JP2002086068A - Ultrasonic vibration unit, ultrasonic cleaner, and ultrasonic cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic vibration unit which uses a high temperature liquid as a cleaning liquid and gives a high cleaning efficiency even in the case that the cleaning liquid flows slowly, and to provide an ultrasonic cleaner using the ultrasonic vibration unit. SOLUTION: The flow channels of cooling water are formed between vibration plates 18, 18a, 18b, 18c, 18d, and vibration transmission plates 19, 19a, 19b, 19c, 19d, thereby constituting the ultrasonic vibration unit so that the bonded parts of ultrasonic vibrators 17a to 17d and vibration plates 18 to 18d can be cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic vibration unit, an ultrasonic cleaning apparatus, and an ultrasonic cleaning method suitable for precisely cleaning an object to be processed by ultrasonic processing.

[0002]

2. Description of the Related Art In a process of manufacturing a semiconductor substrate or a glass substrate for a liquid crystal display device, submicron-order particles attached to the semiconductor substrate or the glass substrate are removed before and after various kinds of fine processing. . For this purpose, a high-frequency ultrasonic cleaning device of about 1 MHz is usually used for precision cleaning. The size of the particles that must be removed during cleaning is on the order of 0.1 μm, and it is necessary to prevent metal ions from being eluted in the cleaning solution.

As an ultrasonic cleaning apparatus used in the cleaning step, a dip type or a slit type is often used. In the dip type, cleaning is performed by immersing an object to be processed filled with a cleaning liquid and irradiating the cleaning liquid with ultrasonic waves from an ultrasonic vibrator attached to the bottom or side surface of the cleaning tank.

However, when the size of the object to be processed becomes large, such as a glass substrate having a size of 1 m square or more, or a semiconductor substrate having a size of 12 inches or more, for example, 25 carriers are processed in one dip type carrier. It is difficult to put things in and process at the same time. For this reason, a slit type, which is a single-wafer type in which processing is performed one by one, is often used. In this slit type, an object to be processed is usually transferred by a conveyor, and various necessary processes such as cleaning are performed in this process.

The cleaning unit of the slit type has a hollow main body in which a slit is formed. The cleaning liquid supply pipe is connected to the main body, and the cleaning liquid supplied from the supply pipe into the main body flows out of the slit.

A diaphragm made of a thin metal plate or a quartz plate is provided inside the main body so as to face the flow path of the cleaning liquid, and a vibrator is adhered and fixed to the diaphragm. Therefore, when a voltage is applied to the vibrator to ultrasonically vibrate the vibration plate, the ultrasonic vibration is applied to the cleaning liquid flowing into the main body, so that the object to be processed is favorably cleaned by the cleaning liquid flowing out of the slit. can do.

The temperature of the cleaning liquid is usually 25 ° C.
５０50 ° C., the flow rate is 1.0-2.0 l / min.
This value is determined from the endurance temperature of the vibrator.
Since the cleaning liquid to which the ultrasonic wave is applied also plays the role of the cooling water for the vibrator, a sufficient cooling effect cannot be obtained when the liquid temperature is high or the flow rate is low.

[0008]

Generally, the cleaning effect of ultrasonic cleaning often increases when the temperature of the cleaning liquid is increased. The reason is that, for example, when the temperature of the cleaning liquid is raised from the normal temperature of 25 ° C., the vapor pressure increases with the temperature rise, so that bubbles are easily generated in the cleaning liquid, and the cleaning liquid is easily present. At the time of cleaning, since ultrasonic waves are applied to the cleaning liquid in a state in which bubbles are easily generated by a diaphragm fixed to an ultrasonic vibrator, the number of bubbles in the cleaning liquid increases, and
It is considered that the object to be processed can be cleaned in a state where propagation of ultrasonic waves in the cleaning liquid is good. It has been experimentally confirmed that the use of a high-temperature liquid as the cleaning liquid in ultrasonic cleaning is effective in increasing the cleaning efficiency.

