JP2008302479A - Washing device and method of polishing head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely wash and eliminate foreign matter adhering in a pore of an elastic sheet without increasing washing man-hour. <P>SOLUTION: This washing device 1 washes retainer ring 5 and elastic sheet 4 provided in a lower surface part of a polishing head 3. The washing device 1 holds the elastic sheet 4 by curving the elastic sheet 4 downwards by air blow, etc. when washing the elastic sheet 4, and is provided with a pressure reducing mechanism such as a drain pump 22 for reducing pressure, while discharging air in a head washing part 6. The elastic sheet 4 is washed in the curved state, that is, in an expanded state of an opening part of the pore 27 of a protective sheet part 4B by reducing pressure in the head washing part 6. By immersing the lower surface part of the polishing head 3 in a washing liquid in the head washing part 6, ultrasonic washing is performed for particles 29 fixed and left in the pore 27 by driving an ultrasonic vibrator 19. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polishing head cleaning apparatus and cleaning method, and more particularly to a polishing head cleaning apparatus and cleaning method that removes and cleans foreign substances adhering to pores on the surface of an elastic sheet.

  Conventionally, a CMP apparatus for chemically and mechanically polishing a wafer surface includes a polishing head for pressing the wafer against a rotating polishing pad. The polishing head has a retainer ring provided on the lower outer peripheral portion of the polishing head, a carrier provided on the upper side of the wafer, and a bendable elastic sheet provided between the carrier and the wafer. It has been known. Further, the wafer is pressed downward by an elastic sheet by air pressure during polishing, so that the wafer is pressed against the upper surface of the polishing pad with uniform pressure.

  As described above, the wafer is held by the retainer ring provided in the polishing head and is polished by holding the wafer with the elastic sheet inside the retainer ring. However, foreign matter adheres to the surface of the retainer ring or the elastic sheet. If so, defects such as damage (scratch) occur on the wafer surface due to the foreign matter. Further, due to the foreign matter, the pressure distribution of the wafer at the time of polishing becomes uneven, and defects such as polishing failure occur on the surface of the wafer.

Therefore, in order to prevent the foreign matter from being damaged on the wafer surface, the lower surface of the polishing head is periodically cleaned with a brush or the like (see, for example, Patent Document 1).
JP 2003-289058 A

  By the way, when an elastic sheet having a protective sheet part bonded to the lower surface of the membrane sheet part is used, a large number of pores (cavities) are formed on the surface of the protective sheet part in the manufacturing process. For this reason, foreign matter such as fine dust (about 40 to 80 μm) is likely to adhere and remain in the pore. That is, as shown in FIG. 6, the protective sheet portion S made of synthetic resin has pores A formed therein during the molding process.

  In the next step, after the protective sheet portion S is scraped off by sandpaper along the scraping line CL, the pore A is exposed to the scraping surface and the foreign matter P adheres to the pore A as shown in FIG. . In particular, when pressing is performed after the protective sheet portion A is bonded to the membrane sheet portion, the foreign matter P adheres and remains in the pore A in a compressed state. Further, even when polishing is performed for a long time using the same elastic sheet, the foreign matter P adheres and is buried in the pore A in a compressed state.

  The conventional cleaning method using a brush can remove foreign substances adhering to the surface of the protective sheet. However, foreign substances adhering to the pores in a compressed state have a narrow pore opening. It is difficult to remove them even if they are rubbed or sprayed with strong washing water into the pores. When the wafer is polished using an elastic sheet with foreign matter remaining in the pores, as described above, the pressure distribution in the wafer surface becomes uneven, so defects such as damage to the wafer surface (including the back surface) Occurs and degrades the device performance of the wafer.

In particular, in recent years, with the miniaturization of semiconductors, defects such as damage occurring on the wafer surface have been strictly checked. Therefore, it is a big problem to surely remove the foreign matter adhering to the pores of the elastic sheet surface, particularly the protective sheet portion surface, without increasing the number of cleaning steps.

  Therefore, there is a technical problem to be solved in order to effectively clean and remove the foreign matter adhering in the pores on the elastic sheet surface without increasing the number of cleaning steps, and the present invention solves this problem. For the purpose.

