Ultrasonic cleaning unit for improved cleaning performance and substrate cleaning equipment including the same.

Abstract

This invention relates to an ultrasonic cleaning unit that improves the overall substrate cleaning performance by improving the structure of the cleaning head of the ultrasonic cleaning unit. The unit includes: a drive unit that receives an external power source to cause an internal vibrator to vibrate; and a cleaning head that protrudes downward from the bottom of the drive unit, acoustically couples with the vibrator to transmit high-frequency acoustic energy to the cleaning fluid on the substrate, and the bottom surface of the cleaning head includes an arc portion with a curvature corresponding to the outer contour circle of the substrate at its edge.

Description

Technical Field

[0001] This invention relates to an ultrasonic cleaning unit for improving cleaning performance and a substrate cleaning apparatus including the same, and more specifically, to an ultrasonic cleaning unit for improving cleaning performance and a substrate cleaning apparatus including the same, which can improve the overall cleaning performance of the substrate by improving the structure of the cleaning head of the ultrasonic cleaning unit. Background Technology

[0002] One of the most fundamental technologies in semiconductor manufacturing is cleaning technology. During semiconductor manufacturing, various processes are involved to form the surface of the substrate. During these processes, various contaminants are generated and remain on the semiconductor substrate and the semiconductor manufacturing equipment. Therefore, it is necessary to clean the semiconductor substrate and the semiconductor manufacturing equipment at predetermined time intervals before proceeding with the next process. Thus, cleaning technology uses physical and chemical methods to remove various contaminants generated during the semiconductor manufacturing process.

[0003] Here, chemical methods remove surface contaminants through washing, etching, redox reactions, etc., using various chemicals or gases. Adhered particles are removed with pure water or cleaning solutions, organic matter is removed by dissolving in solvents or by oxidizing acids or carbonizing from oxygen plasma, and, depending on the situation, the surface is etched in a predetermined amount to expose a new, clean surface.

[0004] As another physical method, the deposits are peeled off using ultrasonic energy, brushed, or removed using high-pressure water. Physical methods are often combined with chemical methods for effective cleaning.

[0005] In other words, ultrasonic cleaning removes contaminants adhering to the object being cleaned through physical (ultrasound) or chemical methods (cleaning liquid, cleaning solution), preventing the contaminants from re-adhering. The physical phenomenon utilized in ultrasonic cleaning refers to the cavitation (void) phenomenon. This cavitation phenomenon occurs when the energy of ultrasound propagates in a liquid, and the pressure of the ultrasound creates and destroys microbubbles, simultaneously generating extremely high pressures (tens to hundreds of atmospheres) and high temperatures (hundreds to thousands of degrees Celsius).

[0006] The aforementioned phenomenon occurs and disappears repeatedly within an extremely short time (from a fraction of a second to a fraction of a second). This shockwave allows for the rapid cleaning of even the most hidden, internal parts of objects submerged in liquid.

[0007] In practice, in addition to the impact energy generated by cavitation, the stirring effect and thermal effect generated by the radiation pressure of ultrasound itself, together with the detergent, produce a synergistic effect, resulting in a high cleaning effect.

[0008] Ultrasonic cleaning is mainly used for cleaning or rinsing glass substrates for liquid crystal displays (LCDs), semiconductor substrates, and hard disks used for data storage. Ultrasonic waves apply vibrational energy to the particles on the object being cleaned, effectively removing particles and other contaminants.

[0009] With the increasing integration of semiconductor devices, the patterns formed on the substrate have become very small. Therefore, even contamination of the patterns on the substrate by very fine particles can lead to defects in semiconductor devices, making cleaning processes increasingly important.

[0010] Generally speaking, substrate cleaning is carried out using cleaning fluid and ultrasound. The substrate is supported on the chuck base of the substrate support device and rotated at high speed, while cleaning fluid is supplied to the surface or the other side of the substrate.

[0011] During the rotation of the chuck base, in order to prevent the substrate from detaching from the side of the chuck base, a plurality of guide pins are provided along the periphery of the chuck base. The substrate support device is configured to include the guide pins, the chuck base, a mechanism (structure), and a drive unit for activating the mechanism.

