JP2003311226A - Cleaning method and cleaning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning method and a cleaning apparatus for reducing the amount of a cleaning liquid to be used and cleaning the object to be treated to high cleanliness. <P>SOLUTION: This cleaning method comprises: the first step to convey a plate-like object 3 to be treated on a rack 5 by a conveying means and treat at least one side of the conveyed object 3 to impart hydrophilicity; the second step to form a liquid film 24a on the hydrophilicity-imparted side of the object 3; and the third step to clean the object 3 by irradiating the object 3 with the ultrasonic wave emitted from an ultrasonic oscillating surface 28c arranged in the vicinity of a spot which may come into contact with the film 24a formed on the hydrophilicity-imparted side of the object 3. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning processing method and a cleaning processing apparatus, and more particularly to a water-saving type cleaning processing method and a cleaning processing apparatus used for wet processing including cleaning, etching, development and peeling.

[0002]

2. Description of the Related Art Silicon substrates, liquid crystal display substrates, solar cell substrates, magnetic substrates, plastic package substrates, and other large-sized substrates (hereinafter also referred to as "substrates") from the viewpoint of cleaning of conventional techniques and fluid treatment of the surface. The problem is explained.

As a conventional cleaning processing apparatus, for example, there is one described in Japanese Patent Laid-Open No. 6-461. Below, FIG.
18 and FIG. 18, a conventional cleaning processing apparatus will be described. 17 is a cross-sectional view of the conventional cleaning processing apparatus as seen from the front, and FIG. 18 is a bottom view of the conventional cleaning processing apparatus shown in FIG.

As shown in FIG. 17, a cleaning processing device 130.
Is a case 1 having a substantially concave cross section and formed in a box shape in the longitudinal direction.
11, the ultrasonic transducer 115 arranged in the concave portion of the case 111, and the ultrasonic transducer 115, for example, at 950 kHz.
And an ultrasonic oscillator 116 that is driven by the ultrasonic signal.

The case 111 includes an upper case including a vibrating plate 111a of the ultrasonic vibrator 115 disposed in the recess, and an ultrasonic vibrator 115 provided so as to face the vibrating plate 111a.
And a lower case including a reflection plate 111b that is provided at an angle of θ (0 <θ <10 °).

The upper case and the lower case are bolts 12
1 and nut 122 are fastened and fixed via packing 119. Then, as also shown in FIG. 18, three cleaning liquid supply ports 112 are provided on the side surface of the lower case,
Two overflow outlets 114 provided on the side surface on the opposite side of the cleaning liquid supply port 112, a cleaning liquid outlet 126 formed in a longitudinal shape in the center of the reflection plate 111b, and a slit formed in the center of the cleaning liquid outlet 126. 125 and.

A rectifying plate 118 having a substantially L-shaped cross section is attached to one side of the packing 119. Baffle plate 1
A plurality of slits 120 are formed in the lower part of 18 and act as a member for rectifying.

Next, the operation of the cleaning processing device 130 will be described.

As shown in FIG. 17, when a cleaning liquid 124 such as ultrapure water or hydrogen water is supplied from the cleaning liquid supply port 112 into the case 111 in the direction of the arrow X, the cleaning liquid 124 is caused by the slit 120 of the straightening plate 118. It is rectified, flows as a laminar flow in the case 111, becomes uniform in shape along the cleaning liquid ejection port 113, and is ejected from the cleaning liquid ejection port 113 onto the workpiece 117. At this time, the ultrasonic transducer 1
The vibration plate 15 is driven by a voltage of a predetermined frequency.
Ultrasonic waves are radiated toward the reflection plate 111b, which is the bottom surface of the case 111, via the la 1a. Since the reflection plate 111b is inclined by a predetermined angle θ, the ultrasonic waves 123a and 123b reflected by the reflection plate 111b are repeatedly focused and finally converged on the cleaning liquid ejection port 113, and the ultrasonic wave deriving section 126 is also used. Is guided to the slit 12
The object 117 to be treated is irradiated with a strong ultrasonic cleaning liquid from 5.

Therefore, the conventional ultrasonic cleaning device 130 is
For example, a processed object 117 such as a semiconductor wafer or a glass substrate
By a conveying means (not shown) such as a roller,
It is configured to pass under the cleaning liquid ejection port 113 at a constant speed in the direction of the arrow Y for cleaning.

[0011]

However, the cleaning apparatus 1
Since 30 has a configuration in which the cleaning liquid 124 is ejected from the slit 125, the irradiation area of the cleaning liquid 124 excited by ultrasonic waves on the object to be processed 117 is extremely small, and in order to obtain a sufficient cleaning effect, Ultrasonic cleaning device 1
It is necessary to use a plurality of 30 together. as a result,
The cleaning liquid tends to be expensive and the cleaning liquid 124
The amount used is also relatively large. For example, 550 mm x 65
When cleaning a 0 mm × t0.7 mm square object to be treated with a cleaning liquid such as hydrogen gas saturated ultrapure water, a minimum of 25 to 30 L of cleaning liquid and rinse cleaning water is required to stably apply ultrasonic waves. / Min. The amount of the used liquid of about 25 to 30 L / min is because the frequency of the ultrasonic wave is increased and the width of the ultrasonic cleaning nozzle slit is reduced. Furthermore, when the size of the board increases,
Further, a large amount of cleaning liquid and rinse cleaning water are required.