  The present invention has been proposed in order to achieve the above object, and the invention according to claim 1 is a polishing head cleaning apparatus in which an elastic sheet is curvedly stretched inside a retainer ring. A head cleaning unit having a concave longitudinal section that is formed in the upper surface of the apparatus so that the lower surface of the polishing head is fitted and mounted so that it can be cleaned, and a vacuum that discharges and depressurizes the air in the head cleaning unit. The head cleaning section has a cleaning liquid supply port for supplying a cleaning liquid into the head cleaning section, and an ultrasonic vibrator is provided at the bottom of the head cleaning section, and the elastic sheet Provides a polishing head cleaning apparatus configured to perform ultrasonic cleaning after vacuum cleaning in a state of being bent downward.

  According to this configuration, when cleaning the polishing head, first, the lower surface portion of the polishing head is fitted and attached to the head cleaning portion so that it can be cleaned, and a sealed space for cleaning is provided between the polishing head and the head cleaning portion. Form. Next, the elastic sheet of the polishing head is bent downward by air pressure or the like.

  At this time, the shape of the pore formed on the lower surface side of the elastic sheet is deformed, and the opening of the pore is expanded. As a result, the compressed state of the foreign matter adhered in the pore in the compressed state is released, and the foreign matter diffuses and moves toward the opening of the pore.

  Thus, if the pressure is reduced while discharging the air in the sealed space of the head cleaning unit with the elastic sheet being bent, the suction removal action for the foreign matter increases and remains in the pore. The foreign matter that has been removed is discharged and removed together with the air flow.

  After the vacuum cleaning, a cleaning liquid such as pure water is accumulated in the head cleaning section (cleaning tank) from the cleaning liquid supply port to a predetermined depth with the elastic sheet bent downward toward the head cleaning section. As a result, the retainer ring and the elastic sheet on the lower surface of the polishing head are submerged.

  Thereafter, the ultrasonic vibrator is driven to generate and eliminate a large number of small bubbles in the water, thereby causing a cavitation action. By this cavitation action, both the front and back surfaces of the retainer ring and the elastic sheet are washed, and in particular, foreign matters in the pore are surely removed by the impact force accompanying the explosion of bubbles.

  According to a second aspect of the present invention, there is provided the polishing head cleaning device according to the first aspect, wherein the head cleaning section has a drainage mechanism at the bottom.

  According to this configuration, after the ultrasonic cleaning, the cleaning liquid in the head cleaning unit is discharged from the drainage mechanism. At this time, the foreign matter remaining in the inner depth of the pore is discharged to the outside together with the cleaning liquid and air by the flowing action of the cleaning liquid or the suction removing action that occurs along with the discharge of the cleaning liquid.

  According to a third aspect of the present invention, the head cleaning section includes a seal mechanism for sealing a gap generated between the polishing head and the polishing head when the polishing head is fitted and mounted. A polishing head cleaning apparatus is provided.

According to this configuration, the gap between the head cleaning unit and the polishing head is sealed by the sealing mechanism, so that the airtightness of the sealed space in the head cleaning unit is improved. Therefore, the suction pressure reducing action by the pressure reducing mechanism for the sealed space is further increased during head cleaning.

  According to a fourth aspect of the present invention, there is provided a cleaning method using the polishing head cleaning apparatus according to the first, second, or third aspect, the step of fitting and mounting a lower surface portion of the polishing head on the head cleaning portion, and the head Including a step of performing vacuum cleaning while discharging air in the cleaning unit, and a step of supplying ultrasonic cleaning liquid to the head cleaning unit after the vacuum cleaning and performing ultrasonic cleaning while the elastic sheet is bent downward A polishing head cleaning method for performing ultrasonic cleaning after the cleaning is provided.

  According to this method, first, the lower surface portion of the polishing head is fitted and attached to the head cleaning portion so that it can be cleaned, and a sealed space for cleaning is formed between the polishing head and the head cleaning portion. Next, the elastic sheet of the polishing head is bent downward by air pressure or the like.

  At this time, the shape of the pore formed on the lower surface side of the elastic sheet is deformed, and the opening of the pore is expanded. As a result, the compressed state of the foreign matter adhering in the pore in the compressed state is released, and the foreign matter diffuses and moves toward the opening side of the pore.

  Thus, when the elastic sheet is bent and the pressure is reduced while discharging the air in the sealed space of the head cleaning unit by the pressure reducing mechanism, the suction and removing action with respect to the foreign matter increases and remains in the pore. The foreign matter that has been removed is discharged and removed together with the air flow.

