Cleaning method and cleaning apparatus

Abstract

To suppress remaining of foreign matters after cleaning.SOLUTION: The cleaning method includes a cleaning step 101 of cleaning the holding surface or the exposed surface by supplying a cleaning liquid from a first supply port to the holding surface or a first point on the exposed surface and supplying the cleaning liquid from a second supply port to the holding surface or a second point on the exposed surface while rotating the holding table about an axis passing through the center of the holding surface, and a residence breaking step 102 of breaking a residence portion of the cleaning liquid formed in the cleaning step 101.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a cleaning method and a cleaning device for cleaning the holding surface of a holding table or the exposed surface of an object held by the holding table. [Background technology]

[0002] BACKGROUND ART In semiconductor manufacturing processes, cleaning devices for cleaning objects to be held, such as wafers, are widely used (see, for example, Patent Document 1).

[0003] The cleaning device shown in Patent Document 1 and the like is required to prevent foreign matter from adhering to the held object after cleaning. Also, if the object is held with foreign matter adhering to the holding surface of the holding table, the foreign matter will adhere to the held surface of the object to be cleaned, so it is required to clean the holding surface and remove the foreign matter.

[0004] Furthermore, in semiconductor manufacturing processes, grinding devices that grind objects such as wafers are widely used (see, for example, Patent Document 2).

[0005] In the grinding device shown in Patent Document 2, etc., an object held on a holding table is ground with a grinding tool, and then cleaning is performed by supplying a cleaning liquid to the ground object while it is still held on the holding table.

[0006] Furthermore, when foreign matter adheres to the holding surface of the holding table of the grinding device, the holding surface of the holding table is cleaned to prevent the foreign matter from adhering to the held surface of the object to be held. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2023-169951 [Patent Document 2] Japanese Patent Application Publication No. 2023-117909 Summary of the Invention [Problem to be solved by the invention]

[0008] The cleaning devices and grinding devices shown in Patent Documents 1 and 2 mentioned above have the risk of foreign matter remaining on the object to be held or the holding surface of the holding table after cleaning, and there is a strong demand for improvements in the cleaning of the object to be held and the holding surface of the holding table.

[0009] An object of the present invention is to provide a cleaning method and a cleaning apparatus that can suppress the remaining of foreign matter after cleaning. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems and achieve the object, the cleaning method of the present invention is a cleaning method for cleaning the holding surface of a holding table having a holding surface that holds an object to be held, or the exposed surface of an object to be held on the holding surface, and is characterized by comprising: a cleaning step in which, while rotating the holding table around an axis passing through the center of the holding surface, cleaning liquid is supplied from a first supply port to a first point on the holding surface or the exposed surface, and cleaning liquid is supplied from a second supply port to a second point on the holding surface or the exposed surface, thereby cleaning the holding surface or the exposed surface; and a retention breaking step in which retention portions of the cleaning liquid formed in the cleaning step are broken.

[0011] The cleaning method may further include a second cleaning step of, after performing the retention breaking step, supplying a cleaning liquid from the first supply port to the first point and supplying a cleaning liquid from the second supply port to the second point while rotating the holding table around the axis, thereby cleaning the holding surface or the exposed surface.

[0012] In the cleaning method, in the retention breaking step, the rotation speed of the holding table may be increased more than that in the cleaning step without stopping the supply of the cleaning liquid from the first supply port and the second supply port.

[0013] In the cleaning method, in the retention breaking step, the supply of cleaning liquid from the second supply port may be stopped without stopping the supply of cleaning liquid from the first supply port while rotating the holding table around the axis.

[0014] The cleaning device of the present invention comprises a holding table having a holding surface that holds an object to be held and that is rotatable around an axis passing through the center of the holding surface; a first supply unit having a first supply port that supplies cleaning liquid to a first point on the holding surface or on the object to be held on the holding surface; a second supply unit having a second supply port that supplies cleaning liquid to a second point on the holding surface or on the object to be held on the holding surface; and a controller that controls the holding table, the first supply unit, and the second supply unit, wherein the controller controls at least one of the holding table and the second supply unit to rotate the holding table around the axis, supply cleaning liquid from the first supply port to the first point, and supply cleaning liquid from the second supply port to the second point, thereby cleaning the holding surface or the exposed surface of the object to be held on the holding surface, and then destroy any stagnation of the cleaning liquid formed on the holding surface or the exposed surface. [Effects of the Invention]

[0015] The present invention has an effect of suppressing the remaining of foreign matter after cleaning. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view schematically illustrating an example of the configuration of a processing device according to the first embodiment. [Figure 2] FIG. 2 is a perspective view schematically showing a held object to be processed by the processing device shown in FIG. [Figure 3] FIG. 3 is a plan view schematically showing a plurality of holding tables, a first supply unit, and a second supply unit of the processing apparatus shown in FIG. [Figure 4] FIG. 4 is a flowchart showing the flow of the cleaning method according to the first embodiment. [Figure 5] FIG. 5 is a plan view schematically showing the cleaning step of the cleaning method shown in FIG. [Figure 6] FIG. 6 is a plan view schematically showing the retention breaking step of the cleaning method shown in FIG. [Figure 7] FIG. 7 is a plan view schematically showing the second cleaning liquid flow in the retention breaking step shown in FIG. [Figure 8] FIG. 8 is a plan view schematically showing the retention breaking step of the cleaning method according to the second embodiment. [Figure 9] FIG. 9 is a diagram showing the timing of performing the cleaning step and the retention breaking step of the cleaning method according to the second embodiment. [Figure 10] FIG. 10 is a plan view schematically showing a cleaning step of a cleaning method according to a modification of the first and second embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0017] Modes (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made within the scope of the gist of the present invention.

[0018] [Embodiment 1] A processing apparatus 1, which is a cleaning apparatus according to a first embodiment of the present invention, will be described with reference to the drawings. Fig. 1 is a perspective view schematically showing an example of the configuration of the processing apparatus according to the first embodiment. Fig. 2 is a perspective view schematically showing an object to be held that is to be processed by the processing apparatus shown in Fig. 1. Fig. 3 is a plan view schematically showing a plurality of holding tables, a first supply unit, and a second supply unit of the processing apparatus shown in Fig. 1.

