JP2010287841A - Ultrasonic cleaning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic cleaning apparatus, capable of suppressing damage to an object to be cleaned and exhibiting desired cleaning performance. <P>SOLUTION: The ultrasonic cleaning apparatus 1 includes: a cleaning processor 100 for applying ultrasonic cleaning processing to an object to be cleaned 800, by using a cleaning liquid 700; a vibrator 200 for applying ultrasonic vibration to the cleaning liquid 700; an oscillator 300 for supplying an electric signal of a desired amplitude, at a desired frequency to the vibrator 200 for causing the ultrasonic vibration of the vibrator 200 by the piezoelectric effect; a gas-dissolving section 400 for dissolving a desired gas 410 in the cleaning liquid 700; a gas concentration measuring section 500 for measuring the concentration of the gas 410 dissolved in the cleaning liquid 700; and a controller 600 for calculating an output range of the ultrasonic waves based on a database. The controller 600 controls the output value of the ultrasonic waves supplied by the oscillator 300 to the vibrator 200 and controls the electric signal supplied by the oscillator 300 to the vibrator 200, on the basis on the relation between the concentration of the gas 410 and the output range of the ultrasonic waves. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a substrate for a semiconductor integrated device, a glass substrate for a display device, a substrate for a photomask, a substrate for an optical disk, a substrate for a magnetic disk, a film substrate, a mechanical component, etc. The present invention relates to an ultrasonic cleaning apparatus that performs ultrasonic cleaning processing.

  2. Description of the Related Art In recent years, in semiconductor integrated device manufacturing processes, advanced cleaning techniques for cleaning precision-processed products have been required along with miniaturization of wiring patterns and an increase in the diameter of silicon wafers used for manufacturing. A wiring pattern, a silicon wafer, and a precision processed product are objects to be cleaned.

  The above-described cleaning technology is particularly required to remove ultra-fine particles, reduce the amount of chemicals used, reduce the amount of oxidation / etching, support new wiring materials and new insulating film materials. Yes.

  In order to deal with such a problem, generally, a cleaning technique cleans an object to be cleaned by a chemical action based on a chemical solution. However, such a cleaning technique may change the quality of a new wiring material and a new insulating film material in which the amount of oxidation / etching is excessive. For this reason, it is becoming difficult for the above-described cleaning technique to cope with cleaning of an object to be cleaned in recent years.

  For these reasons, in recent cleaning techniques, there is an increasing expectation that an object to be cleaned is cleaned by a physical action that does not use a chemical solution.

  The cleaning technique based on physical action includes, for example, ultrasonic cleaning which is excellent in cleaning performance. With ultrasonic cleaning, the object to be cleaned is cleaned using a medium such as gas or liquid irradiated with mechanical vibrations (ultrasonic vibrations) having a frequency of 20 kHz or higher (20,000 vibrations per second). This is a cleaning method. The cleaning effect is manifested by the physical action of such ultrasonic vibration.

  In general, in the manufacturing process of a semiconductor integrated device, ultrasonic cleaning using high frequency ultrasonic waves having a frequency of 500 kHz or more is applied.

  The ultrasonic cleaning as described above corresponds to both batch type (immersion type) cleaning and single wafer cleaning. Batch-type cleaning is a cleaning method in which an object to be cleaned is accommodated (immersed) in a processing tank in which a cleaning liquid is stored and ultrasonic cleaning is performed. Single wafer cleaning is a cleaning method in which ultrasonic cleaning is performed while discharging a cleaning liquid to an object to be cleaned.

  For example, Patent Document 1 discloses an ultrasonic sound pressure measuring apparatus that can perform measurement representing an absolute value of ultrasonic sound pressure and display the ultrasonic sound pressure measurement value. This ultrasonic sound pressure measuring device accurately measures the ultrasonic sound pressure used for ultrasonic cleaning.

JP 2007-292625 A

  For example, the wiring pattern of the semiconductor integrated device as described above, which is the object to be cleaned, is reduced in resistance to physical action due to miniaturization as described above. Therefore, the wiring pattern may be damaged (destroyed) by ultrasonic cleaning. Therefore, in the manufacturing process of the semiconductor integrated device, there is a possibility that the cleaning process using ultrasonic cleaning is limited.

  Therefore, in view of the above circumstances, an object of the present invention is to provide an ultrasonic cleaning apparatus capable of suppressing damage to an object to be cleaned and exhibiting a desired cleaning performance.

  In order to achieve the object, the present invention provides a cleaning processing unit that ultrasonically cleans an object to be cleaned using a cleaning liquid, the vibrator that irradiates the cleaning liquid with ultrasonic vibration, and the vibrator having a piezoelectric effect. In order to vibrate ultrasonically, an oscillator that applies an electric signal having a desired frequency and a desired amplitude to the vibrator, a gas dissolving part that dissolves a desired gas in the cleaning liquid, and a solution that dissolves in the cleaning liquid A gas concentration measuring unit for measuring the concentration of the gas being, a desired condition for ultrasonic cleaning, and a cleaning performance based on the number of particles of the object to be removed remaining on the object to be cleaned A database that stores a relationship, a relationship between the desired condition for ultrasonic cleaning, and a damage to the object to be cleaned indicating the number of elements on the main surface of the object to be cleaned damaged by the ultrasonic cleaning Based on A control unit that calculates an output range of ultrasonic waves for exhibiting a desired cleaning performance while suppressing damage to the object to be cleaned to a desired value or less, and the control unit measures the gas concentration Based on the relationship between the concentration of the gas dissolved in the cleaning liquid measured in the section and the output range of the ultrasonic wave, the output value of the ultrasonic wave that the oscillator applies to the vibrator is controlled, There is provided an ultrasonic cleaning apparatus, wherein an oscillator controls an electrical signal applied to the vibrator.

  ADVANTAGE OF THE INVENTION According to this invention, the ultrasonic cleaning apparatus which can suppress the damage with respect to a to-be-cleaned object, and can exhibit desired cleaning performance can be provided.

FIG. 1 is a diagram showing a configuration of an ultrasonic cleaning apparatus according to the first embodiment of the present invention. FIG. 2 is a diagram illustrating the relationship between the output value of ultrasonic waves and the cleaning performance. FIG. 3 is a diagram showing the relationship between the concentration of nitrogen and the cleaning performance. FIG. 4 is a diagram showing the relationship between the output value of the ultrasonic wave and the number of elements on the main surface of the object to be cleaned damaged by the ultrasonic cleaning. FIG. 5 is a diagram showing the relationship between the concentration of nitrogen and the number of elements on the main surface of an object to be cleaned damaged by ultrasonic cleaning. FIG. 6 is a diagram showing the relationship between the nitrogen concentration, the ultrasonic output value, and the optimum ultrasonic output range. FIG. 7 is a flowchart showing the operation of the ultrasonic cleaning apparatus in the present embodiment. FIG. 8 is a diagram showing a configuration of an ultrasonic cleaning apparatus according to the second embodiment of the present invention. FIG. 9 is a flowchart showing the operation of the ultrasonic cleaning apparatus in the present embodiment.

Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS.
In the present embodiment, the ultrasonic cleaning apparatus 1 performs an ultrasonic cleaning process on the object to be cleaned 800 using, for example, a liquid such as water or a chemical solution that has been irradiated with ultrasonic vibration.

In the present embodiment, batch-type cleaning is used in which the object to be cleaned 800 is accommodated in the processing tank 110 in which the cleaning liquid 700 is stored, and the object to be cleaned 800 immersed in the cleaning liquid 700 is ultrasonically cleaned.
For example, a machine part or the like is suitable for the object 800 to be cleaned ultrasonically by the batch cleaning.

  The ultrasonic cleaning apparatus 1 includes a cleaning processing unit 100 that performs ultrasonic cleaning processing on an object to be cleaned 800 using a cleaning liquid 700, a vibrator 200 that irradiates ultrasonic vibration to the cleaning liquid 700, and a piezoelectric effect of the vibrator 200. In order to oscillate ultrasonically, an oscillator 300 that applies an electric signal having a desired frequency (frequency is, for example, 20 kHz or more) to the vibrator 200, and a gas that dissolves the desired gas 410 in the cleaning liquid 700 Dissolving unit 400, gas concentration measuring unit 500 for measuring the concentration of gas 410 dissolved in cleaning liquid 700, desired conditions for ultrasonic cleaning, and the object to be removed remaining in object to be cleaned 800 Relationship between cleaning performance based on the number of particles of an object, desired conditions for ultrasonic cleaning, and elements on the main surface of an object to be cleaned 800 damaged by ultrasonic cleaning The output range of ultrasonic waves for exhibiting a desired cleaning performance while suppressing the damage to the object to be cleaned 800 to a desired value or less based on a database storing the relationship with the damage to the object to be cleaned 800 indicating the number And the ultrasonic wave applied to the vibrator 200 by the oscillator 300 based on the relationship between the concentration of the gas 410 dissolved in the cleaning liquid 700 measured by the gas concentration measuring unit 500 and the output range of the ultrasonic wave. The control unit 600 controls the output value and controls the electrical signal that the oscillator 300 gives to the vibrator 200.

  The cleaning processing unit 100 stores the object to be cleaned 800 and stores the cleaning liquid 700, the cleaning liquid preparation mechanism 120 that prepares the cleaning liquid 700 stored in the processing tank 110, and the cleaning liquid 700 stored in the processing tank 110. The propagation tank 140 that stores the propagation liquid 130 that propagates the ultrasonic vibration irradiated by the vibrator 200 and the propagation liquid preparation mechanism 150 that prepares the propagation liquid 130 that the propagation tank 140 stores are provided. .

  The treatment tank 110 is made of a material that has high permeability of ultrasonic vibration, does not cause dust generation due to deterioration in use, and does not cause elution of metal components. Such a material is, for example, quartz glass. Although the processing tank 110 does not specifically limit the shape of the object to be cleaned 800 to be accommodated, it is preferable to accommodate the object to be cleaned 800 such as a machine part as described above.

  Near the bottom 110a of the processing tank 110, a supply pipe 111 for supplying the cleaning liquid 700 prepared by the cleaning liquid preparation mechanism 120 from the cleaning liquid preparation mechanism 120 to the processing tank 110 is disposed. The supply pipe 111 is connected to the gas dissolving part 400. Further, the upper surface 110b of the processing tank 110 is open. Therefore, an outer tank 112 for temporarily storing the cleaning liquid 700 overflowing from the processing tank 110 is disposed on the outer peripheral surface 110d of the upper end 110c of the processing tank 110. The outer tank 112 is connected to a drain pipe 113 for draining the cleaning liquid 700 that is temporarily stored as waste liquid from the outer tank 112.

  The cleaning liquid preparation mechanism 120 prepares the cleaning liquid 700 so that the cleaning liquid 700 is stored in the processing tank 110. The cleaning liquid preparation mechanism 120 has a tank 121 that temporarily stores the cleaning liquid 700 supplied to the treatment tank 110 (more specifically, the gas dissolving unit 400), and the temperature of the cleaning liquid 700 that is temporarily stored in the tank 121. A temperature controller 122 that is a temperature adjusting unit to be adjusted, and a pump that is a flow rate control unit that controls the flow rate of the cleaning liquid 700 supplied to the treatment tank 110 (more specifically, the gas dissolving unit 400) to a desired speed. 123, and a supply pipe 124 that supplies the cleaning liquid 700 whose flow rate is controlled by the pump 123 to the gas dissolving unit 400. The supply pipe 124 is connected to the gas dissolving part 400.

  In the propagation tank 140, the propagation liquid 130 is interposed between the bottom 110 a of the processing tank 110 and the upper surface (vibration surface) 200 a of the vibrator 200, and from the vibrator 200 to the cleaning liquid 700 stored in the processing tank 110. Propagates the irradiated ultrasonic vibration. The propagation liquid 130 is preferably a liquid that does not generate bubbles that hinder the propagation of ultrasonic vibrations and efficiently releases heat generated on the vibration surface 200a of the vibrator 200. This liquid is water in which no gas is dissolved.

  An opening 140b is disposed in a part of the bottom 140a of the propagation tank 140. The vibrator 200 is attached to the opening 140b. The propagation tank 140 is provided with a supply pipe 141 that supplies the propagation liquid 130 from the propagation liquid preparation mechanism 150 to the propagation tank 140 and a drainage pipe 142 that drains the propagation liquid 130 that becomes waste liquid from the propagation tank 140. ing.

  The propagation liquid preparation mechanism 150 prepares the propagation liquid 130 so that the propagation liquid 130 is stored in the propagation tank 140. The propagation liquid preparation mechanism 150 includes a tank 151 that temporarily stores the propagation liquid 130 supplied to the propagation tank 140, and a dissolved gas removal mechanism 152 that removes gas previously dissolved in the propagation liquid 130 stored in the tank 151. And have.

  The vibrator 200 propagates the ultrasonic vibration generated on the vibration surface 200a to the bottom 110a of the processing tank 110 via the propagation liquid 130, and transmits the bottom 110a of the processing tank 110, thereby cleaning the cleaning liquid 700 in the processing tank 110. Irradiate. The cleaning liquid 700 irradiated with the ultrasonic vibration brings a cleaning action on the object 800 by the physical action of the ultrasonic vibration.

