Cleaning processing device

Abstract

To provide a cleaning processing device that enables ultrasonic cleaning by maintaining a gap between a horn and a polishing cloth with high accuracy even when equipped with a horn-type ultrasonic generator.SOLUTION: A cleaning processing device 1 comprises a horn-type ultrasonic generator 5 which propagates ultrasonic waves to the cleaning liquid supplied to a polishing cloth 109 of a polishing device 100 that has a lower surface plate 101 in which the polishing cloth 109 is affixed to its upper surface, a sun gear 105 which is provided on the inner side of the lower surface plate 101, and an internal gear 107 which is provided on the outer side of the lower surface plate 101. The cleaning processing device 1 further includes a rail 3 which is fixed across the lower surface plate 101 on the sun gear 105 and the internal gear 107 and on which the ultrasonic generator 5 is mounted. The ultrasonic generator 5 is movable on the rail 3, generates ultrasonic waves with a horn as the ultrasonic generator 5 moves on the rail 3, and performs the ultrasonic cleaning by propagating the ultrasonic waves through the cleaning liquid to the polishing cloth 109.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cleaning treatment apparatus. [Background technology]

[0002] Generally, in the process of polishing semiconductor wafers, when a polishing cloth such as a foamed polyurethane pad is used to polish the wafer, slurry aggregates and polishing residues generated from the wafer accumulate inside the foamed portion of the polishing cloth.

[0003] These deposits accumulate inside the polishing cloth and solidify, causing scratches on the surface of the wafer being polished. Furthermore, the life of the polishing cloth is determined by the deterioration of the wafer quality, and the shortening of the polishing cloth life due to the deposits is a problem. Therefore, a method for cleaning the polishing cloth that can sufficiently remove the deposits from inside the polishing cloth has been desired.

[0004] Patent Document 1 describes a method for conditioning the surface of a polishing cloth using a high-pressure spray of a cleaning solution toward the polishing cloth or a running water type ultrasonic generator, while Patent Document 2 describes a method for cleaning the surface of a polishing cloth using a horn type ultrasonic generator. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-142851 A [Patent Document 2] JP 2003-282506 A Summary of the Invention [Problem to be solved by the invention]

[0006] Ultrasonic cleaning as described in Patent Document 2 is effective in removing foreign matter adhering to or inside the polishing cloth, but in order to maintain a more effective frequency and output, it is better to use an ultrasonic generator that is horn-type with a frequency of 100 kHz or less and an amplitude of 10 μm or more.

[0007] However, devices that meet these conditions have large casings and are heavy, and the design of a hand with an ultrasonic generator attached to the tip, which is inserted from outside the base as in Patent Document 1, does not provide sufficient rigidity for the hand, resulting in distortion and vibration and making it impossible to maintain the distance between the abrasive cloth and the horn of the ultrasonic generator, resulting in problems such as the risk of contact and the failure to achieve the expected cleaning effect.

[0008] The present invention has been made to solve the above problems, and aims to provide a cleaning processing apparatus that is capable of ultrasonic cleaning by maintaining the distance between the horn and the abrasive cloth with high precision, even when it is equipped with a horn-type ultrasonic generator. [Means for solving the problem]

[0009] The present invention has been made in order to achieve the above-mentioned object, and provides a cleaning treatment device that includes a horn-type ultrasonic generator that propagates ultrasonic waves to a cleaning liquid supplied to the abrasive cloth of a polishing device having a lower platen with an abrasive cloth attached to its upper surface, a sun gear provided inside the lower platen, and an internal gear provided outside the lower platen, and that ultrasonically cleans the abrasive cloth, the cleaning treatment device including a rail that is fixed on the sun gear and the internal gear so as to straddle the lower platen and on which the ultrasonic generator is mounted, the ultrasonic generator being movable on the rail, and the ultrasonic generator generating ultrasonic waves with the horn as it moves on the rail, and the generated ultrasonic waves being propagated to the abrasive cloth via the cleaning liquid to perform ultrasonic cleaning.