[0012] However, compared to the increasingly larger substrates, the ultrasonic cleaning units that provide ultrasonic waves on the substrate are smaller. Therefore, in order to move the entire substrate for coverage, unnecessary scanning movements increase, resulting in an increase in the overall cleaning time required.

[0013] In addition, structural interference occurs at the outer edge of the substrate between the guide pin protruding from the top of the substrate and the cleaning head during scanning operation, resulting in a reduction in ultrasonic cleaning force at the substrate edge. Summary of the Invention

[0014] Technical issues

[0015] The present invention is proposed to solve the above-mentioned problems, and its purpose is to provide an ultrasonic cleaning unit and a substrate cleaning device including the ultrasonic cleaning unit that improves the overall substrate cleaning performance by improving the structure of the cleaning head of the ultrasonic cleaning unit.

[0016] Technical solution

[0017] To achieve the above objectives, the present invention provides an ultrasonic cleaning unit, comprising: a drive unit that receives an external power source to cause an internal vibrator to vibrate; and a cleaning head that is formed to protrude downward from the bottom of the drive unit, and to acoustically couple with the vibrator to transmit high-frequency acoustic wave energy to a cleaning fluid on a substrate, wherein the edge of the bottom surface of the cleaning head includes an arc portion formed having a curvature corresponding to the outer contour circle of the substrate.

[0018] Preferably, the edges of the bottom surface of the cleaning head are separated by the following structure: two straight sections formed as straight lines facing each other in the horizontal direction; two arc sections formed as arcs facing each other in the vertical direction between the two straight sections; and four curved sections formed as curves connecting the ends of the respective straight sections and the respective arc sections.

[0019] Preferably, the two straight sections are elements that determine the bottom surface area of ​​the cleaning head; the longer their length, the larger the bottom surface area of ​​the cleaning head.

[0020] Preferably, the two arcuate portions are elements in the cleaning head responsible for the periphery of the substrate edge, formed as a portion of a circle having a curvature corresponding to the outer contour circle of the substrate.

[0021] Preferably, the drive unit includes: a terminal block protruding on one side, into which an external power cable is inserted; a vibrator connected to the cable and vibrating by a power supply; a gas guide section spaced around the configuration area of ​​the vibrator; and a gas inlet and a gas outlet formed at one end and the other end of the gas guide section, respectively, for injecting and discharging heating control gas.

[0022] Preferably, a stepped unit is formed on the bottom surface of the cleaning head, which is concave inward along the arc portion.

[0023] Preferably, the stepped unit is formed in only one of the two arcuate portions on the bottom surface of the cleaning head, or in both.

[0024] In addition, according to another aspect of the present invention, a substrate cleaning apparatus is provided, comprising: a substrate support device that, while supporting a substrate, causes the substrate to rotate by a rotation drive structure; a fluid supply unit that supplies a cleaning liquid for treating the substrate to the substrate on the substrate support device; and an ultrasonic cleaning unit that, according to any of the above features, transmits high-frequency acoustic energy to the cleaning liquid on the substrate.

[0025] Beneficial effects

[0026] According to the present invention, the following effects are achieved: by improving the structure of the cleaning head of the ultrasonic cleaning unit, the overall substrate cleaning performance can be improved.

[0027] In particular, it has the following effect: by forming the shape of the edge portion of the contact surface of the lower cleaning head of the ultrasonic cleaning unit corresponding to the shape of the edge portion of the substrate, unnecessary scanning movement of the cleaning head is prevented, thereby shortening the overall cleaning time and improving cleaning efficiency.

[0028] In addition, it has the following effect: by forming a stepped unit with a concave shape on the edge of the contact surface of the lower cleaning head of the ultrasonic cleaning unit, structural interference with the guide pin is avoided, thereby improving the cleaning efficiency of the edge part of the substrate.

[0029] In addition, it has the following effect: the closer the lower cleaning head of the ultrasonic cleaning unit is to the edge of the substrate, the lower the scanning speed, thereby improving the cleaning efficiency of the edge of the substrate. Attached Figure Description

[0030] Figure 1 The attached diagram illustrates a substrate cleaning apparatus for explaining prior art techniques.

