Processing equipment

Abstract

To save water and power by cleaning an inner wall of a processing chamber by using a cleaning drain water.SOLUTION: In a grinding device (processing device) 1 comprising: a chuck table 10 holding a wafer W with a holding surface 10a; grinding units (processing means) 20 and 30 of processing the wafer W held by the holding surface 10a with rotating grind stones (processing tools) 25b and 35b; processing chambers S1 and S2 housing the chuck table 10 and the grind stones 25b and 35b; grinding water supply means (processing liquid supply means) 40 of supplying grinding water (processing liquid) to the grind stones 25b and 35b; and cleaning units 60 and 80 of cleaning the wafer W or the holding surface 10a of the chuck table 10 with the cleaning water, a cleaning drain water after the wafer W or the holding surface 10a of the chuck table 10 is cleaned with the cleaning units 60 and 80 is absorbed to clean the inner wall of the processing chambers S1 and S2.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a processing apparatus for processing a workpiece such as a wafer held on a chuck table.

Background Art

[0002] For example, in the manufacturing process of semiconductor devices such as ICs and LSIs used in electronic devices, in order to miniaturize and lighten the semiconductor devices, the back surface of the wafer is ground by a grinding apparatus to thin the wafer to a predetermined thickness. In particular, in recent years, in order to meet the requirements such as thinning and miniaturization of electronic devices, it has been required to form semiconductor devices thinly.

[0003] Here, a wafer grinding apparatus includes a chuck table that holds a wafer on a holding surface, a grinding unit that grinds the wafer held on the holding surface of the chuck table with a grindstone as a processing tool, a processing chamber that houses the chuck table and the grindstone, a grinding water supply means that supplies grinding water as a processing liquid to the grindstone, and a cleaning unit that cleans the holding surface of the wafer or the chuck table with cleaning water. In such a grinding apparatus, the upper surface of the wafer held on the holding surface of the chuck table is ground by bringing the rotating grindstone into contact with the upper surface of the wafer. For example, in Patent Document 1, a configuration has been proposed in which a two-fluid of air and water is ejected from the holding surface through the suction path of the chuck table to clean the holding surface from the inside.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in wafer grinding equipment, the chuck table and grinding wheel are housed in the processing chamber. During grinding, the processing chamber is filled with grinding water, and the rotating grinding wheel grinds the wafer, causing a spray of grinding water containing grinding debris to be scattered. As a result, the spray of grinding water containing grinding debris adheres to the inner walls of the processing chamber (especially the inner walls of the side plates and top plates).

[0006] Furthermore, the rotation of the grinding wheel creates an airflow within the processing chamber, which dries any moisture from the spray adhering to the inner walls of the chamber, causing grinding debris to adhere to the inner walls. As the wafer is continuously ground, the accumulated grinding debris gradually grows larger, and when the processing chamber vibrates during the grinding process, the larger pieces of debris may fall onto the top surface of the wafer.

[0007] As described above, when grinding debris that has adhered to the inner wall of the processing chamber falls onto the top surface of the wafer, this debris can get trapped between the wafer and the grinding wheel, forming deep scratches on the wafer's surface. These deep scratches create a pattern on the wafer's surface that differs from the grinding pattern formed by the grinding wheel, and these scratches can adversely affect the device.

[0008] Therefore, in order to clean the inner wall of the processing chamber, for example, Patent Document 2 provides a cleaning water supply unit that supplies cleaning water to the grinding wheel from the top of the spindle, passing through the spindle, and the cleaning water supplied from this cleaning water supply unit is scattered toward the inner wall of the processing chamber by the centrifugal force caused by the rotation of the grinding wheel.

[0009] However, as mentioned above, spraying cleaning water to clean the inner walls of the processing chamber results in wasted cleaning water. Furthermore, there is a problem of wasted electricity because the grinding wheel needs to be rotated in order to spray the cleaning water towards the inner walls of the processing chamber.

[0010] This invention has been made in view of the above problems, and its purpose is to provide a processing apparatus that can conserve water and electricity by using wastewater from the cleaning to clean the inner walls of the processing chamber. [Means for solving the problem]

[0011] The present invention, for solving the above problems, is a processing apparatus comprising: a chuck table that holds a wafer on a holding surface; processing means for processing the wafer held on the holding surface with a rotating processing tool; a processing chamber that houses the chuck table and the processing tool; processing fluid supply means for supplying processing fluid to the processing tool; and a cleaning unit for cleaning the wafer or the holding surface of the chuck table with cleaning water. The cleaning unit comprises a wafer cleaning mechanism for cleaning wafers with cleaning water or a holding surface cleaning mechanism for cleaning the holding surface with cleaning water, a storage section for collecting cleaning wastewater, an injection mechanism for drawing in the cleaning wastewater from the storage section and spraying it into the inner wall of the processing chamber, and a control unit for controlling the injection mechanism, wherein the injection mechanism comprises an air supply source, a flow path for air from the air supply source, and an intake channel that connects one end to the flow path, the intake channel having one end opening into the storage section as an intake port, The flow path has one end connected to an air supply source and the other end connected to the processing chamber via an injection nozzle. The other end of the intake channel is equipped with a negative pressure generating unit that generates negative pressure by the Bernoulli effect at the point where it merges. The control unit controls the flow of air into the flow path and generates negative pressure in the negative pressure generating unit based on the flow velocity of the air flowing through the flow path. This negative pressure draws in the cleaning wastewater from the storage section through the intake port, and the two fluids, the cleaning wastewater and air, are injected from the injection nozzle to clean the inner wall of the processing chamber. . [Effects of the Invention]

[0012] According to the present invention, the wastewater from the cleaning unit, after being used to clean wafers or the holding surface of the chuck table, is sucked up and supplied to the processing chamber. This wastewater is then used to clean the inner wall of the processing chamber. As a result, water conservation can be achieved by effectively utilizing the wastewater without using separate cleaning water for cleaning the inner wall of the processing chamber. Furthermore, since it is not necessary to rotate the chuck table when cleaning the inner wall of the processing chamber, unnecessary power consumption is eliminated, thus saving electricity. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view showing a part of a processing apparatus (grinding apparatus) according to the first embodiment of the present invention, with a section cut away. [Figure 2] This is a cross-sectional side view of the second cleaning unit of a processing apparatus (grinding apparatus) according to the first embodiment of the present invention. [Figure 3] This is a perspective view showing a part of a processing apparatus (grinding apparatus) according to a second embodiment of the present invention, with the part shown in a fractured section. [Figure 4] This is a perspective view of the first cleaning unit of a processing apparatus (grinding apparatus) according to a second embodiment of the present invention. [Figure 5]This is a block diagram showing the supply path of cleaning water to the holding surface of each chuck table of a processing apparatus (grinding apparatus) according to a second embodiment of the present invention. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the accompanying drawings. <First Embodiment> First, the configuration of a wafer grinding apparatus as one embodiment of the processing apparatus according to the first embodiment of the present invention will be described with reference to Figure 1. In the following description, the arrow directions shown in Figure 1 will be the X-axis direction (left-right direction), the Y-axis direction (front-back direction), and the Z-axis direction (up-down direction), respectively.