  The oscillator 300 has a signal output line 320. The signal output line 320 is connected to the vibrator 200 and transmits an electric signal to be applied to the vibrator 200 controlled by the control unit 600 to the vibrator 200. As a result, the oscillator 300 causes the vibrator 200 to vibrate ultrasonically.

  The gas dissolving unit 400 dissolves a desired gas 410 in the cleaning liquid 700 supplied from the cleaning liquid preparation mechanism 120. The gas 410 includes, for example, at least one of hydrogen, helium, nitrogen, oxygen, neon, argon, krypton, xenon, radon, carbon dioxide, and ammonia.

  The gas dissolution unit 400 supplies the gas 410 to the cleaning liquid 700 from which the gas previously dissolved in the cleaning liquid 700 in the supply pipe 124 is removed from the cleaning liquid 700 and the cleaning liquid 700 from which the gas has been removed by the dissolved gas removal mechanism 440. The gas supply part 420 and the gas supply pipe 430 for supplying the gas 410 discharged from the gas supply part 420 to the cleaning liquid 700 in the supply pipe 111 from which the gas has been removed by the dissolved gas removal mechanism 440 are provided.

  The gas concentration measuring unit 500 measures the concentration of the gas 410 dissolved in the cleaning liquid 700 in the cleaning liquid 700 supplied from the gas dissolving unit 400 to the treatment tank 110 by the supply pipe 111. The gas concentration measuring unit 500 branches from the supply pipe 111 and branches the cleaning liquid 700 flowing through the supply pipe 111 to measure the concentration of the gas 410, and the concentration of the gas 410 dissolved in the cleaning liquid 700. A measurement tank 520 that temporarily stores the cleaning liquid 700 that flows from the branch pipe 510 for measurement, a heater 530 that is a heating unit that heats the cleaning liquid 700 stored in the measurement tank 520, and the cleaning liquid heated by the heater 530 And a measurement sensor 540 that is a measurement unit that measures the concentration of the gas 410 dissolved in the cleaning liquid 700 from 700.

  The branch pipe 510 may be branched from at least one of the processing tank 110, the supply pipe 111, the supply pipe 124, and the gas supply pipe 430. That is, the gas concentration measuring unit 500 connects the cleaning processing unit 100, the gas dissolving unit 400, the cleaning processing unit 100, and the gas dissolving unit 400 in order to measure the concentration of the gas 410 dissolved in the cleaning liquid 700. It is only necessary to branch from at least one of the supply pipe 111 and the supply pipe 124.

Here, measurement of the concentration of the gas 410 dissolved in the cleaning liquid 700 by the measurement sensor 540 will be described.
The measurement sensor 540 first measures the thermal conductivity of the cleaning liquid 700 based on the result of the temperature change of the cleaning liquid 700 heated by the heater 530. This thermal conductivity depends on the composition of the cleaning liquid 700, the composition of the gas 410, and the concentration of the gas 410 dissolved in the cleaning liquid 700. In the present embodiment, the composition of the cleaning liquid 700 and the composition of the gas 410 are set in advance as desired. Therefore, if the composition of the cleaning liquid 700 and the composition of the gas 410 are set in advance as desired, the measurement sensor 540 can measure the concentration of the gas 410 dissolved in the cleaning liquid 700 based on the measured thermal conductivity. It becomes. As described above, in the present embodiment, the gas 410 dissolved in the cleaning liquid 700 based on the composition of the cleaning liquid 700 and the composition of the gas 410 set in advance as desired and the thermal conductivity measured by the measurement sensor 540. Measure the concentration.

  The measurement sensor 540 outputs the measurement result to the control unit 600. This measurement result is concentration information indicating the concentration of the gas 410 dissolved in the cleaning liquid 700.

  The control unit 600 includes a signal input line 610, a signal output line 620, a recording device 630, a central processing unit 640, an operation unit 650, and a display unit 660.

  The signal input line 610 is connected to the measurement sensor 540 and the central processing unit 640. The signal input line 610 inputs the measurement result measured by the measurement sensor 540 from the measurement sensor 540 to the central processing unit 640. This measurement result is concentration information indicating the concentration of the gas 410 dissolved in the cleaning liquid 700 described above.

  The signal output line 620 is connected to the oscillator 300 and the central processing unit 640. The signal output line 620 inputs a controlled electric signal applied to the vibrator 200 from the central processing unit 640 to the oscillator 300 as an input signal.

  The recording device 630 records density information input through the signal input line 610 and the central processing unit 640. Further, the recording device 630 stores a database of a relationship between desired conditions for ultrasonic cleaning and cleaning performance, and a relationship between desired conditions for ultrasonic cleaning and damage to the object 800 to be cleaned.

  Desired conditions for ultrasonic cleaning are the size (size) of the vibration surface 200a of the vibrator 200, and the frequency and amplitude of the electrical signal that the oscillator 300 applies to the vibrator 200 (output value of the ultrasonic wave). And the composition and temperature of the cleaning liquid 700, and the composition and concentration of the gas 410 dissolved in the cleaning liquid 700. The concentration of the gas 410 is based on the concentration information measured by the measurement sensor 540.

The cleaning performance is based on the number of particles of the object to be removed remaining in the object to be cleaned 800 as described above. More specifically, the cleaning performance is obtained by measuring the number of particles of the object to be removed remaining on the object to be cleaned 800 before the ultrasonic cleaning process, after the ultrasonic cleaning process and after the drying process. Further details will be described later.
This cleaning performance depends on the desired conditions for ultrasonic cleaning and the type of object to be removed from the object to be cleaned 800 by the ultrasonic cleaning process described above.

  Further, the damage to the object to be cleaned 800 indicates the number of elements on the main surface of the object to be cleaned 800 damaged by the ultrasonic cleaning as described above after the ultrasonic cleaning process and after the drying process. The number of elements on the main surface of the object 800 to be cleaned damaged by the ultrasonic cleaning includes the desired conditions for ultrasonic cleaning and the elements on the main surface of the object 800 to be cleaned damaged by ultrasonic cleaning. Depends on the type of.

  The database includes the shape and type of the object 800 to be cleaned, the type of object to be removed from the object 800 to be cleaned by ultrasonic cleaning, and the elements on the main surface of the object 800 to be damaged by ultrasonic cleaning. Further, information indicating the relationship between the nitrogen concentration, the ultrasonic output value, and the optimum ultrasonic output range shown in FIG. 6 to be described later is further stored.

  The central processing unit 640 calculates, based on the database stored in the recording device 630, an ultrasonic output range for exhibiting a desired cleaning performance while suppressing damage to the object to be cleaned 800 below a desired value. Then, based on the relationship between the concentration of the gas 410 dissolved in the cleaning liquid 700 (concentration information described above) measured by the gas concentration measurement unit 500 and the output range of the ultrasonic wave, the oscillator 300 applies to the vibrator 200. The output value of the ultrasonic wave to be controlled is controlled, and the electric signal that the oscillator 300 gives to the vibrator 200 is controlled.