[0009] However, in the ultrasonic cleaning apparatus having the above-described structure, the cleaning liquid is, for example, from 80 ° C to 13 ° C.
When ultrasonic waves are applied using a high-temperature liquid of about 0 ° C., there are the following problems. (A) There is a problem in the heat resistance of the adhesive bonding the vibrator and the diaphragm. That is, the adhesive used for bonding the vibrator and the diaphragm is usually an epoxy-based thermosetting type adhesive, and its substantial heat-resistant temperature is about 140 ° C. in Max. Therefore, the resonance frequency of the vibrator and the voltage applied to the vibrator due to various deterioration over time, such as the bonding state between the vibrating plate and the vibrator being deteriorated and the bonding area where the two are bonded are reduced. There is a deviation from the frequency.
If the resonance frequency of the vibrator shifts, the sound pressure generated from the vibrator decreases, so that the ultrasonic vibration applied to the cleaning liquid is weakened, and the cleaning action is also reduced. (B) The ultrasonic nozzle unit cannot operate normally when the temperature becomes about 120 ° C. to 140 ° C. due to the problem of the heat resistant temperature of PZT and the problem of the adhesive.

PZT generates heat by its own vibration (the temperature rises by about 40 ° C. when the cleaning liquid is at room temperature). Under such circumstances, only a liquid up to a temperature slightly higher than room temperature can be used as the cleaning liquid, and an efficient high-temperature cleaning liquid cannot be used. (C) Since the cleaning liquid also plays a role of the cooling water for the vibrator, a sufficient cooling effect cannot be obtained when the flow rate is low.

The present invention has been made based on these circumstances, and an ultrasonic vibration unit that uses a high-temperature liquid as a cleaning liquid and that can efficiently irradiate ultrasonic waves even when the cleaning liquid has a low flow rate. An object of the present invention is to provide an ultrasonic cleaning apparatus and an ultrasonic cleaning method using the same.

[0012]

According to the first aspect of the present invention, there is provided a vibration transmitting plate disposed to face an object to be processed and an ultrasonic vibrator disposed to face the vibration transmitting plate. A vibration plate fixedly adhered thereto, and a supply / discharge unit for supplying / discharging cooling water to / from a space formed by the vibration transmission plate and the vibration plate; An ultrasonic vibration unit that irradiates an ultrasonic vibration to a cleaning wave supplied therebetween.

According to the second aspect of the present invention,
The vibration transmission plate is an ultrasonic vibration unit, wherein a surface facing the object to be processed is formed in a convex shape.

According to the third aspect of the present invention,
The ultrasonic vibration unit irradiated with the ultrasonic vibration emitted from the ultrasonic vibrator is tilted and irradiated to the vibration transmission plate.

According to a fourth aspect of the present invention,
Holding means for holding the object to be processed, cleaning liquid supply means for supplying a cleaning liquid to the surface of the object to be processed, a vibration transmission plate arranged to face the object to be processed, and a vibration transmission plate arranged to face the vibration transmission plate A vibration plate having an ultrasonic vibrator bonded and fixed thereto, and a supply / discharge unit for supplying / discharging cooling water to / from a space formed by the vibration transmission plate and the vibration plate; An ultrasonic vibration unit which irradiates ultrasonic vibration to a cleaning liquid supplied between the vibration transmission plate and the cleaning liquid.

According to a fifth aspect of the present invention, in the ultrasonic cleaning apparatus, the surface of the vibration transmission plate facing the object to be processed is formed in a convex shape.

According to a sixth aspect of the present invention, there is provided an ultrasonic cleaning apparatus, wherein the ultrasonic vibration applied from the ultrasonic vibrator is applied to the vibration transmitting plate at an angle. It is.

According to a seventh aspect of the present invention, a step of supplying a cleaning liquid to a mounted object to be processed, a vibration transmission plate arranged to face the object to be processed, A step of cooling the vibration plate of an ultrasonic vibration unit having a transmission plate and a vibration plate to which an ultrasonic vibrator is bonded and fixed, and driving the ultrasonic vibrator to drive the vibration plate and the cooling; Irradiating the cleaning liquid with ultrasonic vibrations through water and the vibration transmission plate.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an ultrasonic cleaning unit according to the present invention.

FIG. 1 is a schematic diagram of a cleaning part constituted by an ultrasonic cleaning unit of an ultrasonic cleaning apparatus.

The ultrasonic cleaning device is a single wafer spin cleaning device,
For example, a semiconductor substrate 1 a, which is the object to be cleaned 1, is held by a plurality of pins 3 erected on a turntable 2.
The rotating shaft 5 of the turntable 2 is supported by a bearing 7 and is driven to rotate by a motor 6. The bearing 7 is fixed to the casing 8. The upper part of the casing 8 is opened, and the ultrasonic vibration unit 10 and the nozzle 11 are arranged in the opening. The ultrasonic vibration unit 10 has a built-in vibrator and a vibrating plate, which will be described later, and is provided so as to be movable in parallel with the surface of the object 1 to be cleaned. Further, outlets 9a and 9b of the cleaning liquid 4 are provided at a lower portion of the casing 8.

