JPH09283485A - Wet treatment method and wet treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide ultrasonic sound to a treatment surface of an object uniformly and treat the entire surface uniformly. SOLUTION: Oscillators 3, 3 are provided to an outside of two side walls of an ultrasonic container 2 which are not opposed. A cleaning container 1 is installed in the ultrasonic container 2 and cleaning water such as ultra-pure water and electrolytic ionic water is put in the cleaning container 1. A board holder 5 which supports a board 4 is put in the cleaning container 1 and ultrasonic sound is applied parallel on the board 4 in two intersecting directions from the oscillators 3, 3. As a result, ultrasonic sound is applied uniformly all over a surface of the board 4 and a sticking matter to a surface of the board 4 can be removed entirely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet treatment method and a wet treatment for removing contaminants adhering to the surface of a substrate or the like in a manufacturing process of a liquid crystal display device substrate or a semiconductor manufacturing process. Regarding the device.

[0002]

2. Description of the Related Art In the process of manufacturing a substrate for a liquid crystal display element, a step of forming a transparent conductive film by sputtering indium tin oxide (ITO) or the like on the surface of the substrate, and forming a resist layer on this transparent conductive film. A step of etching the resist layer to form a transparent electrode by partially removing the transparent conductive film, and a step of forming an alignment film on the transparent electrode. Further, in a manufacturing process of a liquid crystal substrate using a TFT, a step of forming a metal film and a semiconductor film by sputtering or CVD for forming a TFT, a coating step of forming a resist layer, a part of the metal film or the semiconductor film is performed. An etching step for removing is included.

In the process of manufacturing such a substrate, particles in the air adhere to the surface of the substrate, in the steps of forming a resist layer and etching, metals, organic substances and fine particles adhere to the surface of the substrate, and in addition to the semiconductor film. The surface is oxidized by oxygen in the air to form a natural oxide film. If such contaminants are attached, the electrodes may be peeled off or the pattern of the electrodes may be abnormal, resulting in increased resistance and defective wiring. Therefore, it is necessary to clean the surface of the substrate at each stage of manufacturing the substrate to remove the deposits.

As the above-mentioned cleaning work, there is a method of dropping pure water on the substrate to perform brushing. In this brushing process, large particles and organic substances can be removed.
Fine particles and metals cannot be removed. Also,
The surface of the substrate is damaged by the brush, and the electrodes formed on the surface of the substrate are easily damaged. Therefore, a cleaning method in which ultrasonic waves are applied is implemented. In this method, an object to be treated is immersed in a container containing pure water, and ultrasonic waves are applied to the pure water by an oscillating device provided outside the side wall of the container for cleaning.

The frequency of ultrasonic waves applied to the pure water is 1
Low frequencies below 00 kHz, eg 40 kHz or 50
In the case of kHz or the like, vibration is reflected on the surface of pure water to form coarseness and denseness in the liquid and cavities are generated in the dense portion (cavitation effect). 10 due to this cavitation effect
It is possible to remove particles and organic substances having a size of about μm or more. When high-frequency vibration of 1 MHz or more is applied to pure water, the cavitation effect does not occur, but the vibration propagating in pure water gives an excessive acceleration or shock wave to the surface of the object to be cleaned, and the acceleration or shock wave causes 2 μm. The following small particles and metals can be removed.

[0006]

In the conventional cleaning method and cleaning apparatus using ultrasonic waves, the ultrasonic waves are applied to the object to be cleaned from only one direction, so that the surface of the substrate, which is the object to be cleaned, is exposed. If there are irregularities, or if the edges or corners of the substrate are positioned on the support base with pins, etc., the irregularities or pins block the ultrasonic waves and create a shadow that prevents the ultrasonic waves from hitting the entire surface of the substrate. On the other hand, effective cleaning using ultrasonic waves cannot be performed.