[0010] With this type of ultrasonic generator, a rail is fixed to straddle the lower platen above the sun gear and internal gear, and the ultrasonic generator is mounted on the rail, so that the ultrasonic generator is held on both the sun gear and internal gear via the rail.

[0011] Therefore, the rigidity of the rail can be ensured compared to a cantilever beam structure such as a hand with an ultrasonic generator attached to the tip, and ultrasonic cleaning can be performed by maintaining the distance between the horn and the abrasive cloth with high precision.

[0012] In this case, the rail may have gear fixing holes provided on a surface that contacts the sun gear and the internal gear, and may be fixed to the sun gear and the internal gear through the gear fixing holes.

[0013] This allows the rail to be completely fixed to the sun gear and the internal gear.

[0014] In this case, the rail can be configured so that the distance in the height direction between the horn of the ultrasonic generator and the polishing cloth can be adjusted by moving the sun gear or the internal gear up and down.

[0015] As a result, even if the rail or ultrasonic generator itself does not have the function of raising and lowering the horn, the horizontality and height of the rail can be adjusted and maintained with high precision by adjusting the height of the sun gear and internal gear, and the distance between the horn and the polishing cloth can be kept constant.

[0016] In this case, the ultrasonic generator can be movable on the rail in the direction toward the sun gear or the internal gear while the lower platen is rotating.

[0017] This allows ultrasonic cleaning to be performed while rotating the platen and moving the ultrasonic generator from the center of the platen to its outer periphery or vice versa, making it possible to efficiently clean the entire surface of the polishing cloth.

[0018] In this case, the rail may be made of stainless steel or titanium.

[0019] This makes it easier to ensure that the rail has sufficient rigidity to withstand the weight of the ultrasonic generator.

[0020] In this case, the material of the horn of the ultrasonic generator may be stainless steel or titanium.

[0021] This increases the tensile strength of the horn and enables it to withstand high amplitudes, making it possible to generate ultrasonic waves with high amplitudes.

[0022] In this case, a cleaning liquid supply nozzle may be provided for supplying the cleaning liquid onto the polishing cloth so that the space between the horn and the polishing cloth is water-sealed.

[0023] This ensures that the cleaning liquid fills the space between the horn and the surface of the polishing cloth during ultrasonic cleaning, ensuring reliable cleaning. Effect of the Invention

[0024] As described above, according to the cleaning processing apparatus of the present invention, even when the apparatus is equipped with a horn-type ultrasonic generator, ultrasonic cleaning can be performed while maintaining the distance between the horn and the polishing cloth with high precision.

[0025] Specifically, the present invention makes it possible to maintain the distance between the ultrasonic generator and the base plate with high precision, which was difficult with conventional devices, and significantly reduces the possibility of contact between the base plate and the ultrasonic generator.

[0026] In addition, it will become possible to install heavy ultrasonic generators, and a horn-type ultrasonic generator with a vibrator with a frequency of 100 kHz or less can be attached. Furthermore, since the possibility of contact with the surface plate is extremely low, ultrasonic cleaning can be performed by rotating the surface plate and moving the ultrasonic generator from the center of the surface plate to its periphery or vice versa. [Brief description of the drawings]

[0027] [Figure 1] 1 is a top view of a cleaning apparatus according to an embodiment of the present invention, and a polishing apparatus provided with a polishing cloth to be cleaned by the cleaning apparatus; [Diagram 2] FIG. 2 is a perspective view of the cleaning treatment apparatus of FIG. [Diagram 3] FIG. 2 is a side view showing a state in which the cleaning treatment device is fixed to the polishing device. [Figure 4] The measurement position of the gap between the horn and the polishing cloth is shown as the radial distance from the inner peripheral edge of the polishing cloth. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The present invention will be described in detail below, but the present invention is not limited thereto.

[0029] As described above, there has been a demand for a cleaning processing apparatus that is capable of performing ultrasonic cleaning while maintaining the distance between the horn and the polishing cloth with high precision, even when the apparatus is equipped with a horn-type ultrasonic generator.