[0019] (object to be held) The processing apparatus 1, which is a cleaning apparatus shown in Fig. 1 according to the first embodiment, is a grinding apparatus that grinds a held object 200 shown in Fig. 2. The held object 200, which is the processing target of the processing apparatus 1 shown in Fig. 1, is a wafer such as a disk-shaped semiconductor wafer or an optical device wafer, whose substrate is made of silicon, sapphire, gallium, or the like. The held object 200 has devices (not shown) formed in each region defined by planned division lines set in a grid pattern on a surface 201 of the substrate shown in Fig. 2.

[0020] The device is, for example, an integrated circuit such as an IC (Integrated Circuit) or an LSI (Large Scale Integration), an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), a MEMS (Micro Electro Mechanical Systems), or a semiconductor memory (storage device).

[0021] In addition, in embodiment 1, the back surface 202 behind the front surface 201 of the object to be held 200 is ground by the processing device 1 to thin it to a predetermined finished thickness, and then it is divided into individual devices along the planned division lines.

[0022] 2, in the first embodiment, the object to be held 200 has a surface protection tape 210 for protecting a device adhered to a surface 201. Note that in the present invention, the object to be held 200 does not necessarily have to have a device formed on the surface 201, and the surface protection tape 210 does not necessarily have to be adhered to the surface 201.

[0023] (Processing equipment) The processing apparatus 1, which is a cleaning apparatus according to the first embodiment, is a grinding apparatus that grinds the back surface 202 of the object 200 to thin the object 200 to a predetermined finishing thickness. As shown in Fig. 1, the processing apparatus 1 includes an apparatus base 2, a turntable 5, a plurality of holding tables 6 (three in the first embodiment) installed on the turntable 5, a rough grinding unit 10, a finish grinding unit 20, a grinding feed unit 30, a cassette mounting table 8, an alignment unit 40, a transport unit 50, a cleaning unit 60, and a control unit 100 that serves as a controller.

[0024] The turntable 5 is a disk-shaped table provided on the upper surface of the device base 2, and is rotatable about an axis parallel to the Z-axis direction in a horizontal plane, and is rotationally driven at a predetermined timing. The Z-axis direction is parallel to the vertical direction. On the turntable 5, for example, three holding tables 6 are arranged at equal intervals, for example, at a phase angle of 120 degrees. That is, the turntable 5 has multiple holding tables 6 arranged at equal angles (120 degrees in the first embodiment) in the circumferential direction.

[0025] The upper surfaces of these three holding tables 6 are made of a porous material such as porous ceramics, and serve as holding surfaces 61 on which the object to be held 200 is placed via surface protection tape 210. That is, the holding tables 6 have holding surfaces 61. The holding surfaces 61 of the holding tables 6 are connected to a suction source (not shown), and the holding surfaces 61 are sucked by the suction source, thereby suction-holding the object to be held 200 placed on the holding surfaces 61 to the holding surfaces 61 via the surface protection tape 210.

[0026] During grinding, the holding table 6 is rotated by a rotation mechanism around an axis that passes through the center 62 (shown in FIG. 3) of the holding surface 61 and is parallel to the Z-axis direction and is indicated by an arrow 63 in FIG. 3 (hereinafter referred to as the rotation direction). By the rotation of the turntable 5, the holding table 6 is moved sequentially to a carry-in / out position 301, a rough grinding position 302, a finish grinding position 303, and the carry-in / out position 301. That is, the turntable 5 rotates around its axis to position each holding table 6 at the predetermined grinding positions 302, 303. In the first embodiment, the rotation direction 63 of the holding table 6 on the outer periphery of the turntable 5 is opposite to the rotation direction of the turntable 5.

[0027] The loading / unloading position 301 is an area where the object 200 is loaded onto or unloaded from the holding table 6, the rough grinding position 302 is an area where the object 200 held on the holding table 6 is roughly ground (corresponding to grinding) by the rough grinding unit 10, and the finish grinding position 303 is an area where the object 200 held on the holding table 6 is finish ground (corresponding to grinding) by the finish grinding unit 20.

[0028] The rough grinding unit 10 is a processing unit that is disposed above the holding table 6 positioned at the rough grinding position 302, and is equipped with a rough grinding wheel 11 having an annular arrangement of rough grinding grinding stones 112 for rough grinding the exposed upper back surface 202 of the held object 200 held on the holding surface 61 of the holding table 6 at the rough grinding position 302. The finish grinding unit 20 is disposed above the holding table 6 positioned at the finish grinding position 303, and is equipped with a finish grinding wheel 21 having an annular arrangement of finish grinding grinding stones 212 for finish grinding the back surface 202 of the held object 200 held on the holding surface 61 of the holding table 6 at the finish grinding position 303.

[0029] The grinding units 10 and 20 are supported via a grinding feed unit 30 on an upright column 3 erected from one end of the device base 2 in the Y-axis direction parallel to the horizontal direction. As shown in Fig. 3, the grinding units 10 and 20 have spindles 12 and 22 arranged extending along the Z-axis direction, spindle motors 13 and 23 that rotate the spindle 22 about its axis, spindle housings 14 and 24 (corresponding to housings) that support the spindle 22 rotatably about its axis, and grinding wheels 11 and 21 (corresponding to processing tools).

[0030] The spindles 12, 22 are formed in a cylindrical shape with their axes aligned along the Z-axis direction, which is the vertical direction. The spindle 22 has a disk-shaped mount 121, 221 at its lower end, which is one of its tips, to which the grinding wheels 11, 21 can be fixed. In other words, the grinding wheels 11, 21 are fixed to the lower ends of the spindles 12, 22. The spindles 12, 22 are arranged coaxially with the mounts 121, 221.