Further, in the method of applying ultrasonic waves from the outside of a container filled with cleaning water such as pure water, it is necessary to process the outer surface of the container on which the oscillator for generating ultrasonic waves is installed into a highly accurate flat surface. is there. Materials that can be easily processed into a flat surface include stainless steel and the like, but metallic materials such as stainless steel are easily damaged when ultrasonic waves are continuously applied. Therefore, if a cleaning container for containing cleaning water such as pure water is formed of this kind of metal material, impurities are easily mixed into the pure water inside from the wall surface of the container. Quartz is a material that is not easily damaged by ultrasonic waves. When a cleaning container is formed from this quartz, it is difficult to process its outer surface into a flat surface. The loss of ultrasonic waves becomes large due to the unevenness of the surface.

[0008] The present invention is to solve the above problems,
Ultrasonic waves can be uniformly applied to the processed surface of the object to be processed,
An object of the present invention is to provide a wet processing method and a wet processing apparatus capable of uniformly processing the entire processing surface.

Further, the present invention is a wet treatment in which ultrasonic waves are effectively propagated in the treatment liquid in which the object to be treated is immersed and impurities can be prevented from being mixed into the treatment liquid by the ultrasonic waves. The purpose is to provide a device.

[0010]

In the wet treatment method of the present invention, an object to be treated is immersed in a container in which water is accumulated or flowing, and ultrasonic waves are applied to the object to be treated in the container from at least two intersecting directions. It is characterized by irradiating continuously or intermittently. In addition, the ultrasonic waves from each of the above directions are emitted substantially parallel to the processing surface of the object to be processed. Further, it is preferable to vibrate or rotate the object to be processed in the container while irradiating the ultrasonic waves from the respective directions. Pure water or electrolytic ionized water is used as water in the container.

Further, the wet treatment apparatus of the present invention has a container in which water is accumulated or flows, a holder for the object to be treated inserted into the container, and at least two members which intersect the object to be treated in the container. And an oscillating means for irradiating ultrasonic waves from the direction. Further, the container in which the object to be treated is placed is made of quartz that easily transmits ultrasonic waves, a metal container is arranged outside the container with a liquid layer interposed therebetween, and the oscillation means is installed on the outer surface of the metal container. It is preferable. Further, the orientation of each oscillating means is set so that the processing surface of the object to be processed is irradiated with the ultrasonic waves from the respective directions substantially in parallel.

Further, it is preferable to provide a driving means for moving the holder by vibrating or rotating it in the container.

Further, at a position where the ultrasonic wave emitted from at least one of the oscillating means passes through the object to be processed, there is provided a return preventing means for absorbing the ultrasonic wave or reflecting the ultrasonic wave in a direction not returning to the oscillating means. The above structure can be adopted, and further, a structure can be adopted in which a supply path for supplying field ion water is provided in the container.

In the wet treatment method of the present invention, the object to be treated is immersed in a container containing water. Water is continuously or intermittently supplied from the water supply pipe into the container, and the water is in a state of staying or flowing. Therefore, by adjusting the supply of water from the water supply pipe, the water in the container can be replaced and can be kept clean. The water used for the treatment is pure water or ultrapure water.

Then, ultrasonic waves are continuously or intermittently oscillated from at least two directions intersecting by the oscillating means,
Irradiate the object to be processed. In the present invention, acoustic vibration having a frequency of 30 kHz or higher is called an ultrasonic wave. By irradiating the ultrasonic wave from at least two directions, the ultrasonic wave also hits a portion that is shaded by unevenness of the object to be processed, and the object can be uniformly irradiated with the ultrasonic wave. Further, when the edge or the corner of the liquid crystal substrate, which is the object to be processed, is supported by the pins or the projections, ultrasonic waves can be applied to those shadowed parts. Further, when the object to be processed is moved by vibrating or rotating in the container while being irradiated with the ultrasonic wave, the ultrasonic wave can be uniformly applied to the entire processing surface of the object to be processed. Therefore, when using this method to clean liquid crystal substrates, etc.,
Ultrasonic waves are applied to the entire area along the surface of the substrate, and the ultrasonic waves can remove deposits on the surface of the substrate evenly.