When hydrogen gas-saturated ultrapure water is used as a cleaning liquid for cleaning by the cleaning processing device 130, a hydrogen gas-saturated ultrapure water production device capable of stably supplying a large amount of hydrogen gas-saturated ultrapure water. Is required. Therefore, inevitably, the electrode required for electrolysis of water becomes large, and the module (permeation membrane) for efficiently dissolving the gas (ozone, hydrogen) generated by electrolysis in the cleaning liquid also becomes large, The equipment is large and costly.

Further, in the cleaning processing apparatus 130, since the distance between the ultrasonic element (ultrasonic vibrator 115) and the object to be processed 117 is long, the ultrasonic power is greatly attenuated. MHz
For cleaning using ultrasonic waves in the vicinity of the band, 0.7 to 1.5M
Although ultrasonic waves of Hz are used, in the case of the lower limit range of 0.7 MHz, the influence of cavitation on the workpiece 117 is taken into consideration, and in the case of the upper limit of use of 1.5 MHz, cleaning, etc. Because the effective power that can be used for is not obtained. The effective power in the region of 1.5 MHz or higher is a circuit problem of the ultrasonic element, and as shown in FIG. 17, the ultrasonic element (ultrasonic transducer 115) and the workpiece 1 are processed.
This is because the distance to 17 is long and the attenuation of ultrasonic power is large.

Therefore, an object of the present invention is to provide a cleaning treatment method and a cleaning treatment apparatus which can reduce the amount of cleaning liquid used and can obtain high cleanliness.

[0015]

According to a first aspect of the present invention, there is provided a cleaning treatment method in which a plate-shaped object to be treated is conveyed on a gantry by a conveying means and at least one surface of the object is subjected to a hydrophilic treatment.
And a second step of forming a liquid film on the hydrophilic surface of the object to be treated, and an ultrasonic wave provided in the vicinity of the liquid film formed on the surface of the object to be treated. A third step of irradiating the object to be processed with ultrasonic energy from the oscillation surface and cleaning the object.

The hydrophilic treatment of the cleaning treatment method according to the present invention is light cleaning or ozone water cleaning.

The light cleaning of the cleaning method according to the present invention is performed by irradiating the object to be processed with ultraviolet rays by an excimer lamp or a low pressure mercury lamp.

The liquid film of the cleaning method according to the present invention comprises:
It is formed by hydrogen gas saturated ultrapure water.

The hydrogen gas saturated ultrapure water of the cleaning method according to the present invention has a hydrogen gas saturation concentration of 0.8 ppm or more.

The liquid film of the cleaning treatment method according to the present invention comprises:
It is mixed with air and applied from a two-fluid nozzle onto the hydrophilically treated surface of the object to be treated.

The object to be treated in the cleaning method according to the present invention is moved by the conveying means in the horizontal direction or the vertical direction for cleaning.

In the cleaning treatment method of the cleaning treatment method according to the present invention, as a fourth step, the object to be treated is dried by any one of IPA vapor drying, spin drying, Marangoni drying and air knife drying, or a combination thereof.

The cleaning apparatus according to the present invention comprises a transport unit for transporting a plate-shaped object to be treated on a gantry by means of a conveying means, a hydrophilic treatment unit for subjecting at least one surface of the object to be hydrophilically treated, and the aforementioned object. An ultrasonic cleaning unit including a cleaning liquid supply device that forms a liquid film on the hydrophilic surface of the object to be processed, and an ultrasonic vibration device provided near the liquid film formed on the surface of the object to be processed. Then, ultrasonic energy is applied to the object to be processed for cleaning.

The hydrophilic treatment unit of the cleaning treatment apparatus according to the present invention comprises an ultraviolet irradiation device or an ozone water cleaning device.

The ultraviolet irradiation device of the cleaning processing apparatus according to the present invention is performed by irradiating the object to be processed with ultraviolet light by an excimer lamp or a low pressure mercury lamp.

The liquid film of the cleaning apparatus according to the present invention is characterized by being formed by a hydrogen gas saturated ultrapure water supply apparatus.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a cleaning treatment method and a cleaning treatment apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an outline of a cleaning treatment apparatus according to the present invention. (A) shows a dry unit of a fourth step constituted by a spin dryer, and (b) shows a cleaning step of the fourth step. The dry unit is configured by an air knife, and FIG. 2 is a schematic explanatory view showing a transporting step of the cleaning processing apparatus according to the present invention.

As shown in FIGS. 1 and 2, the cleaning processing apparatus 1 includes a hydrophilic processing unit 10, an ultrasonic cleaning unit 20, a dry unit 30, on a pedestal 5 formed in a longitudinal direction.
Moreover, it has the brush unit 40 as needed.

According to the present invention, the organic substances adhering to the surface of the substrate 3 are removed by the ultraviolet rays 14 to improve the wettability and the particles are removed by ultrasonic waves. That is, in the first step, by irradiating the substrate 3 with the ultraviolet rays 14 or washing with ozone water, organic substances are decomposed and separated from the surface of the substrate 3, and the organic substances attached to the surface of the substrate 3 decrease. A hydrophilic treatment is performed by utilizing the fact that it becomes hydrophilic (becomes wettable). When hydrogen gas-saturated ultrapure water is supplied to the substrate 3 in the second step, the hydrogen gas is saturated on the substrate 3 easily with a small amount of liquid because the hydrophilic treatment (wettability) is performed in the first step. The liquid film 24a of the ultrapure water 24 can be formed. Further, in the third step, since the ultrasonic wave oscillating surface 28c is provided in the vicinity where the liquid film of the hydrogen gas saturated ultrapure water 24 formed on the substrate 3 can be contacted, the ultrasonic power is attenuated. In combination with the use of hydrogen gas-saturated ultrapure water as the cleaning liquid, a high cleaning effect can be obtained, and ultrasonic power can be applied to the substrate 3 with a small amount of liquid.
Can be propagated to.