[0031] The spindle motors 13 and 23 are attached to the upper ends (corresponding to the other ends) of the spindles 12 and 22.

[0032] The spindle housings 14, 24 are cylindrical and accommodate the spindles 12, 22 therein so as to be rotatable about their axes, with the upper and lower ends of the spindles 12, 22 exposed.

[0033] The grinding wheels 11, 21 are fixed to the underside of the mounts 121, 221. The grinding wheels 11, 21 include a wheel base 111, 211 formed in an annular shape and fixed to the underside of the mounts 121, 221, and a plurality of grinding stones 112, 212 arranged in an annular shape on the underside of the wheel base 111, 211. The grinding stones 112, 212 are arranged at equal intervals in the circumferential direction of the wheel base 111, 211, and are fixed to the underside of the wheel base 111, 211 in plurality.

[0034] The grinding wheels 112, 212 are configured as so-called segmented grinding wheels formed into a single mass by mixing abrasive grains such as diamond or CBN (Cubic Boron Nitride) with a bonding material (also called a bond material) made of metal, ceramic, resin, or the like. The grinding wheels 112, 212 grind the back surface 202 of the workpiece 200. In the first embodiment, the diameter of the circle formed by connecting the outer edges of the grinding wheels 212 is equal to the outer diameter of the workpiece 200, but this does not have to be the same.

[0035] The grinding units 10, 20 rotate the spindles 12, 22 and grinding wheels 11, 21 around their axes using the spindle motors 13, 23, and supply grinding water to the back surface 202 of the object 200 held on the holding table 6 at the grinding positions 302, 303, while the grinding feed unit 30 moves the grinding wheels 112, 212 closer to the holding table 6 at a predetermined feed speed, thereby rough-grinding or finish-grinding the back surface 202 of the object 200.

[0036] The grinding feed unit 30 moves the grinding units 10, 20 in the Z-axis direction, thereby moving the grinding units 10, 20 relatively closer to and farther away from the holding table 6. In the first embodiment, the grinding feed unit 30 is mounted on an upright column 3 that stands from one end of the device base 2 in the Y-axis direction, which is parallel to the horizontal direction. The grinding feed unit 30 includes a well-known ball screw that is rotatable about its axis, a well-known motor that rotates the ball screw about its axis, and well-known guide rails that support the spindle housings 14, 24 of the grinding units 10, 20 so that they are movable in the Z-axis direction.

[0037] In embodiment 1, the rough grinding unit 10 and the finish grinding unit 20 are arranged such that the axes which are the centers of rotation of the grinding wheels 11, 21 and the axis which is the center of rotation of the holding table 6 are parallel and spaced apart horizontally, and the grinding wheels 112, 212 pass over the center of the back surface 202 of the workpiece 200 held on the holding table 6.

[0038] The cassette 7 is placed on the cassette placing table 8. The cassette 7 is a storage container having a plurality of slots for storing a plurality of objects 200 to be held. The cassette 7 stores a plurality of objects 200 before and after grinding. In embodiment 1, a pair of cassette placing tables 8 are provided, and a cassette 7 is placed on each of them. The cassette placing tables 8 support the cassette 7 so that it can be raised and lowered along the Z-axis direction. The alignment unit 40 is a table on which the object 200 to be held that has been removed from the cassette 7 is temporarily placed and its center is aligned.

[0039] The transport unit 50 transports the object to be held 200. The transport unit 50 includes a carry-in unit 51, a carry-out unit 52, and a carry-in / out unit 53.

[0040] The carry-in unit 51 has a suction pad 511 at its tip end that adsorbs the object to be held 200, and is formed in the shape of an arm that is provided on the device base 2 so as to be able to swing freely around its base end. The carry-in unit 51 adsorbs and holds the object to be held 200, which has been aligned by the alignment unit 40, onto the suction pad 511, and carries it onto the holding table 6 located at the carry-in / out position 301.

[0041] The carry-out unit 52 has a suction pad 521 at its tip end that adsorbs the held object 200, and is formed in the shape of an arm that is provided on the apparatus base 2 so as to be able to swing freely around its base end. The carry-out unit 52 adsorbs and holds the ground held object 200 on the holding table 6 located at the carry-in / out position 301 to the suction pad 521, and carries it out to the cleaning unit 60.

[0042] The carry-in / out unit 53 removes the held object 200 before grinding from the cassette 7 and transports it to the alignment unit 40, and also removes the held object 200 after grinding from the cleaning unit 60 and transports it to the cassette 7. The carry-in / out unit 53 is, for example, a robot pick equipped with a U-shaped hand 531, which adsorbs and holds the held object 200 and transports it.

[0043] The cleaning unit 60 cleans the held object 200 after grinding, and removes foreign matter such as grinding dust adhering to the back surface 202 that has been ground.

[0044] 3, the processing apparatus 1 includes a first supply unit 71 and a second supply unit 72. The first supply unit 71 has a first supply port 711 that supplies a cleaning liquid 712 (pure water in the first embodiment) to a first point 64 on the holding surface 61 of the holding table 6. In the first embodiment, the first supply unit 71 sprays the cleaning liquid 712 from the first supply port 711 toward the center 62, which is the center of rotation of the holding surface 61 of the holding table 6 at the carry-in / out position 301, and supplies the cleaning liquid 712 to a first point 64 on the holding surface 61 that is closer to the first supply port 711 than the center 62. In this way, the first supply unit 71 supplies the cleaning liquid 712 from the first supply port 711 to the holding surface 61 so that a line segment connecting the center of the first supply port 711 and the first point 64 passes through the center 62 of the holding surface 61. The first point 64 is a position on the holding surface 61 where the cleaning liquid 712 supplied from the first supply port 711 of the first supply unit 71 lands.