[0015] [Configuration of the grinding machine] The grinding apparatus 1 shown in Figure 1 is a device for grinding a disc-shaped wafer W (see Figure 2), which is the workpiece to be ground. It comprises three chuck tables 10 arranged on a rotatable disc-shaped turntable 2, a rough grinding unit 20 and a finish grinding unit 30 which are processing means for grinding the wafer W held on the chuck tables 10, processing chambers S1 and S2 which house the chuck tables 10 and grinding wheels 25b, 35b, etc., located in the rough grinding area R2 and the finish grinding area R3, respectively, and the rough grinding unit 20 and the finish grinding unit The main components of the device include a grinding water supply means (processing fluid supply means) 40 that supplies grinding water, which is a processing fluid, to each of the grinding wheels 25b and 35b of the 30, wafer thickness measuring instruments 50 and 51 that measure the thickness of the wafer W during grinding, a first cleaning unit 60 that cleans the holding surface 10a of the chuck table 10 located in the wafer loading / unloading area R1 and the wafer W before grinding, a second cleaning unit 80 that cleans the upper surface (polished surface) of the wafer W after finish grinding, and a transport unit 100 that transports the wafer W.

[0016] Here, the wafer W is a thin disk-shaped member made of a single-crystal silicon base material. On the surface facing downward in the state shown in FIG. 2, a plurality of devices (not shown) are formed. These devices are protected by a protective tape T (see FIG. 2) adhered to the surface of the wafer W. The wafer W is suction-held by the chuck table 10 through the protective tape T on its surface, and its back surface (the upper surface in FIG. 2) is ground by the grinding device 1.

[0017] Next, the configurations of the chuck table 10, the rough grinding unit 20, the finish grinding unit 30, the processing chambers S1, S2, the grinding water supply means 40, the wafer thickness measuring devices 50, 51, the first cleaning unit 60, the second cleaning unit 80, and the transfer unit 100, which are the main components of the grinding device 1, will be described respectively.

[0018] (Chuck Table) The three chuck tables 10 are disk-shaped members and are arranged on a turntable 2 that rotates intermittently around a central axis perpendicular to the Z-axis direction at an equal angular pitch (120° pitch) in the circumferential direction. These chuck tables 10 revolve by 120 degrees each around the axis center perpendicular to the Z-axis direction of the turntable 2 due to the intermittent rotation of the turntable 2, sequentially moving between the wafer loading / unloading region R1, the rough grinding region R2, and the finish grinding region R3, and rotate around the axis center perpendicular to the Z-axis direction at a predetermined speed by a rotation drive mechanism (not shown).

[0019] In addition, each chuck table 10 incorporates a disk-shaped porous member 10A made of porous ceramic or the like at the central part, and the upper surface of each porous member 10A constitutes a holding surface 10a for suction-holding the disk-shaped wafer W.

[0020] (Rough Grinding Unit and Finish Grinding Unit) The rough grinding unit 20 and the finish grinding unit 30 are positioned perpendicularly along the X-axis direction (left-right direction) at the +Y-axis end (rear end) of a rectangular box-shaped base 200 that is long in the Y-axis direction (front-to-back direction). Here, the rough grinding unit 20 is a unit that rough grinds the upper surface (workpiece surface) of the wafer W held on the holding surface 10a of the chuck table 10 located in the rough grinding region R2, and the finish grinding unit 30 is a unit that finish grinds the upper surface (workpiece surface) of the wafer W held on the holding surface 10a of the chuck table 10 located in the finish grinding region R3, and the basic configuration of both is the same.

[0021] In other words, the rough grinding unit 20 comprises a spindle motor 22 fixed to a holder 21, a vertical spindle 23 rotationally driven by the spindle motor 22, a disc-shaped mount 24 attached to the lower end of the spindle 23, and a grinding wheel 25 detachably mounted on the lower surface of the mount 24. Here, the grinding wheel 25 is composed of a disc-shaped base 25a and a plurality of grinding wheels 25b, which are processing tools, attached in an annular shape to the lower surface of the base 25a.

[0022] Furthermore, the finish grinding unit 30, like the rough grinding unit 20, includes a spindle motor 32 fixed to a holder 31, a vertical spindle 33 rotationally driven by the spindle motor 32, a disc-shaped mount 34 attached to the lower end of the spindle 33, and a grinding wheel 35 detachably mounted on the lower surface of the mount 34. Here, the grinding wheel 35 is composed of a disc-shaped base 35a and a plurality of grinding wheels 35b, which are processing tools attached in an annular shape to the lower surface of the base 35a. These grinding wheels 35b are composed of finer abrasive grains than the grinding wheel 25b of the rough grinding unit 20.

[0023] Incidentally, the rough grinding unit 20 and the finish grinding unit 30 are supported so as to be able to move up and down by a lifting mechanism 3 provided on each of the -Y axis end faces (front faces) of a pair of block-shaped columns 201 that are erected vertically along the X axis (left-right direction) at the +Y axis end (rear end) of the base 200. Here, since the configuration of both lifting mechanisms 3 is the same, corresponding components will be denoted by the same reference numerals below.

[0024] Each lifting mechanism 3 moves a rough grinding unit 20 and a finish grinding unit 30 up and down along the Z-axis direction (vertical direction), and is equipped with a rectangular plate-shaped lifting plate 4 and a pair of left and right guide rails 5 to guide the lifting movement of the lifting plate 4. Here, the rough grinding unit 20 and the finish grinding unit 30 are attached to each lifting plate 4. The pair of left and right guide rails 5 are arranged perpendicularly and parallel to each other on the front surface of the column 201.

[0025] A rotatable ball screw shaft 6 is erected vertically between a pair of left and right guide rails 5, along the Z-axis direction (up and down direction). The upper end of the ball screw shaft 6 is connected to a reversible electric motor 7, which is the drive source. The lower end of the ball screw shaft 6 is rotatably supported by a bearing (not shown) on a column 201, and a nut member (not shown) that protrudes horizontally toward the rear (+Y-axis direction) from the back of the lifting plate 4 is screwed onto this ball screw shaft 6.