  Further, after the vacuum cleaning, the cleaning liquid is stored in the head cleaning section from the cleaning liquid supply port to a predetermined depth with the elastic sheet bent downward toward the head cleaning section. As a result, the retainer ring and the elastic sheet on the lower surface of the polishing head are submerged. Thereafter, by driving the ultrasonic vibrator, a large number of small bubbles are generated and disappeared in the water, thereby causing a cavitation action. By this cavitation action, both the front and back surfaces of the retainer ring and the elastic sheet are washed, and in particular, foreign matters in the pore are surely removed by the impact force accompanying the explosion of bubbles.

  According to the first aspect of the present invention, it is possible to release and relieve the compressed state of the foreign matter adhering to and remaining in the pores on the lower surface of the elastic sheet, and to enlarge the opening of the pore to discharge the foreign matter together with the air. . Therefore, it is possible to reliably remove foreign matters in the pores that have been difficult to remove without increasing the number of cleaning steps, and to prevent the occurrence of defects such as scratches on the wafer surface based on the foreign matters. Device performance can be improved as compared to the conventional device.

  Furthermore, since the cavitation is applied to the retainer ring and the elastic sheet by the ultrasonic vibrator after the vacuum cleaning, the cleaning effect on the front and back surfaces of the retainer ring and the elastic sheet is further improved. In particular, it is possible to efficiently remove foreign matters that are stuck and remain in the inner back of the pore. Further, unlike conventional brush cleaning, the surface of the elastic sheet or the like is not damaged.

  According to the second aspect of the present invention, the foreign matter remaining in the inner depth of the pore during drainage can be removed to the outside together with the cleaning liquid or the like by the flow action or suction action accompanying the discharge of the cleaning liquid. In addition to the above effect, it is possible to further enhance the suction cleaning effect on the foreign matter in the pore without spraying high pressure cleaning liquid into the pore by the cleaning nozzle as in the prior art.

  According to the third aspect of the present invention, since the sealed space in the head cleaning section can be effectively sucked and depressurized by the sealing mechanism during head cleaning, in addition to the effects of the first or second aspect, it is possible to prevent residual foreign matter in the pore. The removal effect is further improved.

  The invention according to claim 4 expands the opening of the pore of the elastic sheet, and sucks and discharges foreign matter together with air in a reduced pressure state, so that foreign matter in the pore is reliably removed without increasing the number of cleaning steps. It is possible to prevent the occurrence of defects such as scratches on the wafer surface based on the foreign matter.

  Furthermore, since the cavitation is applied to the retainer ring and the elastic sheet by the ultrasonic vibrator after the vacuum cleaning, the cleaning effect on both the front and back surfaces of the retainer ring and the elastic sheet is further improved. In particular, it is possible to efficiently remove foreign matters that are fixed and remaining in the inner back of the pore without damaging the surface of the elastic sheet or the like.

  In order to achieve the object of completely removing foreign matter in the pores of an elastic sheet without increasing the number of cleaning steps, the present invention cleans a polishing head in which an elastic sheet is stretched so as to bend inside a retainer ring. In the apparatus, the head cleaning section is formed in an opening on the upper surface portion of the cleaning device and has a concave section in a longitudinal section in which the lower surface portion of the polishing head is fitted and mounted so as to be cleaned, and air in the head cleaning section is discharged. A depressurization mechanism for depressurizing the head, and the head cleaning section has a cleaning liquid supply port for supplying a cleaning liquid into the head cleaning section, and an ultrasonic transducer is provided at the bottom of the head cleaning section. The elastic sheet was realized by performing ultrasonic cleaning after cleaning under reduced pressure while being curved downward.

  A preferred embodiment of the present invention will be described below with reference to FIGS. This embodiment is applied to the case where the polishing head lower surface portion of the CMP apparatus is cleaned. At the time of head cleaning, the elastic sheet provided on the polishing head lower surface portion is curved and the air in the head cleaning portion is discharged. By cleaning under reduced pressure, the pores on the bottom surface of the elastic sheet are enlarged and the particles (foreign matter such as dust) adhering to the pores are removed by suction, and the bottom surface of the polishing head is submerged. In this way, the elastic sheet and the retainer ring are subjected to ultrasonic cleaning.

  The overall configuration of the cleaning apparatus will be described with reference to the explanatory diagram of FIG. In the figure, reference numeral 1 denotes a cleaning device. When cleaning the lower surface portion of the movable polishing head 3 constituting the CMP device 2, for example, before or after polishing of the wafer, or bendable elastic sheet 4 or retainer. Used when the ring 5 is replaced with a new one for cleaning. A head cleaning section 6 having a concave longitudinal section having a cleaning space is formed on the upper surface of the cleaning apparatus 1 so as to open on the upper surface, and the polishing head 3 is detachably fitted to the head cleaning section 6. It is configured.