When a low frequency of 100 kHz or less is oscillated as the ultrasonic wave, the vibration is reflected on the surface of pure water to form coarseness and denseness in the liquid and cavities are generated in the dense portion (cavitation effect). Pollutants can be removed by this cavitation effect. When high-frequency vibration of 1 MHz or more is applied to pure water, the cavitation effect does not occur, but vibration propagating in pure water gives excessive acceleration or shock wave to the surface of the object to be treated, and contaminants can be removed.

In the present invention, the oscillation frequency is selected and used according to the purpose of the processing step. For example, when this wet treatment method is used for cleaning a liquid crystal substrate or the like, when removing large particles of 10 μm or more or organic substances adhering to the surface of the substrate, ultrasonic waves of low frequency are oscillated, and these adhering substances are cavitated. To remove. Further, when removing small particles or metals of 2 μm or less, ultrasonic waves having a high frequency of 1 MHz or more are oscillated to give acceleration or shock waves to the surface of the substrate to remove these deposits. Further, different frequencies may be used in combination by irradiating high frequency after irradiating low frequency. Further, the ultrasonic waves applied from the two directions may have the same frequency or different frequencies.

As water (treatment liquid) to be supplied into the container, ozone water, hydrogen water, etc. are used in addition to pure water and ultrapure water. Ozone water and hydrogen water are field ion water generated by electrolysis of water, ozone water is generated on the anode (anode electrode) side, and hydrogen water is generated on the cathode (cathode electrode) side. When these electrolytic ionized water is used for cleaning the substrate, it is possible to remove the deposits such as organic substances and metals that cannot be removed by pure water, and the cleaning effect is enhanced. The deposits are oxidized by anode water such as ozone water, and the organic substances are CO ₂ and H ₂
It is removed by being decomposed into O, etc., and the metal is removed by becoming metal ions (plus ions) and dissolving in water. Further, the cathode water such as hydrogen water is excellent in the effect of removing fine particles, and also has the effect of preventing reattachment of particles and suppressing the generation of static electricity. Therefore, appropriate cleaning water is selected and used according to the type of the contaminant and the purpose of processing the substrate.

Further, in the wet processing apparatus of the present invention, a return preventing means such as a reflecting plate for reflecting the ultrasonic wave after passing through the object to be processed in a direction not returning to the oscillating means, or an absorbing plate for absorbing the ultrasonic wave. Is provided. After passing through the substrate, the ultrasonic waves oscillated by the oscillating means are reflected by the reflecting plate so as not to return to the oscillating means, or absorbed by the absorbing plate. Therefore, the ultrasonic waves do not return to the oscillating means and cause vibration interference.

Further, as a wet treatment apparatus, the container in which the object to be treated is immersed is formed of a material such as quartz that easily transmits ultrasonic waves and is not easily damaged by the ultrasonic waves, and a liquid layer such as water is provided outside the container. If a metal container is placed on the outer surface of the metal container and an oscillating means is installed on the outer surface of the metal container, impurities can be prevented from flowing out of the container in which the object to be treated is immersed in pure water used for the cleaning process. Since the outer surface can be made a highly accurate smooth surface, the ultrasonic wave can be propagated from the oscillating means installed on the outer surface into the double container without loss.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION In the following wet processing apparatus and wet processing method of the present invention, a substrate for a liquid crystal display device is used as an object to be processed, and cleaning of the substrate will be described as an example. The present invention is not limited to this, and can be used for general wet processing for electronic devices such as semiconductors and their substrates, or precision machines. FIG. 1 is a perspective view of the external appearance of the wet processing apparatus of the present invention, and FIG.
11 is a sectional view taken along line II-II of FIG.

Reference numeral 1 is a cleaning container, which is filled with cleaning water 12 such as pure water, ultrapure water, or electrolytic ion water. The upper surface of the cleaning container 1 is open, and an object to be cleaned such as the liquid crystal substrate 4 is put therein. The cleaning container 1 is placed in a larger ultrasonic container 2 so that ultrasonic waves from the oscillation device 3 are transmitted to the cleaning container 1 between the ultrasonic container 2 and the cleaning container 1 inside thereof. Further, it is filled with a liquid 13 such as water. The cleaning container 1 is made of a material, such as quartz, that easily transmits ultrasonic waves and is not easily damaged by ultrasonic waves. Since the oscillator 3 is installed on the side wall of the ultrasonic container 2, it is necessary to process the installation surface flat. For this reason, the ultrasonic container 2 is formed of stainless steel or the like whose surface is easily polished to be flat.