[0031] Figure 2 This is an illustration to illustrate the shape of the lower cleaning head of an ultrasonic cleaning unit in the prior art;

[0032] Figure 3 The accompanying drawings illustrate an ultrasonic cleaning unit used to explain embodiments of the present invention.

[0033] Figure 4 The accompanying drawing illustrates the shape of the lower cleaning head of the ultrasonic cleaning unit in an embodiment of the present invention.

[0034] Figure 5 The accompanying drawings illustrate a substrate cleaning apparatus that includes an ultrasonic cleaning unit according to an embodiment of the present invention.

[0035] Figure 6 The accompanying drawing illustrates the stepped unit shape of the ultrasonic cleaning unit in an embodiment of the present invention.

[0036] Figure 7 and Figure 8 The accompanying drawings illustrate two applicable shapes of the stepped unit for the ultrasonic cleaning unit in an embodiment of the present invention.

[0037] Figure 9 The accompanying drawing illustrates the stepped unit shape of the ultrasonic cleaning unit in an embodiment of the present invention.

[0038] Figure 10The accompanying drawings illustrate the substrate scanning process of the ultrasonic cleaning unit according to an embodiment of the present invention;

[0039] Figure 11 The accompanying drawing shows the sound pressure distribution image of the ultrasonic cleaning unit according to an embodiment of the present invention.

[0040] Explanation of reference numerals in the attached figures

[0041] 100: Ultrasonic cleaning unit; 110: Cleaning head

[0042] 111: Stepped unit; 120: Drive unit

[0043] 121: Gas Inlet 122: Gas Outlet

[0044] 123: Gas guide section; 124: Wiring terminal.

[0045] 125: Vibrator; 200: Fluid supply unit

[0046] 300: Substrate support device; 310: Rotating part

[0047] 320: Chuck base; 330: Guide pin

[0048] 331: Installation Unit; 332: Interception Unit Detailed Implementation

[0049] This invention can be modified and has various embodiments, with specific embodiments illustrated and described in detail in the accompanying drawings. However, it is not intended to limit the invention to specific implementations, and should be understood to include all modifications, equivalents, and substitutions within the spirit and technical scope of the invention. Similar reference numerals are used for similar technical features in the description of the various drawings.

[0050] The terms 1, 2, A, B, etc., can be used to describe various technical features, but the technical features cannot be limited to these terms. These terms are used only to distinguish one technical feature from others. For example, without departing from the scope of this invention, a first technical feature may be named a second technical feature, and similarly, a second technical feature may be named a first technical feature. The terms and / or include a combination of multiple related described items or one of multiple related described items.

[0051] When referring to a technical feature being "connected" or "connected" to other technical features, it should be understood as being directly connected or connected to those other technical features, even if other technical features exist in between. Conversely, when referring to a technical feature being "directly connected" or "directly connected" to other technical features, it should be understood as if no other technical features exist in between.

[0052] The terminology used in this specification is for illustrative purposes only and is not intended to limit the invention. Unless otherwise expressly stated in the context, singular expressions include plural expressions. In this specification, terms such as "comprising" or "having" are used to indicate the presence of features, numbers, steps, actions, technical features, components, or combinations thereof described in the specification, and do not preclude the presence or additional possibilities of one or more other features, numbers, steps, actions, technical features, components, or combinations thereof.

[0053] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms, for example, those defined in commonly used dictionaries, have meanings consistent with the context of the art concerned, and, unless expressly defined in this application, should not be interpreted in an ideal or excessive formal sense.

[0054] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0055] first, Figure 1 The attached diagram illustrates a substrate cleaning apparatus for explaining prior art techniques. Figure 2 This is an illustration showing the shape of the lower cleaning head of an ultrasonic cleaning unit in conventional technology.

[0056] Reference Figure 1 Conventional substrate cleaning equipment includes an ultrasonic cleaning unit 10, a fluid supply unit 20, and a substrate support device 30.

[0057] The substrate support device 30 functions to rotate the substrate (W) by means of a rotation drive structure while supporting the substrate (W) during the process.

[0058] The fluid supply unit 20 supplies cleaning fluid for processing the substrate (W) to the substrate.

