Processing liquid nozzle and cleaning apparatus

A processing liquid nozzle includes: an ultrasonic wave generator including a oscillator that generates ultrasonic waves and a oscillating body that is joined to the oscillator; a first supply flow path configured to supply a first liquid to a position in contact with the oscillating body of the ultrasonic wave generator; an ejection flow path configured to supply the first liquid to which the ultrasonic waves are applied by the ultrasonic wave generator to an ejection port; and a second supply flow path connected to the ejection flow path on a downstream side from the ultrasonic wave generator and configured to supply a second liquid to the ejection flow path.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national phase of PCT application No. PCT/JP2020/034618, filed on 14 Sep. 2020, which claims priority from Japanese patent application No. 2019-174136, filed on 25 Sep. 2019, all of which are incorporated herein by reference.

TECHNICAL FIELD

Embodiments disclosed relate to a processing liquid nozzle and a cleaning apparatus.

BACKGROUND

In the related art, a technology that cleans a surface of a substrate such as a semiconductor wafer (hereinafter, also referred to as a “wafer”) with a cleaning liquid, applied with ultrasonic waves and ejected from a processing liquid nozzle, is known (see Patent Document 1).

PRIOR ART DOCUMENT

Patent Document

DISCLOSURE OF THE INVENTION

Problems to be Solved

The present disclosure provides a technology capable of suppressing an oscillating body that applies ultrasonic waves to a cleaning liquid in a processing liquid nozzle from being damaged.

Means to Solve the Problem

A processing liquid nozzle according to an aspect of the present disclosure includes an ultrasonic wave generator, a first supply flow path, an ejection flow path, and a second supply flow path. The ultrasonic wave generator includes an oscillator that generates ultrasonic waves and an oscillating body that is connected to the oscillator. The first supply flow path supplies a first liquid to a position that is in contact with the oscillating body of the ultrasonic wave generator. The ejection flow path supplies the first liquid to which the ultrasonic waves are applied by the ultrasonic wave generator to an ejection port. The second supply flow path is connected to the ejection flow path on a downstream side from the ultrasonic wave generator and supplies a second liquid to the ejection flow path.

Effect of the Invention

According to the present disclosure, it is possible to suppress an oscillating body that applies ultrasonic waves to a cleaning liquid in a processing liquid nozzle from being damaged.

DETAILED DESCRIPTION TO EXECUTE THE INVENTION

Hereinafter, embodiments of a processing liquid nozzle and a cleaning apparatus disclosed herein will be described in detail with reference to the accompanying drawings. Further, the present disclosure is not limited to the following exemplary embodiments. Further, the drawings are schematic, and the relationship between dimensions of each element, the ratio of each element, or the like may differ from the actual situation. Portions having different dimensional relationships and ratios from each other may be included between drawings.

In the related art, a technology that cleans a surface of a substrate such as a semiconductor wafer (hereinafter, also referred to as a “wafer”) with a cleaning liquid applied with ultrasonic waves and ejected from a processing liquid nozzle, is known. Meanwhile, when an effervescent liquid is used as the cleaning liquid, the bubbles in the liquid are burst by the applied ultrasonic waves, and thus, the oscillating body that applies the ultrasonic waves may be damaged by the impact force when the bubbles are burst.

Therefore, it is expected to realize a technology capable of overcoming the above-described problems and suppressing an oscillating body that applies ultrasonic waves to a cleaning liquid in a processing liquid nozzle from being damaged.

[Outline of Substrate Processing System]

First of all, a schematic configuration of a substrate processing system1according to an embodiment will be described with reference toFIG.1.FIG.1is a view illustrating a schematic configuration of the substrate processing system1according to the embodiment. The substrate processing system1is an example of a cleaning apparatus. In the following, in order to clarify positional relationships, the X-axis, Y-axis, and Z-axis are defined as being orthogonal to each other. The positive Z-axis direction is regarded as a vertically upward direction.

As illustrated inFIG.1, the substrate processing system1includes a carry-in/out station2and a processing station3. The carry-in/out station2and the processing station3are provided adjacent to each other.

The carry-in/out station2is provided with a carrier placing section11and a transfer section12. In the carrier placing section11, a plurality of carriers C is placed to accommodate a plurality of substrates, that is, semiconductor wafers W (hereinafter, referred to as “wafers W”) in the embodiment, in a horizontal state.

The transfer section12is provided adjacent to the carrier placing section11, and provided with a substrate transfer device13and a delivery unit14therein. The substrate transfer device13is provided with a wafer holding mechanism that holds the wafers W. Further, the substrate transfer device13is movable horizontally and vertically and pivotable around a vertical axis, and transfers the wafers W between the carriers C and the delivery unit14by using the wafer holding mechanism.