[0026] Therefore, when the electric motors 7 of each lifting mechanism 3 configured as described above are activated to rotate each ball screw shaft 6 in the forward and reverse directions, each lifting plate 4, which has a nut member (not shown) protruding from it that screws onto each ball screw shaft 6, moves up and down along a pair of left and right guide rails 5. As a result, the rough grinding unit 20 and the finish grinding unit 30 attached to the lifting plate 4 move up and down independently of each other along the Z-axis direction (vertical direction).

[0027] (Processing room) One processing chamber S1, which houses the chuck table 10 located in the rough grinding area R2, the wafer W held therein, and the grinding wheel 25b (grinding wheel 25) for grinding the wafer W, is defined by a rectangular box-shaped cover 8. A rectangular opening 8a is formed in a part of the side plate of the cover 8 through which the turntable 2 and the chuck table 10 pass. In addition, a circular hole 8b is formed in the top plate of the cover 8 for the grinding wheel 25 to pass through from above.

[0028] Similarly, the other processing chamber S2, which houses the chuck table 10 located in the finish grinding area R3, the wafer W held therein, and the grinding wheel 35b for grinding the wafer W, is defined by a rectangular box-shaped cover 9. A rectangular opening 9a is formed in a part of the side plate of the cover 9 through which the turntable 2 and the chuck table 10 pass. In addition, a circular hole 9b is formed in the top plate of the cover 9 for the grinding wheel 35 to pass through from above.

[0029] (Means for supplying grinding water) The grinding water supply means 40 supplies grinding water, which is the processing fluid, to the grinding wheel 25b of the rough grinding unit 20 and the grinding wheel 35b of the finish grinding unit 30 during the grinding process. This grinding water supply means 40 supplies grinding water from the grinding water supply source 41 to the grinding wheels 25b and 35b of the rough grinding unit 20 and the finish grinding unit 30, passing through the axial centers of the spindle motors 22 and 32 and the spindles 23 and 33 of the respective grinding wheels 25 and 35. As a result, the contact surfaces between each grinding wheel 25b and 35b and each wafer W are cooled by the grinding water. Pure water is preferably used as the grinding water.

[0030] (Wafer thickness measuring instrument) One wafer thickness measuring instrument 50 measures the thickness of the wafer W during rough grinding, while the other wafer thickness measuring instrument 51 measures the thickness of the wafer W during finish grinding. Specifically, the one thickness measuring instrument 50 determines the thickness of the wafer W during rough grinding by subtracting the height of the top surface of the chuck table 10 from the height of the top surface of the wafer W, and the other thickness measuring instrument 51 determines the thickness of the wafer W during finish grinding by subtracting the height of the top surface of the chuck table 10 from the height of the top surface of the wafer W.

[0031] (First washing unit) The first cleaning unit 60 is a unit that cleans the wafer W before grinding, which is held on the holding surface 10a of the chuck table 10 located in the wafer loading / unloading area R1, and the holding surface 10a of the chuck table 10 from which the wafer W after grinding has been removed. However, this will be described later with reference to Figure 4 in the second embodiment of the present invention, so the explanation here will be omitted.

[0032] (Second cleaning unit) The second cleaning unit 80 cleans the wafer W that has been finished grinding by the finish grinding unit 30 to remove grinding debris and other materials adhering to its grinding surface (upper surface). It consists of a spinner table 81 that holds and rotates the wafer W after the finish grinding process, and a nozzle 82 that sprays cleaning water (pure water) toward the grinding surface of the wafer W.

[0033] Here, the details of the configuration of the second cleaning unit 80 will be explained based on Figure 2.

[0034] As shown in Figure 2, the second cleaning unit 80 mainly comprises an electric motor 83 that rotates the spinner table 81 around its vertical central axis at a predetermined speed, a nozzle moving means 84 that moves a nozzle 82 positioned above the spinner table 81 (wafer W) in the radial direction (left-right direction in Figure 2) of the wafer W, and a control unit 85 that controls the operation of the nozzle moving means 84 and other components. The spinner table 81, the nozzle 82, and part of the nozzle moving means 84 are housed in a bottomed polygonal cylindrical case 86 that opens at the top.

[0035] The spinner table 81 is a disc-shaped member, and a disc-shaped porous member 81A made of porous ceramic or the like is incorporated in its center. The upper surface of the porous member 81A forms a holding surface 81a that attracts and holds the wafer W via a protective tape T.

[0036] Here, a suction source 87, such as a vacuum pump, and an air supply source 88, such as an air compressor, are connected to the porous member 81A. Specifically, a connecting passage 11 is formed vertically at the axial center of the spinner table 81, and from this connecting passage 11, multiple (only two are shown in Figure 2) horizontal connecting passages 12 extend radially outward. From the outer end of each connecting passage 12, connecting passages 13 extend vertically upward, and each connecting passage 13 opens onto the lower surface of the porous member 81A.

[0037] Furthermore, connecting passages 14 are formed vertically at the centers of the rotating shaft 89 of the spinner table 81 and the axis of the rotary joint 90, and the upper end of these connecting passages 14 is in communication with connecting passage 11. The lower end of the connecting passage 14 is connected to a connecting passage 15 that is formed horizontally along the radial direction of the rotary joint 90, and piping 16 is connected to the connecting passage 15.

[0038] Two branch pipes 16a and 16b branch off from the above-mentioned piping 16. One branch pipe 16a is connected to the suction source 87 via a variable orifice 17 for flow rate adjustment and an electromagnetic valve V1. The other branch pipe 16b is connected to the air supply source 88 via a variable orifice 18 for flow rate adjustment and an electromagnetic valve V2. The electromagnetic valves V1 and V2 are electrically connected to the control unit 85, and their opening and closing operations are controlled by the control unit 85. A pressure gauge 19 is connected between the two branch pipes 16a and 16b of the piping 16.

[0039] Incidentally, the spinner table 81 is rotated at a predetermined speed (800 rpm in this embodiment) around its vertical central axis by an electric motor 83 located below it. The rotating shaft 89, which extends vertically upward from the electric motor 83 via a rotary joint 90, passes through the bottom of the case 86 and faces into the case 86, and the spinner table 81 is horizontally mounted on its upper end.

[0040] Furthermore, an encoder 91 is provided at the bottom of the electric motor 83 to detect the rotational speed, rotational angle, and rotational direction of the electric motor 83. This encoder 91 and the electric motor 83 are electrically connected to the control unit 85. The detection signal from the encoder 91 is transmitted to the control unit 85, which receives the detection signal from the encoder 91 and controls the drive of the electric motor 83.

[0041] Furthermore, a nozzle 82 is provided above the wafer W held on the spinner table 81, which sprays cleaning water toward the upper surface (back surface) of the wafer W. A water source 92, such as a water pump, is connected to this nozzle 82.