Since the cleaning container 1 for containing the object to be processed is made of quartz or the like which easily transmits ultrasonic waves, the cleaning container 1 is not damaged when ultrasonic waves are applied, and the cleaning container 1 is not damaged.
Therefore, the cleaning water 12 can be kept clean without impurities such as metal being mixed into the cleaning water 12 inside. Further, since the ultrasonic container 2 is made of stainless steel or the like and the outer surface on which the oscillator 3 is installed can be easily processed into a flat surface, the oscillator 3 and the ultrasonic container 2 are in close contact with each other,
The vibration from the oscillator 3 is propagated inside the ultrasonic container 2 and further inside the cleaning container 1 without loss.

As shown in FIG. 1, the ultrasonic container 2
Oscillators 3 are installed on the outer sides of the two side walls that do not face each other (side walls that intersect at 90 degrees). The oscillating device 3 is a device that emits vibration of a relatively low frequency of approximately 100 kHz or less, or a high frequency ultrasonic wave of 1 MHz or more, or 750 kHz to 3 MH.
Those that oscillate at any frequency in the z range are used. Further, the two oscillators 3 and 3 may emit vibrations of different frequencies. The ultrasonic vibrations oscillated from the two intersecting directions are transmitted from the wall surface of the ultrasonic container 2 to the liquid 13 and further to the cleaning water 12 in the cleaning container 1 toward the surface of the substrate 4 to be cleaned. Given.

When a low frequency of 100 kHz or less is oscillated from the oscillating device 3, the cleaning water 12 has a cavitational density due to vibrations, resulting in a cavitation effect in which cavities are generated in the dense part. Due to this cavitation effect, large particles of 10 μm or more, organic substances, etc. can be removed. Further, when a high frequency of 1 MHz or more is applied, vibration propagating in the cleaning water 12 gives an excessive acceleration or shock wave to the surface of the object to be cleaned, and the acceleration or shock wave causes 2 μm.
The following small particles and metals are removed.

The frequency of ultrasonic waves is selected according to the type and size of the deposit on the surface of the substrate 4. Since the cavitation effect due to the low frequency cannot remove small particles of 2 μm or less, after irradiating low frequency to remove large particles, high frequency of 1 MHz or more is applied to remove minute particles. Vibrations can also be used in combination.

As shown in FIG. 2B, the hole 1a at the bottom of the cleaning container 1 is connected to the water supply pipe 8, and the water supply pipe 8 passes through the hole 2a at the bottom of the ultrasonic container 2 It extends outside the sonic container 2. The cleaning water 12 is continuously or intermittently supplied into the cleaning container 1 through the water supply pipe 8.
A valve or a valve (not shown) is provided in a portion of the water supply pipe 8 extending to the outside of the ultrasonic container 2 so that the supply flow rate of the cleaning water 12 into the cleaning container 1 can be adjusted.

A drainage groove 9 is provided on the outer periphery of the upper opening of the cleaning container 1. The cleaning water 12 overflowing from the cleaning container 1 is received by the drain groove 9, and is discharged to the outside of the ultrasonic container 2 from the drain pipe 10 attached to the drain groove 9. By continuously or intermittently supplying water from the water supply pipe 8 to circulate and replace the cleaning water 12 in the cleaning container 1, the pollutants removed from the substrate 4 are discharged from the drain groove 9, The cleaning water 12 in the cleaning container 1 can be kept clean.