  Specifically, the central processing unit 640 calculates an ultrasonic output range based on the database, and corresponds to the concentration of the gas 410 dissolved in the cleaning liquid 700 based on the calculated ultrasonic output range. The oscillator 300 is controlled so as to vibrate ultrasonically with the output value of the ultrasonic wave.

  The operation unit 650 is, for example, a touch panel or a keyboard for inputting / outputting a database stored in the recording device 630. As described above, what is input / output includes, for example, desired conditions for ultrasonic cleaning, cleaning performance, the number of elements on the main surface of the object to be cleaned 800 damaged by ultrasonic cleaning, and the like.

  The display unit 660 displays the set value and measured value of the concentration of the gas 410 in the cleaning liquid 700, the set value of the ultrasonic output, the input / output status of the database stored in the recording device 630, the processing status in the central processing unit 640, and the like. Is displayed.

Next, a method for calculating the output range of ultrasonic waves will be described with reference to FIGS.
First, an example of a database input by the operation unit 650 will be described. In this example, desired conditions for ultrasonic cleaning, the shape and type of the object to be cleaned 800, the type of object to be removed from the object to be cleaned 800 by the ultrasonic cleaning process, and damage due to ultrasonic cleaning. It is an element on the main surface of the object 800 to be cleaned.

The dimensions of the vibration surface 200a of the vibrator 200 are, for example, 317 mm long and 317 mm wide.
The frequency of the electrical signal output from the oscillator 300 is 1820 kHz, for example.
The output value of the ultrasonic wave is, for example, 0W to 1200W.
The cleaning liquid 700 is water having a temperature of 25 degrees Celsius, for example.
The gas 410 dissolved in the cleaning liquid 700 is, for example, nitrogen having a concentration of 0 ppm to 20 ppm.
The cleaning object 800 is a silicon wafer having a diameter of 200 mm, for example.
An object to be removed from the object to be cleaned 800 is, for example, silicon particles having a particle diameter of 200 nm to 5000 nm.
The element on the main surface of the cleaning object 800 is, for example, a wiring pattern made of polycrystalline silicon. The wiring of the wiring pattern has, for example, a width of 50 nm and a height of 140 nm, and the gap width between the wirings is, for example, 50 nm.

Next, a specific method for calculating the output range of ultrasonic waves will be described.
The treatment tank 110 stores the cleaning liquid 700 and accommodates an object to be cleaned 800. In this state, the ultrasonic cleaning process is executed for 5 minutes. The ultrasonic cleaning process will be described later in detail with reference to FIG. After the ultrasonic cleaning process, the object to be cleaned 800 is pulled up from the processing tank 110. Then, the object to be cleaned 800 is dried by high-speed spin rotation in a substitution atmosphere using isopropyl alcohol or in a nitrogen atmosphere.

  At this time, the following first to third matters are expressed by the ultrasonic cleaning treatment.

First matter
When ultrasonic vibration is applied to the cleaning liquid 700 by the vibrator 200, a high pressure region and a low pressure region are periodically generated in the cleaning liquid 700.

Second matter
In the region where the pressure is low in the cleaning liquid 700, nitrogen, which is a component having a low saturated vapor pressure, easily forms bubbles. The bubble group is a group composed of bubbles having various diameters. In the bubble group, there is a bubble (resonant bubble) having an optimum diameter for resonating with the irradiated ultrasonic vibration.

Third matter
Resonant bubbles obtain kinetic energy by resonance with ultrasonic vibration and move at a moving speed V while rubbing the main surface of the object 800 to be cleaned, thereby removing particles on the main surface of the object 800 to be cleaned. . This particle | grain is a silicon particle with a particle size of 200 nm-5000 nm which is the target object removed from the to-be-cleaned object 800 mentioned above.

  Note that, according to Reference 1 or Reference 2, the maximum value V of the moving speed of the resonant bubbles can be obtained by Equation (1).

I: acoustic intensity, k: wave number, R: radius of resonant bubble, P: effective sound pressure, f: frequency, ν: vibration speed.
c: Average sound velocity of cleaning liquid 700 containing nitrogen
η: Average viscosity of cleaning liquid 700 containing nitrogen
ρ: Average density of cleaning liquid 700 containing nitrogen
K: Equation (6) is obtained by summarizing the average elastic modulus equations (1) to (5) of the cleaning liquid 700 containing nitrogen.

  When the output value of the ultrasonic wave increases, the vibration speed ν increases, and the moving speed V also increases from the equation (6).

  According to Reference 3, η, ρ, and K can be obtained from equations (7) to (9) using the volume fraction ξ of nitrogen.

η _{H 2 O} : viscosity of cleaning liquid 700 (here, the above-mentioned water) 891 μPa · S
ρ _H2O : density of cleaning liquid 700 (here, the above-mentioned water) 10000 kg / m ³
K _H2O : Elastic modulus of cleaning liquid 700 (here, the above-mentioned water) 2 GPa
η _N2 : Viscosity of nitrogen 18 μPa · S
ρ _N2 : Nitrogen density 1.25 kg / m ³
K _N2 : Elastic modulus of nitrogen 141 kPa

Reference 1 K. Yoshioka, Y. et al. Kawashima, H .; Hirano: Acoustica, 5, 173 (1955)
Reference 2 Mizuki Azagami, Atsushi Kikuchi: Surface Technology, 47, 39 (1996)
Reference 3 Junichi Miyoshi, Yoshimitsu Kikuchi, Otohiko Kumamoto Supervision: Ultrasonic Technical Handbook, 151 (1991)

Further, the relationship between the ultrasonic output value, which is a desired condition for ultrasonic cleaning, and the cleaning performance as shown in FIG. 2 is acquired by the first to third items described above.
The cleaning performance shown in FIG. 2 measures the number of particles of an object to be removed remaining on the object to be cleaned 800 before the ultrasonic cleaning process, after the ultrasonic cleaning process, and after the drying process, as described above. Is required.

That is, the number of particles of the object remaining on the object to be cleaned 800 before the ultrasonic cleaning process is N0, and the number of particles of the object remaining on the object to be cleaned 800 after the ultrasonic cleaning process and the drying process is N. Then,
Cleaning performance (%) = 100 × (N0−N) / N
The cleaning performance is calculated by the following formula.

  The number of particles of the object to be removed remaining on the object to be cleaned 800 is measured by a method of detecting scattered light using a wafer surface inspection apparatus (manufactured by Hitachi High-Technologies Corporation, model: LS-6000). Is done.