The processing station3is provided adjacent to the transfer section12. The processing station3is provided with a transfer section15and a plurality of processing units16. The plurality of processing units16are arranged at both sides of the transfer section15.

The transfer section15is provided with a substrate transfer device17therein. The substrate transfer device17is provided with a wafer holding mechanism that holds the wafer W. Further, the substrate transfer device17is movable horizontally and vertically and pivotable around a vertical axis, and transfers the wafers W between the delivery unit14and the processing units16by using the wafer holding mechanism.

Each processing unit16performs a predetermined substrate processing on the wafers W transferred by the substrate transfer device17.

Further, the substrate processing system1is provided with a control device4. The control device4is, for example, a computer, and includes a controller18and a storage unit19. The storage unit19stores a program that controls various processings performed in the substrate processing system1. The controller18controls the operations of the substrate processing system1by reading and executing the program stored in the storage unit19.

The program may be recorded in a computer-readable recording medium, and installed from the recording medium to the storage unit19of the control device4. The computer-readable recording medium may be, for example, a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), or a memory card.

In the substrate processing system1configured as described above, the substrate transfer device13of the carry-in/out station2first takes out a wafer W from a carrier C placed in the carrier placing section11, and then, places the taken wafer W on the delivery unit14. The wafer W placed on the delivery unit14is taken out from the delivery unit14by the substrate transfer device17of the processing station3, and carried into a processing unit16.

The wafer W carried into the processing unit16is processed by the processing unit16, and then, carried out from the processing unit16and placed on the delivery unit14by the substrate transfer device17. Then, the processed wafer W placed on the delivery unit14is returned to the carrier C of the carrier placing section11by the substrate transfer device13.

[Configuration of Processing Unit]

Next, a configuration of the processing unit16will be described with reference toFIG.2.FIG.2is a schematic view illustrating an example of the configuration of the processing unit16according to the embodiment. As illustrated inFIG.2, the processing unit16is provided with a chamber20, a substrate processing unit30, a liquid supply40, and a recovery cup50.

The chamber20accommodates the substrate processing unit30, the liquid supply40, and the recovery cup50. A fan filter unit (FFU)21is provided on the ceiling of the chamber20. The FFU21forms a downflow in the chamber20.

The substrate processing unit30is provided with a holder31, a column32, and a driver33, and performs a liquid processing on the placed wafer W. The holder31holds the wafer W horizontally. The column32is a vertically extending member, is rotatably supported at the base end portion thereof by the driver33, and supports the holder31horizontally at the tip end portion thereof. The driver33rotates the column32around the vertical axis.

The substrate processing unit30rotates the column32by using the driver33, so that the holder31supported by the column32is rotated, and thus, the wafer W held in the holder31is rotated.

A holding member31ais provided on the upper surface of the holder31provided in the substrate processing unit30to hold the wafer W from the lateral side. The wafer W is held horizontally by the holding member31ain a state of being slightly separated from the upper surface of the holder31. The wafer W is held by the holder31in a state where the surface on which the substrate processing is performed faces upward.

The liquid supply40supplies a processing fluid onto the wafer W. The liquid supply40includes a plurality of (here, two) nozzles41aand41b, arms42aand42bthat horizontally support the nozzles41aand41b, respectively, and pivoting and lifting mechanisms43aand43bthat pivot and lift the arms42aand42b, respectively. The nozzle41ais an example of a processing liquid nozzle.

The nozzle41ais connected to a first liquid supply46avia a valve44aand a flow rate regulator45a, and is connected to a second liquid supply46bvia a valve44band a flow rate regulator45b.

A first liquid L1supplied from the first liquid supply46a(seeFIG.3) is a chemical liquid having a strong acidity or a strong alkalinity, and is, for example, concentrated sulfuric acid or ammonia. A second liquid L2supplied from the second liquid supply46b(seeFIG.3) is a chemical liquid having an effervescent property, and is, for example, hydrogen peroxide solution or deionized water (DIW).

In the present disclosure, “the second liquid L2has an effervescent property” is not limited to a case where the second liquid L2foams by itself, but also includes a case where the second liquid L2foams for the first time when mixed with another liquid (e.g., the first liquid L1).

The nozzle41bis connected to a DIW supply source46cthrough a valve44cand a flow rate regulator45c. DIW is used for, for example, a rinse processing. The processing liquid used for the rinse processing is not limited to DIW.

A mixed liquid M (seeFIG.3) in which the first liquid L1supplied from the first liquid supply46aand the second liquid L2supplied from the second liquid supply46bare mixed is ejected from the nozzle41a. Details of the nozzle41awill be described later. From the nozzle41b, the DIW supplied from the DIW supply source46cis ejected.