[0059] The ultrasonic cleaning unit 10 includes a downwardly protruding cleaning head 11. This cleaning head 11 is coupled to an internal vibrator (not shown) via acoustic waves. Thus, high-frequency acoustic energy from the vibrator, powered by an external power source and vibrating via sound waves or ultrasound, is transmitted to the acoustically coupled cleaning head. Consequently, the vibrator is electrically excited and vibrates, and the cleaning head 11 transmits high-frequency acoustic energy to the cleaning fluid on the substrate (W). The air bubbles generated by the ultrasonic / mega-frequency ultrasonic energy cause particles on the substrate (W) to vibrate. As a result, contaminants vibrate and separate from the surface of the substrate (W), and are removed from the surface of the substrate (W) by the flowing cleaning fluid supplied by the fluid supply unit 20.

[0060] At this time, the substrate support device 30 receives the rotational force of the rotating part 31, causing the chuck base 32 to rotate in the horizontal direction. In order to support the substrate (W) from the bottom while preventing the substrate (W) from falling off in the lateral direction, a plurality of guide pins 33 are provided on the chuck base 32 along the circumferential direction of the chuck base 32.

[0061] Here, a placement unit 33a protruding towards the side of the substrate (W) is formed on the side of the guide pin 33, which can support the substrate (W) from the bottom. An upward-protruding blocking unit 33b is formed on the upper part to prevent the rotating substrate (W) from detaching in the lateral direction. As described above, the blocking unit 33b of the upward-protruding guide pin 33 protrudes to a position higher than the upper surface of the substrate (W). For example, the blocking unit 33b of the guide pin 33 may protrude to a position 0.5 to 2.0 mm higher than the upper surface of the substrate (W).

[0062] As described above, the upward-protruding structure of the blocking unit 33b of the guide pin 33 is ideal for preventing the rotating substrate (W) from detaching laterally. However, there is a risk that the cleaning head 11 of the ultrasonic cleaning unit 10 may come into contact with the outer contour of the scanning substrate (W) during the cleaning process. In particular, in order to help improve the cleaning force, the cleaning head 11 is formed closer (downward) to the substrate (W) before scanning by the ultrasonic cleaning unit 10. During the scanning process, when the cleaning head 11 approaches the outer contour of the substrate (W), the possibility of collision between the guide pin 33, which has a structure protruding upward from the substrate (W), and the cleaning head 11 is necessarily higher. That is, in order to improve the cleaning force, it is necessary to maintain a minimum distance (minimum height difference) that can prevent the cleaning head 11 from contacting the substrate. In order to prevent the substrate (W) from detaching, preferably, the upper part of the guide pin 33 protrudes higher than the upper surface of the substrate (W). However, the upper part of the guide pin 33 may often come into contact with the edge of the bottom surface of the cleaning head 11.

[0063] To avoid contact with the guide pin 33 as described above, the ultrasonic cleaning unit 10 typically forms a scanning path to limit or restrict the entry path to the edge portion of the substrate (W), thereby reducing the cleaning efficiency for the edge portion of the substrate (W).

[0064] and, Figure 2 This indicates the state in which the lower cleaning head 11 of the ultrasonic cleaning unit 10 of the prior art approaches the edge portion of the substrate (W) during the scanning process, showing the bottom surface of the lower cleaning head 11 and the edge portion of the wafer (W).

[0065] Generally, in order to improve scanning efficiency, the bottom surface of the cleaning head 11, which transmits high-frequency acoustic energy to the cleaning fluid on the substrate (W), is elliptical. Furthermore, the substrate (W) is circular.

[0066] There is no major problem when designing a scanning path through the elliptical cleaning head 11 on a small circular substrate (W). However, for the most recent substrates (W) that are gradually becoming larger, in order to carefully clean the edge portion of the substrate (W) using the conventional cleaning head 11, it is necessary to move the cleaning head 11 repeatedly and overlappingly on the edge portion of the substrate (W). Therefore, not only does the scanning speed decrease, but it also causes over-cleaning of the edge portion of the substrate (W).

[0067] Figure 3 The accompanying drawing illustrates an ultrasonic cleaning unit used to explain an embodiment of the present invention.