  As shown in FIG. 2, it can be seen that as the output value of the ultrasonic wave increases, the cleaning performance improves regardless of the nitrogen concentration. It can also be seen that the cleaning performance is saturated when the output value of the ultrasonic wave exceeds a certain value at each nitrogen concentration.

  Therefore, it can be seen that the minimum output value of the ultrasonic wave required for exhibiting the cleaning effect (cleaning performance> 0%) depends on the concentration of nitrogen dissolved in the cleaning liquid 700. Further, it can be seen that when the concentration of nitrogen is high, the cleaning effect is exhibited even if the output value of the ultrasonic wave is small. Further, it can be seen that when the concentration of nitrogen is low, the cleaning effect is hardly exhibited even if the output value of the ultrasonic wave is large. When the concentration of nitrogen is 0 ppm, the cleaning effect is not exhibited at all even if the output value of the ultrasonic wave is increased.

  That is, when the above-described FIG. 2 and the above-described first to third items and the expressions (1) to (9) are put together, when the output value of the ultrasonic wave increases, the pressure in the low-pressure region described above significantly decreases. Therefore, the amount of resonant bubbles increases and the vibration speed ν increases. As a result, the moving speed V is also increased, so that the cleaning performance is improved.

  Further, if the concentration of nitrogen increases, the amount of resonant bubbles increases even if the output value of the ultrasonic wave is small, so that the cleaning effect is exhibited. If the concentration of nitrogen is reduced, the amount of resonant bubbles is reduced even if the output value of the ultrasonic wave is large, so that the cleaning effect is hardly exhibited. Further, when the concentration of nitrogen is 0 ppm, even if the output value of the ultrasonic wave is increased, the bubble group itself is not generated, and thus the cleaning effect is not exhibited at all.

  In addition, the relationship between the nitrogen concentration measured by the measurement sensor 540 and the cleaning performance as shown in FIG. 3 together with FIG. 2 is acquired by the first to third matters described above. The cleaning performance shown in FIG. 3 is obtained by the same method as in FIG.

  As shown in FIG. 3, it can be seen that the cleaning performance improves as the nitrogen concentration increases in the output value of each ultrasonic wave. However, it can be seen that the cleaning performance decreases when the concentration of nitrogen exceeds a certain value in the output value of each ultrasonic wave.

  Therefore, it can be seen that the minimum concentration of nitrogen necessary for exhibiting the cleaning effect (cleaning performance> 0%) depends on the output value of the ultrasonic wave. Further, as shown in FIG. 3, when the ultrasonic output value is 300 W, nitrogen having a concentration of 12 ppm or more is required, when the ultrasonic output value is 600 W, nitrogen is 10 ppm or more, and when the ultrasonic output value is 1200 W, nitrogen is 8 ppm or more. I understand that. In addition, as shown in FIG. 3, it can be seen that the smaller the output value of the ultrasonic wave, the more remarkable the deterioration in the cleaning performance due to the excessive nitrogen concentration.

  Here, the deterioration of the cleaning performance due to the excessive nitrogen concentration in FIG. 3 will be described using the first to third items and the equations (6), (7), (9).

  In the first to third matters described above, when the concentration of nitrogen dissolved in the cleaning liquid 700 becomes excessive, the nitrogen volume fraction ξ increases. As a result, the average viscosity η and the average density ρ are reduced from the equations (7) to (9), and the average elastic modulus K is significantly reduced. As a result, since the moving speed V is reduced from the equation (6), the cleaning performance is deteriorated.

  Further, due to the above-described first to third matters, the ultrasonic output value, which is a desired condition for ultrasonic cleaning, as shown in FIG. 4 together with FIG. 2 and FIG. The relationship with the number of elements on the main surface of the received object 800 to be cleaned is acquired.

  In FIG. 4, the concentration of nitrogen is, for example, 12 ppm. The number of elements on the main surface of the object 800 to be cleaned damaged by ultrasonic cleaning is the same as the defect inspection apparatus (manufactured by KLA-Tencor, model: ILM-2350) and defect review SEM after the ultrasonic cleaning process and the drying process. It is measured using an apparatus (manufactured by JEOL Ltd., model: JWS-7555S). As shown in FIG. 4, when the output value of the ultrasonic wave exceeds a certain value, an element is generated on the main surface of the cleaning object 800 damaged by the ultrasonic cleaning, and the output value of the ultrasonic wave increases. It can be seen that the number of elements on the main surface of the cleaning object 800 damaged by the ultrasonic cleaning increases.

  Further, according to the first to third matters described above, the number of elements on the main surface of the cleaning object 800 damaged by ultrasonic cleaning as shown in FIG. 5 together with FIGS. 2 to 4. The relationship with is acquired.

  In FIG. 5, the output value of the ultrasonic wave is 1200 W, for example. The number of elements on the main surface of the cleaning object 800 damaged by the ultrasonic cleaning is measured by the same method as in FIG.

  In addition, the element on the main surface of the cleaning object 800 damaged by the ultrasonic cleaning is expressed by the following fourth to sixth items.

Fourth matter
When ultrasonic vibration is applied to the cleaning liquid 700 by the vibrator 200, a high pressure area and a low pressure area are periodically generated in the cleaning liquid 700.

Fifth matter
The inertial force of the cleaning liquid 700 is generated with a sudden change in pressure. The inertial force is proportional to the effective sound pressure P expressed by Equation (5).

Sixth matter
The inertial force described above acts on the element disposed on the main surface of the object 800 to be cleaned, causing the element to collapse. As described above, the element on the main surface of the object to be cleaned 800 is damaged by the ultrasonic cleaning.

  As described above, as shown in the fourth to sixth items and FIG. 5, when the concentration of nitrogen increases, the number of elements on the main surface of the object 800 to be cleaned damaged by ultrasonic cleaning decreases. . It can be seen that when the concentration of nitrogen is 20 ppm, for example, even if the output value of the ultrasonic wave is as large as 1200 W, the number of elements on the main surface of the object 800 to be cleaned damaged by the ultrasonic cleaning is almost zero. Conversely, it can be seen that as the nitrogen concentration approaches, for example, 0 ppm, the number of elements on the main surface of the object 800 to be cleaned damaged by ultrasonic cleaning increases significantly.

  Here, regarding the decrease in the number of elements on the main surface of the cleaning object 800 damaged by the ultrasonic cleaning due to the excessive nitrogen concentration in FIG. 5, the fourth to sixth items and the equations (4), ( 5), (8), and (9) are used for explanation.