With these configurations, the cleaning liquid 4 supplied from the nozzle 11 to the surface of the object 1 to be cleaned is applied with ultrasonic waves by the ultrasonic vibration unit 10 to clean the object 1 to be processed.

The temperature of the cleaning liquid 4 is 50 ° C. or higher, and a mixed liquid of ammonia / hydrogen peroxide / water is used.

Although the nozzle 11 is provided separately from the ultrasonic vibration unit 10, it may be incorporated in the ultrasonic vibration unit 10 and integrated therewith.

Next, embodiments of the ultrasonic vibration unit of the present invention will be sequentially described below. (Embodiment 1) In this case, the ultrasonic vibration unit and the nozzle are separately provided separately. FIG. 2 is a schematic diagram illustrating the structure of the ultrasonic vibration unit.

The ultrasonic vibration unit 10a is formed by attaching parts to a support block 14a. A through hole 15a is formed in the center of the support block 14a in the vertical direction, and the oscillation device main body 16a and the vibration transmission plate 19a are attached to the through hole 15a. The vibration transmission plate 19
In a, the other surface faces the object 1 and the object 1
Is formed in a shape in which ultrasonic waves diverge, that is, in a convex lens shape.

The oscillation device main body 16a is provided with a vibration plate 18a and an ultrasonic vibrator 17a bonded and fixed to the vibration plate 18a, and the vibration plate 18a is arranged to face the other surface of the vibration transmission plate 19a. Therefore, the through hole 1 of the support block 14a
The space formed by the side wall 5a, the vibration plate 18a, and the vibration transmission plate 19a becomes a closed chamber 20a. In addition, this closed chamber 20
a is provided on the side wall of the through hole 15a of the support block 14a.
Two communication holes 21a and 22a are provided. One of the communication holes 21a and 22a is an inlet for cooling water, and the other is an outlet for cooling water.

Hereinafter, the cleaning process according to the above configuration will be described. Non-processing body 1
To be cleaned, and the surface to be cleaned and one of the convex surfaces of the vibration transmission plate 19a are held at about 1 to 3 mm. In parallel with this, the cleaning liquid 4 is supplied from the nozzle 11 shown in FIG.
a is filled with the cleaning liquid 4.

On the other hand, by supplying power to the ultrasonic vibrator 17a provided in the transmitting device main body 16a, ultrasonic vibration is generated, and the vibration plate 18a is vibrated. The vibration of the vibration plate 18a propagates through the cooling water filling the closed chamber 20a and indirectly vibrates the vibration transmission plate 19a. The vibration of the vibration transmission plate 19a is applied to the surface to be cleaned of the processing target 1 via the cleaning liquid 4, and the cleaning process is performed. (Embodiment 2) Also in this case, the ultrasonic vibration unit and the nozzle are separately provided separately. Further, the ultrasonic vibration unit has an ultrasonic irradiation surface formed in a rectangular shape and elongated in one direction. FIG. 3 is a schematic diagram showing the structure of the ultrasonic vibration unit 10b.

The super blue wave cleaning unit 10b is formed by attaching parts to a support block 14b. At the center of the support block 14b, a through hole 15b having a tapered cross section in the up-down direction is formed. On one surface of the support block 14b, an oscillating device main body 16b, which will be described later, is sealed with an O-ring 24 and screwed with a mounting screw so as to close one of the through holes 15b.

On the other hand, on the other surface of the support block 14a, a vibration transmitting plate 19b is screwed by a mounting screw 27 using a holder 26 so as to close the other of the through hole 15B. The vibration transmission plate 19b has one surface facing the surface to be cleaned of the object 1 to be processed, and this surface is formed in a shape that emits ultrasonic waves (a shape in which the object 1 to be processed has a convex lens shape). ing.

The oscillating device body 16b comprises a vibrating plate 18b and an ultrasonic vibrator 17b adhered to the vibrating plate 18b. The vibrating plate 18b is screwed to the support block 14b by mounting screws 27. A power supply lead wire 28 is connected to the ultrasonic vibrator 17b, and the oscillation device main body 16b made of these is covered with a cover 30 screwed to the support block 14b.

The vibration plate 18b and the vibration transmission plate 19b are not provided in parallel, but are arranged facing each other with an inclination of 5 to 10 degrees. This is because the ultrasonic wave from the vibration plate 18b is reflected by the vibration transmission plate 19b and the direction of the reflected wave is inclined so as not to be attenuated.

