generating lamp, 7: glass tube, 7a: glass plate, 8: inside of glass tube, 9, 9a: ozone outlet, 10: inside of chamber, 11, 11a: dry air supply tube.

Claims (6)

(57) [Claims] 1. A UV processing apparatus for irradiating a substrate conveyed in a chamber with UV light to decompose and remove contaminants on the substrate, the UV processing apparatus having a substantially columnar shape, and a conveying direction of the substrate. A UV light generating lamp provided above the transfer path of the substrate so as to extend in a direction perpendicular to the substrate; and an ozone discharger provided so as to surround the UV light generating lamp and facing the substrate. A glass tube formed with a hole as an outlet, and a dry air supply tube for supplying dry air to the inside of the glass tube , wherein ozone is generated inside the glass tube and
Spout toward the substrate and inside the glass tube
UV light that did not contribute to the reaction in the part
A UV processing apparatus, wherein the UV light passes through the substrate and passes through the substrate . 2. A UV processing apparatus for irradiating a substrate conveyed in a chamber with UV light to decompose and remove contaminants on the substrate, the UV processing apparatus having a substantially columnar shape, and a conveying direction of the substrate. A UV light generating lamp provided above the transport path of the substrate so as to extend in a direction orthogonal to the substrate; and a UV light generating lamp provided in the chamber to partition the UV light generating lamp side and the substrate side. A glass plate having a plurality of holes formed as ozone discharge ports , and dry air for supplying oxygen to the UV light generating lamp inside the chamber partitioned by the glass plate. It includes a supply pipe, a, o in the upper region of the glass plate inside the chamber
Generates a zon from the ozone outlet toward the substrate
Long wavelength side not sprayed and used for ozone generation
UV light passes through the glass plate and irradiates the substrate.
UV processor, characterized in that it is. 3. The UV light generating lamp is provided in plural numbers along a direction in which the substrate is transported, and the glass tube and the dry air supply tube are provided for each of the lamps. Item 4. A UV processing apparatus according to Item 1. 4. The U according to claim 1, wherein the hole provided in the glass tube is formed in a slit shape along a longitudinal direction of the lamp for generating UV light.
V processing equipment. 5. The UV processing apparatus according to claim 2, wherein a plurality of the UV light generating lamps are provided along a direction in which the substrate is transported. 6. The UV processing apparatus according to claim 2, wherein the plurality of holes formed in the glass plate are formed so as to be dense near the UV light generating lamp.