The recovery cup50is disposed to surround the holder31, and collects the processing liquid scattered from the wafer W by the rotation of the holder31. A drain port51is formed on the bottom of the recovery cup50, and the processing liquid collected by the recovery cup50is discharged from the drain port51to the outside of the processing unit16. Further, an exhaust port52is formed on the bottom of the recovery cup50to discharge a gas supplied from the FFU21to the outside of the processing unit16.

While descriptions have been made on an example in which two nozzles are provided in the processing unit16of the embodiment, the number of nozzles provided in the processing unit16is not limited to two.

[Details of Processing Liquid Nozzle]

Next, descriptions will be made on details of the nozzle41a, which is an example of the processing liquid nozzle according to the embodiment, with reference toFIG.3.FIG.3is a view illustrating the configuration of the processing liquid nozzle according to the embodiment.

As illustrated inFIG.3, the nozzle41ais provided with an ultrasonic wave generator60, a first supply flow path71, an ejection flow path72, and a second supply flow path73. The nozzle41agenerates the mixed liquid M by mixing the first liquid L1supplied from the first supply flow path71and the second liquid L2supplied from the second supply flow path73, applies ultrasonic waves S to the mixed liquid M, and ejects the mixed liquid M from an ejection port74to the wafer W.

Here, as illustrated inFIG.3, the mixed liquid M ejected from the ejection port74is ejected to the wafer W without being interrupted, and thus, the ultrasonic waves S applied by the ultrasonic wave generator60are able to be transmitted to the mixed liquid M arrived onto the wafer W.

That is, when cleaning the wafer W with the mixed liquid M, the nozzle41aaccording to the embodiment may clean the wafer W using the physical force of the ultrasonic wave S. Therefore, according to the embodiment, even when a film (e.g., a sacrificial film) having a high chemical stability is formed on the wafer W, the film having a high chemical stability may be removed with high cleaning capability.

Next, details of each part of the nozzle41awill be described. The ultrasonic wave generator60includes an oscillator61and an oscillating body62.

The oscillator61is made of piezoelectric ceramics such as lead zirconate titanate (PZT). A drive signal having a predetermined oscillation frequency from the outside, and thus, the oscillator61generates the ultrasonic waves S having such a predetermined oscillation frequency. The oscillator61may generate the ultrasonic waves S having a relatively high frequency, for example, 200 KHz or more.

The oscillating body62is firmly connected to the oscillator61. That is, in the ultrasonic wave generator60, the oscillating body62and the oscillator61are configured to oscillate integrally, and thus, the oscillating body62has a function as a load at the time of oscillation.

Therefore, according to the embodiment, by directly bringing the oscillating body62into contact with the first liquid L1to apply the ultrasonic waves S, the fluctuation of impedance may be reduced as compared with a case where the oscillator61is directly brought into contact with the first liquid L1to apply the ultrasonic waves S thereto.

The oscillating body62is made of an inorganic material having chemical resistance and heat resistance. The oscillating body62is made of, for example, a mineral-based material such as quartz or sapphire, or a ceramic material such as alumina, titania, silica, or silicon carbide.

The first supply flow path71supplies the first liquid L1to a position that is in contact with the oscillating body62of the ultrasonic wave generator60. The first supply flow path71is connected to the upstream side of the ejection flow path72in which the oscillating body62is provided. Then, the first supply flow path71supplies the first liquid L1to the upstream side of the ejection flow path72via the first liquid supply46a, the valve44a, and the flow rate regulator45a.

The ejection flow path72is formed inside the nozzle41aso as to extend downward in a straight line. In the ejection flow path72, the oscillating body62of the ultrasonic wave generator60is provided on the upstream side, and the ejection port74of the nozzle41ais formed on the downstream side. Then, the ejection flow path72supplies the first liquid L1to which the ultrasonic waves S are applied by the ultrasonic wave generator60or the mixed liquid M generated by using the first liquid L1to the ejection port74.

In the embodiment, since the ejection flow path72is formed in a straight line, the ultrasonic waves S applied by the ultrasonic wave generator60may be smoothly transmitted to the surface of the wafer W.

The second supply flow path73supplies the second liquid L2to the ejection flow path72. The second supply flow path73is connected to the ejection flow path72on the downstream side from the ultrasonic wave generator60. Then, the second supply flow path73supplies the second liquid L2to the ejection flow path72on the downstream side from the ultrasonic wave generator60via the second liquid supply46b, the valve44b, and the flow rate regulator45b.

Then, by supplying the second liquid L2from the second supply flow path73to the ejection flow path72, the mixed liquid M of the first liquid L1and the second liquid L2is generated inside the ejection flow path72. Then, in the embodiment, since the second liquid L2has an effervescent property, bubbles B are contained in at least the mixed liquid M.

When hydrogen peroxide solution is used as the second liquid L2, the second liquid L2itself has an effervescent property, and thus, as illustrated inFIG.3, in addition to the mixed liquid M, the second liquid L2also contains the bubbles B.