[0042] The nozzle moving means 84 is a mechanism that moves the nozzle 82 horizontally (parallel to the holding surface 81a of the spinner table 81) above the wafer W along the radial direction (left-right direction in Figure 2) of the wafer W, and is equipped with an electric motor 93 which is a rotation drive source. The rotating shaft 94, which is connected to an output shaft (motor shaft) 93a that extends vertically upward from the electric motor 93, passes through the bottom of the case 86 and faces into the case 86, and one axial end of a horizontally positioned swivel arm 95 is attached to its upper end. The nozzle 82 is attached to the other axial end (tip) of the swivel arm 95 so that its nozzle faces vertically downward.

[0043] Here, the bottom of the case 86 has circular through-holes 86a and 86b through which the rotating shafts 89 and 94 pass, and cylindrical protrusions 86A and 86B are provided projecting upward from the periphery of each through-hole 86a and 86b. In addition, bottomed cylindrical (inverted dish-shaped) sealing members 96 and 97 are fitted to the outer circumference of each rotating shaft 89 and 94, respectively, covering the protrusions 86A and 86B from the outer circumference. These sealing members 96 and 97 and the protrusions 86A and 86B form a labyrinth seal structure, improving the sealing performance of the portion of the bottom of the case 86 through which the rotating shafts 89 and 94 pass.

[0044] Furthermore, an encoder 98 is provided at the bottom of the electric motor 93 to detect the rotation speed, rotation angle, and rotation direction of the electric motor 93. This encoder 98 and the electric motor 93 are electrically connected to the control unit 85. The detection signal from the encoder 98 is transmitted to the control unit 85, which receives the detection signal from the encoder 98 and controls the drive of the electric motor 93.

[0045] In the nozzle moving means 84 configured as described above, when the electric motor 93 is activated and the rotating shaft 94 rotates by a predetermined angle, the swivel arm 95 attached to the upper end of the rotating shaft 94 rotates horizontally, and the nozzle 82 attached to the tip of the swivel arm 95 rotates horizontally above the wafer W and moves radially along the wafer W, drawing an arc from the center to the outer circumference.

[0046] By the way, in the grinding apparatus 1 according to this embodiment, a method is employed in which the wastewater used to clean the wafer W after being sprayed from the nozzle 82 is sucked up and the inner walls of the processing chambers S1 and S2 shown in Figure 1 are cleaned with the wastewater, and the configuration described below is adopted to achieve this.

[0047] Specifically, as shown in Figure 2, the bottom of the case 86 of the second cleaning unit 80 is provided with a storage section 42 for collecting cleaning wastewater after cleaning the wafer W, an injection mechanism 43 for drawing in the cleaning wastewater stored in the storage section 42 and spraying it into the inner walls of the processing chambers S1 and S2 shown in Figure 1, and the control unit 85 for controlling the injection mechanism 43. A drain port 42a is formed at the bottom of the storage section 42, and this drain port 42a is normally closed by a removable plug 42A.

[0048] The injection mechanism 43 described above includes an air supply source 44 such as an air compressor and an ejector 45 that generates negative pressure by the flow of air supplied from the air supply source 44. Here, an intake port 46a opening at one end of a flow path 46 formed in the ejector 45 is connected to the air supply source 44 by an air pipe 47, and an electromagnetic valve V3 is provided in the air pipe 47. The air supply source 44 and the electromagnetic valve V3 are electrically connected to a control unit 85, and their operation is controlled by the control unit 85.

[0049] Furthermore, the injection port 46b opening at the other end of the flow path 46 of the ejector 45 is connected via a two-fluid pipe 48 to nozzles (not shown) provided in the processing chambers S1 and S2, respectively. In the middle of the air flow direction of the flow path 46, a throat section (restriction section) 46A is formed to narrow the air flow, and this throat section 46A constitutes a negative pressure generating section that generates negative pressure through the Bernoulli effect.

[0050] Furthermore, one end of a water intake channel 49 extending from the storage section 42 of the case 86 is open to the throat portion 46A formed in the flow path 46 of the ejector 45, and the other end of the water intake channel 49 is open to the storage section 42 of the case 86 as a water intake port 49a.

[0051] (Transport unit) In the grinding apparatus 1 according to this embodiment, as shown in Figure 1, a cassette 101 for storing multiple wafers W before grinding and a cassette 102 for storing wafers W after grinding are arranged at the front end (-Y axis end) of the base 200. The transport unit 100 includes an loading / unloading means 104 for loading and unloading wafers W into and out of the cassette 101 and transporting the wafers W removed from the cassette 101 to the alignment table 103, a first transport means 105 for transporting the wafers W positioned on the alignment table 103 to the chuck table 10 located in the wafer loading / unloading area R1, and a second transport means 106 for removing the wafers W that have been finished grinding by the finish grinding unit 30 from the chuck table 10 located in the finish grinding area R3 and transporting them to the second cleaning unit 80.

[0052] [Operation of grinding equipment] Next, we will explain the grinding process of wafer W using the grinding apparatus 1 configured as described above.

[0053] When grinding a wafer W, one wafer W before processing is removed from the cassette 101 by the loading / unloading means 104 shown in Figure 1, and the removed wafer W is transferred to the alignment table 103. On the alignment table 103, the wafer W is aligned, and the aligned wafer W is transferred by the first transport means 105 to the chuck table 10 located in the wafer loading / unloading area R1, and is held in place by suction on the chuck table 10.

[0054] Then, the turntable 2 rotates 120° counterclockwise in the direction of the arrow around its vertical axis and moves together with the wafer W to the rough grinding area R2. In this rough grinding area R2, the back surface (top surface) of the wafer W held on the holding surface 10a of the chuck table 10 is roughly ground by the rough grinding unit 20.

[0055] Specifically, the chuck table 10 is driven to rotate at a predetermined speed (e.g., 300 rpm) by a rotational drive mechanism (not shown), and the spindle motor 22 of the rough grinding unit 20 is activated to drive the grinding wheel 25b to rotate at a predetermined speed (e.g., 1000 rpm).

[0056] As described above, with the chuck table 10 and the wafer W and grinding wheel 25b held therein rotating, the lifting mechanism 3 is driven to lower the grinding wheel 25b in the -Z axis direction. That is, when the electric motor 7 is driven and the ball screw shaft 6 rotates, the lifting plate 4, which is provided with a nut member (not shown) that screws onto the ball screw shaft 6, descends in the -Z axis direction together with the rough grinding unit 20. Then, the lower surface (grinding surface) of the grinding wheel 25b comes into contact with the upper surface (back surface) of the wafer W. At this time, grinding water is supplied from the grinding water supply source 41 of the grinding water supply means 40 to the contact surface between the grinding wheel 25b and the wafer W. Then, while receiving this supply of grinding water, the upper surface (back surface) of the wafer W is ground by the rotating grinding wheel 25b, and its thickness is measured by the thickness measuring instrument 50.