As shown in FIGS. 1 and 2, the substrate 3 is provided on the back surface of the substrate 3 which is a thin plate-like and rectangular-shaped object to be processed.
A drive roller 2 for holding and transporting in the horizontal direction is disposed as a transporting unit (transporting unit) at a predetermined interval along the longitudinal direction of the gantry 5. The present invention wets the surface of the substrate 3 to form a liquid film before irradiating the ultrasonic wave, and irradiates with the ultrasonic wave. The liquid film is formed with a small amount of hydrogen gas saturated ultrapure water or ultrapure water. As a first step of the cleaning treatment method, optical cleaning is performed and hydrophilic treatment is performed so that the cleaning liquid 24 such as pure water can be used. The hydrophilic treatment performed in the first step is a step before the hydrogen gas saturated ultrapure water 24 is supplied to the substrate 3 in the second step to form the liquid film 24a. It means that the surface of the substrate 3 is rendered hydrophilic (wettability) by decomposing and peeling off the organic contaminants adhering to the surface of the substrate 3 by irradiating with or cleaning with ozone water.

As shown in FIGS. 1 and 2, the ultraviolet irradiation device 11 irradiates the front and back surfaces of the substrate 3 conveyed by the rotational driving of the driving roller 2 with the ultraviolet rays 14. Light cleaning by this ultraviolet irradiation, by light and active oxygen species,
Although it is possible to remove organic contaminants, it is generally performed by irradiating the substrate with ultraviolet rays using a low pressure mercury lamp (not shown) or an excimer lamp 12 (shown in FIG. 3). Both excimer lamps or low pressure mercury lamps can be used. Irradiating ultraviolet rays to oxygen-containing air or oxygen gas to generate ozone, generate active oxygen species that is a decomposition gas of ozone from this ozone, and contact the substrate to cut organic substances on the substrate, Further, oxygen molecules existing around the substrate are bonded to atoms such as carbon that is cut by being converted to an active oxygen species by receiving ultraviolet rays, and become carbon dioxide gas or the like to be decomposed and peeled off from the substrate.

The ultraviolet irradiation 11 is arranged in pairs in a vertical direction through the substrate 3 corresponding to both front and back surfaces of the substrate 3, but when cleaning is performed on only one side, only one side is processed. However, when cleaning both sides of the substrate 3, it is preferable to irradiate both the front and back sides. Further, the ultraviolet irradiation device 11 may be arranged on only one side. The amount of the ultraviolet rays 14 to be irradiated can be set as appropriate depending on the transport speed and the type of substrate, but is 10 to 200 mJ / cm ²
It is preferable that the strength is within the range.

FIG. 3 is a diagram showing an example of the excimer lamp 12. As shown in FIG. 3, the excimer lamp 12 is
A discharge gas 12c such as xenon is sealed in the space between the inner cylindrical tube 12a and the outer cylindrical tube 12b made of quartz glass, and a high voltage is applied between the electrodes 12e1 and 12e2 provided inside and outside by an AC power supply 12d. , By this, ultraviolet rays 14
Radiates. That is, quartz glass, which is a dielectric to which a high voltage is applied, generates a minute discharge 12f by dielectric barrier discharge (silent discharge), and the energy thereof excites and bonds the discharge gas 63 enclosed inside, The gas molecules in the excited state emit light of a wavelength peculiar to the gas in the process of returning to the ground state.

The ultraviolet rays 14 emitted from the excimer lamp 12 generate ozone and characteristic oxygen species by the photochemical reaction in the atmosphere containing oxygen on the substrate 3 and bring them into contact with the surface of the substrate 3, Further, the ultraviolet rays 14 are directly applied to the substrate 3, and the cleaning or modification of the surface of the object to be processed is achieved by these cooperative operations.

That is, as a principle of light cleaning, oxygen O ₂ absorbs ultraviolet rays to generate ozone O ₃ . The generated ozone is decomposed to generate active oxygen O ( ¹ D). Ozone and active oxygen generated in these processes have the ability to oxidize contaminants adhering to the substrate surface. O ₂ + hv → O ( ³ P) + O ( ³ P) O ₂ + O ( ³ P) → O ₃ → O ₂ + O ( ¹ D) Also, the energy of ultraviolet light itself is very high, and the binding energy of many organic compounds. And break the bond. Organic substances are decomposed and oxidized by the combined action of these, and are scattered and removed from the substrate surface as water (H ₂ O) or carbon dioxide (CO ₂ ).

Further, the light having a wavelength of 172 nm emitted from the excimer lamp 12 is absorbed by oxygen molecules. The oxygen molecule absorbs light below a wavelength 175 nm, immediately generate excited like active oxygen O (1 ^D). O ₂ + hv (172 nm) → O ( ¹ D) + O ( ³ D) Therefore, active oxygen is efficiently generated, and ultraviolet rays of 172 nm, which is a shorter wavelength, excels in chemical bond cleavage of pollutants. Can perform light cleaning.

By irradiating the substrate 3 with the ultraviolet rays 14, the organic substances adhering to the substrate 3 are decomposed and peeled to be reduced, and as the organic substances are reduced (wettability is increased), the contact angle is decreased and the hydrophilic property is increased. Rises (hydrophilic treatment is performed). Therefore, in the present invention, the organic matter is removed by the ultraviolet rays 14 to improve the wettability, and the particles are removed by ultrasonic waves.