[0045] The second supply unit 72 has a second supply port 721 that supplies a cleaning liquid 722 (pure water in the first embodiment) to a second point 65 on the holding surface 61 of the holding table 6. In the first embodiment, the second supply unit 72 sprays the cleaning liquid 722 from the second supply port 721 toward the center 62, which is the center of rotation of the holding surface 61 of the holding table 6 at the loading / unloading position 301, and supplies the cleaning liquid 722 to a second point 65 that is closer to the second supply port 721 than the center 62 on the holding surface 61. In this way, the second supply unit 72 supplies the cleaning liquid 722 from the second supply port 721 to the holding surface 61 so that the line segment connecting the center of the second supply port 721 and the second point 65 passes through the center 62 of the holding surface 61. The second point 65 is a position on the holding surface 61 where the cleaning liquid 722 supplied from the second supply port 721 of the second supply unit 72 lands.

[0046] Furthermore, in the first embodiment, a first point 64 at which the cleaning liquid 712 supplied by the first supply unit 71 lands is located closer to the center 62 of the holding surface 61 than a second point 65 at which the cleaning liquid 722 supplied by the second supply unit 72 lands, and the second point 65 at which the cleaning liquid 722 supplied by the second supply unit 72 lands is located closer to the outer periphery of the holding surface 61 than the first point 64 at which the cleaning liquid 712 supplied by the first supply unit 71 lands. Furthermore, in the first embodiment, the first supply unit 71 and the second supply unit 72 are disposed at positions where the rotation direction 63 of the holding table 6 faces from the second supply unit 72 to the first supply unit 71 on the outer periphery side of the turntable 5. Furthermore, in the first embodiment, the first supply unit 71 and the second supply unit 72 are disposed on the outer periphery side of the turntable 5 and fixed to the apparatus base 2.

[0047] The control unit 100 controls each of the above-mentioned constituent units constituting the processing apparatus 1, causing the processing apparatus 1 to perform processing operations on the held object 200. That is, the control unit 100 controls at least the holding table 6, the first supply unit 71, and the second supply unit 72. The control unit 100 is a computer having an arithmetic processing device having a microprocessor such as a CPU (central processing unit), a storage device having memory such as a ROM (read only memory) or RAM (random access memory), and an input / output interface device.

[0048] The arithmetic processing device of the control unit 100 performs arithmetic processing in accordance with a computer program stored in the storage device, and outputs control signals for controlling the processing device 1 to the above-mentioned components of the processing device 1 via the input / output interface device. The control unit 100 is also connected to a display unit configured with a liquid crystal display device or the like that displays the status and images of the processing operation, an input unit that the operator uses to register processing content information, and a notification unit that notifies the operator.

[0049] The input unit is composed of at least one of a touch panel provided on the display unit, a keyboard, etc. The notification unit notifies the operator by emitting at least one of sound, light, and a message on the touch panel.

[0050] Next, a description will be given of the processing operation of the processing device 1. In the first embodiment, the operator places the cassette 7 containing the object 200 to be held on the cassette mounting table 8 of the device base 2 with the back surface 202 facing upward in the processing device 1. The processing device 1 starts the processing operation when the processing conditions are registered in the control unit 100 and the control unit 100 receives an instruction to start the processing operation from the operator.

[0051] In the first embodiment, in the processing operation, the control unit 100 of the processing device 1 rotates the spindles 12, 22 of the grinding units 10, 20 around their axes at rotation speeds determined by the processing conditions. In the first embodiment, in the processing operation, the processing device 1 causes the carry-in / out unit 53 to take out one of the objects 200 to be held from one of the cassettes 7 and carry it into the alignment unit 40, and causes the alignment unit 40 to align the center of the object 200 to be held.

[0052] In the processing operation of the first embodiment, the control unit 100 of the processing device 1 suction-holds the object to be held 200, which is aligned with the suction pad 511 of the carry-in unit 51, and causes the carry-in unit 51 to carry it onto the holding surface 61 of the holding table 6, which is positioned at the carry-in / out position 301. In the processing operation of the first embodiment, the control unit 100 of the processing device 1 suction-holds the object to be held 200 onto the holding surface 61 of the holding table 6, which is positioned at the carry-in / out position 301, via the surface protection tape 210.

[0053] In the first embodiment, in a processing operation, the control unit 100 of the processing apparatus 1 rotates the turntable 5 to move the holding table 6 holding the object 200 at the carry-in / out position 301 to the rough grinding position 302. In the first embodiment, in a processing operation, the control unit 100 of the processing apparatus 1 rotates the holding table 6 about its axis, supplies grinding water, and rough grinds the object 200 with the rough grinding unit 10. In the first embodiment, in a processing operation, the control unit 100 of the processing apparatus 1 rough grinds the object 200, and then rotates the turntable 5 to move the holding table 6 holding the object 200 after rough grinding to the finish grinding position 303.

[0054] In the first embodiment, in the processing operation, the control unit 100 of the processing device 1 supplies grinding water and the finish grinding unit 20 finish-grinds the held object 200. In the first embodiment, in the processing operation, the control unit 100 finish-grinds the held object 200, and then the processing device 1 rotates the turntable 5 to move the holding table 6, which holds the held object 200 after the finish grinding and whose rotation around its axis has stopped, to the carry-in / out position 301.

[0055] In the first embodiment, in the processing operation, the processing device 1 stops the rotation and suction holding of the holding table 6 located at the carry-in / out position 301. In the first embodiment, in the processing operation, the control unit 100 causes the carry-out unit 52 to transport the object 200 to be held after finish grinding from the holding table 6 at the carry-in / out position 301 to the cleaning unit 60, where it is washed and dried, and then the carry-in / out unit 53 stores the object 200 in the cassette 7.

[0056] In addition, each time the control unit 100 rotates the turntable 5 by 120 degrees, the processing device 1 transports the held object 200 from the holding table 6 at the loading / unloading position 301, which holds the held object 200 after finish grinding, to the cleaning unit 60, loads the held object 200 before grinding onto the holding table 6 located at the loading / unloading position 301, roughly grinds the held object 200 before grinding held on the holding table 6 at the rough grinding position 302, and finishes grinding the held object 200 after rough grinding held on the holding table 6 at the finish grinding position 303.