[0057] Then, as described above, once the wafer W is roughly ground to a predetermined thickness by the rough grinding unit 20, the lifting mechanism 3 raises the rough grinding unit 20 in the +Z axis direction, and the grinding wheel 25b moves away from the upper surface of the wafer W. The turntable 2 then rotates 120° around its vertical axis, and the wafer W, which has been roughly ground in the rough grinding region R2, and the chuck table 10 holding it move to the finish grinding region R3, where the upper (back) surface of the wafer W is finish-ground by the finish grinding unit 30. Note that the finish grinding of the wafer W by the finish grinding unit 30 is performed in the same way as the rough grinding of the wafer W by the rough grinding unit 20, so the explanation of this finish grinding is omitted.

[0058] During the finish grinding of the wafer W, grinding water is supplied from the grinding water supply means 40 to the contact surface between the grinding wheel 35b and the wafer W. The thickness of the wafer W during the finish grinding is measured by the thickness measuring instrument 51.

[0059] Then, when the wafer W is finished grinding to a predetermined thickness by the finish grinding unit 30, the lifting mechanism 3 raises the finish grinding unit 30 in the +Z axis direction, and the grinding wheel 35b moves away from the upper surface of the wafer W. The turntable 2 then rotates by an angle of 120° around its vertical axis, and the wafer W that has been finished grinding in the finish grinding area R3 and the chuck table 10 that holds it move to the wafer loading / unloading area R1. In this wafer loading / unloading area R1, the wafer W is removed from the chuck table 10 by the second transport means 106 and transported to the second cleaning unit 80, and the holding surface 10a of the chuck table 10 from which the wafer W has been removed is cleaned by the first cleaning unit 60. Note that in the wafer loading / unloading area R1, the holding surface 10a of the chuck table 10 and the wafer W before grinding are cleaned by the first cleaning unit 60, but these cleaning procedures will be described later in the second embodiment of the present invention, so the explanation is omitted here.

[0060] The cleaning of wafer W by the second cleaning unit 80 will be described below with reference to Figure 2.

[0061] The wafer W, which has been finished grinding by the finishing grinding unit 30 as described above, is transported to the second cleaning unit 80 by the second transport means 106 and placed on the holding surface 81a of the spinner table 81 with the protective tape T facing downwards. When the control unit 85 opens one of the electromagnetic valves V1 from this state, the air inside the porous member 81A is drawn to the suction source 87 through the communication passages 13, 12, 11, 14, 15 and the piping 16 and branch pipe 16a in sequence, thereby generating negative pressure in the porous member 81A. The wafer W, together with the protective tape T, is attracted and held on the holding surface 81a of the spinner table 81 by this negative pressure. At this time, the other electromagnetic valve V2 is closed.

[0062] Next, the electric motor 83 is started, and the spinner table 81 holding the wafer W on the holding surface 81a is rotated around a vertical central axis at a predetermined speed (800 rpm in this embodiment). The nozzle 82, which sprays cleaning water toward the center of the wafer W, is moved at a predetermined speed in the radial direction of the wafer W (in the direction of the arrow in Figure 2) by the nozzle moving means 84, thereby cleaning the upper surface of the wafer W with cleaning water. That is, when the electric motor 93 of the nozzle moving means 84 is started and the rotation axis 94 rotates by a predetermined angle at a predetermined speed, the swivel arm 95 and the nozzle 82 attached to its tip rotate horizontally around the rotation axis 94. As a result, the nozzle 82 moves radially from a position above the center of the wafer W toward the outer circumference of the wafer W, drawing an arc.

[0063] As described above, when the upper surface of the rotating wafer W is cleaned by cleaning water sprayed from a nozzle 82 that moves radially, the control unit 85 closes one electromagnetic valve V1 and opens the other electromagnetic valve V2. Then, compressed air is supplied from the air supply source 88 to the porous member 81A sequentially through the branch pipe 16b, piping 16, and connecting passages 15, 14, 11, 12, and 13. As this compressed air is ejected from the holding surface 81a of the porous member 81A, the suction force on the wafer W disappears, and the wafer W can be easily removed from the holding surface 81a together with the protective tape T.

[0064] Then, the wafer W is removed from the spinner table 81 by the loading / unloading means 104 shown in Figure 1 and stored in the cassette 102, completing the series of grinding and cleaning processes for the wafer W.

[0065] By the way, in the grinding apparatus 1 that rough grinds and finish grinds the wafer W using the rough grinding unit 20 and the finish grinding unit 30 as described above, during the grinding process, the grinding of the wafer W by the grinding wheels 25b and 35b, which rotate while receiving a supply of grinding water, causes a spray of grinding water containing grinding debris to scatter and adhere to the inner walls of the processing chambers S1 and S2 (especially the inner walls of the side plate and the top plate).

[0066] Therefore, in this embodiment, the cleaning wastewater used to clean the wafer W in the second cleaning unit 80 and stored in the storage section 42 of the case 86 is sucked up by the spray mechanism 43 shown in Figure 2, and this cleaning wastewater is supplied to each processing chamber S1 and S2 and sprayed into each processing chamber S1 and S2, thereby removing the grinding water spray containing grinding debris adhering to the inner walls of each processing chamber S1 and S2, and preventing the grinding debris from sticking to the inner walls due to the drying of the spray.

[0067] Specifically, when the control unit 85 drives the air supply source 44 to open the electromagnetic valve V3, compressed air flows through the flow path 46 of the ejector 45 of the injection mechanism 43 in the direction of the arrow in Figure 2. When air flows through the flow path 46 of the ejector 45 in this way, the air is constricted at the throat portion 46A of the flow path 46, increasing its flow velocity (speeding up), and thus negative pressure is generated at the throat portion 46A due to the Bernoulli effect (the effect of static pressure decreasing by the amount of dynamic pressure increase).

[0068] As described above, when negative pressure is generated in the throat portion 46A of the flow path 46 of the ejector 45, the cleaning wastewater stored in the reservoir 42 formed at the bottom of the case 86 is drawn in by this negative pressure and sucked into the intake channel 49 from the intake port 49a and flows toward the throat portion 46A of the ejector 45. This cleaning wastewater is mixed with the high-speed air flowing through the throat portion 46A of the ejector 45 to form two fluids: air and cleaning wastewater. These two fluids, air and cleaning wastewater, are then supplied from the injection port 46b of the flow path 46 of the ejector 45 through the two-fluid piping 48 to each processing chamber S1 and S2, and injected into each processing chamber S1 and S2. As a result, grinding debris that has adhered to the inner walls of each processing chamber S1 and S2 due to the drying of spray and moisture is effectively removed by cleaning with the cleaning wastewater.