  The polishing head 3 includes a ring-shaped retainer ring 5 provided on a lower outer peripheral portion thereof to restrict movement of the wafer W in the radial direction, a carrier 7 provided on the upper side of the wafer W, and the carrier 7 and the wafer. And a bendable circular elastic sheet 4 provided between W. Moreover, although an example of the detailed structure of the said polishing head 3 lower surface part is shown in FIG. 2, this invention is not limited to the example of illustration. As shown in the figure, the retainer ring 5 is attached to the lower surface of a retainer ring holder 8 disposed on the outer peripheral side of the carrier 7 with bolts 9, and an elastic sheet 4 is stretched on the inner peripheral portion of the retainer ring 5. ing.

  As shown in FIG. 1, a suction / blowing groove 10 for air is formed on the lower surface of the carrier 7, and the suction / blowing groove 10 is connected to an intake pump 12 and an air supply via an air pipe 11. The pump 13 is connected to be switchable. Further, as shown in FIG. 3, the elastic sheet 4 is composed of upper and lower two layers having required flexibility, and a lower layer portion (hereinafter referred to as “protective sheet portion 4B”) on the lower surface of the upper layer portion (hereinafter referred to as “membrane sheet portion 4A”). ") And then press working.

  As shown in FIG. 2, the elastic sheet 4 has a plurality of small holes 15, 15... That function as wafer suction holes during wafer transfer. It functions as an air pressure supply hole during polishing. As shown in FIG. 4, the lower surface portion of the polishing head 3 is fitted and attached to the head cleaning unit 6 of the cleaning apparatus 1 during cleaning, and the retainer ring 5 and the elastic sheet 4 of the polishing head 3 are connected to the head cleaning unit 6. It is cleaned while facing inside. Further, the elastic sheet 4 is held curvedly so as to protrude in a substantially arc shape on the lower side, that is, on the head cleaning unit 6 side during cleaning. In this case, by blowing air from the suction / blowing groove 10, the elastic sheet 4 is formed so as to bend downward by an air blow method.

  The suction / blowout groove 10 functions as a sheet bending means. However, the sheet bending means according to the present invention should not be limited to this, and a sheet bending means may be provided in the head cleaning unit 6. . For example, an air suction mechanism (decompression mechanism) 16 is installed below the elastic sheet 4 in the head cleaning unit 6, and the cleaning space in the head cleaning unit 6 is evacuated by the air suction mechanism 16, whereby the elastic sheet 4. The lower surface central portion of the substrate can be bent by vacuum suction.

  In the present embodiment, the air suction mechanism 16 serves as a pressure reducing mechanism for reducing the pressure in the head cleaning unit 6, and an exhaust pump or a vacuum pump (for reducing pressure while discharging the air in the head cleaning unit 6 ( (Not shown).

  Next, the configuration of the cleaning device 1 will be described in more detail. The head cleaning section 6 of the cleaning apparatus 1 serves as a cleaning tank for accumulating cleaning liquid and ultrasonically cleaning the lower surface of the polishing head 3. A cleaning liquid supply port 18 is provided at an appropriate position on the inner surface of the head cleaning unit 6. By supplying a cleaning liquid such as pure water (DIW) from the cleaning liquid supply port 18 to the cleaning space in the head cleaning unit 6, the head cleaning unit The lower surface portion of the polishing head 3 attached to 6, that is, the retainer ring 5 and the entire elastic sheet 4 can be completely submerged. In the present invention, the cleaning nozzle (see reference numeral 17 in FIG. 1) for cleaning the bottom surface of the polishing head 3 by spraying the cleaning liquid with high pressure is not an essential member and can be omitted.

  An ultrasonic transducer 19 is provided on the bottom surface of the head cleaning unit 6. Therefore, cavitation can be generated on both the front and back surfaces of the retainer ring 5 and the elastic sheet 4 by driving the ultrasonic vibrator 19 after the bottom surface of the polishing head 3 is submerged.

  In addition, a drainage mechanism such as a drainage valve and a drainage pump for discharging the cleaning liquid stored in the head cleaning unit 6 after ultrasonic cleaning can be installed at the bottom of the head cleaning unit 6.