Inside the ultrasonic container 2 and outside the cleaning container 1 and on the inner surface of the side wall facing each oscillating device 3,
A reflection plate 11 is installed as a return prevention means. The ultrasonic waves oscillated from the oscillating device 3 pass through the cleaning container 1 and then hit the reflecting plate 11, and are reflected in a direction forming an angle of 90 degrees with the oscillating direction. Therefore, the ultrasonic waves oscillated by the oscillator 3 are not reflected by the inner wall of the ultrasonic container 2 and returned to the oscillator 3, and it is possible to prevent a decrease in the oscillation intensity due to the interference of the ultrasonic waves. Also, as a return prevention means,
Instead of the reflection plate 11, an absorption plate such as Teflon (tetrafluoroethylene) that absorbs ultrasonic waves and prevents the ultrasonic waves from returning to the oscillation device 3 may be provided.

The substrate 4, which is an object to be processed (object to be cleaned), is placed on the substrate holder 5. As shown in FIG. 1, an opening 5b is formed in the center of the substrate holder 5 leaving a portion for holding the substrate 4, and the four corners of the opening 5b form a pair of pin holders 6a. Is fixed, and further, inside each pin holder 6a, a support pin 6b having a smaller dimension in the height direction than the pin holder 6a is provided. The board 4 is positioned and held such that each corner is placed on the support pin 6b and sandwiched between the pair of pin holders 6a, 6a. Therefore, as shown in FIG. 2B, the substrate 4 is held by the substrate holder 5 in a state of being floated from the surface of the substrate holder 5 by the height dimension of the support pin 6b. The cleaning water 12 and the ultrasonic waves reach the back surface of the substrate 4 through the gap between the back surface of the substrate 4 and the surface of the substrate holder 5. FIG. 2A is a plan view showing a state where the substrate 4 is installed on the substrate holder 5. Thus, the substrate 4
While being held by the substrate holder 5, it is put into the cleaning container 1 from above. As shown in FIG. 2A, a gap (a) is formed between the outer periphery of the substrate 4 and the substrate holder 5 by the opening 5b. The bubbles generated by the irradiation of ultrasonic waves escape from this gap B, so that the bubbles do not remain on the back surface of the substrate 4. Therefore, the cleaning water 12 and the ultrasonic waves are sufficiently spread over the back surface of the substrate 4 without being disturbed by the bubbles, and the contaminants on the back surface of the substrate 4 can be removed.

The substrate holder 5 has a convex portion 5 in addition to the substrate mounting portion.
a is formed, and a support rod 7 for supporting the substrate holder 5 is provided in this portion. In the configuration example shown in FIG. 2 (B), the support rod 7 is interlocked with the vibrating device 14, and the vibrating device 14 causes the vibrating device 14 to move horizontally or vertically with respect to the substrate holder 5 or in the horizontal and vertical directions. Vibration is applied to both. By moving the substrate 4 in the cleaning water 12, it is easy for the ultrasonic waves to uniformly hit the front surface and the back surface of the substrate 4, and the contaminants cleaned and removed from the front surface of the substrate 4 easily separate from the substrate 4.

In the modification shown in FIG. 3, the support rod 7 is attached to the center of the back surface of the substrate mounting surface of the substrate holder 5. Holes 1b and 2b having the same diameter are formed at the center of the bottom surface of the cleaning container 1 and the bottom surface of the ultrasonic container 2, and a bearing 16 having a sealing property is provided in the hole, and the support rod 7 is rotated by the bearing 16. It is supported freely and extends to the outside of the bottom of the ultrasonic container 2. The support rod 7 is interlocked with the rotation driving means 15 having a motor or the like, and the power of the rotation driving means 15 rotates the substrate holder 5 and the substrate 4 in the cleaning water 12. By this rotation, ultrasonic waves applied from two directions are uniformly applied to the entire surface of the substrate 4. That is, if the substrate 4 is not rotated, the ultrasonic cleaning effect differs between the portions close to and far from the oscillators 3, 3, but by rotating the substrate 4, the ultrasonic cleaning unevenness does not occur. Further, the substance removed from the surface of the substrate 4 is easily dissolved in the cleaning water 12.