[0030] As a result of intensive research into the above-mentioned problems, the inventors have found that a cleaning treatment device for ultrasonically cleaning the abrasive cloth of a polishing apparatus having a lower platen with an abrasive cloth attached to its upper surface, a sun gear provided inside the lower platen, and an internal gear provided outside the lower platen, is provided with a horn-type ultrasonic generator that propagates ultrasonic waves to a cleaning liquid supplied to the abrasive cloth, the cleaning treatment device comprising: a rail fixed to the sun gear and the internal gear so as to straddle the lower platen and on which the ultrasonic generator is mounted, the ultrasonic generator being movable on the rail, the ultrasonic generator generating ultrasonic waves with the horn as it moves on the rail, and the generated ultrasonic waves being propagated to the abrasive cloth via the cleaning liquid to perform ultrasonic cleaning, even when the cleaning treatment device is provided with a horn-type ultrasonic generator, making it possible to maintain the distance between the horn and the abrasive cloth with high precision, and have completed the present invention.

[0031] Hereinafter, a cleaning treatment apparatus according to an embodiment of the present invention will be described with reference to FIGS.

[0032] Here, a cleaning device for a polishing cloth to be attached to a polishing device for polishing semiconductor single crystal wafers, particularly silicon wafers, is shown as an example.

[0033] First, a schematic configuration of a polishing apparatus having an abrasive cloth to be cleaned by the cleaning treatment apparatus of this embodiment will be described with reference to Fig. 1. As shown in Fig. 1, the polishing apparatus 100 includes a lower platen 101, an abrasive cloth 109, a sun gear 105, and an internal gear 107.

[0034] The lower surface plate 101 is a surface plate with an abrasive cloth 109 attached to the upper surface thereof, and here has a disk-like shape with a circular hole in the center. The abrasive cloth 109 is a member for polishing the silicon wafer W, and can be exemplified by a foam material such as a polyurethane foam pad.

[0035] The sun gear 105 is a spur gear provided on the inside of the inner periphery 101 a of the lower surface plate 101 , and the internal gear 107 is an internal gear provided on the outside of the outer periphery 101 b of the lower surface plate 101 .

[0036] The polishing apparatus 100 holds the silicon wafer W by meshing a spur gear called a carrier 111 with a sun gear 105 and an internal gear 107, rotates the lower platen 101 about the axis of the disk while supplying a polishing liquid such as slurry to the polishing cloth 109, and further presses the silicon wafer W against the polishing cloth 109, thereby polishing the underside of the silicon wafer W.

[0037] During polishing, the upper surface of the silicon wafer W can be pressed via an upper platen with an abrasive cloth attached thereto. In this manner, in a structure in which plates are provided both above and below the carrier 111, both sides of the silicon wafer W can be polished, so that the polishing apparatus 100 is a double-sided polishing apparatus.

[0038] On the other hand, when the platen is only the lower platen 101 and the upper surface of the silicon wafer W is pressed without being polished, only the lower surface of the silicon wafer W can be polished, so that the polishing apparatus 100 becomes a single-side polishing apparatus.

[0039] When a silicon wafer W is polished using a foamed polyurethane pad or the like as the polishing cloth 109, slurry aggregates and polishing residues generated from the silicon wafer W accumulate inside the foamed portion of the polishing cloth 109.

[0040] If these deposits accumulate inside the polishing cloth 109 and solidify, they may cause scratches on the surface of the silicon wafer W being polished, so it is necessary to periodically clean the polishing cloth 109 by washing away the deposits.

[0041] Next, the configuration of the cleaning treatment device will be described with reference to FIGS. The cleaning device 1 shown in FIGS. 1 to 4 is a device that ultrasonically cleans a polishing cloth with a horn-type ultrasonic generator 5 while supplying a cleaning liquid to the polishing cloth, and includes a rail 3, the ultrasonic generator 5, and a cleaning liquid supply nozzle .

[0042] The rail 3 is a member on which the ultrasonic generator 5 is mounted, and is fixed onto the sun gear 105 and the internal gear 107 so as to straddle the inner periphery 101a and the outer periphery 101b of the lower surface plate 101 in the radial direction, as shown in FIG.