Here, in the embodiment, by connecting the second supply flow path73to the downstream side from the ultrasonic wave generator60, the mixed liquid M containing the bubbles B may be generated on the downstream side from the ultrasonic wave generator60.

That is, in the embodiment, since the mixed liquid M containing the bubbles B may be generated at a position separated from the ultrasonic wave generator60, even when the bubbles B in the mixed liquid M are burst due to the ultrasonic waves S, the impact force generated when such bubbles B are burst may be hardly transmitted to the oscillating body62.

Therefore, according to the embodiment, the oscillating body62may be suppressed from being damaged inside the nozzle41adue to the ultrasonic waves S applied to the mixed liquid M and the bubbles B contained in the mixed liquid M.

Further, in the embodiment, since the mixed liquid M having an effervescent property is positioned on the downstream side of the ejection flow path72, when the cleaning processing is completed and the ejection of the mixed liquid M is stopped, the amount of the mixed liquid M remaining inside the nozzle41amay be suppressed to the minimum.

Therefore, when the foaming continues inside the mixed liquid M and the volume of the mixed liquid M expands, the expansion of the volume may be suppressed to the minimum. Therefore, according to the embodiment, the mixed liquid M may be suppressed from expanding and dripping from the ejection port74when the ejection of the mixed liquid M is stopped.

Further, in the embodiment, the first liquid L1may have a strong acidity or a strong alkalinity, and the second liquid L2may have an effervescent property. Therefore, even when a film having a high chemical stability such as a sacrificial film is formed on the wafer W, the film having a high chemical stability may be removed with high cleaning capability.

Further, in the embodiment, a static elimination unit (not illustrated) configured to statically eliminate the mixed liquid M ejected from the ejection port74may further be provided. Such a static elimination unit is constituted by, for example, a wiring connecting between the main body of the nozzle41aand the ultrasonic wave generator60, or the ground potential.

Therefore, when charging or arcing of the wafer W becomes a problem, the charging or arcing of the wafer W may be suppressed form occurring when the cleaning processing using the mixed liquid M is performed.

Further, the upstream side of the second supply flow path73is connected to a drain unit DR via a valve81. The valve81and the drain unit DR are positioned below the second supply flow path73. Subsequently, details of a liquid dripping suppression processing using the valve81will be described with reference toFIGS.4and5.

FIGS.4and5are views illustrating the liquid dripping suppression processing of the processing liquid nozzle according to the embodiment. Further,FIG.4illustrates a case where the cleaning processing of the wafer W is performed by ejecting the mixed liquid M to which the ultrasonic waves S are applied from the nozzle41a.

When the cleaning processing of the wafer W is performed using the nozzle41a, both the valve44aconnected to the first supply flow path71and the valve44bconnected to the second supply flow path73are opened (also indicated as “O” in the following drawings).

Further, in this case, the valve81is closed (also indicated as “C” in the following drawings), and the ultrasonic waves S are output from the ultrasonic wave generator60. Therefore, the mixed liquid M to which the ultrasonic waves S are applied may be ejected from the ejection port74of the nozzle41a.

Then, when the cleaning processing of the wafer W is completed and the ejection of the mixed liquid M is ended, as illustrated inFIG.5, the controller18(seeFIG.1) first stops the output of the ultrasonic wave S by the ultrasonic wave generator60(step S01). Next, the controller18closes the valve44a, and stops the supply of the first liquid L1to the ejection flow path72(step S02).

In this manner, by stopping the supply of the first liquid L1after the output of the ultrasonic wave S is stopped, the ultrasonic wave generator60may be suppressed from wasting the ultrasonic waves S. Therefore, according to the embodiment, the ultrasonic wave generator60may be suppressed from being damaged by wasting the ultrasonic waves S.

Next, the controller18closes the valve44b, and stops the supply of the second liquid L2to the ejection flow path72(step S03). This step S03may be performed at the same time as step S02described above.

Then, the controller18opens the valve81, and discharges the second liquid L2remaining in the second supply flow path73to the drain unit DR (step S04). Therefore, the mixed liquid M remaining in the vicinity of the ejection port74may be returned to the upstream side of the ejection flow path72.

By the processing that has been described, in the embodiment, the mixed liquid M remaining in the vicinity of the ejection port74may be suppressed from dripping to the outside.

When the cleaning processing of the wafer W is started again, the ultrasonic waves S may be output from the ultrasonic wave generator60after the first liquid L1is supplied from the first supply flow path71to the ejection flow path72. Therefore, the ultrasonic wave generator60may be suppressed from wasting the ultrasonic waves S, and thus, the ultrasonic wave generator60may be suppressed from being damaged by wasting the ultrasonic waves S.