[0068] according to Figure 3 The improved ultrasonic cleaning unit 100 shown in the embodiments of the present invention can be applied to substrate cleaning equipment that does not require structural changes, including the conventional substrate support device 300 and fluid supply unit 200.

[0069] The ultrasonic cleaning unit 100 includes: a drive unit 120, which receives an external power supply to cause an internal vibrator 125 to vibrate; and a cleaning head 110, which protrudes downward from the bottom of the drive unit 120 and is acoustically coupled to the vibrator 125 to transmit high-frequency acoustic energy to the cleaning fluid on the substrate (W).

[0070] Figure 3 (a) is a perspective view of the ultrasonic cleaning unit 100 in which the upper drive unit 120 and the lower cleaning head 110 are combined. Figure 3 (b) represents a cross-sectional view of the bonded state.

[0071] Reference Figure 3 The drive unit 120 may include: a terminal block 124 protruding on one side into which an external power cable is inserted; a vibrator 125 connected to the cable and vibrating by a power supply; a gas guide section 123, which is a space separated around the configuration area of ​​the vibrator 125; and a gas inlet 121 and a gas outlet 122 formed at one end and the other end of the gas guide section 123, respectively, for injecting and discharging heating control gas.

[0072] Here, the gas flowing along the gas guide section 123 can control the heat generated by the vibrator 125, and CDA, N2, inert gas, etc. can be used.

[0073] The cleaning head 110, which is attached to the bottom of the drive unit 120, is acoustically coupled to the vibrator 125 and is configured to have a larger cross-sectional area towards the bottom. Thus, the high-frequency acoustic energy generated by the vibrator 125 is transmitted to the cleaning fluid on the substrate (W) through the large bottom surface.

[0074] Figure 4 This indicates the shape of the lower cleaning head 110 of the ultrasonic cleaning unit 100.

[0075] first, Figure 4 (a) represents the shape of the edge of the bottom surface of the cleaning head 110 in terms of each interval.

[0076] The bottom surface of the cleaning head 110 is separated by the following structure: two straight sections (S1, S2) of a straight line that are horizontally separated from each other; two arc sections (A1, A2) of an arc that are vertically separated from each other between the two straight sections (S1, S2); and four curved sections (C1, C2, C3, C4) of a curve connecting the ends of each straight section (S1, S2) and each arc section (A1, A2).

[0077] The two straight sections (S1, S2) are elements that directly determine the bottom surface area of ​​the cleaning head 110; the longer the length, the larger the bottom surface area of ​​the cleaning head 110. Preferably, the two straight sections (S1, S2) are straight lines, but they can also be formed into a gentle elliptical curve shape.

[0078] The two arcuate portions (A1, A2) are elements in the cleaning head 110 that cover the periphery of the substrate (W)'s edge, and are formed with the same curvature as the outer circle of the substrate (W). That is, the two arcuate portions (A1, A2) are parts of a circle with the same radius as the outer circle of the substrate (W). The radius of the outer circle of the substrate (W) is the same as the radius of curvature formed by the two arcuate portions (A1, A2). Therefore, for large-area substrates (W) with a larger radius, the virtual radius forming the two arcuate portions (A1, A2) will be equally large, while for small- to medium-area substrates (W) with a smaller radius compared to the large radius, the virtual radius forming the two arcuate portions (A1, A2) will be equally small. Thus, by changing the curvature of the two arcuate portions (A1, A2) according to the size of the substrate (W) to be processed, substrates (W) of all sizes can be conveniently processed.

[0079] The four curved sections (C1, C2, C3, C4) are formed by curves, which can smoothly connect the straight sections (S1, S2) with the arc sections (A1, A2).

[0080] Figure 4 (b) indicates the state in which the lower cleaning head 110 of the ultrasonic cleaning unit 100 of the present invention approaches the edge portion of the substrate (W) during the scanning process, showing the bottom surface of the lower cleaning head 110 and the edge portion of the wafer (W).