FIG. 15 shows an example in which how the surface condition of the substrate changes depending on the presence or absence of the ultraviolet treatment. FIG. 15 is a diagram showing a contact angle evaluation with and without UV treatment on a glass substrate. When treated with ultraviolet rays, the organic substances and the like adhering to the surface of the substrate 3 are decomposed, and the surface generally becomes hydrophilic. Since the hydrophilic surface has high wettability, the contact angle becomes small. (5 ° or less) Therefore, in order to confirm the effect of the ultraviolet ray treatment, the contact angle of the substrate surface was measured to examine how the wettability of the substrate surface changed. The result is shown in FIG.
Was confirmed to have a smaller contact angle.

The hydrophilic treatment in the first step can also be carried out by performing ozone water cleaning for removing organic substances and metals with ozone water having a high oxidizing power, instead of optical cleaning by irradiation with ultraviolet rays 14. . There is a correlation between the reduction of organic contaminants on the surface of the substrate and the hydrophilicity. By cleaning with ozone water, the organic substances on the surface of the substrate are reduced, and thus the contact angle is reduced (wettability is increased). Hydrophilic treatment is performed. When cleaning with ozone water as the first step, it is intended to reduce organic substances on the surface of the substrate and increase hydrophilicity, and a large amount of liquid is required as in the case of cleaning with only ozone water. Instead, a small amount of liquid that can be hydrophilically processed is sufficient.

By cleaning with ozone water as the first step,
When hydrophilic treatment is performed, ozone gas and hydrogen gas can be simultaneously produced by water electrolysis, so ozone water and hydrogen gas that are subjected to hydrophilic treatment are dissolved in ultrapure water through the gas dissolving module, respectively. Then, both liquids of hydrogen-saturated ultrapure water which are supplied to the substrate 3 to form a liquid film in the second step can be manufactured by one facility.

After the hydrophilic treatment in the first step, the substrate 3 is transferred by the driving rotor 2 to the second step, that is, the hydrogen gas saturated ultrapure water supply step. As shown in FIG. 1, after passing through the hydrophilic treatment unit 10 in the first step, the substrate 3 is transferred to the ultrasonic cleaning unit 20 that performs the second step and the third step.

If necessary, the brush unit 40 is arranged before the third step, and the protrusions 42 provided on the rotary brush 41 cause particles that cannot be completely cleaned by the ultrasonic cleaning in the third step. Can also be removed. Figure 2
In the embodiment of the present invention, as shown in FIG. 5, the second step is the step of supplying the hydrogen gas saturated ultrapure water 24 onto the substrate 3 to form the liquid film 24a, and the ultrasonic cleaning with the rotary brush 41. Then, particles that cannot be cleaned are removed in the same process to enhance the cleaning effect. In order to form the liquid film 24a on the substrate 3 before the ultrasonic cleaning in the third step, the hydrogen gas saturated ultrapure water supply device 21 is arranged, and in this embodiment, the hydrogen gas saturated ultrapure water is supplied. Since the brush unit 40 is provided in the step of supplying the hydrogen gas saturated ultrapure water 24 onto the substrate 3 by the water supply device 21, the hydrogen gas saturated ultrapure water 24 is supplied onto the substrate 3 to form the liquid film 24. Rotation of the hydrogen gas saturated ultrapure water 21b and the brush unit 40, which replenish the liquid film 24a with the hydrogen gas saturated ultrapure water 24 before ultrasonic cleaning with the hydrogen gas saturated ultrapure water supply device 21a and the ultrasonic excitation device 26. A hydrogen gas saturated ultrapure water supply device 21c for supplying the hydrogen gas saturated ultrapure water 24 to the brush 41 to wet the rotating brush 40 itself is provided. When the liquid film 24a is formed on the substrate 3 by the hydrogen gas saturated ultrapure water supply device 21a and the particles on the surface of the substrate 3 are removed by the rotating brush 41, the hydrogen gas saturated ultrapure water supply device 21 is used.
b, the rotary brush 41 itself is replaced with hydrogen gas saturated ultrapure water 2
4 enhances the cleaning effect, and compensates for the decrease in the hydrogen gas-saturated ultrapure water 24 dropped from the substrate 3 during the transportation to the third step of ultrasonic cleaning by the hydrogen gas-saturated ultrapure water supply device 24c. .

The ultrasonic cleaning unit 20 is composed of a hydrogen gas saturated ultrapure water supply device 21b which constitutes the second step and an ultrasonic excitation device 26 which performs the third step.

As shown in FIGS. 2, 5 and 6, in order to enhance the ultrasonic cleaning effect in the third step and prevent the liquid amount of the liquid film 24a formed on the substrate 3 in the previous step from being insufficient. In front of the ultrasonic excitation device 26, the hydrogen gas saturated ultrapure water supply device 2
1b is installed. This is to prevent the ultrasonic wave from propagating to the substrate 3 because the liquid film 24a does not come into contact with the oscillation surface 28c of the ultrasonic wave excitation device 26 due to insufficient liquid volume.