  According to the fourth to sixth items described above, when the output value of the ultrasonic wave increases, the vibration velocity ν in the equation (5) increases, and the inertial force described above increases. The number of elements on the main surface of the object to be cleaned 800 increases. If the concentration of nitrogen increases, the volume fraction ξ of nitrogen increases, and both the average sound velocity c and the average density ρ decrease according to the equations (4), (8), and (9). The effective sound pressure P is further reduced, and the aforementioned inertial force is reduced. As a result, the number of elements on the main surface of the cleaning object 800 damaged by the ultrasonic cleaning is reduced.

  2 to 5, the relationship between the nitrogen concentration, the ultrasonic output value, and the optimum ultrasonic output range as shown in FIG. 6 is calculated.

  A curve indicated by a solid line in FIG. 6 indicates the minimum value of the output value of the ultrasonic wave that is obtained from FIGS. 2 and 3 and obtains a cleaning performance of 80% or more. Further, the broken line indicates the minimum value of the output value of the ultrasonic wave that is obtained from FIGS. 4 and 5 when the element is generated on the main surface of the cleaning object 800 damaged by the ultrasonic cleaning. A region α indicated by shading is an optimum ultrasonic wave output range. The optimum ultrasonic output range is an ultrasonic output range in which no element is generated on the main surface of the object 800 to be cleaned, which is damaged by ultrasonic cleaning, and a cleaning performance of 80% or more is obtained.

  For example, when the concentration of nitrogen, which is measured by the gas concentration measuring unit 500 and dissolved in the cleaning liquid 700, is 15 ppm, the optimum ultrasonic output range is based on the optimum ultrasonic output range. 900W to 1200W. Therefore, the control unit 600 controls the oscillator 300 so that the output value of the ultrasonic wave is 900 W to 1200 W.

  The relationship between the nitrogen concentration, the ultrasonic output value, and the optimum ultrasonic output range shown in FIG. 6 is based on the shape and type of the object 800 and the object to be cleaned by the ultrasonic cleaning process as described above. It is stored in the recording device 630 (database) together with the type of the object to be removed from 800 and the elements on the main surface of the object 800 to be damaged by ultrasonic cleaning.

  Next, the operation of the ultrasonic cleaning apparatus 1 in the present embodiment will be described with reference to FIG.

  The propagation liquid preparation mechanism 150 starts supplying the propagation liquid 130, and the propagation liquid 130 is stored in the propagation tank 140 (Step 1). More specifically, in the propagation liquid 130 temporarily stored in the tank 151, the gas dissolved in the propagation liquid 130 is removed by the dissolved gas removal mechanism 152 and supplied to the propagation tank 140 via the supply pipe 141. Is done. Further, the propagation liquid 130 is discharged from the propagation tank 140 via the drainage pipe 142.

  The supply of the propagation liquid 130 is continuously continued from before the object 800 to be cleaned is accommodated in the processing tank 110 until the ultrasonic cleaning process for the object 800 is completed.

  The object to be cleaned 800 is accommodated in the treatment tank 110 (Step 2).

  The cleaning liquid preparation mechanism 120 starts supplying the cleaning liquid 700 to the gas dissolving unit 400 (Step 3). More specifically, the temperature of the cleaning liquid 700 temporarily stored in the tank 121 is adjusted by the temperature controller 122, and the flow rate is controlled by the pump 123 so as to be a desired flow rate. Then, the cleaning liquid 700 is supplied by the pump 123 to the gas dissolving part 400 via the supply pipe 124.

  The supply of the cleaning liquid 700 is continuously continued until the ultrasonic cleaning process for the object to be cleaned 800 is completed.

  The gas dissolving unit 400 removes the gas dissolved in the cleaning liquid 700 from the cleaning liquid 700, supplies the gas 410 to the cleaning liquid 700, and supplies the cleaning liquid 700 supplied with the gas 410 to the processing tank 110 and the gas concentration measuring unit 500. Supply (Step 4). More specifically, in the gas dissolving part 400, the cleaning liquid 700 is supplied with the gas 410 by the gas supply part 420 via the gas supply pipe 430 by removing the gas dissolved in the cleaning liquid 700 by the dissolved gas removing mechanism 440. The Thereafter, the cleaning liquid 700 flows into the supply pipe 111.

  Note that the removal of gas, the supply of gas 410, and the supply of cleaning liquid 700 are continuously continued until the ultrasonic cleaning process for the object to be cleaned 800 is completed.

  The gas concentration measuring unit 500 measures the concentration of the gas 410 dissolved in the cleaning liquid 700 and outputs the concentration information obtained by the measurement to the control unit 600 (Step 5).

  More specifically, a part of the cleaning liquid 700 that has flowed into the supply pipe 111 is stored in the measurement tank 520 via the branch pipe 510. The cleaning liquid 700 stored in the measurement tank 520 is heated by the heater 530, and the concentration of the gas 410 dissolved in the cleaning liquid 700 is measured by the measurement sensor 540. The concentration information of the gas 410 is input from the measurement sensor 540 to the control unit 600 through the signal input line 610. The measured cleaning liquid 700 flows again to the supply pipe 111 via the branch pipe 510.

  The measurement of the concentration and the input of the concentration information to the control unit 600 are continuously continued until the ultrasonic cleaning process for the object to be cleaned 800 is completed.

  The cleaning liquid preparation mechanism 120 supplies the cleaning liquid 700 to the processing tank 110 until the cleaning liquid 700 overflows in the processing tank 110 (Step 6). As a result, the object to be cleaned 800 is immersed in the cleaning liquid 700. Then, after overflowing the processing tank 110, the cleaning liquid 700 is temporarily stored in the outer tank 112 and is discharged via the drain pipe 113.

  The controller 600 calculates the optimum ultrasonic wave output range shown in FIGS. 2 to 6 based on the database. Then, the control unit 600 controls the output value of the ultrasonic wave that the oscillator 300 applies to the vibrator 200 based on the relationship between the concentration information of the gas 410 and the output range of the ultrasonic wave. The electric signal to be applied is controlled (Step 7).

  Specifically, the control unit 600 performs ultrasonic vibration with an ultrasonic output value corresponding to the concentration information output from the gas concentration measurement unit 500 based on the calculated ultrasonic output range. The oscillator 300 is controlled. As described above, the control unit 600 associates the concentration of the gas 410 dissolved in the cleaning liquid 700 with the output value of the ultrasonic wave applied from the oscillator 300 to the vibrator 200 based on the output range of the ultrasonic wave.

  The calculation of the optimal ultrasonic output range and the control of the ultrasonic output value applied to the transducer 200 corresponding to the concentration of the gas 410 are always continued in synchronization with Step 5.

  Since the database has been described above with reference to FIGS. 2 to 6, detailed description thereof will be omitted.

  Here, calculation of the output range of the ultrasonic wave based on the database in Step 7 will be described.