Further, a supply portion (not shown) for the cleaning water 12 is connected to the water supply pipe 8. In the wash water supply section,
A pure water generator for producing pure water or ultrapure water is used. Alternatively, an electrolyzer that electrolyzes pure water is used. By using electrolyzed ionized water, it is possible to completely remove metals and organic substances that are difficult to remove with pure water or ultrapure water. By applying the ultrasonic waves using pure water or ultrapure water, particles of medium particle size on the surface of the substrate 4 are removed. When the anode water such as ozone water from the electrolyzer is used, the organic substances and metals attached during the resist layer formation and the etching process are oxidized, and the organic substances become C
It is decomposed into O ₂ and H ₂ O, and the metal is removed by being converted into positive metal ions and dissolved in water.
When reducing cathode water such as hydrogen water is used, it is possible to remove particles having a small particle size, prevent particles from reattaching, and further suppress the generation of static electricity.

By providing a switching valve between the water supply pipe 8 and the supply part of the cleaning water 12 and selecting the cleaning water 12 according to the contaminants adhered in each manufacturing process of the substrate 4,
The effect of removing contaminants can be enhanced, and the surface of the substrate can be cleaned.

Next, a wet processing method using the wet processing apparatus will be described. Wash water 1 in the washing container 1
2 stays, or the wash water 12 is supplied from the water supply pipe 8 and flows. The cleaning water 12 is selected from ultrapure water or electrolytic ionized water such as ozone water or hydrogen water. For example, ozone water is used to remove metals and organic substances in the formation of the resist layer and cleaning after the etching process. Since the contaminants attached to each substrate manufacturing process are different, an appropriate cleaning water 12 is selected and used for each cleaning process.

A substrate holder 5 to which a substrate 4 to be cleaned is attached is put into the cleaning container 1 from above. Further, as shown in FIG. 3, a rotary substrate holder 5 is provided in the cleaning container 1.
When the substrate 4 is provided, the substrate 4 is held by the transfer arm that transfers the substrate 4, and the transfer arm is put into the cleaning water 12 from above the cleaning container 1 and placed on the substrate holder 5.

Wash water 12 is supplied from the water supply pipe 8 into the wash container 1.
Is continuously or intermittently supplied, and the ultrasonic wave is oscillated continuously or intermittently from the oscillating device 3. At this time, ultrasonic waves are also applied to the back surface of the substrate 4 through the gap between the back surface of the substrate 4 and the surface of the substrate holder 5, and bubbles generated by the irradiation of ultrasonic waves are generated on the outer periphery of the substrate 4 and the substrate holding member. Bubbles do not leave the gap (a) between the bodies 5 and remain on the back surface of the substrate 4. Therefore, the cleaning water 12 and the ultrasonic waves are sufficiently spread to the back surface of the substrate 4, so that not only the front surface of the substrate 4 but also the back surface can be cleaned. Since the oscillating devices 3 and 3 are installed outside the side walls of the ultrasonic container 2 that do not face each other, the ultrasonic waves oscillated from the two intersecting directions do not reach the other oscillating devices 3 and the oscillating devices 3 and Vibration interference does not occur with other oscillators 3. Further, since the reflection plate 11 or the absorption plate as the return prevention means is provided, the ultrasonic vibration does not return to the oscillation device 3 and the interference due to the return vibration can be prevented.

Ultrasonic waves from two directions are applied parallel to the surface of the substrate 4. Ultrasonic waves may be simultaneously oscillated from the two oscillating devices 3 and 3, or may not be oscillated from another oscillating device while oscillating from one oscillating device. Alternatively, both oscillators 3 and 3 may oscillate at the same frequency,
Ultrasonic waves of different frequencies may be combined. Since the ultrasonic waves are oscillated from two intersecting directions, it is possible to uniformly irradiate the ultrasonic waves on the surface of the substrate without forming a shadow portion where the ultrasonic waves do not hit the surface of the substrate. In particular, one of the ultrasonic waves from two directions always hits a portion of the surface of the substrate 4 which is behind the pin holder 6a, and the entire surface of the substrate can be cleaned by the ultrasonic wave.