The first method of supplying this hydrogen gas saturated ultrapure water
An example of is shown in FIG. 5 and FIG. Hydrogen gas-saturated ultrapure water 24 is previously manufactured (not shown), and for example, a plurality of openings 21 are formed.
Hydrogen gas saturated ultrapure water 24 is jetted toward the substrate 3 from the jet pipe 21 in which a is formed toward the substrate 3, and is supplied to both front and back surfaces of the substrate 3. As shown in FIG. 5, the jet pipe 21 has a structure in which the entire surface of the substrate is wet with the hydrogen gas-saturated ultrapure water 24. Since the hydrophilic treatment is performed in the first step, the hydrogen gas-saturated ultrapure water 24 is easily adapted to the substrate 3, and the liquid film 24a can be easily formed with a small amount of the hydrogen gas-saturated ultrapure water 24.

FIG. 6 (b) is a diagram showing a second example of the method for supplying hydrogen gas saturated ultrapure water. As shown in FIG. 6, a plurality of two-fluid nozzles 21b that mix air and water and atomize are installed toward the substrate 3, and a fine mist is jetted onto the substrate 3 instead of a jet pipe. When the two-fluid nozzle 21b is used, not only hydrogen gas-saturated ultrapure water but also air is jetted and hydrophilic treatment is performed in the first step, so that the hydrogen gas-saturated ultrapure water 24 is easily adapted to the substrate 3 and a small amount of hydrogen is used. In addition to the fact that the liquid film 24a can be easily formed from the gas-saturated ultrapure water 24, the substrate (550 mm
X 650 mm x t 0.7 mm), the flow rate is 5 L / mi
It is possible to suppress it to n or less, and it is possible to significantly reduce the amount of hydrogen gas saturated ultrapure water used. In addition, the cleaning liquid itself has a cleaning effect by being sprayed from the two-fluid nozzle 21b.

As the cleaning liquid 24 supplied to the substrate 3, hydrogen gas-saturated ultrapure water, which is evaluated to be highly effective in removing particles adhering to the substrate 3 when combined with ultrasonic irradiation, is used. As a matter of course, pure water, hydrochloric acid, ammonia, hydrofluoric acid, hydrogen peroxide solution, ozone water, alkaline aqueous solution, chemical solution having oxidizing power or reducing property, or anion system may be used. A solution that enhances the ultrasonic cleaning effect is particularly preferable.

As an example of cleaning evaluation with hydrogen gas-saturated ultrapure water, the substrate used was an 8-inch silicon substrate (bare silicon), and the surface was previously contaminated with an abrasive such as a slurry with particles. The contaminated substrates were washed with pure water, degassed water, and hydrogen gas-saturated ultrapure water in combination with ultrasonic waves of 1 MHZ. As a result, as shown in FIG. 12, the order was hydrogen gas saturated ultrapure water> deaerated water> pure water. From this result, it is clear that the cleaning effect of hydrogen gas saturated ultrapure water is high.

Further, the supplied hydrogen gas-saturated ultrapure water 24
The flow rate depends on the transfer speed and the size of the substrate 3, but is preferably 5 L / min to 50 L / min. Further, the saturated concentration of hydrogen gas in the hydrogen gas-saturated ultrapure water is preferably 0.8 ppm or more in consideration of the effect of removing particles.

As apparent from FIGS. 2 and 5, the second
When the hydrogen gas saturated ultrapure water 24 is supplied to the substrate 3 and the liquid film 24a is formed in the step (3), ultrasonic waves are transmitted from the ultrasonic exciter 26 to the substrate 3 through the liquid film 24a in the third step.

The ultrasonic excitation device 26 shown in FIG. 5 will be described.

The ultrasonic excitation device 26 is formed into a rectangular parallelepiped waveguide 28 and a rectangular plate shape, and the waveguide 2 is formed on one side.
8 is an upper surface of the waveguide body 28, which has a vibrator 27 coupled to 8 by an adhesive or the like, and an oscillator (not shown) that applies a voltage of a predetermined driving frequency to the vibrator 27. The structure is used such that the surface facing the surface having the vibrator 27, that is, the oscillating surface 28c that oscillates ultrasonic waves is on the lower side.

The oscillation surface 28c is provided near the liquid film 24a formed on the substrate 3 so as to be in contact therewith. In the embodiment according to the present invention, it is selected to be 2 mm or less, and is arranged so as to be parallel to the surface of the plate-shaped substrate 3.

The vibrator 27 is a PZT (piezoele).
The electrode plate 27a and the electrode plate 27b are adhered to both surfaces of the (ctric: piezoelectric) element, and a part of the electrode plate 27b on the lower surface side is folded back to the upper surface side without contacting the electrode plate 27a. It is a part 27c. Further, the length and width of the vibrator 27 are set to be substantially equal to the length L and width W of the waveguide 28, and the electrode portion 27c and the electrode plate 27 are set.
A pair of power transmission wires 29 that apply a voltage of a predetermined driving frequency from an oscillator (not shown) are connected to the predetermined positions of a, respectively.

When a voltage of a predetermined driving frequency is applied to the vibrator 27 by an oscillator (not shown),
Ultrasonic vibration of this frequency is generated.

The waveguide 28 resonates with the ultrasonic vibration generated by the vibrator 27 and acts as a member for transmitting the ultrasonic vibration to the liquid film 24a of the previously formed hydrogen gas saturated ultrapure water 24. To do.

Next, the operation of the ultrasonic excitation device 26 will be described. First, when a voltage of a predetermined driving frequency is applied to the vibrator 27 from an oscillator (not shown), the vibrator 27 is excited and ultrasonic vibration of this frequency is generated. Then, the generated ultrasonic vibration passes through the waveguide 28,
It is configured to be transmitted to the liquid film 24a of the hydrogen gas-saturated ultrapure water 24 supplied as an external load below the waveguide 28.