  FIG. 1 is a configuration example using a drain valve and a drain pump as a drain mechanism. As shown in the figure, a drainage channel (also used as an exhaust channel) 20 is opened at the center of the bottom surface of the head cleaning unit 6, and drainage that can be opened and closed at an intermediate position downstream of the drainage channel 20. A valve 21 is installed. Further, a drain pump (can also be used as an intake pump) 22 is provided on the downstream side of the drain valve (can also be used as an intake valve) 21, but an aspirator may be installed in place of the drain pump 22. In addition, an air suction mechanism (decompression mechanism) 16 can be installed in the middle of the drainage channel (also used as an exhaust channel) 20.

  A seal mechanism 28 made of an O-ring, packing, or the like is provided on the peripheral edge of the opening of the head cleaning unit 6. For this reason, when the polishing head 3 is attached to the head cleaning unit 6, the gap between the polishing head 3 and the head cleaning unit 6 is completely sealed by the seal mechanism 28. Therefore, the internal space of the head cleaning unit 6 is kept airtight.

  In addition, each drive part of the washing | cleaning apparatus 1 which concerns on a present Example, ie, the air suction mechanism 16, the ultrasonic transducer | vibrator 19, the drainage pump 22, etc., is electrically connected to the control means which is not shown in figure. Therefore, each drive unit of the cleaning apparatus 1 is controlled and controlled by the control unit.

  Next, the procedure for cleaning the polishing head 3 will be described. First, after polishing the wafer W, the polishing head 3 is moved to the position of the head cleaning unit 6 of the cleaning apparatus 1. Then, by lowering the polishing head 3, the polishing head 3 is fitted and attached to the head cleaning unit 6, and the elastic sheet 4 and the retainer ring 5 on the lower surface of the polishing head 3 are set in the head cleaning unit 6 so that they can be cleaned. To do. At this time, the space between the head cleaning unit 6 and the polishing head 3 is hermetically sealed by the seal mechanism 28.

  In the next vacuum cleaning step, air is constantly ejected from the suction / blowing groove 10 below the carrier 7, so that the elastic sheet 4 is bulged downward and formed into a curved shape by an air blow method. When the elastic sheet 4 is curved downward as described above, the opening of the pore 27 on the surface of the protective sheet portion 4B is deformed and enlarged as shown in FIG.

  Along with the deformation of the inner surface shape of the pore 27, a large number of particles 29 adhering to the pore 27 in a compressed state are relaxed so as to be separated from each other, and some of them diffuse and move toward the opening side of the pore 27. As a result, coupled with the reduced pressure in the pore 27, the particles 29 in the pore 27 are easily discharged to the outside, and a part of the particles 29 is discharged from the opening.

  Thereafter, if the pressure is reduced while discharging the air in the head cleaning unit 6 by the air suction mechanism 16 while the elastic sheet 4 is held in a curved state, the suction removal action on the particles 29 increases, and the pore 27 The particles 29 remaining inside are discharged and removed together with the air flow. In this case, since the space between the head cleaning unit 6 and the polishing head 3 is hermetically sealed by the sealing mechanism 28, the air in the head cleaning unit 6 is more effectively suctioned and depressurized.

  Thus, a predetermined amount of pure water is supplied from the cleaning liquid supply port 18 into the head cleaning unit 6 so that the lower surface of the polishing head 3 is submerged. Note that the hatched portion in FIG. 4 indicates a cleaning liquid such as pure water. Next, by driving the ultrasonic vibrator 19 provided on the bottom surface of the head cleaning unit 6 for a predetermined time, cavitation occurs on both the front and back surfaces of the retainer ring 5 and the elastic sheet 4. That is, the liquid phase in the cleaning liquid is changed to a gas phase by ultrasonic waves, and countless small explosions occur in water.

  As a result, the particles 29 adhering to both the front and back surfaces of the retainer ring 5 and the elastic sheet 4 are efficiently removed and washed. In addition, the impact force due to cavitation reaches the inner part of the pore 27 and acts directly. For this reason, the particles 29 adhered and remaining in the inner back portion of the pore 27 are also efficiently removed and cleaned.

  After the ultrasonic cleaning process is completed, the drain valve 21 installed in the drain channel 20 of the head cleaning unit 6 is opened and the drain pump 22 is driven. Thereby, the cleaning liquid (including air) in the head cleaning unit 6 is discharged to the outside. At this time, the particles 29 in the pore 27 move together with the cleaning liquid and are completely discharged.

  As described above, according to the present embodiment, at the time of cleaning, the elastic sheet 4 is bent to expand the opening of the pore 27 of the protective sheet portion 4B, and in this state, the air in the head cleaning unit 6 is discharged by the air suction mechanism 16. Aspirate while discharging. Thus, the suction removal action on the particles 29 is increased, and the particles 29 remaining in the pores 27 are easily discharged and removed together with the air.