In the closed chamber 20b formed by the vibration plate 18b, the vibration transmission plate 19b, and the through hole 15b, two walls (in the direction perpendicular to the paper surface) of the through hole 15b of the support block 14b are provided.
Two communication holes (not shown) are provided in the closed chamber 20b.
It is configured to supply and discharge cooling water to

The cleaning process according to the above configuration will be described. As in the first embodiment, the ultrasonic vibration unit 10b is brought close to the surface of the object 1 to be cleaned, and the surface to be cleaned and the vibration transmission plate 1 are moved.
9b is filled with the cleaning liquid 4, and ultrasonic power is supplied to the ultrasonic vibrator 17a provided in the transmitting device main body 16a, so that ultrasonic vibration is generated by the vibration plate 18a, the cooling water filling the closed chamber 20a, and the vibration transmission plate 19b. Then, the surface to be cleaned is propagated with the cleaning liquid 4 to perform a cleaning process. (Embodiment 3) In this case, the ultrasonic vibration unit is provided with a nozzle incorporated therein. FIG. 4 is a schematic diagram showing the structure of the ultrasonic vibration unit.

The ultrasonic vibration unit 10c is formed by attaching parts to a support block 14c. A through hole 15c is vertically formed in the center of the support block 14c, and an oscillation device main body 16c and a vibration transmission plate 19c are respectively mounted so as to close openings at both ends of the through hole 15c. The other surface of the vibration transmission plate 19c is opposed to the object 1 to be processed, and the opposed surface is formed in a shape in which ultrasonic waves diverge, that is, in a convex lens shape.

The oscillation device main body 16c is composed of a vibration plate 18c and an ultrasonic vibrator 17c bonded and fixed to the vibration plate 18c. The vibration plate 18c and the vibration transmission plate 19c are arranged at an angle of 5 to 10 degrees as in the above-described second embodiment.
A closed chamber 20c formed by the through hole 15c of the support block 14c, the vibration plate 18c, and the vibration transmission plate 19c is provided with two communication holes 21c and 22c, and the cooling water is supplied from one of the communication holes 21c and 22c. Flows in, and the cooling water is discharged from the other side.

The support block 14c is provided with a nozzle 11c for supplying the cleaning liquid 4 between the vibration transmission plate 19c and the object 1 to be processed.

The cleaning by these structures is performed by irradiating ultrasonic waves supplied between the processing target 1 and the vibration transmitting plate 19c from the nozzle, similarly to the first and second embodiments.
The surface to be cleaned is cleaned. (Embodiment 4) In this case as well, the nozzle is incorporated in the ultrasonic vibration unit. FIG. 5A is a schematic view showing the structure of the ultrasonic vibration unit, and FIG. 5B is a plan view thereof.

The ultrasonic vibration unit 10d is formed by attaching parts to a support block 14d. At the center of the support block 14d, a conduit 31 penetrating vertically is formed. This conduit 31 is a flow path through which the cleaning liquid 4 flows. That is, it functions as a nozzle that supplies the cleaning liquid 4 between the object 1 and the ultrasonic vibration unit 10d.

As shown in FIG. 5 (b), the conduit 31 has six support arms 32a, 32 provided at intervals of 120 degrees, three at a tilt angle of 5 to 10 degrees.
b, 32c, 33a, 33b, and 33c are supported by the main body 34 of the support block 14d. Between the upper support arms 32a, 32b, 32c, the diaphragm 18
d and an ultrasonic vibrator 17d adhered thereto, and a vibration transmission plate 19d is provided between the lower supporting arms 33a, 33b, and 33c. Therefore, the closed chamber 20d is formed by the vibration plate 18d, the vibration transmission plate 19d, the main body 34 of the support block 14d, and the outer wall of the conduit 31.
Is formed. In the closed chamber 20d, two communication holes 21d, 2d, 2d provided in the body 34 of the support block 14d are provided.
2d is provided, one of the communication holes 21d and 22d is an inlet for cooling water, and the other is an outlet for cooling water.

In the cleaning process using these structures, the ultrasonic vibration is applied to the object 1 to be processed, the vibration transmitting plate 19d, and the cleaning liquid 4 supplied between the fields, as in the above-described embodiments, and the cleaning surface is cleaned. Washing is performed.

In each of the above embodiments, the material of the vibration plate and the vibration transmission plate is not particularly described, but the material may be quartz or sapphire, and the combination thereof is also its own weight.