[0043] As shown in FIG. 2, the rail 3 includes frame-shaped rail members 3a and 3b, upper connecting members 11 and 13, and lower connecting members 15 and 17. The frame-shaped rail members 3a and 3b are rectangular frame-shaped rails on which the ultrasonic generator 5 is mounted, with the long sides of the rectangle facing horizontally, in this case the radial direction of the lower surface plate 101, and the short sides facing vertically. The frame-shaped rail members 3a, 3b may have reinforcing members such as braces provided within the frames. Also, the rail 3 in Fig. 2 includes a pair of frame-shaped rail members 3a, 3b, but the number of frame-shaped rail members is not limited to two.

[0044] The upper connecting members 11, 13 are plate members that connect the upper end faces in the longitudinal direction of the frame-shaped rail members 3a and 3b, with the upper connecting member 11 connecting one end in the longitudinal direction and the upper connecting member 13 connecting the other end in the longitudinal direction. The means for joining the upper connecting members 11, 13 to the frame-shaped rail members 3a, 3b is not particularly limited, and they may be fastened with bolts, nuts, etc., or may be joined by welding, etc.

[0045] The lower connecting members 15, 17 connect the lower end faces in the longitudinal direction of the frame-shaped rail members 3a, 3b located below and facing the upper frame-shaped rail members 3a, 3b, and have a surface on the lower surface that contacts the sun gear 105 and the internal gear 107 when the rail 3 is fixed to the sun gear 105 and the internal gear 107. In the following explanation, an example will be given in which the lower surface of the lower connecting member 15 contacts the sun gear 105, and the lower surface of the lower connecting member 17 contacts the internal gear 107.

[0046] 2, lower connecting member 15 connects one end in the longitudinal direction, and lower connecting member 17 connects the other end in the longitudinal direction. The means for joining lower connecting member 15, lower connecting member 17 to frame-shaped rail members 3a, 3b is not particularly limited, and they may be fastened with bolts, nuts, etc., or may be joined by welding, etc.

[0047] As shown in Fig. 2, the lower connecting members 15, 17 preferably have gear fixing holes 15a, 17a provided on the surfaces that contact the sun gear 105 and the internal gear 107. The gear fixing holes 15a, 17a are holes for fixing the rail 3 to the sun gear 105 and the internal gear 107, and Fig. 2 illustrates through holes that vertically pass through the lower connecting members 15, 17.

[0048] For example, as shown in FIG. 3, by placing the lower connecting members 15, 17 on the sun gear 105 and the internal gear 107 and passing the pin 31a through the gear fixing holes 15a, 17a and further inserting the pin 31a through holes provided in the sun gear 105 and the internal gear 107, the rail 3 is completely fixed to the sun gear 105 and the internal gear 107 through the gear fixing holes 15a, 17a.

[0049] The gear fixing holes 15a and 17a may be female screws having a screw groove on the inside. In this case, the pin 31a is a male screw such as a bolt that screws into the gear fixing holes 15a and 17a.

[0050] The frame-shaped rail members 3a and 3b, the upper connecting members 11 and 13, and the lower connecting members 15 and 17 constituting the rail 3 are preferably made of materials with high rigidity. Specifically, stainless steel or titanium is preferable because it is easy to ensure that the rail 3 has sufficient rigidity to withstand the weight of the ultrasonic generator 5, but resin or the like may also be used.

[0051] The ultrasonic generator 5 is a horn-type ultrasonic generator that propagates ultrasonic waves to the cleaning liquid supplied to the polishing cloth 109 of the polishing apparatus 100, and includes a main body 21, a horn 23, and a slide portion 25 as shown in FIGS.

[0052] The main body 21 is a member equipped with an oscillator that vibrates the horn 23. The frequency of the oscillator is preferably 15 to 100 kHz. The horn 23 is a member that generates ultrasonic waves by being vibrated by the oscillator, and is connected to the main body 21 so as to face the polishing cloth 109 to be cleaned. Specifically, when cleaning the polishing cloth 109 attached to the lower surface plate 101, the horn 23 is arranged facing downward.