[0057] In this way, the processing device 1 cleans, carries out, and carries in the held object 200 to the holding table 6 at the carry-in / out position 301 every time the control unit 100 rotates the turntable 5 by 120 degrees, and positions the held object 200 held on the holding surface 61 of the holding table 6 at the rough grinding position 302 and the finish grinding position 303 in that order, and performs rough grinding and finish grinding in that order. When the control unit 100 has performed rough grinding and finish grinding on all of the held objects 200 in the cassette 7, the processing device 1 ends its processing operation.

[0058] (Cleaning method) Furthermore, the processing apparatus 1 according to the first embodiment performs the cleaning method according to the first embodiment during the period from when the ground object 200 is carried out from the holding table 6 positioned at the carry-in / out position 301 during processing operation until the held object 200 before grinding is carried into the holding table 6 positioned at the carry-in / out position 301. Fig. 4 is a flowchart showing the flow of the cleaning method according to the first embodiment.

[0059] The cleaning method according to the first embodiment is a method for cleaning the holding surface 61 of the holding table 6, which has the holding surface 61 for holding the object to be held 200. The cleaning method according to the first embodiment is a method for cleaning the holding surface 61 of the holding table 6 after the holding table 6 is positioned at the carry-in / out position 301 and the object to be held 200 after grinding has been carried out toward the cleaning unit 60. The cleaning method according to the first embodiment is started after the holding table 6 is positioned at the carry-in / out position 301 and the object to be held 200 after grinding has been carried out toward the cleaning unit 60, and includes a cleaning step 101 and a retention / destruction step 102, as shown in FIG.

[0060] (Washing step) Fig. 5 is a plan view schematically showing the cleaning step of the cleaning method shown in Fig. 4. The cleaning step 101 is a step in which the holding surface 61 is cleaned by supplying a cleaning liquid 712 from a first supply port 711 to a first point 64 on the holding surface 61 and supplying a cleaning liquid 722 from a second supply port 721 to a second point 65 on the holding surface 61 while rotating the holding table 6 around an axis passing through the center 62 of the holding surface 61.

[0061] In the first embodiment, in the cleaning step 101, the control unit 100 of the processing apparatus 1 positions the holding table 6 at the carry-in / out position 301, and while rotating the holding table 6, from which the ground object 200 has been carried out, once around its axis, continues to supply the cleaning liquid 712 from the first supply port 711 of the first supply unit 71 toward the first point 64, and also continues to supply the cleaning liquid 722 from the second supply port 721 of the second supply unit 72 toward the second point 65. Note that in the first embodiment, the control unit 100 of the processing apparatus 1 rotates the holding table 6, which is positioned at the carry-in / out position 301, once in the rotation direction 63 at 60 rpm.

[0062] 5, in the cleaning step 101, the cleaning liquid 712 supplied from the first supply unit 71 to the holding surface 61 lands at a first point 64, and then becomes a first cleaning liquid flow 713 (indicated by an arrow in FIG. 5) that passes between the first point 64 and the center 62 of the holding surface 61, and attempts to flow on the holding surface 61. Also, in the cleaning step 101, as shown in FIG. 5, the cleaning liquid 722 supplied from the second supply unit 72 to the holding surface 61 lands at a second point 65, and then becomes a second cleaning liquid flow 723 (indicated by an arrow in FIG. 5) that passes through the second point 65 toward the center 62 of the holding surface 61, and attempts to flow on the holding surface 61.

[0063] Then, in the cleaning step 101, since the holding table 6 rotates in the rotation direction 63 around an axis passing through the center 62, the first cleaning liquid flow 713 rotates together with the holding surface 61 toward the second cleaning liquid flow 723, and the cleaning liquid 712 supplied from the first supply port 711 accumulates on the upstream side of the second cleaning liquid flow 723 in the rotation direction 63 (indicated by the dashed line in FIG. 5 ). The position where the cleaning liquid 712 supplied from the first supply port 711 accumulates is hereinafter referred to as an accumulation portion 714. In this way, in the cleaning step 101, the accumulation portion 714 is formed on the holding surface 61 upstream of the second cleaning liquid flow 723 in the rotation direction 63 of the holding table 6.

[0064] (Retention destruction step) Fig. 6 is a plan view schematically showing the retention breaking step of the cleaning method shown in Fig. 4. Fig. 7 is a plan view schematically showing the second cleaning liquid flow in the retention breaking step shown in Fig. 6. The retention breaking step 102 is a step of breaking up retention portions 714 of cleaning liquid 712 formed in the cleaning step 101.

[0065] In the first embodiment, in the retention destruction step 102, the processing apparatus 1 causes the control unit 100 to rotate the holding table 6 positioned at the carry-in / out position 301 at least once around its axis, while continuing from the cleaning step 101 to supply the cleaning liquids 712, 722 from the first supply port 711 of the first supply unit 71 and the second supply unit 72 of the second supply unit 72 toward the first point 64 and the second point 65 without stopping, and also increases the rotation speed, which is the rotation speed of the holding table 6, compared to that in the cleaning step 101. Note that in the first embodiment, the processing apparatus 1 causes the control unit 100 to rotate the holding table 6 positioned at the carry-in / out position 301 in the rotation direction 63 at 120 rpm.

[0066] 6, in the retention breaking step 102, the cleaning liquid 712 supplied from the first supply unit 71 to the holding surface 61 lands on the first point 64, and then becomes a first cleaning liquid flow 713 (indicated by an arrow in FIG. 6) that passes between the first point 64 and the center 62 of the holding surface 61, and attempts to flow on the holding surface 61. In the retention breaking step 102, as in the cleaning step 101, the holding table 6 rotates in the rotation direction 63 around the axis that passes through the center 62.