Also, since the ultrasonic vibrator is arranged at an angle of 5 to 10 degrees with respect to the vibration transmitting plate, the ultrasonic vibrator can reduce the influence of the reflected wave from the vibration transmitting plate, and thus has a high durability. Is better.

As described above, in the ultrasonic cleaning unit and the ultrasonic cleaning apparatus of the present invention, the ultrasonic vibration unit is cooled by the cooling water even if a high-temperature cleaning liquid having high cleaning efficiency is used. Good cleaning can be performed without performing.

[0046]

According to the present invention, a highly durable ultrasonic vibration unit using a high-temperature cleaning liquid with high cleaning efficiency,
An ultrasonic cleaning device and an ultrasonic cleaning method are obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of a cleaning part configured by an ultrasonic vibration unit or the like of an ultrasonic cleaning device.

FIG. 2 is a schematic view showing an embodiment of an ultrasonic vibration unit according to the present invention.

FIG. 3 is a schematic view showing an embodiment of the ultrasonic vibration unit of the present invention.

FIG. 4 is a schematic view showing an embodiment of the ultrasonic vibration unit of the present invention.

5A is a schematic diagram showing an embodiment of the ultrasonic vibration unit of the present invention, and FIG. 5B is a plan view thereof.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Workpiece, 2 ... Turntable, 10, 10a, 1
0b, 10c, 10d: ultrasonic vibration unit, 11, 1
1c: Nozzle, 17, 17a, 17b, 17c, 17d
... Ultrasonic vibrators, 18, 18a, 18b, 18c, 18
d: diaphragm, 19, 19a, 19b, 19c, 19d ...
Vibration transmission plate, 20a, 20b, 20c, 20d: closed chamber, 21a, 21b, 21c, 21d: communication hole, 22
a, 22b, 22c, 22d ... communicating holes

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidehiro Watanabe 1st address, Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Inside (72) Inventor Kenji Masui Komukai, Koyuki-ku, Kawasaki-shi, Kanagawa No. 1, Toshiba-cho, Toshiba Microelectronics Center (72) Inventor Akio Kosaka, No. 1, Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture F-term in Toshiba Microelectronics Center, Inc. 3B201 AA03 AB01 AB34 AB42 BB22 BB82 BB84 BB85 BB86 BB92 CB01 5D107 AA09 AA20 BB11 CC20 FF01 FF05 FF09

Claims (7)

[Claims] A vibration transmission plate disposed opposite to the object to be processed; a vibration plate disposed opposite to the vibration transmission plate and having an ultrasonic vibrator bonded and fixed thereto; and the vibration transmission plate and the vibration A supply / discharge means for supplying / discharging cooling water to / from a space formed by the plate, and irradiating ultrasonic waves to a cleaning wave supplied between the object to be processed and the vibration transmission plate. An ultrasonic vibration unit characterized by the above-mentioned. 2. The ultrasonic vibration unit according to claim 1, wherein the surface of the vibration transmission plate facing the object to be processed is formed in a convex shape. 3. The ultrasonic vibration unit according to claim 1, wherein the ultrasonic vibration applied from the ultrasonic vibrator is applied to the vibration transmission plate at an angle. 4. A holding means for holding an object to be processed, a cleaning liquid supply means for supplying a cleaning liquid to the surface of the object to be processed, a vibration transmission plate arranged to face the object to be processed, and the vibration transmission plate A vibration plate having an ultrasonic vibrator bonded and fixed to face thereto, and supply / discharge means for supplying / discharging cooling water to / from a space formed by the vibration transmission plate and the vibration plate, An ultrasonic cleaning apparatus, comprising: an ultrasonic vibration unit that irradiates ultrasonic vibration to a cleaning liquid supplied between an object to be processed and the vibration transmission plate. 5. The ultrasonic cleaning apparatus according to claim 4, wherein the surface of the vibration transmission plate facing the object to be processed is formed in a convex shape. 6. The ultrasonic cleaning apparatus according to claim 4, wherein the ultrasonic vibration applied from the ultrasonic vibrator is applied obliquely to the vibration transmission plate. 7. A step of supplying a cleaning liquid to a placed object to be processed, a vibration transmission plate arranged to face the object to be processed, and an ultrasonic wave arranged to face the vibration transmission plate. A step of cooling the vibration plate of an ultrasonic vibration unit having a vibration plate to which a vibrator is bonded and fixed; anddriving the ultrasonic vibrator, the vibration plate, the cooling water,
And irradiating the cleaning liquid with ultrasonic vibration via the vibration transmission plate.