[0053] However, the orientation of horn 23 may be variable. For example, when polishing apparatus 100 is a double-sided polishing apparatus and a polishing cloth affixed to the upper platen is also to be cleaned, horn 23 may be made rotatable about a horizontal axis (not shown) so that horn 23 can be turned upside down from the state shown in FIG. 2 and positioned facing upward so as to face abrasive cloth 109 affixed to the upper platen.

[0054] Horn 23 is preferably capable of generating ultrasonic waves of high amplitude, and specifically, is preferably capable of applying ultrasonic waves of 10 μm or more and 40 μm or less.

[0055] The material of horn 23 with higher tensile strength is more resistant to high amplitude ultrasonic waves, so a material with high tensile strength such as stainless steel or titanium is preferred. In addition, titanium has an advantage in terms of high tensile strength compared to stainless steel. Stainless steel or titanium is also preferred because it is less likely to become an impurity even if it adheres to polishing cloth 109 when cleaning polishing cloth 109.

[0056] The slide portion 25 is a member provided across the frame-shaped rail members 3a and 3b, and allows the ultrasonic generator 5 to move on the rail 3. Specifically, the slide portion 25 is a member that moves the ultrasonic generator 5 by moving on the frame-shaped rail members 3a and 3b in the long side direction, that is, in the sun gear direction A or the internal gear direction B in Figs. 1 and 3.

[0057] In Figures 2 and 3, for the sake of simplicity, the sliding portion 25 is a flat member placed directly on the upper surface of the frame-shaped rail members 3a, 3b, and the ultrasonic generator 5 slides along the rail 3 by sliding on the frame-shaped rail members 3a, 3b, but the sliding method is not limited to this.

[0058] For example, in the case of the sliding method, it is possible to provide bearings, wheels, caterpillar tracks, etc. on the sliding portion 25 of the ultrasonic generator 5 or the frame-shaped rail members 3a and 3b of the rail 3 to allow sliding. In the case of wheels, it is desirable to provide a flange on the outer periphery of the wheel so that it fits inside the frame-shaped rail members 3a and 3b, and to make the tread surface conical or arc-shaped.

[0059] The sliding method may be manual or automatic. In the automatic sliding method, a method of rotating an axle by a gear or a method of attaching a rope or the like to the sliding part 25 of the ultrasonic generator 5 and pulling the rope may be considered.

[0060] In particular, it is preferable that the ultrasonic generator 5 is movable on the rail 3 in the sun gear direction A or the internal gear direction B while the lower platen 101 is rotating. By performing ultrasonic cleaning while rotating the lower platen 101 in this way and moving the ultrasonic generator 5 from the center (inner periphery 101a in FIG. 1) of the lower platen 101 toward the outer periphery 101b, or in the opposite direction, it becomes possible to efficiently clean the entire surface of the polishing cloth 109.

[0061] It is preferable that the rail 3 is capable of adjusting the heightwise distance H between the horn 23 of the ultrasonic generator 5 and the polishing cloth 109 shown in Fig. 4. For example, a mechanism for raising and lowering the ultrasonic generator 5 may be provided on the rail 3, but it is preferable that the distance H be adjustable by raising and lowering the sun gear 105 or the internal gear 107 to raise and lower the ultrasonic generator 5 together with the rail 3.

[0062] In this case, even if the rail 3 or the ultrasonic generator 5 itself does not have the function of raising and lowering the horn 23, the horizontality and height of the rail 3 can be adjusted and maintained with high precision by adjusting the height of the sun gear 105 or the internal gear 107, and the distance (spacing H) between the horn 23 and the polishing cloth 109 can be kept constant.