[0067] 6, in the retention breaking step 102, the rotation speed of the holding table 6 is higher than in the cleaning step 101, and therefore the cleaning liquid 722 supplied from the second supply unit 72 to the holding surface 61 lands at the second point 65, and then becomes a second cleaning liquid flow 723 (indicated by an arrow in FIG. 6) that flows from the second point 65 toward the first point 64 along the rotation direction 63, and attempts to flow on the holding surface 61. Then, in the retention breaking step 102, the second cleaning liquid flow 723 passes the outer circumferential side of the first point 64 and flows on the holding surface 61 along the rotation direction 63, and because the second cleaning liquid flow 723 flows in this manner, the first cleaning liquid flow 713 rotating in the rotation direction 63 flows on the holding surface 61 without colliding with the second cleaning liquid flow 723, i.e., without forming a retention portion 714.

[0068] In this way, in the retention destruction step 102, the second cleaning liquid flow 723 passes along the outer periphery of the first point 64 and flows on the holding surface 61 in the rotation direction 63, causing the cleaning liquid 712 that constitutes the retention portion 714 to flow in the outer periphery direction on the holding surface 61 due to centrifugal force accompanying the rotation of the holding table 6, etc., and destroys the retention portion 714.

[0069] 7 is divided into a vector V1 in the tangential direction of the holding table 6 and a vector V2 in the radial direction of the holding table 6. Since 1 rpm=2π / 60 (rad / sec), when the rotation speed of the holding table 6 is N (rpm), the angular velocity ω (rad / sec) of the vector V1 satisfies the following formula 1.

[0070] ω=2πN / 60 Equation 1

[0071] Furthermore, if the distance between the second point 65 and the center 62 of the holding table 6 is r, then the vector V1 satisfies V1=r×ω, and therefore satisfies the following formula 2.

[0072] V1=πrN / 30...Equation 2

[0073] The flow rate Q (m 3 / sec) satisfies the following formula 3, where D (m) is the diameter of the second supply port 721.

[0074] Q=(D / 2) 2 ×π×V2...Equation 3

[0075] Therefore, the vector V2 satisfies the following equation 4.

[0076] V2=4Q / (πD 2 )...Equation 4

[0077] Here, if the flow rate Q is 1 (L / min) and D=4 mm, then based on equation 4, the vector V2 is 1.32 m / sec.

[0078] Here, in order for the second cleaning liquid flow 723 to flow on the outer periphery side of the first point 64 on the holding surface 61, the following formula 5 must be satisfied, where ΔX1 is the distance from the center 62 to the first point 64 and ΔX2 is the distance from the center 62 to the second point 65.

[0079] V1 / V2>ΔX1 / ΔX2 Equation 5

[0080] For example, when the above-mentioned vector V2 is 1.32 m / sec, ΔX1=0.045 m and ΔX2=0.049, in order to satisfy Equation 5, vector V1 satisfies the following Equation 6.

[0081] V1>1.21m / sec...Formula 6

[0082] By substituting the vector V1=1.21 m / sec into equation 2, the rotation speed N (rpm) of the holding table 6 that satisfies equation 6 satisfies the following equation 7.

[0083] N>115rpm...Formula 7

[0084] As described above, in the retention breaking step 102 of the first embodiment, the positions of the first point 64 and the second point 65, the rotation speed N (rpm) of the holding table 6, and the diameter D (m) of the second supply port 721 are set so as to satisfy the above-described formulas 2, 4, and 5. As described above, in the retention breaking step 102 of the first embodiment, the positions of the first point 64 and the second point 65, the rotation speed N (rpm) of the holding table 6, and the diameter D (m) of the second supply port 721 are set so as to satisfy the above-described formulas 2, 4, and 5, whereby the second cleaning liquid flow 723 passes the outer circumferential side of the first point 64 and flows on the holding surface 61 in the rotation direction 63, thereby breaking up the retention portion 714.

[0085] In the cleaning method of the first embodiment, after the retention breaking step 102, the control unit 100 determines whether or not the cleaning step 101 and the retention breaking step 102 have been repeated a predetermined number of times (step 103 in FIG. 4). If the control unit 100 determines that the cleaning step 101 and the retention breaking step 102 have not been repeated a predetermined number of times (step 103: No), the process returns to the cleaning step 101. In the returned cleaning step 101, the holding surface 61 is cleaned with the cleaning liquids 712 and 722 in the same manner as before.

[0086] In this way, the cleaning step 101 returned from step 103 is a second cleaning step in which, after the retention breaking step 102 has been performed, the holding table 6 is rotated around its axis, and the cleaning liquid 712 is supplied from the first supply port 711 to the first point 64, and the cleaning liquid 722 is supplied from the second supply port 721 to the second point 65, to clean the holding surface 61. When the control unit 100 determines that the cleaning step 101 and the retention breaking step 102 have been repeated a predetermined number of times (step 103: Yes), the cleaning method is terminated. When the cleaning method is terminated, the processing apparatus 1 continues the processing operation by, for example, having the control unit 100 load the held object 200 before grinding onto the holding table 6 positioned at the load / unload position 301.

[0087] Thus, in the cleaning method, the control unit 100 rotates the holding table 6 around its axis in the cleaning step 101 while supplying cleaning liquid 712 from the first supply port 711 to the first point 64 and supplying cleaning liquid 722 from the second supply port 721 to the second point 65 to clean the holding surface 61, and then controls at least one of the holding table 6 and the second supply unit 72 to destroy the stagnation portion 714 of the cleaning liquid 712 formed on the holding surface 61 in the stagnation destruction step 102.

[0088] As described above, in the cleaning step 101, the cleaning method and processing apparatus 1 according to embodiment 1 supply the cleaning liquid 712 to the first point 64 on the holding surface 61 of the rotating holding table 6 and also supply the cleaning liquid 722 to the second point 65, thereby enabling multiple areas to be cleaned simultaneously, thereby achieving excellent cleaning results.