Further, in the example inFIGS.4and5, the example in which the second liquid L2remaining in the second supply flow path73is discharged to the drain unit DR due to its own weight by using the valve81provided below the second supply flow path73is illustrated. However, in the embodiment, the second liquid L2remaining in the second supply flow path73may be forcibly discharged to the drain unit DR.

For example, the second liquid L2remaining in the second supply flow path73may be forcibly discharged to the drain unit DR by adding an aspirator or an ejector between the valve81and the second supply flow path73and operating the aspirator or the ejector.

Subsequently, an appropriate dimension of each part in the nozzle41awill be described with reference toFIG.6.FIG.6is a view illustrating the configuration of the processing liquid nozzle according to the embodiment.

In the following description, as illustrated inFIG.6, an inner diameter of the first supply flow path71is Da, an inner diameter of the ejection flow path72is Db, an inner diameter of the second supply flow path73is Dc, and a diameter of the ejection port74is Dd. Further, in the ejection flow path72, a length from the connection portion with the first supply flow path71to the connection portion with the second supply flow path73is La, and a length from the connection portion with the second supply flow path73to the ejection port74is Lb.

In the embodiment, the length La from the connection portion with the first supply flow path71to the connection portion with the second supply flow path73may be equal to or larger than the diameter Dd of the ejection port74. Therefore, the bubbles B contained in the second liquid L2or the mixed liquid M may be suppressed from flowing back to the vicinity of the oscillating body62.

Therefore, according to the embodiment, the oscillating body62may be further suppressed from being damaged inside the nozzle41adue to the bubbles B. The diameter Dd of the ejection port74itself is not particularly limited, and may be appropriately set according to the ejection flow rate of the mixed liquid M required for the cleaning processing of the wafer W.

Further, the inner diameter Da of the first supply flow path71or the inner diameter Dc of the second supply flow path73are not particularly limited, and may be appropriately set according to the supply flow rate of the first liquid L1and the second liquid L2required for the cleaning processing of the wafer W.

For example, when the mixing ratio of the first liquid L1and the second liquid L2is 2:1, the ratio of the inner diameter Da and the inner diameter Dc may be set to 2:1, or the inner diameter Da and the inner diameter Dc may be set to the same value.

Further, in the embodiment, the length Lb from the connection portion with the second supply flow path73to the ejection port74may be equal to or larger than the diameter Dd of the ejection port74. Therefore, a sufficient length of the flow path may be secured for mixing the first liquid L1and the second liquid L2.

Further, in the embodiment, when the viscosity of the first liquid L1is larger than the viscosity of the second liquid L2, the length Lb from the connection portion with the second supply flow path73to the ejection port74may be longer than the length La from the connection portion with the first supply flow path71to the connection portion with the second supply flow path73.

In this manner, when the second liquid L2has a low viscosity, it is possible for the mixed liquid M in the vicinity of the ejection port74to secure a sufficient surface tension by setting the value of the length Lb to be large. Therefore, according to the embodiment, the mixed liquid M may be suppressed from dripping from the ejection port74. When the second liquid L2has a high viscosity, the value of the length Lb may be set to be small.

Further, in the embodiment, when the flow rate of the first liquid L1is smaller than the flow rate of the second liquid L2, the length La from the connection portion with the first supply flow path71to the connection portion with the second supply flow path73may be longer than the length Lb from the connection portion with the second supply flow path73to the ejection port74.

In this manner, when the flow rate of the first liquid L1is smaller than the flow rate of the second liquid L2, the second liquid L2may be suppressed from flowing back to the first supply flow path71by setting the value of the length La to be large.

In this manner, when the flow rate of the first liquid L1is larger than the flow rate of the second liquid L2, the second liquid L2is less likely to flow back to the first supply flow path71.

Further, in the embodiment, the supply pressure of the first liquid L1may be larger than the supply pressure of the second liquid L2. Therefore, even when the length La from the connection portion with the first supply flow path71to the connection portion with the second supply flow path73is set to be short, the second liquid L2may be suppressed from flowing back to the first supply flow path71.

Further, in the embodiment, when reaction heat is generated when the first liquid L1and the second liquid L2are mixed, the length La from the connection portion with the first supply flow path71to the connection portion with the second supply flow path73may be longer than the length Lb from the connection portion with the second supply flow path73to the ejection port74.

In this manner, when the reaction heat is generated when the first liquid L1and the second liquid L2are mixed, the reaction heat generated by the mixed liquid M may be suppressed from being transmitted to the oscillating body62by setting the value of the length La to be large.

Therefore, according to the embodiment, the connected surface of the oscillating body62and the oscillator61may be suppressed from being damaged due to the reaction heat generated by the mixed liquid M.