[0081] and Figure 2 Comparison and reference Figure 4 In case (b), such as Figure 2 In the conventional simple elliptical cleaning head 11 shown, the portion opposite to the edge (circumference) of the substrate (W) is relatively small. Therefore, in order to scan the entire edge of the substrate (W), the cleaning head 11 must move repeatedly and overlappingly. However, as Figure 4 As shown in (b), the cleaning head 110 of the present invention has two arc portions (A1, A2) with the same curvature as the outer circle of the substrate (W). The arc portions (A1, A2) can be accurately aligned with the edge portion (around the circle) of the substrate (W). Therefore, the overlap movement of the cleaning head 11 can be reduced, the overall scanning speed can be significantly reduced, and over-cleaning of the edge portion of the substrate (W) can be prevented.

[0082] Then, Figure 5 The accompanying drawings illustrate a substrate cleaning apparatus that includes an ultrasonic cleaning unit according to an embodiment of the present invention.

[0083] Reference Figure 5 The substrate cleaning equipment of the present invention includes: an ultrasonic cleaning unit 100, a fluid supply unit 200, and a substrate support device 300.

[0084] The substrate support device 300 functions to rotate the substrate (W) by means of a rotation drive structure while supporting the substrate (W) during the process.

[0085] The fluid supply unit 200 supplies cleaning fluid for processing the substrate (W) to the substrate.

[0086] The improved ultrasonic cleaning unit 100 according to the embodiments of the present invention can be applied to substrate cleaning equipment including conventional substrate support device 300 and fluid supply unit 200 without structural changes.

[0087] As described above, the ultrasonic cleaning unit 100 includes: a drive unit 120 that receives an external power supply and causes an internal vibrator 125 to vibrate; and a cleaning head 110 that protrudes downward from the bottom of the drive unit 120 and is acoustically coupled to the vibrator 125 to transmit high-frequency acoustic energy to the cleaning fluid on the substrate (W).

[0088] Here, the substrate support device 300 receives the rotational force of the rotating part 310, causing the chuck base 320 to rotate in the horizontal direction. The chuck base 320 is provided with a plurality of guide pins 330 along the circumferential direction, which can support the substrate (W) from the bottom while preventing the substrate (W) from dislodging in the lateral direction.

[0089] Here, a mounting unit 331 protruding towards the side of the substrate (W) is formed on the side of the guide pin 330, which can support the substrate (W) from the bottom. In order to prevent the substrate (W) from detaching in the lateral direction, an upwardly protruding blocking unit 332 is formed on the upper part. As described above, the blocking unit 332 of the guide pin 330 protrudes to a position higher than the upper surface of the substrate (W). For example, the blocking unit 332 of the guide pin 330 may protrude to a position 0.5 to 2.0 mm higher than the upper surface of the substrate (W).

[0090] Figure 6 The accompanying drawing illustrates the stepped unit shape of the ultrasonic cleaning unit in an embodiment of the present invention.

[0091] like Figure 6 As shown, according to an embodiment of the present invention, a stepped unit 111 is formed on the bottom surface of the cleaning head 110, which is recessed inward along the arc portion (A1, A2).

[0092] Reference Figure 7 The concave width (w1) of the aforementioned stepped unit 111 is formed corresponding to the thickness of the protruding blocking unit 332 of the guide pin 330, and preferably, it is formed to be larger than the thickness of the blocking unit 332.

[0093] Furthermore, the recessed depth (d1) of the aforementioned stepped unit 111 is formed corresponding to the protruding height of the protruding blocking unit 332 of the guide pin 330, and preferably, it is formed deeper than the height of the blocking unit 332 that protrudes above the substrate (W).

[0094] The stepped unit 111 is formed to completely block structural interference between the cleaning head 110 and the guide pin 330 of the support substrate (W). That is, when the cleaning head 110 scans, the arc portion (A1, A2) moves towards the edge of the substrate, and the cleaning head 110 can also be prevented from contacting the guide pin 330 due to the concave stepped unit 111.

[0095] like Figure 7 As shown, the stepped unit 111 can be formed only in one of the two arcuate portions (A1, A2) on the bottom surface. It is applicable to... Figure 10The two scanning operations shown are a half-scan mode in which the cleaning head 110 repeatedly moves from the center to the edge of the substrate (W). In this mode, the stepped units 111 formed in the two arc portions (A1, A2) are located opposite the edge of the substrate (W).