[0069] The injection mechanism 43 may also use a water pump. The water pump may draw in the cleaning wastewater stored in the storage section 42 and supply it from the injection port 46b to each processing chamber S1 and S2, and inject it into each processing chamber S1 and S2. Furthermore, the injection of cleaning wastewater into each processing chamber S1 and S2 is performed when rough grinding and finish grinding of the wafer W are not being performed in each processing chamber S1 and S2, that is, when each chuck table 10 and each grinding wheel 25 and 35 are not rotating.

[0070] Furthermore, the spraying of cleaning wastewater into each processing chamber S1, S2 may be performed while each chuck table 10 and each grinding wheel 25, 35 are rotating. For example, the cleaning wastewater may be sprayed onto the rotating wheels 25, 35, and the rotation of the wheels 25, 35 may cause the cleaning wastewater to be scattered within the processing chambers S1, S2. Alternatively, the grinding wheels 25b, 35b may be cleaned by spraying the cleaning wastewater onto the wheels 25, 35.

[0071] As described above, in this embodiment, the wastewater used to clean the wafer W in the second cleaning unit 80 is sucked up by the spray mechanism 43 and supplied to each processing chamber S1 and S2, respectively. The inner walls of each processing chamber S1 and S2 are then cleaned using this wastewater. As a result, by effectively utilizing the wastewater, it is possible to effectively remove spray and grinding debris adhering to the inner walls of each processing chamber S1 and S2 without using separate cleaning water, thereby saving water. Furthermore, when cleaning the inner walls of each processing chamber S1 and S2, it is not necessary to rotate the chuck tables 10 within each processing chamber S1 and S2. Therefore, the power required to rotate these chuck tables 10 is eliminated, resulting in energy savings.

[0072] <Second Embodiment> Next, the grinding apparatus 1A according to the second embodiment of the present invention will be described below with reference to Figures 3 to 5.

[0073] Since the basic configuration of the grinding apparatus 1A according to this embodiment is the same as the basic configuration of the grinding apparatus 1 according to the first embodiment, the same reference numerals are used for the same elements in Figures 3 to 5, and further explanation of them will be omitted below.

[0074] This embodiment is characterized in that, in the first cleaning unit 60, the cleaning wastewater after cleaning the wafer W before grinding and the cleaning wastewater after cleaning the holding surface 10a of the chuck table 10 are supplied to each processing chamber S1 and S2 by a spray mechanism 43, similar to the first embodiment, and the inner walls of each processing chamber S1 and S2 are cleaned by spraying the cleaning wastewater into each processing chamber S1 and S2. For this reason, as shown in Figure 3, a storage section 42 for storing cleaning wastewater is formed in the upper part of the base 200, and this storage section 42 is provided with a spray mechanism 43 similar to the first embodiment and a control unit 85 for controlling it.

[0075] The configuration of the first cleaning unit 60 will now be described below based on Figures 4 and 5.

[0076] The first cleaning unit 60 includes a wafer cleaning mechanism 61 for cleaning wafers W before grinding, which are held on a chuck table 10 located in the wafer loading / unloading area R1 (see Figure 3), and a holding surface cleaning mechanism 71 for cleaning the holding surface 10a of the chuck table 10 after the wafers W have been removed after grinding. As shown in Figure 4, the wafer cleaning mechanism 61 and the holding surface cleaning mechanism 71 are supported so as to be movable in the X-axis direction (left-right direction) on a gate-shaped support frame 202 erected on a base 200 (see Figure 3).

[0077] Specifically, a pair of upper and lower guide rails 53 extending in the X-axis direction (left-right direction) are mounted parallel to each other on the left and right vertical support columns 202a of the support frame 202, and a pair of left and right rectangular plate-shaped sliders 54 and 55 are supported on these guide rails 53 so as to be slidable along the guide rails 53 in the X-axis direction (left-right direction). A wafer cleaning mechanism 61 and a holding surface cleaning mechanism 71 are attached to each of the sliders 54 and 55, respectively.

[0078] Here, the wafer cleaning mechanism 61 includes a cleaning brush 63 that is rotationally driven by an electric motor 62, and a lifting mechanism 64 that raises and lowers the electric motor 62 and the cleaning brush 63 in the Z-axis direction (vertical direction). The holding surface cleaning mechanism 71 also includes a cleaning grinding wheel 73 that is rotationally driven by an electric motor 72, and a lifting mechanism 74 that raises and lowers the electric motor 72 and the cleaning grinding wheel 73 in the Z-axis direction (vertical direction).

[0079] Furthermore, as shown in Figure 4, a pair of rotatable ball screw shafts 56 extending in the X-axis direction (left-right direction) are arranged parallel to each other between a pair of upper and lower guide rails 53. One axial end (left end) of the upper ball screw shaft 56 is connected to an electric motor (not shown) which is a drive source, and the other axial end (right end) of the ball screw shaft 56 is rotatably supported by a support frame 202 by a bearing 57. Similarly, one axial end (right end) of the lower ball screw shaft 56 is connected to an electric motor 58 which is a drive source, and the other axial end (left end) of the ball screw shaft 56 is rotatably supported by a support frame 202 by a bearing (not shown).

[0080] A block-shaped nut portion 54a, which is integrally attached to one slider 54, is screwed onto the upper ball screw shaft 56, and a block-shaped nut portion 55a, which is integrally attached to the other slider 55, is screwed onto the lower ball screw shaft 56. Therefore, when the upper ball screw shaft 56 is rotated forward and backward by an electric motor (not shown), the slider 54, which has the nut portion 54a that screws onto the ball screw shaft 56, reciprocates along the guide rail 53 in the X-axis direction (left-right direction) together with the wafer cleaning mechanism 61. Similarly, when the lower ball screw shaft 56 is rotated forward and backward by an electric motor 58, the other slider 55, which has the nut portion 55a that screws onto the ball screw shaft 56, reciprocates along the guide rail 53 in the X-axis direction (left-right direction) together with the holding surface cleaning mechanism 71. In this way, the wafer cleaning mechanism 61 and the holding surface cleaning mechanism 71 can reciprocate independently of each other along the guide rail 53 in the X-axis direction (left-right direction).