[0063] 1 is a nozzle that supplies cleaning water onto the polishing cloth 109. The cleaning liquid supply nozzle 7 preferably supplies cleaning liquid onto the polishing cloth 109 so that the space between the horn 23 and the polishing cloth 109 is water-sealed. This ensures that the space between the horn 23 and the surface of the polishing cloth 109 is filled with cleaning liquid during ultrasonic cleaning, and ultrasonic waves are transmitted to the cleaning liquid to clean the polishing cloth 109. In other words, there is no risk of the horn 23 and the surface of the cleaning liquid becoming separated from each other, preventing the ultrasonic waves from being transmitted to the cleaning liquid.

[0064] Here, "the space between horn 23 and abrasive cloth 109 is water-sealed" does not only mean that the tip of horn 23 and the abrasive cloth are sealed with water, but also means that when a liquid other than water is used as the cleaning liquid, the space between the horn tip and the abrasive cloth is sealed with that liquid.

[0065] The installation position of the cleaning liquid supply nozzle 7 is not particularly limited as long as it is within a range where cleaning water can be supplied onto the polishing cloth 109, but it is preferable to install it near the horn 23 so that the space between the horn 23 and the polishing cloth 109 is water-sealed. Therefore, when the ultrasonic generator 5 is moved on the rail 3, it is more preferable to use a mechanism that moves the cleaning liquid supply nozzle 7 in the same way.

[0066] In this way, the cleaning processing device 1 can perform ultrasonic cleaning by generating ultrasonic waves with the horn 23 while the ultrasonic generator 5 moves on the rail 3, and propagating the generated ultrasonic waves to the polishing cloth 109 via the cleaning liquid.

[0067] Next, an example of a method for cleaning the polishing pad 109 using the cleaning apparatus 1 will be briefly described. First, the cleaning device 1 is fixed to the sun gear 105 and internal gear 107 of the polishing device 100. Furthermore, the horn 23 is directed toward the polishing cloth 109 to be cleaned, and the distance H between the horn 23 and the polishing cloth 109 is set. The distance H is preferably set to a level that allows water to be sealed between the horn 23 and the polishing cloth 109, and specifically, is set to 5 mm or less. The lower limit of the distance H is 0 mm, and the horn 23 and the polishing cloth 109 may be brought into contact with each other.

[0068] Next, a cleaning liquid such as pure water or an alkaline aqueous solution of ammonia water, KOH, NaOH, or TMAH (tetramethylammonium hydroxide) is supplied from the cleaning liquid supply nozzle 7 to seal the space between the horn 23 and the polishing cloth 109 with water, while the ultrasonic generator 5 is driven to generate ultrasonic waves from the horn 23. The ultrasonic waves are then propagated through the cleaning liquid to the inside of the polishing cloth 109, thereby performing cleaning to remove any accumulated material.

[0069] Since ultrasonic waves are more easily propagated through liquid, applying ultrasonic waves after allowing the cleaning liquid to penetrate into the inside of the polishing cloth 109 makes it easier for the ultrasonic waves to propagate through the cleaning liquid, improving the ability to remove accumulated material inside the polishing cloth 109.

[0070] During cleaning, the lower platen 101 can be moved on the rails 3 in the sun gear direction A or the internal gear direction B shown in Figures 1 and 3 while rotating, thereby efficiently cleaning the entire surface of the polishing cloth 109.

[0071] When polishing apparatus 100 is a double-sided polishing apparatus equipped with an upper platen, the polishing cloth attached to the upper platen can also be cleaned.

[0072] Specifically, horn 23 is pointed upward toward abrasive cloth 109 attached to the upper platen, and cleaning liquid is supplied from cleaning liquid supply nozzle 7 toward the abrasive cloth attached to the upper platen while ultrasonic generator 5 is driven to generate ultrasonic waves from horn 23 while sealing the space between horn 23 and abrasive cloth 109 with water, and the ultrasonic waves are propagated through the cleaning liquid to the inside of abrasive cloth 109, performing cleaning to remove accumulated material.

[0073] At this time, the cleaning liquid flows down from the polishing cloth 109 due to its own weight, but by setting the distance between the horn 23 and the polishing cloth 109 so that the surface tension of the cleaning liquid can create a water seal between the horn 23 and the polishing cloth 109, the surface tension of the cleaning liquid can maintain the water seal even when the cleaning liquid flows down.