  Accordingly, it is possible to reliably eliminate the adhesion and accumulation of the particles 29 in the pore 27, and the polishing head 3 can be continuously used. As a result, the occurrence of defects such as scratches on the wafer surface due to the particles 29 is prevented in advance. Since the particles 29 are fixed inside the pores 27 in a compressed state, it has been difficult or impossible to remove by the conventional technique.

  Further, in the state where the lower surface portion of the polishing head 3 is submerged in the cleaning liquid in the head cleaning section 6, the ultrasonic vibrator 19 is driven to repeatedly generate and eliminate countless small bubbles in the cleaning liquid, thereby causing a cavitation action. Invite. As a result, the front and back surfaces of the retainer ring 5 and the elastic sheet 4 are effectively cleaned by the cavitation action.

  In particular, the impact force associated with the explosion of bubbles in the cleaning liquid can efficiently remove and clean the particles 29 adhered and remaining in the inner part of the pore 27. In this case, as in the conventional brush cleaning method, the elastic sheet is used for cleaning. There is no risk of scratching the surface of 4 etc.

  Further, when the cleaning liquid in the head cleaning unit 6 is discharged from the drain valve 21 and the drain pump 22 after the ultrasonic cleaning, the particles 29 that remain firmly in the inner part of the pore 27 are flowed along with the discharge of the cleaning liquid. Alternatively, it is forcibly discharged to the outside together with the cleaning liquid and air by a suction removing action (evacuation action). Therefore, it is not necessary to spray a high-pressure cleaning liquid into the pore 27 as in the prior art.

  The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified one.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-sectional front view (explanatory view) illustrating a cleaning apparatus in a state where a polishing head is mounted according to an embodiment of the present invention. FIG. 3 is a detailed cross-sectional view partially showing a configuration example of a polishing head according to an embodiment. The front view which shows the elastic sheet of the two-layer structure which concerns on one Example. Explanatory drawing which illustrates a state when mounting | wearing the polishing head with the washing | cleaning apparatus which concerns on one Example. Sectional drawing explaining the state which curved the elastic sheet which concerns on one Example. It is a figure explaining the pore of the protection sheet part of an elastic sheet, and sectional drawing which shows the state before cutting an elastic sheet with sandpaper. It is a figure explaining the pore of the protection sheet part of an elastic sheet, and sectional drawing which shows a state after shaving an elastic sheet with sandpaper.

Explanation of symbols

1 Cleaning device 2 CMP device (wafer polishing device)
3 Polishing head (wafer holding head)
4 Elastic sheet 4A Membrane sheet part 4B Protective sheet part 5 Retainer ring 6 Head washing part 16 Air suction mechanism (sheet bending means combined decompression mechanism)
18 Cleaning liquid supply port 19 Ultrasonic vibrator 21 Drain valve 22 Drain pump 27 Pore 28 Seal mechanism 29 Particles (foreign matter)

Claims (4)

In a polishing head cleaning device in which an elastic sheet is stretched in a retainer ring so as to be bent,
A head cleaning section having a concave longitudinal section that is formed in an upper surface of the cleaning device and is fitted and mounted so that the lower surface of the polishing head can be cleaned;
A pressure reducing mechanism for discharging and depressurizing the air in the head cleaning section,
The head cleaning section has a cleaning liquid supply port for supplying a cleaning liquid into the head cleaning section, and an ultrasonic vibrator is provided at the bottom of the head cleaning section,
A polishing head cleaning apparatus, wherein the elastic sheet is configured to perform ultrasonic cleaning after cleaning under reduced pressure in a curved state downward.   2. The polishing head cleaning apparatus according to claim 1, wherein the head cleaning section includes a drainage mechanism at the bottom.   3. The polishing head cleaning apparatus according to claim 1, wherein the head cleaning section includes a sealing mechanism for sealing a gap generated between the polishing head and the polishing head when the polishing head is fitted and mounted. . A cleaning method using the polishing head cleaning apparatus according to claim 1, 2 or 3,
Fitting and mounting the lower surface of the polishing head to the head cleaning section;
Washing under reduced pressure while discharging air in the head washing section;
A step of supplying a cleaning liquid into the head cleaning unit after the vacuum cleaning and performing ultrasonic cleaning,
A method of cleaning a polishing head, wherein ultrasonic cleaning is performed after the elastic sheet is subjected to vacuum cleaning in a state of being bent downward.

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