[0081] In this embodiment, cleaning water and compressed air are selectively supplied to the holding surfaces 10a (see Figure 3) of the three chuck tables 10 arranged on the turntable 2 from a water supply source 75 and an air supply source 76, as shown in Figure 5. Also, as shown in Figure 5, each porous member 10A of the three chuck tables 10 is selectively evacuated by a suction source 77.

[0082] Specifically, branch pipes 78a extending from the water supply source 75 and 78b extending from the air supply source 76 merge into piping 79, from which three branch pipes 79a, 79b, and 79c branch off. Variable orifices 26 and 27 for flow rate adjustment and solenoid valves V4 and V5 are provided in the middle of branch pipes 78a and 78b, respectively. The three branch pipes 79a, 79b, and 79c open into the porous members 10A of each chuck table 10, and solenoid valves V7 are provided in the middle of each. Here, solenoid valves V4, V5 and the three solenoid valves V7 are electrically connected to the control unit 85, and their opening and closing operations are controlled by the control unit 85.

[0083] Furthermore, a branch pipe 78c extending from the suction source 77 merges with piping 78, and three branch pipes 78d, 78e, and 78f branch off from piping 78. Each branch pipe 78d, 78e, and 78f opens onto the lower surface of the porous member 10A of each chuck table 10. Each branch pipe 78c is equipped with a variable orifice 28 for flow rate adjustment and an electromagnetic valve V6. Each branch pipe 78d, 78e, and 78f is also equipped with an electromagnetic valve V. Each electromagnetic valve V6 and each electromagnetic valve V are electrically connected to the control unit 85, and their opening and closing operations are controlled by the control unit 85. When cleaning the wafer W before processing using the wafer cleaning mechanism 61, cleaning water is sprayed onto the wafer W from a nozzle 36 located in the center of the turntable 2.

[0084] As described above, the wafer cleaning mechanism 61 of the first cleaning unit 60 cleans the wafer W before processing, and the holding surface 10a of the chuck table 10 from which the processed wafer W has been removed is cleaned by the holding surface cleaning mechanism 71 as follows.

[0085] Specifically, the cleaning brush 63 of the wafer cleaning mechanism 61 shown in Figure 4 moves above the wafer W before grinding, which is held on the chuck table 10 located in the wafer loading / unloading area R1 shown in Figure 3. In this state, the chuck table 10 and the wafer W held thereon are rotated at a predetermined speed, and the cleaning brush 63 is also rotated at a predetermined speed by the electric motor 62. As cleaning water is supplied from the nozzle 36 toward the upper surface of the wafer W, the cleaning brush 63 is lowered in the -Z axis direction by the lifting mechanism 64 of the wafer cleaning mechanism 61 and rotates while in contact with the upper surface of the wafer W, thereby cleaning the upper surface of the wafer W. Once the upper surface of the wafer W before grinding is cleaned in this way, the cleaning brush 63 is raised in the +Z axis direction by the lifting mechanism 64 of the wafer cleaning mechanism 61 and moves away from the upper surface of the wafer W. The wafer cleaning mechanism 61 may also be a wafer cleaning nozzle that sprays two fluids onto the upper surface of the wafer W instead of the cleaning brush 63. The lifting mechanism 64 lowers the wafer cleaning nozzle above the wafer W held on the holding surface 10a. Then, the two fluids are sprayed from the wafer cleaning nozzle onto the upper surface 10a of the wafer W to clean the upper surface of the wafer.

[0086] Furthermore, after the ground wafer W is removed from the chuck table 10 located in the wafer loading / unloading area R1, the holding surface 10a of the chuck table 10 is cleaned by the holding surface cleaning mechanism 71 as follows.

[0087] Specifically, the control unit 85 opens the electromagnetic valve V4 shown in Figure 5, and also opens an electromagnetic valve V7 located in a branch pipe 79a (79b, 79c) connected to a chuck table 10 in the wafer loading / unloading area R1. As a result, cleaning water is ejected from the water supply source 75 through the branch pipe 78a, piping 79, and branch pipes 79a (79b, 79c) to the holding surface 10a of the porous member 10A of the chuck table 10 located in the wafer loading / unloading area R1.

[0088] At the same time, the cleaning wheel 73 of the holding surface cleaning mechanism 71 shown in Figure 4 is moved above one of the chuck tables 10 located in the wafer loading / unloading area R1. While the chuck table 10 and the cleaning wheel 73 are rotated at predetermined speeds, the lifting mechanism 74 of the holding surface cleaning mechanism 71 lowers the cleaning wheel 73 in the -Z axis direction. As the cleaning wheel 73 rotates while in contact with the holding surface 10a of the chuck table 10, the holding surface 10a from which the cleaning water is ejected is cleaned by the cleaning wheel 73. Once the holding surface 10a of the chuck table 10 is cleaned in this way, the lifting mechanism 74 of the holding surface cleaning mechanism 71 raises the cleaning wheel 73 in the +Z axis direction, separating it from the holding surface 10a of the chuck table 10. The holding surface cleaning mechanism 71 may also be a holding surface cleaning nozzle that sprays two fluids onto the holding surface 10a instead of the cleaning wheel 73. The lifting mechanism 74 lowers the retaining surface cleaning nozzle above the retaining surface 10a. Then, the two fluids are sprayed from the retaining surface cleaning nozzle onto the retaining surface 10a for cleaning.

[0089] As described above, in the wafer loading / unloading area R1, when the wafer W before grinding and the holding surface 10a of the chuck table 10 after the wafer W has been removed are cleaned, the wastewater from these cleaning processes is stored in a storage section 42 formed in the base 200 shown in Figure 3. The wastewater stored in the storage section 42 is then drawn towards the throat section 46A of the ejector 45 of the injection mechanism 43 by the negative pressure generated therein, similar to the first embodiment. This wastewater is mixed with the high-speed air flowing through the throat section 46A of the ejector 45 to form two fluids: air and wastewater. These two fluids, air and wastewater, are then supplied from the injection port 46b of the flow path 46 of the ejector 45 through the two-fluid piping 48 to each processing chamber S1 and S2, and injected into each processing chamber S1 and S2. Therefore, grinding debris adhering to the inner walls of each processing chamber S1 and S2, which has hardened due to the drying of spray and moisture, is effectively removed by washing with the washing wastewater. The spraying mechanism 43 may also use a water pump. Alternatively, the washing wastewater stored in the storage section 42 may be drawn in by the water pump and supplied to each processing chamber S1 and S2 from the spray nozzle 46b, and sprayed into each processing chamber S1 and S2.