[0089] Incidentally, when cleaning liquids 712, 722 are supplied to a plurality of points 64, 65 on the rotating holding surface 61, the cleaning liquids 712, 722 that land at the respective points 64, 65 collide with each other as they flow, forming stagnation areas 714 where the cleaning liquids 712, 722 accumulate. Foreign matter taken in by the cleaning liquids 712, 722 accumulates in the stagnation areas 714, and there is a risk that the foreign matter may remain even after cleaning. The cleaning method and processing apparatus 1 according to the first embodiment perform the stagnation destruction step 102 of destroying the stagnation areas 714 after the cleaning step 101, and therefore have the effect of suppressing foreign matter from remaining on the holding surface 61 after cleaning.

[0090] (Embodiment 2) A cleaning method according to embodiment 2 will be described. Fig. 8 is a plan view schematically showing the retention breaking step of the cleaning method according to embodiment 2. Fig. 9 is a diagram showing the timing for carrying out the cleaning step and retention breaking step of the cleaning method according to embodiment 2. In Fig. 9, the same parts as those in embodiment 1 are designated by the same reference numerals, and their description will be omitted.

[0091] Similar to the first embodiment, the cleaning method according to the second embodiment is a method for cleaning the holding surface 61 of the holding table 6 having the holding surface 61 for holding the object to be held 200. Similar to the first embodiment, the cleaning method according to the second embodiment is a method for cleaning the holding surface 61 of the holding table 6 positioned at the carry-in / out position 301 after the ground object to be held 200 has been carried out toward the cleaning unit 60. Similar to the first embodiment, the cleaning method according to the second embodiment is started after the ground object to be held 200 has been carried out toward the cleaning unit 60 from the holding table 6 positioned at the carry-in / out position 301, and includes a cleaning step 101 and a retention / destruction step 102.

[0092] In the cleaning method according to the second embodiment, the processing apparatus 1 performs the cleaning step 101 in the same manner as in the first embodiment. In the cleaning method according to the second embodiment, in the retention breaking step 102, the control unit 100 of the processing apparatus 1 stops the supply of the cleaning liquid 722 from the second supply port 721 without stopping the supply of the cleaning liquid 712 from the first supply port 711 while rotating the holding table 6 around its axis, as shown in Fig. 8. In the second embodiment, in the retention breaking step 102, the processing apparatus 1 stops the supply of the cleaning liquid 722 from the second supply port 721, thereby causing the cleaning liquid 712 in the retention portion 714 to flow onto the holding surface 61, thereby breaking up the retention portion 714.

[0093] In the cleaning method according to the second embodiment, in the retention breaking step 102, the processing apparatus 1 sets the flow rate of the cleaning liquid 712 from the first supply port 711 and the rotation speed of the holding table 6 to be the same as those in the cleaning step 101. In the cleaning method according to the second embodiment, as shown in FIG. 9 , the control unit 100 supplies the cleaning liquid 722 from the second supply port 721 for a predetermined time T, i.e., performs the cleaning step 101. Then, the control unit 100 stops the supply of the cleaning liquid 712 from the second supply port 721 for a predetermined time t, i.e., performs the retention breaking step 102, repeating the cleaning step 101 for the predetermined time T and the retention breaking step 102 for the predetermined time t a predetermined number of times. In FIG. 9 , the timing of supplying the cleaning liquid 722 is indicated by ON, and the timing of stopping the supply of the cleaning liquid 722 is indicated by OFF. In FIG. 9 , the horizontal axis indicates time.

[0094] In order to destroy the stagnation portion 714, the cleaning liquid 712 in the stagnation portion 714 needs to flow across the position where the second cleaning liquid flow 723 flows and on the holding surface 61 while the supply of the cleaning liquid 722 from the second supply port 721 is stopped. For this reason, in order to destroy the stagnation portion 714, when the width of the second cleaning liquid flow 723, i.e., the diameter of the second supply port 721, is l (mm), the predetermined time t for performing the stagnation destruction step 102 needs to satisfy the following formulas 8 and 9 based on formula 2.

[0095] V1=l / t=πrN / 30...Equation 8 t=l×30 / (πrN)...Equation 9

[0096] As described above, in the retention / destruction step 102 of the second embodiment, the positions of the first point 64 and the second point 65 and the rotation speed N (rpm) of the holding table 6 are set so as to satisfy the above-mentioned formula 9. As described above, in the retention / destruction step 102 of the second embodiment, the positions of the first point 64 and the second point 65 and the rotation speed N (rpm) of the holding table 6 are set so as to satisfy the above-mentioned formula 9, whereby the cleaning liquid 712 in the retention portion 714 formed in the cleaning step 101 flows on the holding surface 61 along the rotation direction 63 and destroys the retention portion 714.

[0097] As in the first embodiment, the cleaning method and processing apparatus 1 according to the second embodiment perform the retention breaking step 102 of breaking the retention portion 714 after the cleaning step 101, thereby achieving the effect of suppressing the remaining of foreign matter on the holding surface 61 after cleaning. Note that in the second embodiment, if the time for which the cleaning liquid 722 from the second supply unit 72 is stopped is too long, the cleaning effect of the second supply unit 72 is impaired and the cleaning power is reduced. On the other hand, in the second embodiment, stopping the cleaning liquid 722 from the second supply unit 72 has the advantage of being able to reduce the amount of cleaning liquid 722 used, so it is desirable to appropriately set the upper limit of the stop time depending on the cleaning effect and cleaning time.

[0098] (Variation) Next, a cleaning method according to a modification of Embodiment 1 and Embodiment 2 will be described. Fig. 10 is a plan view schematically showing cleaning steps of the cleaning method according to a modification of Embodiment 1 and Embodiment 2. In Fig. 10, the same parts as those in Embodiments 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.

[0099] 10 , the cleaning method according to the modified example is a method for cleaning the back surface 202, which is the exposed surface of the ground object 200 held on the holding surface 61 of the holding table 6 positioned at the carry-in / out position 301 of the processing apparatus 1. The cleaning method according to the modified example is performed during a processing operation of the processing apparatus 1, from before the holding table 6 holding the ground object 200 is positioned at the carry-in / out position 301 and the held object 200 is carried out from the holding table 6 positioned at the carry-in / out position 301 until the held object 200 before grinding is carried into the holding table 6 positioned at the carry-in / out position 301. In the modified example, the first supply unit 71 has a first supply port 711 that supplies cleaning liquid 712 to a first point 64 of the held object 200 held on the holding surface 61. In addition, in the modified example, the second supply unit 72 has a second supply port 721 that supplies the cleaning liquid 722 to the second point 65 of the object 200 held on the holding surface 61.