[0096] In addition, such as Figure 8 As shown, the stepped unit 111 can be formed entirely on both arcuate portions (A1, A2) of the bottom surface. It is applicable to... Figure 10 The two scanning operations shown in the figure are a full scan mode in which the cleaning head 110 moves from one edge portion of the substrate (W) to another edge portion within a radius range.

[0097] Of the two arc sections (A1, A2), only one has a stepped unit 111 formed. Figure 7 For example, the stepped unit 111 prevents the cleaning head 110 from contacting the guide pin 330, therefore, as Figure 9 As shown, the cleaning head 110 is capable of scanning up to the edge of the substrate (W).

[0098] Furthermore, in the two arc sections A1 and A2, only one has a stepped unit 111 formed. Figure 7 For example, in Figure 11 As can be confirmed from the sound pressure distribution image shown, a sufficient sound pressure distribution is also formed in the step unit 111 forming portion of the cleaning head 110 (indicated by the arrow), which means that the reduction of the cleaning force of the cleaning head 110 can be prevented by the formation of the step unit 111.

[0099] Therefore, the stepped units 111 formed on the bottom surface of the cleaning head 110 can ultimately improve the cleaning efficiency of the edge portion of the substrate (W) and achieve homogenization of the overall cleaning degree of the substrate (W), thereby improving the cleaning quality.

[0100] As described above, preferred embodiments are disclosed in the accompanying drawings and specification. Specific terminology is used herein, but it is used merely for illustrative purposes and not for limiting the meaning or scope of the invention as set forth in the patent claims. Therefore, those skilled in the art will understand that various modifications and equivalent embodiments are possible. Consequently, the true scope of protection of this invention should be defined according to the technical concept of the appended patent claims.

Claims

1. An ultrasonic cleaning unit, characterized in that, include: The drive unit is used to receive external power and cause the internal vibrator to vibrate. as well as The cleaning head is formed to protrude downward from the bottom of the drive unit. The cleaning head has a cross-sectional area that widens towards the bottom, thereby acoustically coupling with the vibrator and transmitting high-frequency acoustic wave energy to the cleaning fluid on the substrate through the wide bottom surface of the cleaning head. The bottom surface of the cleaning head includes an arc-shaped portion with a curvature corresponding to the outer circle of the substrate at its edge. The edge of the bottom surface of the cleaning head is separated by the following structure: two straight sections formed as straight lines facing each other in the horizontal direction; two curved sections formed as curved lines facing each other in the vertical direction between the two straight sections; and four curved sections formed as curves connecting the ends of the straight sections and the ends of the curved sections. The bottom surface of the cleaning head has a stepped unit that is concave inward along the arc portion. The stepped unit thus prevents structural interference between the cleaning head and the guide pins supporting the substrate.

2. The ultrasonic cleaning unit according to claim 1, characterized in that, The two straight sections are elements that determine the area of ​​the bottom surface of the cleaning head; the longer the two straight sections are, the larger the area of ​​the bottom surface of the cleaning head.

3. The ultrasonic cleaning unit according to claim 1, characterized in that, The two arcuate portions are elements in the cleaning head responsible for the surrounding portion of the edge of the substrate, and the two arcuate portions are formed into the shape of a part of a circle having a curvature corresponding to the outer contour circle of the substrate.

4. The ultrasonic cleaning unit according to claim 1, characterized in that, The driving unit includes: A terminal block protrudes on one side, into which an external power cable is inserted; A vibrator, connected to the cable, vibrates via a power supply; Gas guide sections are spaced around the configuration area of ​​the vibrator; and A gas inlet and a gas outlet are formed at one end and the other end of the gas guide, respectively, to inject and discharge heating control gas.

5. The ultrasonic cleaning unit according to claim 1, characterized in that, The stepped unit is formed only in one of the two arcuate portions on the bottom surface of the cleaning head, or in both.

6. A substrate cleaning device, characterized in that, include: A substrate support device, in a state of supporting a substrate, causes the substrate to rotate via a rotation drive structure; A fluid supply unit supplies cleaning fluid for processing the substrate to the substrate on the substrate support device; as well as An ultrasonic cleaning unit according to any one of claims 1 to 5 delivers high-frequency acoustic energy to the cleaning fluid on the substrate.

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