Oscillation surface 28 of waveguide 28 for supplying ultrasonic waves
c is provided in the vicinity of the liquid film 24a formed on the substrate 3 so as to be in contact therewith, and is selected to be 2 mm or less in the embodiment of the present invention. Therefore, the distance between the ultrasonic transducer 27 and the substrate 3 is short. The attenuation of ultrasonic power is small, and the resonance frequency of the ultrasonic element is 15 kHz to 3 MHz.

In the ultrasonic excitation device 26, if the hydrogen gas-saturated ultrapure water 24 is not supplied as an external load to the lower part of the oscillation surface 28c, the substrate 3 as the object 3 to be processed such as a glass substrate.
On the other hand, ultrasonic vibration is not transmitted.

The gap between the surface of the substrate 3 and the oscillation surface 28c, that is, the separation distance is set to about 2 mm or less, and the substrate 3
The arrow X (Fig.
(Shown in FIG. 2) in the transport direction.

Therefore, hydrophilic treatment is performed in advance in the first step, and hydrogen gas saturated ultrapure water 24 is applied to the substrate 3 during the second step.
Since the liquid film 24a is supplied above and the liquid film 24a is formed by the action of surface tension, the gap between the surface of the substrate 3 and the oscillating surface 28c contacts through the liquid film 24a, and ultrasonic vibration from the vibrator 27 is generated. It is transmitted to the substrate 3. Therefore, the ultrasonic exciter 26 can clean the substrate 3 by the action of the liquid film 24 a of the hydrogen gas saturated ultrapure water 24.

In the above-described embodiment, the ultrasonic cleaning units 20 are arranged in a pair vertically corresponding to both front and back surfaces of the substrate 3, with the substrate 3 interposed therebetween. When the cleaning is limited to one side instead of both sides, the cleaning may be performed by forming the liquid film 24a only on the cleaning side, or the ultrasonic cleaning unit 20 may be arranged only on one side. is there. Correspondingly, the ultraviolet irradiation in the first step may be performed on only one side or the ultraviolet irradiation device 11 may be arranged on only one side.

Further, as shown in FIG. 2, depending on the size of the substrate 3, the particle attachment rate, and the required cleanliness,
A plurality of ultrasonic cleaning units 20 are installed for cleaning.
However, the same number of hydrogen gas-saturated ultrapure water supply devices 21 are installed in each ultrasonic excitation device 26 according to the number of ultrasonic excitation devices 26 installed.
It is not necessary to supply the hydrogen gas saturated ultrapure water 24 to the substrate 3 to form a liquid film in front of the substrate, and if the liquid film is formed in the previous step, the second and subsequent ultrasonic excitation devices Two
A configuration in which the hydrogen gas saturated ultrapure water supply device 21 is not provided in front of 6 is also possible. Further, the same number of hydrogen gas saturated ultrapure water supply devices 21 depending on the number of installed ultrasonic exciters 26.
Is installed in front of the ultrasonic excitation device 26, or a plurality of hydrogen gas saturated ultrapure water supply devices 21 are installed,
When omitting a part of the hydrogen gas-saturated ultrapure water supply device 21, the same amount of hydrogen gas saturated as the hydrogen gas-saturated ultrapure water supply device 21 installed in front of the first ultrasonic vibration device 26 is saturated. It is not necessary to supply ultrapure water, and ultrasonic excitation device 2
It is also possible to reduce the amount of hydrogen gas-saturated ultrapure water supplied from the second or subsequent hydrogen gas-saturated ultrapure water supply device 21 installed between the ultrasonic wave excitation device 26 and the ultrasonic excitation device 26, and supply supplementally. It is possible.

When three ultrasonic exciters 26 are installed below, a hydrogen gas saturated ultrapure water supply device 2 is provided in front of all three ultrasonic exciters 26.
In the case where 1 is added (condition 1), the hydrogen gas saturated ultrapure water supply device 21 is installed before the cleaning result of the second ultrasonic wave excitation device 26.
The result of cleaning in the case of omitting without adding (condition 1) is shown.

FIG. 7 is a diagram showing a state where three ultrasonic excitation devices 26 are installed and hydrogen gas saturated ultrapure water supply devices 21 are added in front of all three ultrasonic excitation devices 26. FIG. 8 shows ultrasonic excitation devices. When three devices 26 are installed, a view showing a state in which the hydrogen gas saturated ultrapure water supply device 21 is omitted without being added in front of the second ultrasonic excitation device 26, and FIG. 9 is the cleaning in the case of FIG. 7. FIG. 10 is a table showing the results, FIG. 10 is a table showing the cleaning results in the case of FIG. 8, and FIG. 11 is a graph showing a comparison of the cleaning results shown in FIGS. 9 and 10.

As is clear from FIGS. 9 to 11, when three ultrasonic exciters 26 are installed, and hydrogen gas saturated ultrapure water supply devices 21 are added in front of all three (condition 1). When the hydrogen gas saturated ultrapure water supply device 21 is not added in front of the second ultrasonic excitation device 26 and is omitted (condition 2), it is apparent that there is no difference in the cleaning result. Therefore, the same number of hydrogen gas-saturated ultrapure water supply devices 21 are installed in front of the ultrasonic excitation devices 26 according to the number of the ultrasonic excitation devices 26 installed, and the hydrogen gas saturated ultrapure water 2 is installed.
It is not necessary to supply 4 to the substrate 3 to form a liquid film, and as long as the liquid film is formed, the second and subsequent ultrasonic excitation devices 26 are provided with the hydrogen gas saturated ultrapure water supply device 21. A configuration not provided is also possible.