In the embodiment, the temperature of the first liquid L1itself that is brought into contact with the oscillating body62may be low (e.g., room temperature or lower). Therefore, the connected surface of the oscillating body62and the oscillator61may be suppressed from being damaged.

Further, in the embodiment, the inner diameter Db of the ejection flow path72may be equal to the diameter Dd of the ejection port74. Therefore, it is possible to minimize the pressure loss of the first liquid L1or the mixed liquid M flowing through the ejection flow path72, and thus, the mixed liquid M may be efficiently ejected.

The inner diameter Db of the ejection flow path72is not limited to be equal to the diameter Dd of the ejection port74.FIG.7is a view illustrating a configuration of a processing liquid nozzle according to a modification of the embodiment. As illustrated inFIG.7, in the modification, an inner diameter Db1of the ejection flow path72on the upstream side is larger than the diameter Dd of the ejection port74. That is, in the modification, the inner diameter Db1of the ejection flow path72on the upstream side is larger than an inner diameter Db2on the downstream side connected to the ejection port74.

Therefore, the diameter Dd of the ejection port74may be appropriately set according to the ejection flow rate of the mixed liquid M (seeFIG.3) required for the cleaning processing of the wafer W, and the oscillating body62having a larger size than the diameter Dd may be provided on the upstream side of the ejection flow path72.

Therefore, according to the modification, the ultrasonic waves S (seeFIG.3) having a higher output may be applied to the mixed liquid M, and thus, the wafer W may be cleaned with higher cleaning capability.

Further, in the modification, a taper72amay be provided at a portion of the ejection flow path72where the inner diameter is changed from Db to Dc. Therefore, the ultrasonic waves S transmitted from the oscillating body62may be suppressed from hitting the inner wall of the ejection flow path72and directly bouncing back to the oscillating body62.

Further, in the embodiment that has been described, the example in which the mixed liquid M is generated by mixing two kinds of liquids is illustrated. However, the mixed liquid M may be generated by mixing three or more kinds of liquids. For example, the mixed liquid M may be generated by using ammonia as the first liquid L1, hydrogen peroxide solution as the second liquid L2, and DIW as a third liquid.

Then, when the mixed liquid M is generated by further mixing the third liquid, a third supply flow path that supplies the third liquid may be connected to the first supply flow path71, or to the ejection flow path72on the upstream side from the connection portion with the second supply flow path73.

Further, in the example inFIG.3, the example in which the mixed liquid M is ejected to the wafer W with the ejection flow path62directed substantially vertically is illustrated. However, the mixed liquid may be ejected to the wafer W with the ejection flow path62directed diagonally. Therefore, the mixed liquid M bounced back from the wafer W may be suppressed from adhering to the nozzle41and contaminating the nozzle41a.

Further, in this case, the controller18may control the position of the nozzle41aso that the mixed liquid M is ejected in the direction facing the rotation direction of the wafer W in the first half portion of the cleaning processing of the wafer W, and the mixed liquid M is ejected in the direction along the rotation direction of the wafer W in the latter half portion of the cleaning processing.

Therefore, in the first half portion of the cleaning processing, the residence time of the ultrasonic wave S on the wafer W may further extend, and thus, the film having high chemical stability may be efficiently removed. Further, in the latter half portion of the cleaning processing, the residence time of the ultrasonic wave S on the wafer W may be short, and thus, the surface of the wafer W from which the film is peeled may be suppressed from being damaged.

[Detail of Liquid Dripping Suppress Mechanism]

Subsequently, details of a liquid dripping suppress mechanism according to the embodiment will be described with reference toFIGS.8to10.FIG.8is a view illustrating a configuration of a dummy dispense bath82according to the embodiment. The dummy dispense bath82described in the following is an example of the liquid dripping suppress mechanism.

The dummy dispense bath82is provided inside the chamber20(FIG.2) of the processing unit16(seeFIG.2), and is disposed below the standby position of the nozzle41a. During the dummy dispense processing for the purpose of eliminating air bubbles or foreign substances in each flow path connected to the nozzle41a, the dummy dispense bath82receives the mixed liquid M ejected from the nozzle41a, and discharge the received mixed liquid M to the drain unit DR.

Further, in addition to the function of receiving the mixed liquid M ejected from the nozzle41a, the dummy dispense bath82according to the embodiment is provided with a suction nozzle83that sucks the droplets of the mixed liquid M adhering to the ejection port74of the nozzle41a.

Then, the suction nozzle83is operated to suck the droplets of the mixed liquid M adhering to the ejection port74of the nozzle41a, and thus, the mixed liquid M may be suppressed from dripping from the ejection port74.

Further, before the wafer W is cleaned by the substrate processing unit30, the controller18may use the suction nozzle83to suck the mixed liquid M adhering to the ejection port74of the nozzle41awaiting in the dummy dispense bath82.