Example 1: When the concentration of nitrogen is 15 ppm.
In this case, as shown in FIG. 6, the optimum ultrasonic wave output range is 900 W to 1200 W. Therefore, the control unit 600 controls the oscillator 300 so that the output value of the ultrasonic wave is 900 W to 1200 W.

Example 2: When the concentration of nitrogen is 8 ppm.
In this case, as shown in FIG. 6, there is no optimal ultrasonic output range. Therefore, the control unit 600 sets the ultrasonic output value to 0 W in order to suppress damage to the object to be cleaned 800 (the number of elements on the main surface of the object 800 to be cleaned damaged by ultrasonic cleaning). The oscillator 300 is controlled to reduce the ultrasonic cleaning action. Next, the display unit 660 displays an alarm indicating that the nitrogen concentration is abnormal, and the recording device 630 records an alarm occurrence history.

  As described above, when the concentration value of the gas 410 is equal to or lower than the desired value, the control unit 600 controls the oscillator 300 so that the output value of the ultrasonic wave applied from the oscillator 300 to the vibrator 200 is lower than the desired value. To do. As a result, the control unit 600 reduces the ultrasonic cleaning processing action.

  The oscillator 300 is controlled by the control unit 600 and transmits an electric signal to be applied to the vibrator 200 to the vibrator 200 through the signal output line 320 to cause the vibrator 200 to vibrate ultrasonically (Step 8). Simultaneously with the ultrasonic vibration of the vibrator 200, the object 800 to be cleaned is subjected to an ultrasonic cleaning process.

  The oscillator 300 stops the ultrasonic vibration of the vibrator 200 (Step 9). After the stop, the cleaning liquid preparation mechanism 120 supplies the cleaning liquid 700 to the processing tank 110 continuously for a predetermined time. The object removed from the object to be cleaned 800 by the ultrasonic cleaning process flows into the outer tank 112 together with the cleaning liquid 700 that overflows from the processing tank 110, and is discharged through the drain pipe 113.

The cleaning object 800 is pulled up from the processing tank 110 and conveyed to a drying device (not shown) (Step 10). In the case where the cleaning liquid 700 is a chemical liquid, the object 800 to be cleaned is transported to the drying device through a rinsing process.
This completes the operation.

  As described above, in the present embodiment, the ultrasonic output range is calculated based on the database, and the ultrasonic output corresponding to the concentration of the gas 410 dissolved in the cleaning liquid 700 is calculated based on the calculated ultrasonic output range. The value of the oscillator 300 is controlled so as to vibrate ultrasonically.

  Thereby, in this embodiment, it is not necessary to prepare time for the gas 410 to be uniformly present in the cleaning liquid 700 without preparing a dangerous or harmful chemical substance or a high-pressure environment. The number of elements on the main surface of the object 800 to be cleaned damaged by ultrasonic cleaning can be suppressed to a desired value or less, and desired cleaning performance can be exhibited.

  Further, in the present embodiment, in order to ultrasonically clean the object to be cleaned 800 immersed in the cleaning liquid 700 in the treatment tank 110, ultrasonic cleaning is performed accurately and precisely without giving the surface of the object to be cleaned 800. Can do.

  Next, a second embodiment according to the present invention will be described with reference to FIGS. About the same structure as 1st Embodiment, description is abbreviate | omitted by attaching | subjecting the same referential mark as 1st Embodiment.

In the present embodiment, single wafer cleaning is used in which the cleaning object 800 is ultrasonically cleaned while discharging the cleaning liquid to the cleaning object 800.
Examples of the object 800 to be cleaned ultrasonically by the single wafer cleaning include substrates for semiconductor integrated devices, glass substrates for display devices, substrates for photomasks, substrates for optical disks, substrates for magnetic disks, and film substrates. Is preferred.

  The ultrasonic cleaning apparatus 1 includes a cleaning processing unit 100, an oscillator 300, a gas dissolving unit 400, a gas concentration measuring unit 500, and a control unit 600.

  The cleaning processing unit 100 includes a cleaning liquid preparation mechanism 120 that prepares the cleaning liquid 700, a holding mechanism 170 that holds the object to be cleaned 800, a rotation mechanism 180 that rotates the object to be cleaned 800 by rotating the holding mechanism 170, and a cleaning liquid. It has a nozzle 190 that is a discharge unit that discharges the cleaning liquid 700 that has been prepared by the preparation mechanism 120 and has propagated the ultrasonic vibration propagated by the oscillator 300 toward the main surface of the object 800 to be cleaned. ing.

  The holding mechanism 170 has a plurality of chuck pins 171 and a spin base 172. The chuck pins 171 hold a flat object to be cleaned 800 such as a substrate. Therefore, at least three chuck pins 171 are arranged along the peripheral edge of the upper surface of the spin base 172. The spin base 172 is a holding rotation unit that holds the chuck pin 171 and is rotated by the rotation mechanism 180.

  The rotation mechanism 180 is disposed on the lower surface side of the spin base 172. The rotation mechanism 180 has a rotation shaft 181 and a motor 182. The upper end of the rotation shaft 181 is fixed to the central portion of the lower surface of the spin base 172. The lower end of the rotating shaft 181 is connected to the motor 182. When the motor 182 is driven, the rotating shaft 181 rotates. As a result, the spin base 172 rotates, and the cleaning object 800 held by the chuck pins 171 rotates horizontally integrally with the spin base 172.

  The nozzle 190 is disposed above the holding mechanism 170 so as to face the main surface of the cleaning object 800 held by the chuck pin 171. The nozzle 190 is connected to the supply pipe 111 and is provided in the supply pipe 191 that supplies the cleaning liquid 700 to the object 800 to be cleaned, and the vibrator that irradiates the cleaning liquid 700 in the supply pipe 191 with ultrasonic vibration. 192.

  The discharge port 190 a of the nozzle 190 that is the outlet of the supply pipe 191 faces the upper surface of the spin base 172. In the nozzle 190, an opening 190 c is disposed between the inlet 190 b of the supply pipe 191 that is a connection portion with the supply pipe 111 and the outlet of the supply pipe 191. A vibration surface 192a of the vibrator 192 is attached to the opening 190c. The vibrator 192 is connected to the oscillator 300.

Next, the operation of the ultrasonic cleaning apparatus 1 of the present embodiment will be described with reference to FIG.
In the present embodiment, the cleaning liquid 700 is irradiated with ultrasonic vibration from the vibration surface 192a of the vibrator 192 via the cleaning liquid preparation mechanism 120, the gas dissolving unit 400, the supply pipe 111, and the inlet 190b. The liquid reaches the discharge port 190a and is discharged from the discharge port 190a toward the main surface of the cleaning object 800 held by the holding mechanism 170.

  In the operation of the ultrasonic cleaning apparatus 1, Step 3 to Step 5 and Step 7 are sequentially performed.