13 to 15 show cleaning evaluation examples of the cleaning method and cleaning apparatus according to the present invention. Figure 13
FIG. 14 is a diagram showing particle results with and without UV treatment on the base glass substrate, and FIG. 14 is a diagram showing particle results with and without UV treatment on the substrate with a Cr film.

The substrate is a raw glass (680 × 880 mm ×
t0.7 mm) and a substrate on which chromium was grown (hereinafter referred to as Cr substrate 550 × 650 mm × t0.7 mm) were used.
When the substrate 3 before cleaning and the substrate 3 with the Cr film were measured, particles on the surface of the substrate were 233
0, 2481 (1.0 μm or more) (Fig. 13), Cr
The number of particles with a film was 2774 and 2823 (FIG. 14). UV treatment (70mJ / cm2 12
The substrate not irradiated with the second substrate) was subjected to cleaning treatment with hydrogen water and ultrasonic waves, and the particles of the substrate 3 after cleaning were measured. For measurement, Hitachi Electronics GI4
920 was used. As a result, as shown in FIG. 13 and FIG. 14, it was shown that both the base glass and the base with the Cr film had a smaller number of remaining particles and a higher cleaning effect on the base subjected to the UV treatment. Further, in the contact angle evaluation with and without UV treatment on the plain glass substrate shown in FIG. 15, the contact angle was smaller (the number of remaining particles was smaller) and the cleaning effect was higher when the UV treatment was performed. Was done.

After the ultrasonic cleaning in the second step, the substrate 3 is transferred by the driving rotor 2 to the third step of drying the substrate, which is wet with the hydrogen gas saturated ultrapure water 24. The substrate 3 which is present is dried. As the drying method in the dry unit 30, spin drying, IPA vapor drying, Marangoni drying, and air knife drying are generally known, and the object to be treated is dried by any one of the drying methods or a combination thereof. For example, in spin drying,
As shown in FIGS. 1A and 16, the substrate 3 is rotated by a spin dryer 31 and dried. In addition, FIG.
Also, as shown in FIG. 2, for air knife drying, a large amount of air is blown onto the substrate or wafer to dry it. For IPA vapor drying, the substrate 3 wet with water is pulled up and dried while being replaced with vapor of IPA (isopropyl alcohol). As for Marangoni drying, the Marangoni effect is used for drying.

Therefore, according to the present invention, in the first step,
By irradiating the substrate 3 with the ultraviolet rays 14 or by washing with ozone water, organic substances are decomposed and separated from the surface of the substrate 3 and become hydrophilic as the organic substances attached to the surface of the substrate 3 decrease (wetness is improved). It is used to perform hydrophilic treatment. When hydrogen gas-saturated ultrapure water is supplied to the substrate 3 in the second step, the hydrogen gas is saturated on the substrate 3 easily with a small amount of liquid because the hydrophilic treatment (wettability) is performed in the first step. The liquid film 24a of the ultrapure water 24 can be formed. Further, in the third step, since the ultrasonic wave oscillating surface 28c is provided in the vicinity where the liquid film of the hydrogen gas saturated ultrapure water 24 formed on the substrate 3 can be contacted, the ultrasonic power is attenuated. In combination with the use of hydrogen gas-saturated ultrapure water as a cleaning liquid, a high cleaning effect can be obtained, and ultrasonic power can be propagated to the substrate 3 with a small amount of liquid.

[0071]

As described above, according to the present invention, the wettability is enhanced and the cleaning effect is enhanced by hydrophilically treating the substrate surface (the surface to be cleaned). By using hydrogen gas saturated ultrapure water, a higher cleaning effect than that of ultrapure water can be obtained. Further, by irradiating the ultrasonic wave in the vicinity of the liquid film formed on the substrate, the amount of the cleaning liquid used is significantly reduced and the attenuation of the ultrasonic power is reduced. Further, since the substrate is hydrophilically treated, a liquid film can be easily formed, and the amount of cleaning liquid used can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a cleaning processing apparatus according to the present invention, in which (a) is a dry unit of a fourth step constituted by a spin dryer, and (b) is a fourth step. The dry unit is composed of an air knife.

FIG. 2 is a process diagram of horizontal conveyance in the cleaning method according to the present invention.

FIG. 3 is a diagram showing the principle of ultraviolet ray generation in an excimer lamp.

FIG. 4 is a diagram showing a principle of light cleaning in the ultraviolet processing apparatus.

FIG. 5 is a perspective view showing a state in which hydrogen gas saturated ultrapure water is supplied to an object to be processed from an opening provided in a jet pipe of the hydrogen gas saturated ultrapure water supply device and an ultrasonic exciter.

FIG. 6 is a side view showing a method of supplying hydrogen gas saturated ultrapure water in a hydrogen gas saturated ultrapure water supply device, FIG.
Is a side view showing a state in which hydrogen gas-saturated ultrapure water is supplied to an object to be processed from a plurality of openings provided in a jet pipe,
(B) is a side view showing a state in which hydrogen gas saturated ultrapure water is supplied to the object to be processed from a plurality of two-fluid nozzles.

FIG. 7 shows the case where three ultrasonic excitation devices 26 are installed,
It is a figure which shows the state which added the hydrogen gas saturated ultrapure water supply apparatus 21 to all three sets.

FIG. 8 is a diagram showing a state where three ultrasonic exciters 26 are installed and the hydrogen gas saturated ultrapure water supply device 21 is not added to the second ultrasonic exciter 26 and is omitted.