Therefore, when the nozzle41ais moved above the wafer W before the cleaning processing, the mixed liquid M may be suppressed from mistakenly dripping onto the wafer W.

In the example inFIG.8, the example in which the suction nozzle83is provided in the dummy dispense bath82is illustrated. However, the location in which the suction nozzle83is provided is not limited to the dummy dispense bath82.FIG.9is a view illustrating a configuration of a processing liquid nozzle according to another modification of the embodiment.

As illustrated inFIG.9, the above-described suction nozzle83may be provided on the arm42aso that the suction port is provided in the vicinity of the ejection port74of the nozzle41a. Therefore, even in a state where the nozzle41ais not waiting at the standby position, the mixed liquid M may be suppressed from dripping from the ejection port74.

For example, in an example inFIG.9, the suction nozzle83may be operated when the cleaning processing is completed and the nozzle41ais returned to the standby position so as to suck the droplets of the mixed liquid M adhering to the ejection port74of the nozzle41a.

FIG.10is a view illustrating a configuration of the dummy dispense bath82according to a modification of the embodiment. As illustrated inFIG.10, in addition to the function of receiving the mixed liquid M ejected from the nozzle41a, the dummy dispense bath82according to the modification is provided with an air blower84that air-blows the droplets of the mixed liquid M adhering to the ejection port74of the nozzle41a.

Then, the air blower84is operated to air-blow the droplets of the mixed liquid M adhering to the ejection port74of the nozzle41a, and thus, the mixed liquid M may be suppressed from dripping from the ejection port74.

Further, before the wafer W is cleaned by the substrate processing unit30, the controller18may use the air blower84to air-blow the mixed liquid M adhering to the ejection port74of the nozzle41awaiting in the dummy dispense bath82.

Therefore, when the nozzle41ais moved above the wafer W before the cleaning processing, the mixed liquid M may be suppressed from mistakenly dripping onto the wafer W. The droplets of the mixed liquid M air-blown by the air blower84are received by the dummy dispense bath82and are discharged to the drain unit DR.

The processing liquid nozzle (nozzle41a) according to the embodiment is provided with the ultrasonic wave generator60, the first supply flow path71, the ejection flow path72, and the second supply flow path73. The ultrasonic wave generator60includes the oscillator61that generates the ultrasonic waves S and the oscillating body62connected to the oscillator61. The first supply flow path71supplies the first liquid L1to the position that is in contact with the oscillating body62of the ultrasonic wave generator60. The ejection flow path72supplies the first liquid L1to which the ultrasonic waves S are applied by the ultrasonic wave generator60to the ejection port74. The second supply flow path73is connected to the ejection flow path72on the downstream side from the ultrasonic wave generator60, and supplies the second liquid L2to the ejection flow path72. Therefore, the oscillating body62may be suppressed from being damaged inside the nozzle41adue to the ultrasonic waves S applied to the mixed liquid M and the bubbles B contained in the mixed liquid M.

Further, in the processing liquid nozzle (nozzle41a) according to the embodiment, the first liquid L1has a strong acidity or a strong alkalinity, and the second liquid L2has an effervescent property. Therefore, even when a film having a high chemical stability such as a sacrificial film is formed on the wafer W, the film having a high chemical stability may be removed with high cleaning capability.

Further, in the processing liquid nozzle (nozzle41a) according to the embodiment, in the ejection flow path72, the length La from the connection portion with the first supply flow path71to the connection portion with the second supply flow path73is equal to or larger than the diameter Dd of the ejection port74. Therefore, the oscillating body62may be further suppressed from being damaged inside the nozzle41adue to the bubbles B.

Further, in the processing liquid nozzle (nozzle41a) according to the embodiment, in the ejection flow path72, the length Lb from the connection portion with the second supply flow path73to the ejection port74is equal to or larger than the diameter Dd of the ejection port74. Therefore, a sufficient length of the flow path may be secured for mixing the first liquid L1and the second liquid L2.

Further, in the processing liquid nozzle (nozzle41a) according to the embodiment, the inner diameter Db of the ejection flow path72is equal to the diameter Dd of the ejection port74. Therefore, it is possible to minimize the pressure loss of the first liquid L1or the mixed liquid M flowing through the ejection flow path72, and thus, the mixed liquid M may be efficiently ejected.

Further, in the processing liquid nozzle (nozzle41a) according to the embodiment, the inner diameter Db1of the ejection flow path72on the upstream side is larger than the diameter Dd of the ejection port74. Therefore, since the ultrasonic waves S having a higher output may be applied to the mixed liquid M, the wafer W may be cleaned with higher cleaning capability.