[0090] In this embodiment as well, the spraying of cleaning wastewater into each processing chamber S1 and S2 is performed when rough grinding and finish grinding of the wafer W are not being performed in each processing chamber S1 and S2, that is, when each chuck table 10 and each grinding wheel 25 and 35 are not rotating. Alternatively, the spraying of cleaning wastewater into each processing chamber S1 and S2 may be performed when each chuck table 10 and each grinding wheel 25 and 35 are rotating. For example, cleaning wastewater may be sprayed onto the rotating wheels 25 and 35, and the cleaning wastewater may be scattered within the processing chambers S1 and S2 by the rotation of the wheels 25 and 35. Alternatively, the grinding wheels 25b and 35b may be cleaned by spraying cleaning wastewater onto the wheels 25 and 35.

[0091] As described above, in this embodiment, the wastewater used for cleaning the wafer W and the holding surface 10a of the chuck table 10 in the wafer loading / unloading area R1 is sucked up by the spray mechanism 43 and supplied to each processing chamber S1 and S2, respectively. The inner walls of each processing chamber S1 and S2 are then cleaned with this wastewater. As a result, water can be saved by effectively utilizing the wastewater without using separate cleaning water just to clean the inner walls of each processing chamber S1 and S2. Furthermore, since it is not necessary to rotate the chuck table 10 within each processing chamber S1 and S2 when cleaning the inner walls of each processing chamber S1 and S2, the power required to rotate these chuck tables 10 is eliminated, thereby saving electricity.

[0092] Although the above description has used a wafer grinding apparatus as an example of the processing apparatus according to the present invention, the present invention also applies to grinding apparatuses for any other workpieces other than wafers, as well as any other processing apparatus other than grinding apparatuses, such as polishing apparatuses and cutting apparatuses.

[0093] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the technical idea described in the claims, specification, and drawings. [Explanation of Symbols]

[0094] 1,1A: Grinding machine (processing machine), 2: Turntable, 3: Lifting mechanism, 4: Lifting plate, 5: Guide rail, 6: Ball screw shaft, 7: Electric motor, 8,9: Cover, 8a, 9a: Opening of the cover, 8b, 9b: Circular hole in the cover, 10: Chuck table, 10A: Porous member, 10a: Retaining surface, 11-15: Connecting passage, 16: Piping, 16a, 16b: Branch pipe, 17, 18: Variable orifice, 19: Pressure gauge, 20: Rough grinding unit (processing means), 21: Holder, 22: Spindle motor, 23: Spindle, 24: Mount, 25: Grinding wheel, 25a: Base, 25b: Grinding wheel (working tool), 30: Finishing grinding unit (working means), 31: Holder, 32: Spindle motor, 33: Spindle, 34: Mount, 35: Grinding wheel 35a: Base, 35b: Grinding wheel (working tool), 36: Nozzle, 40: Grinding water supply means (processing fluid supply means), 41: Grinding water supply source, 42: Storage section, 42A: Plug, 42a: Drain port, 43: Injection mechanism, 44: Air supply source, 45: Ejector, 46: Flow channel, 46A: Throat section (negative pressure generation section) 46a: Intake port, 46b: Injection port, 47: Air piping, 48: Two-fluid piping, 49: Water intake channel, 49a: Water intake port, 50, 51: Wafer thickness measuring instrument, 53: Guide rail, 54, 55: Slider, 54a, 55a: Nut part, 56: Ball screw shaft, 57: Bearing, 58: Electric motor, 60: First cleaning unit (cleaning unit), 61: Wafer cleaning mechanism, 62: Electric motor, 63: Cleaning brush, 64: Lifting mechanism, 71: Holding surface cleaning mechanism, 72: Electric motor, 73: Washing wheel, 74: Lifting mechanism, 75: Water supply source, 76: Air supply source, 77: Suction source, 78: Piping, 78a~78f: Branch pipes, 79: Piping, 79a, 79b, 79c: Branch pipes, 80: Second washing unit (washing unit), 81: Spinner table, 81A: Porous member, 81a: Holding surface, 82: Nozzle, 83: Electric motor, 84: Nozzle moving means, 85: Control unit, 86: Case, 86A, 86B: Protrusions, 86a, 86b: Through hole, 87: Suction source, 88: Air supply source, 89: Rotating shaft, 90: Rotary joint, 91: Encoder, 92: Water source, 93: Electric motor, 93a: Output shaft, 94: Rotation shaft, 95: Swivel arm, 96, 97: Seal members, 98: Encoder, 100: Transport unit, 101, 102: Cassette, 103: Alignment table, 104: Loading / unloading means, 105: First conveying means, 106: Second transport means, 200: Base, 201: Column, 202: Support frame, 202a: Support column section, R1: Wafer loading / unloading area, R2: Rough grinding area, R3: Finish grinding area, S1, S2: Processing chamber, T: Protective tape, V, V1~V7: Electromagnetic switch valve, W: Wafer

Claims

1. A processing apparatus comprising: a chuck table that holds a wafer on a holding surface; processing means for processing the wafer held on the holding surface with a rotating processing tool; a processing chamber that houses the chuck table and the processing tool; processing fluid supply means for supplying processing fluid to the processing tool; and a cleaning unit for cleaning the wafer or the holding surface of the chuck table with cleaning water, The cleaning unit comprises a wafer cleaning mechanism for cleaning wafers with cleaning water or a holding surface cleaning mechanism for cleaning the holding surface with cleaning water, a storage section for collecting cleaning wastewater, a spraying mechanism for drawing in the cleaning wastewater from the storage section and spraying it into the inner wall of the processing chamber, and a control unit for controlling the spraying mechanism. The injection mechanism comprises an air supply source, a flow path for the air from the air supply source, and a water intake channel that connects one end to the flow path. The water intake channel has one end that opens as a water intake port in the storage section. The flow path has one end connected to an air supply source, the other end with an injection nozzle connected to the processing chamber, and the other end of the water intake passage is equipped with a negative pressure generating section that generates negative pressure by the Bernoulli effect at the point where they merge. The control unit controls the flow of air into the flow path, A processing apparatus that generates negative pressure in a negative pressure generating section based on the flow velocity of air flowing through the flow path, uses this negative pressure to draw in cleaning wastewater from the storage section through the water intake, and sprays the two fluids of cleaning wastewater and air from the spray nozzle onto the inner wall of the processing chamber to clean the inner wall.

2. The processing apparatus according to claim 1, comprising a wafer cleaning water supply unit that supplies cleaning water to the upper surface of the wafer outside the processing chamber, and a wafer cleaning tool that cleans the upper surface of the wafer.

3. The processing apparatus according to claim 1, comprising a retaining surface cleaning mechanism, a retaining surface cleaning water supply unit that supplies cleaning water to the retaining surface of the chuck table outside the processing chamber, and a retaining surface cleaning tool for cleaning the retaining surface.

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