[0100] As in the first and second embodiments, the cleaning method according to the modified example performs a cleaning step 101 and a retention / breaking step 102 to clean the back surface 202 of the object 200 held on the holding surface 61 of the holding table 6 positioned at the carry-in / out position 301. That is, in the modified example, the cleaning step 101 is a step of supplying a cleaning liquid 712 from a first supply port 711 to a first point 64 on the back surface 202 and supplying a cleaning liquid 722 from a second supply port 721 to a second point 65 on the back surface 202 while rotating the holding table 6 around an axis passing through the center 62 of the holding surface 61, thereby cleaning the back surface 202. In addition, in a modified example, the cleaning step 101 returned from step 103 is a second cleaning step in which, after the retention breaking step 102 is performed, the holding table 6 is rotated around its axis, and a cleaning liquid 712 is supplied from the first supply port 711 to the first point 64, and a cleaning liquid 722 is supplied from the second supply port 721 to the second point 65, thereby cleaning the back surface 202.

[0101] In addition, in the modified example, the retention breaking step 102 is a step of breaking retention portions 714 of the cleaning liquid 712 formed in the cleaning step 101, as in the first and second embodiments. Thus, in the modified example, the control unit 100 of the processing apparatus 1 performs the cleaning step 101 and the retention breaking step 102, thereby rotating the holding table 6 around its axis in the cleaning step 101, supplying the cleaning liquid 712 from the first supply port 711 to the first point 64 and supplying the cleaning liquid 722 from the second supply port 721 to the second point 65, thereby cleaning the back surface 202 of the object 200 held on the holding surface 61, and then controlling at least one of the holding table 6 and the second supply unit 72 to break retention portions 714 of the cleaning liquid 712 formed on the back surface 202 in the retention breaking step 102.

[0102] In addition, in the modified example, the processing device 1 cleans the back surface 202 of the ground object 200 held on the holding table 6 positioned at the carry-in / out position 301, and then unloads the ground object 200 from the holding table 6, and cleans the holding surface 61 of the holding table 6 positioned at the carry-in / out position 301, similar to the first and second embodiments. In the modified example, the processing device 1 cleans the holding surface 61 of the holding table 6 positioned at the carry-in / out position 301, similar to the first and second embodiments, and then ends the cleaning method, similar to the first embodiment.

[0103] The cleaning method and processing apparatus 1 according to the modified example, like those of the first and second embodiments, performs the retention destruction step 102 of destroying the retention portion 714 after the cleaning step 101, thereby achieving the effect of suppressing the remaining of foreign matter on the back surface 202 of the object to be held 200 after cleaning.

[0104] The present invention is not limited to the above-described embodiment. In other words, various modifications can be made without departing from the gist of the present invention. Furthermore, in the present invention, the holding surface 61 or the back surface 202 of the object 200 may be cleaned in the cleaning step 101 and the retention breaking step 102 by using cleaning stones or cleaning brushes in combination. Furthermore, the present invention is not limited to the processing apparatus 1 as a cleaning device, and is also suitable for a spinner cleaning device. [Explanation of symbols]

[0105] 1 Processing equipment (cleaning equipment) 6 Holding table 61 Holding surface 62 center 64 1st point 65 Second point 71 1st supply section 72 2nd supply section 100 Control unit (controller) 101 Cleaning step (second cleaning step) 102 Retention Destruction Step 200 Object to be held 202 Back side (exposed surface) 711 1st supply port 712 cleaning fluid 721 2nd supply port 722 cleaning solution

Claims

1. A cleaning method for cleaning a holding surface of a holding table having a holding surface for holding an object to be held, or an exposed surface of an object to be held on the holding surface, comprising: a cleaning step of supplying a cleaning liquid from a first supply port to a first point on the holding surface or the exposed surface and supplying the cleaning liquid from a second supply port to a second point on the holding surface or the exposed surface while rotating the holding table around an axis passing through the center of the holding surface, thereby cleaning the holding surface or the exposed surface; a retention breaking step of breaking up the retention portion of the cleaning liquid formed in the cleaning step.

2. 2. The cleaning method according to claim 1, further comprising a second cleaning step of, after performing the retention breaking step, supplying a cleaning liquid from the first supply port to the first point and supplying a cleaning liquid from the second supply port to the second point while rotating the holding table around the axis, thereby cleaning the holding surface or the exposed surface.

3. 3. The cleaning method according to claim 1, wherein in the retention breaking step, the rotation speed of the holding table is increased to be higher than that in the cleaning step without stopping the supply of the cleaning liquid from the first supply port and the second supply port.

4. 3. The cleaning method according to claim 1, wherein in the retention breaking step, the supply of the cleaning liquid from the second supply port is stopped without stopping the supply of the cleaning liquid from the first supply port while rotating the holding table around the axis.

5. a holding table having a holding surface for holding an object to be held and rotatable around an axis passing through the center of the holding surface; a first supply unit having a first supply port that supplies a cleaning liquid to a first point on the holding surface or on an object held on the holding surface; a second supply unit having a second supply port that supplies a cleaning liquid to a second point on the holding surface or on the object held on the holding surface; a controller that controls the holding table, the first supply unit, and the second supply unit; the controller controls at least one of the holding table and the second supply unit to rotate the holding table around the axis, supply cleaning liquid from the first supply port to the first point, and supply cleaning liquid from the second supply port to the second point, thereby cleaning the holding surface or the exposed surface of the object held on the holding surface, and then destroy any stagnation of the cleaning liquid formed on the holding surface or the exposed surface.

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