Further, in the processing liquid nozzle (nozzle41a) according to the embodiment, when the viscosity of the first liquid L1is larger than the viscosity of the second liquid L2, the length Lb is longer than the length La. The length Lb is the length from the connection portion with the second supply flow path73to the ejection port74in the ejection flow path72, and the length La is the length from the connection portion with the first supply flow path71to the connection portion with the second supply flow path73in the ejection flow path72. Therefore, the mixed liquid M may be suppressed from dripping from the ejection port74.

Further, in the processing liquid nozzle (nozzle41a) according to the embodiment, when the flow rate of the first liquid L1is smaller than the flow rate of the second liquid L2, the length La is longer than the length Lb. Therefore, the second liquid L2may be suppressed from flowing back to the first supply flow path71.

Further, in the processing liquid nozzle (nozzle41a) according to the embodiment, the supply pressure of the first liquid L1is larger than the supply pressure of the second liquid L2. Therefore, even when the length La from the connection portion with the first supply flow path71to the connection portion with the second supply flow path73is set to be short, the second liquid L2may be suppressed from flowing back to the first supply flow path71.

Further, in the processing liquid nozzle (nozzle41a) according to the embodiment, when the reaction heat is generated when the first liquid L1and the second liquid L2are mixed, the length La is longer than the length Lb. Therefore, the connected surface of the oscillating body62and the oscillator61may be suppressed from being damaged due to the reaction heat generated from the mixed liquid M.

Further, the processing liquid nozzle (nozzle41a) according to the embodiment is further provided with the third supply flow path that is connected to the first supply flow path71, or to the ejection flow path72on the upstream side from the connection portion with the second supply flow path73, and supplies the third liquid. Therefore, the cleaning processing may be performed with the mixed liquid M in which three kinds of liquids are mixed.

Further, the processing liquid nozzle (nozzle41a) according to the embodiment is further provided with the static elimination unit configured to statically eliminate the mixed liquid M ejected from the ejection port74. Therefore, when charging or arcing of the wafer W becomes a problem, the charging or arcing of the wafer W may be suppressed form occurring when the cleaning processing using the mixed liquid M is performed.

The cleaning apparatus (substrate processing system1) according to the embodiment is provided with the above-described processing liquid nozzle (nozzle41a), and the substrate processing unit30that holds and rotates the substrate (waver W). Therefore, it is possible to realize a cleaning apparatus in which damage to the oscillating body62is suppressed inside the nozzle41a.

Further, the cleaning apparatus (substrate processing system1) according to the embodiment is further provided with the dummy dispense bath82provided at the standby position of the processing liquid nozzle (nozzle41a). Then, the dummy dispense bath82includes the suction nozzle83that sucks the liquid (mixed liquid M) adhering to the ejection port74. Therefore, the mixed liquid M may be suppressed from dripping from the ejection port74.

Further, the cleaning apparatus (substrate processing system1) according to the embodiment is further provided with the controller18that controls each part. Then, before the substrate (wafer W) is processed by the substrate processing unit30, the controller18uses the suction nozzle83to suck the liquid (mixed liquid M) adhering to the ejection port74of the processing liquid nozzle (nozzle41a) waiting in the dummy dispense bath82. Therefore, when the nozzle41ais moved above the wafer W before the cleaning processing, the mixed liquid M may be suppressed from mistakenly dripping onto the wafer W.

Further, the cleaning apparatus (substrate processing system1) according to the embodiment is further provided with the dummy dispense bath82provided at the standby position of the processing liquid nozzle (nozzle41a). Then, the dummy dispense bath82includes the air blower84that air-blows the liquid (mixed liquid M) adhering to the ejection port74. Therefore, the mixed liquid M may be suppressed from dripping from the ejection port74.

Further, the cleaning apparatus (substrate processing system1) according to the embodiment is further provided with the controller18that controls each part. Then, before the substrate (wafer W) is processed by the substrate processing unit30, the controller18uses the air blower84to air-blow the liquid (mixed liquid M) adhering to the ejection port74of the processing liquid nozzle (nozzle41a) waiting in the dummy dispense bath82. Therefore, when the nozzle41ais moved above the wafer W before the cleaning processing, the mixed liquid M may be suppressed from mistakenly dripping onto the wafer W.

In the above, although the embodiment of the present disclosure has been described, the present disclosure is not limited to the above embodiment, and various modifications may be made without departing from the gist of the present disclosure. For example, in the above embodiment, the example in which the nozzle41ais applied for the cleaning processing of the wafer W is described. However, the processing in which the nozzle41ais applied is not limited to the cleaning processing of the wafer W, but the nozzle41amay be applied to various liquid processings.

It should be considered that the embodiments disclosed in here are exemplary and not restrictive in all aspects. In practice, the embodiments described above may be implemented in various forms. Further, the above embodiments may be omitted, replaced, or changed in various forms without departing from the scope of accompanying claims and the gist thereof.

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