FIG. 9 is a table showing the cleaning results in the case of FIG. 7.

FIG. 10 is a table showing cleaning results in the case of FIG.

FIG. 11 is a graph showing a comparison of the cleaning results shown in FIGS. 9 and 10.

FIG. 12 is a diagram showing a comparison of cleaning with hydrogen gas-saturated ultrapure water, pure water, and degassed membrane water.

FIG. 13 is a diagram showing particle results with and without UV treatment on a glass substrate.

FIG. 14 is a diagram showing particle results with and without UV treatment on a substrate with a Cr film.

FIG. 15 is a diagram showing contact angle evaluation with and without UV treatment on a glass substrate.

FIG. 16 is a front view showing a configuration of a spin dryer.

FIG. 17 is a cross-sectional view of a conventional cleaning processing apparatus as viewed from the front.

FIG. 18 is a cross-sectional view of a conventional cleaning processing apparatus as viewed from the front.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cleaning treatment apparatus 2 Drive roller 3 Processing object (substrate) 4 Chamber 5 Stand 10 Hydrophilic treatment unit 11 Ultraviolet irradiation device 12 Excimer lamp 12a Inner tube 12b Outer tube 12c Discharge gas 12d AC power supply 12e Electrode 12e1 Inner electrode 12e2 Outer electrode 12f Micro discharge 12g Cooling water 14 Ultraviolet 20 Ultrasonic cleaning unit 21 Cleaning liquid supply device (hydrogen gas saturated ultrapure water supply device) 21a Cleaning liquid supply device 21b Cleaning liquid supply device 21c Cleaning liquid supply device 22 Jet pipe 22a Open hole 22b 2 fluid Nozzle 24 Cleaning liquid (hydrogen gas saturated ultrapure water) 24a Liquid film 26 Ultrasonic excitation device 27 Transducer 27a Electrode plate 27b Electrode plate 27c Electrode portion 28 Waveguide 28a Flange portion 28b Through hole 28c Oscillation surface 30 Dry unit 31 Spin dryer 32 Air knife 40 Shi unit 41 rotating brush 42 protrusion

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) F26B 5/08 F26B 5/08 G03F 7/38 501 G03F 7/38 501 H01L 21/027 H01L 21/304 643D 21/304 643 645C 645 21/30 569F 572B (72) Inventor Kaoru Kazuka 3-1-5 Sakaemachi, Hamura-shi, Tokyo F-term in kaijo Co., Ltd. (reference) 2H096 AA25 AA27 AA28 CA01 LA30 3B116 AA01 AB14 BB22 BB83 BC01 CC01 CC03 3B201 AA01 AB14 BB22 BB38 BB83 BB95 BB98 BC01 CC12 3L113 AA03 AB06 AB08 AB09 AC05 AC11 BA34 5F046 LA12 LA14 MA04 MA05 MA10

Claims (12)

[Claims] 1. A first step of carrying a plate-like object to be processed on a gantry by a carrying means to perform hydrophilic treatment on at least one surface of the object to be treated, and a hydrophilically treated surface of the object to be treated. Second to form a liquid film on the
And a third step of irradiating the object to be treated with ultrasonic energy from an ultrasonic wave oscillating surface provided near the liquid film formed on the surface of the object to be treated and cleaning the same. A cleaning method characterized by the above. 2. The cleaning method according to claim 1, wherein the hydrophilic treatment is light cleaning or ozone water cleaning. 3. The cleaning method according to claim 2, wherein the light cleaning is performed by irradiating the object to be processed with ultraviolet rays using an excimer lamp or a low pressure mercury lamp. 4. The cleaning method according to claim 1, wherein the liquid film is formed of hydrogen gas saturated ultrapure water. 5. The cleaning method according to claim 4, wherein the hydrogen gas saturated ultrapure water has a hydrogen gas saturation concentration of 0.8 ppm or more. 6. The cleaning method according to claim 1, wherein the liquid film is formed by being mixed with air and applied from a two-fluid nozzle onto a surface of the object to be treated which is hydrophilic. 7. The cleaning method according to claim 1, wherein the object to be processed is moved in a horizontal direction or a vertical direction by a conveying means to be cleaned. 8. The cleaning method according to claim 4, wherein the fourth step is to dry the object to be processed by any one of IPA vapor drying, spin drying, Marangoni drying and air knife drying, or a combination thereof. Item 1. The cleaning apparatus according to Item 1. 9. A transport unit for transporting a plate-shaped object to be processed on a gantry by means of a transport means, a hydrophilic treatment unit for applying a hydrophilic treatment to at least one surface of the object to be treated, and a hydrophilic treatment of the object to be treated. Ultrasonic energy is supplied by an ultrasonic cleaning unit including a cleaning liquid supply device that forms a liquid film on the upper surface and an ultrasonic vibration device that is provided in the vicinity of the liquid film formed on the surface of the object to be processed. A treatment apparatus for irradiating an object to be treated with the substance to be washed. 10. The cleaning processing apparatus according to claim 9, wherein the hydrophilic processing unit comprises an ultraviolet irradiation device or an ozone water cleaning device. 11. The cleaning processing apparatus according to claim 9, wherein the ultraviolet irradiation apparatus irradiates the object to be processed with ultraviolet rays using an excimer lamp or a low-pressure mercury lamp. 12. The cleaning apparatus according to claim 9, wherein the liquid film is formed by a hydrogen gas saturated ultrapure water supply device.