[0074] Incidentally, whether the horn 23 is facing upward or downward, the gap at which the water seal can be maintained by surface tension is 5 mm or less when the cleaning liquid is pure water. EXAMPLES

[0075] The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

[0076] (Example) The cleaning device 1 shown in FIGS. 1 to 4 was fixed to the polishing device 100, and cleaning of the polishing cloth 109 attached to the lower platen 101 was attempted. Specifically, first, a cleaning device 1 was prepared, which had a stainless steel rail 3 and a titanium horn 23 as an ultrasonic generator 5. The rail 3 had lower connecting members 15 and 17 each having gear fixing holes 15a and 17a.

[0077] Next, the rail 3 of the prepared cleaning device 1 was fixed to the sun gear 105 and the internal gear 107 of the polishing device 100 through the gear fixing holes 15a and 17a. The polishing cloth 109 of the polishing device 100 had a radial length of 1500 mm and was made of a polyurethane foam pad.

[0078] Furthermore, with the tip of horn 23 facing the polishing cloth 109, sun gear 105 and internal gear 107 were raised and lowered so that the distance (spacing H) between polishing cloth 109 and horn 23 became the target distances of 1 mm, 3 mm, and 5 mm. While generating ultrasonic waves in this state, the distance (spacing H) was actually measured every 250 mm in the measurement position range of 0 mm to 1500 mm.

[0079] The results are shown in Table 1. Note that the "measurement position" in Table 1 indicates the radial distance from the inner circumferential end of polishing cloth 109 when the position of the inner circumferential end of polishing cloth 109 on the sun gear 105 side is set to 0 mm.

[0080] [Table 1]

[0081] As shown in Table 1, for all target distances, the actual measured value of the distance (spacing H) was the same as the target distance, and it was found that the cleaning processing device 1 can maintain a constant distance (spacing H) between the horn 23 and the polishing cloth 109 when fixed to the polishing device 100.

[0082] Next, the distance (distance H) between the polishing cloth 109 and the horn 23 was set to a target distance of 3 mm, and while supplying pure water at 25° C. as a cleaning liquid to the polishing cloth 109, the ultrasonic generator 5 was driven to generate ultrasonic waves from the horn 23 while sealing the space between the horn 23 and the polishing cloth 109 with water. The amplitude of the ultrasonic waves was 20 μm, and the frequency of the oscillator of the ultrasonic generator 5 was 40 kHz.

[0083] Furthermore, while rotating the lower platen 101 counterclockwise, the ultrasonic generator 5 was manually slid on the rails 3 to ultrasonically clean the entire surface of the polishing cloth 109 . After the ultrasonic cleaning, the degree to which the accumulated matter had fallen off inside the polishing cloth 109 was checked, and the presence or absence of the effect of removing the accumulated matter was evaluated. As a result, the effect of removing the accumulated matter was observed, and the surface of the polishing cloth 109 was not damaged.

[0084] (Comparative Example) An attempt was made to attach the ultrasonic generator 5 used in the embodiment to a stainless steel hand and hold it above the polishing cloth 109 of the polishing apparatus 100, but the hand was not rigid enough to maintain a constant distance (spacing H) between the polishing cloth 109 and the horn 23.

[0085] As described above, according to the embodiment of the present invention, even when equipped with a horn-type ultrasonic generator 5, the cleaning processing device 1 was able to maintain the distance H between the horn 23 and the abrasive cloth 109 with high precision and efficiently perform ultrasonic cleaning of the abrasive cloth 109.