Then, as shown in FIG. 2 (B), while applying ultrasonic waves from the oscillator 3, the substrate holder 5
The vibrating device 14 vibrates the support rod 7 provided in the substrate holder 5 to vibrate in the cleaning container 1. Alternatively, as shown in FIG. 3, the support rod 7 provided on the back surface of the substrate holder 5 is rotated by the rotation driving means 15 to rotate the substrate holder 5. By vibrating or rotating the substrate holder 5 in this manner, ultrasonic waves can be effectively applied to the entire area of the substrate 4, and the cleaning effect on the substrate 4 can be enhanced.

The wet processing apparatus of the present invention is not limited to the above configuration example, and as shown in FIG. 4, a plurality of substrates 4 such as semiconductor substrates are arranged in parallel in a processing container 17 which is long in the lateral direction, and the processing container 17 is provided with the substrates 4. In two directions in which the oscillators 3 and 3 for oscillating ultrasonic waves are provided on two inclined surfaces orthogonal to each other at the bottom by immersing in pure water or field ion water, and crossing the respective surfaces of the plurality of substrates 4. The ultrasonic waves may be given from.
The plurality of oscillators 3 may be installed in any orientation as long as they do not give ultrasonic oscillation to other oscillators.

[0041]

According to the present invention described in detail above, since it is possible to irradiate an object to be processed such as a substrate with ultrasonic waves in parallel from at least two directions, there is no part where the ultrasonic wave does not hit the object to be processed. Ultrasonic waves can be uniformly applied to the entire object to be processed. Further, ultrasonic waves can be further applied to the entire substrate by moving the object to be processed by vibrating or rotating in the container.

Further, by providing the return prevention device for absorbing or reflecting the ultrasonic wave oscillated from the oscillator, the oscillated ultrasonic wave does not return to the oscillator and interfere with each other, and stable oscillation can be maintained. it can.

[Brief description of drawings]

FIG. 1 is an external perspective view of a wet processing apparatus of the present invention,

2A is a plan view showing a state in which a substrate to be cleaned is installed on a substrate holder, FIG. 2B is a sectional view taken along line II-II in FIG.

FIG. 3 is a cross-sectional view of a wet processing apparatus having another configuration example of the present invention,

FIG. 4 is a perspective view of a wet processing apparatus having another configuration example of the present invention,

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cleaning container 2 Ultrasonic container 3 Oscillator 4 Substrate 5 Substrate holder 7 Support rod 11 Reflector 12 Cleaning water 14 Vibrating device 15 Rotation drive means

Claims (10)

[Claims] 1. A treatment object is immersed in a container in which water is accumulated or flowing, and the treatment object in the container is irradiated with ultrasonic waves continuously or intermittently from at least two intersecting directions. Wet treatment method. 2. The wet processing method according to claim 1, wherein the ultrasonic waves from the respective directions are irradiated substantially parallel to the processing surface of the object to be processed. 3. While irradiating ultrasonic waves from the respective directions,
The wet processing method according to claim 1, wherein the object to be processed is moved within the container. 4. The wet treatment method according to claim 1, wherein the water in the container is field ion water. 5. Ultrasonic waves are applied to a container in which water is accumulated or flowing, a holder for an object to be processed inserted into the container, and an object to be processed in the container from at least two intersecting directions. A wet processing apparatus comprising: an oscillating unit. 6. A container in which an object to be processed is placed is made of quartz, which easily transmits ultrasonic waves, and a metal container is arranged outside the container with a liquid layer interposed therebetween. The oscillating means is provided on the outer surface of the metal container. The wet processing apparatus according to claim 5, which is installed. 7. The wet processing apparatus according to claim 5, wherein the orientations of the respective oscillating means are set so that ultrasonic waves from the respective directions are irradiated substantially parallel to the processing surface of the object to be processed. 8. The wet processing apparatus according to claim 5, further comprising drive means for moving the holding body in the container. 9. A return prevention means is provided at a position where the ultrasonic wave emitted from at least one of the oscillating means passes through the object to be processed and which absorbs the ultrasonic wave or reflects the ultrasonic wave in a direction not returning to the oscillating means. 9. The wet processing apparatus according to claim 5, wherein 10. The wet processing apparatus according to claim 5, wherein a supply path for supplying field ion water is provided in the container.