  The object 800 to be cleaned is held by the chuck pins 171 (Step 31).

  The motor 182 is driven to horizontally rotate the cleaning object 800 through the rotating shaft 181 and the spin base 172 (Step 32). Step 32 is always continued until the ultrasonic cleaning process for the object 800 to be cleaned is completed.

  The oscillator 300 causes the vibrator 192 to vibrate ultrasonically (Step 33). Accordingly, the vibrator 192 irradiates the cleaning liquid 700 with ultrasonic vibration.

  The nozzle 190 discharges the cleaning liquid 700 toward the main surface of the article 800 to be cleaned (Step 34). At this time, the object to be cleaned 800 is ultrasonically cleaned by the cleaning liquid 700 irradiated with ultrasonic vibration while being horizontally rotated by the motor 182.

  The nozzle 190 stops the discharge of the cleaning liquid 700, and the oscillator 300 stops the ultrasonic vibration of the vibrator 192. Thereafter, the motor 182 continues to rotate the object 800 for a certain period of time (Step 35).

  When the cleaning liquid 700 is a chemical liquid, the motor 182 continues to rotate the object 800 horizontally for a certain period of time after the nozzle 190 discharges the rinsed water toward the main surface of the object 800. .

  The object removed from the object to be cleaned 800 by the ultrasonic cleaning process is discharged together with the cleaning liquid flowing in the centrifugal direction (direction from the center of the object to be cleaned 800 toward the outer shape) by the horizontal rotation of the object to be cleaned 800 (Step 36). .

  The motor 182 stops and stops the horizontal rotation of the cleaning object 800 (Step 37).

  The object to be cleaned 800 is pulled up from the spin base 172 and conveyed to the next process (Step 38).

  As described above, in the present embodiment, the cleaning target 700 is held by the holding mechanism 170, and the cleaning target 700 is rotated by rotating the holding mechanism 170 by the rotating mechanism 180. Even if it is discharged toward the cleaning object 800, the same effect as in the first embodiment described above can be obtained.

  In this embodiment, since the propagation liquid preparation mechanism 150 and the vibrator 200 are not required, the entire ultrasonic cleaning apparatus 1 can be made compact and inexpensive.

  Further, this embodiment is particularly effective when the object to be cleaned 800 is a substrate.

  In the first and second embodiments described above, the ultrasonic cleaning apparatus 1 includes a semiconductor integrated device substrate, a display device glass substrate, a photomask substrate, an optical disk substrate, a magnetic disk substrate, a film substrate, and a mechanical component. For example, ultrasonic cleaning treatment is performed using water or chemicals irradiated with ultrasonic vibration.

  In the first and second embodiments described above, in the semiconductor integrated device manufacturing method, the object to be cleaned 800 is cleaned using the ultrasonic cleaning apparatus 1 in at least one of the manufacturing steps of the semiconductor integrated device.

  The present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Ultrasonic cleaning apparatus, 100 ... Cleaning process part, 110 ... Processing tank, 111 ... Supply piping, 112 ... Outer tank, 113 ... Drainage piping, 120 ... Cleaning liquid preparation mechanism, 121 ... Tank, 122 ... Temperature controller, DESCRIPTION OF SYMBOLS 123 ... Pump, 124 ... Supply piping, 130 ... Propagation liquid, 140 ... Propagation tank, 141 ... Supply piping, 142 ... Drainage piping, 150 ... Propagation liquid preparation mechanism, 151 ... Tank, 152 ... Dissolved gas removal mechanism, 170 ... Holding mechanism, 171 ... chuck pin, 172 ... spin base, 180 ... rotating mechanism, 181 ... rotating shaft, 182 ... motor, 190 ... nozzle, 191 ... supply piping, 192 ... vibrator, 192a ... vibrating surface, 200 ... vibrator , 300 ... oscillator, 320 ... signal output line, 400 ... gas dissolving part, 410 ... gas, 420 ... gas supply part, 430 ... gas supply pipe, 440 ... dissolved gas removal mechanism, 5 DESCRIPTION OF SYMBOLS 0 ... Gas concentration measurement part, 510 ... Branch piping, 520 ... Measurement tank, 530 ... Heater, 540 ... Measurement sensor, 600 ... Control part, 610 ... Signal input line, 620 ... Signal output line, 630 ... Recording apparatus, 640 ... Central processing unit, 650, operation unit, 660, display unit, 700, cleaning liquid, 800, object to be cleaned.

Claims (3)

A cleaning processing unit that ultrasonically cleans an object to be cleaned using a cleaning liquid;
The vibrator for irradiating the cleaning liquid with ultrasonic vibration;
In order to ultrasonically vibrate the vibrator by the piezoelectric effect, an oscillator that applies an electric signal having a desired frequency and a desired amplitude to the vibrator;
A gas dissolving part for dissolving a desired gas in the cleaning liquid; a gas concentration measuring part for measuring the concentration of the gas dissolved in the cleaning liquid;
The relationship between the desired conditions for ultrasonic cleaning and the cleaning performance based on the number of particles of the object to be removed remaining in the object to be cleaned; and the desired conditions for ultrasonic cleaning; Based on a database that stores the relationship between damage to the object to be cleaned and indicating the number of elements on the main surface of the object to be cleaned that has been damaged by ultrasonic cleaning, the damage to the object to be cleaned is less than a desired value A control unit for calculating an output range of ultrasonic waves for exhibiting desired cleaning performance while suppressing
Comprising
The control unit is configured so that the oscillator applies to the vibrator based on the relationship between the concentration of the gas dissolved in the cleaning liquid measured by the gas concentration measurement unit and the output range of the ultrasonic wave. An ultrasonic cleaning apparatus, wherein an output value of a sound wave is controlled, and an electric signal applied to the vibrator by the oscillator is controlled. The cleaning processing unit
A processing tank for storing the cleaning object and storing the cleaning liquid;
A cleaning liquid preparation mechanism for preparing the cleaning liquid stored in the processing tank;
A propagation tank for storing a propagation liquid that propagates ultrasonic vibrations irradiated by the vibrator to the cleaning liquid stored in the treatment tank;
A propagation liquid preparation mechanism for preparing the propagation liquid stored in the propagation tank;
The ultrasonic cleaning apparatus according to claim 1, comprising: The cleaning processing unit
A cleaning liquid preparation mechanism for preparing the cleaning liquid;
A holding mechanism for holding the object to be cleaned;
A rotating mechanism that rotates the object to be cleaned by rotating the holding mechanism;
A discharge section for discharging the cleaning liquid prepared by the cleaning liquid preparation mechanism and propagating ultrasonic vibrations by the oscillator toward the main surface of the object to be cleaned;
The ultrasonic cleaning apparatus according to claim 1, comprising:

Images