[0086] The present specification includes the following aspects. [1]: A cleaning device for ultrasonically cleaning the polishing cloth of a polishing device having a lower platen with an abrasive cloth attached to an upper surface thereof, a sun gear provided inside the lower platen, and an internal gear provided outside the lower platen, the cleaning device comprising a horn-type ultrasonic generator that propagates ultrasonic waves to a cleaning liquid supplied to the polishing cloth, the cleaning device comprising: a rail on which the ultrasonic generator is mounted, the rail being fixed to the sun gear and the internal gear so as to straddle the lower surface plate, The ultrasonic generator is movable on the rail, A cleaning processing device characterized in that the ultrasonic generator generates ultrasonic waves with a horn while moving on the rail, and the generated ultrasonic waves are propagated to the polishing cloth through the cleaning liquid, thereby performing ultrasonic cleaning. [2]: The rail is The cleaning treatment device of [1] above, characterized in that it has a gear fixing hole provided on the surface that contacts the sun gear and the internal gear, and is fixed to the sun gear and the internal gear through the gear fixing hole. [3]: The rail is The cleaning processing apparatus of [1] or [2] above, characterized in that the vertical distance between the horn of the ultrasonic generator and the abrasive cloth can be adjusted by moving the sun gear or the internal gear up and down. [4]: The ultrasonic generator is The cleaning treatment device according to any one of the above [1] to [3], characterized in that the lower platen is movable on the rails in a sun gear direction or an internal gear direction while rotating. [5]: The cleaning treatment device according to any one of the above [1] to [4], wherein the rail is made of stainless steel or titanium. [6]: The cleaning treatment device according to any one of the above [1] to [5], wherein the material of the horn of the ultrasonic generator is stainless steel or titanium. [7]: The cleaning processing device according to any one of the above [1] to [6], further comprising a cleaning liquid supply nozzle that supplies the cleaning liquid onto the polishing cloth so that a water seal is formed between the horn and the polishing cloth.

[0087] The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention. [Explanation of symbols]

[0088] 1... cleaning processing device, 3... rail, 3a... frame-shaped rail member, 3b... frame-shaped rail member, 5... ultrasonic generator, 7... cleaning liquid supply nozzle, 11... upper connecting member, 13... upper connecting member, 15... lower connecting member, 15a... gear fixing hole, 17... lower connecting member, 17a... gear fixing hole, 21... main body, 23... horn, 25... slide portion, 31a... pin, 100... polishing device, 101... lower surface plate, 101a... inner circumference, 101b... outer circumference, 105... sun gear, 107... internal gear, 109... polishing cloth, 111... carrier.

Claims

1. A cleaning device for ultrasonically cleaning the polishing cloth of a polishing device having a lower platen with an abrasive cloth attached to an upper surface thereof, a sun gear provided inside the lower platen, and an internal gear provided outside the lower platen, the cleaning device comprising a horn-type ultrasonic generator for propagating ultrasonic waves to a cleaning liquid supplied to the polishing cloth, the cleaning device comprising: a rail on which the ultrasonic generator is mounted, the rail being fixed to the sun gear and the internal gear so as to straddle the lower surface plate, The ultrasonic generator is movable on the rail, A cleaning processing device characterized in that the ultrasonic generator generates ultrasonic waves with a horn while moving on the rail, and the generated ultrasonic waves are propagated to the polishing cloth through the cleaning liquid, thereby performing ultrasonic cleaning.

2. The rail is 2. The cleaning treatment device according to claim 1, further comprising a gear fixing hole provided on a surface in contact with the sun gear and the internal gear, and the cleaning treatment device is fixed to the sun gear and the internal gear through the gear fixing hole.

3. The rail is 2. The cleaning treatment apparatus according to claim 1, wherein a heightwise distance between the horn of the ultrasonic generator and the polishing cloth is adjustable by moving the sun gear or the internal gear up and down.

4. The ultrasonic generator includes:

4. The cleaning treatment apparatus according to claim 1, wherein the lower platen is movable on the rails in a direction toward the sun gear or in a direction toward the internal gear while rotating.

5. 2. The cleaning treatment apparatus according to claim 1, wherein the rail is made of stainless steel or titanium.

6. 2. The cleaning treatment apparatus according to claim 1, wherein the material of the horn of the ultrasonic generator is stainless steel or titanium.

7. 2. The cleaning treatment apparatus according to claim 1, further comprising a cleaning liquid supply nozzle for supplying the cleaning liquid onto the polishing cloth so that a water seal is formed between the horn and the polishing cloth.

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