TW201842983A - Apparatus and method for cleaning back surface of substrate capable of removing particles from a back surface of a substrate with a higher removal rate - Google Patents

Abstract

The present invention provides an apparatus and a method for cleaning a back surface of a substrate, which is capable of removing particles, such as polishing debris, from the back surface with a higher removal rate. The apparatus for cleaning a back surface of a substrate W includes a substrate holder 105 configured to rotate the substrate W while holding the substrate W with the back surface of the substrate W facing upward; a scrub cleaning tool 108 configured to be rotatable; a two-fluid nozzle 109 disposed above the substrate holder 105; and a housing 100 defining a cleaning chamber 99 in which the substrate holder 105, the scrub cleaning tool 108, and the two-fluid nozzle 109 are disposed.

Description

 Device and method for cleaning substrate  

The present invention relates to an apparatus and method for cleaning the back side of a substrate such as a wafer.

In recent years, components such as memory circuits, logic circuits, and image sensors (such as CMOS sensors) are becoming more integrated. In the process of forming these elements, foreign matter such as fine particles or dust may adhere to the element. Foreign matter attached to the component may cause a short circuit between the wirings and a malfunction of the circuit. Therefore, in order to improve the reliability of the element, it is necessary to clean the wafer on which the element is formed to remove foreign matter on the wafer. Foreign matter such as fine particles and dust as described above may adhere to the back surface (non-element surface) of the wafer. When such foreign matter adheres to the back surface of the wafer, the wafer is separated from the mounting table reference surface of the exposure apparatus, or the wafer surface is inclined with respect to the mounting table reference surface, resulting in deviation of the pattern and deviation of the focal length.

In order to prevent such a problem, it is necessary to remove foreign matter attached to the back surface of the wafer. However, in the conventional cleaning technique in which the wafer is rubbed with a pen-type brush or a sponge roller while rotating the wafer, it is particularly difficult to remove foreign matter in a state in which a film is deposited on a foreign matter, or to be difficult to remove from the wafer. Remove foreign matter from the entire back. Therefore, in order to cope with such a problem, in recent years, the following technique has been proposed (see Patent Document 1): it is possible to remove foreign matter attached to the inclined surface portion and the outer peripheral portion of the back surface of the substrate such as a wafer at a high removal rate. It is also possible to remove foreign matter attached to the entire back surface with a high removal rate.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2014-150178.

According to this new technique, the back surface of the wafer is slightly ground by slidingly contacting the polishing tool with the back surface of the wafer, so that foreign matter can be removed from the back surface with a high removal rate. However, in a conventional cleaning technique performed after polishing the back surface of the wafer, polishing debris may remain on the back surface of the wafer. Such abrasive chips are separated from the wafer in the wafer cassette after the wafer has dried, and will fall on other wafers in the wafer cassette.

Accordingly, an object of the present invention is to provide an apparatus and method capable of removing fine particles such as grinding debris from the back surface of a substrate such as a wafer with a high removal rate. Further, the present invention provides a substrate processing apparatus that polishes a back surface of a substrate such as a wafer and also cleans the back surface.

An aspect of the present invention provides an apparatus for cleaning a back surface of a substrate, comprising: a substrate holding portion that rotates the substrate while holding the substrate while the back surface of the substrate faces upward; The scrubbing device is configured to be rotatable; the two-fluid nozzle is disposed above the substrate holding portion; and the outer casing forms a cleaning chamber for the substrate holding portion and the scrubbing device And the two-fluid nozzle configuration.

A preferred aspect of the present invention is characterized by further comprising: an arm fixed to the scrubbing appliance and the two-fluid nozzle; and a swing motor that causes the arm, the scrubbing appliance, and the The two-fluid nozzle rotates clockwise and counterclockwise at a specified angle centered on the specified axis of revolution.

A preferred aspect of the invention is characterized in that the distance between the scrubbing fixture and the designated axis of revolution is equal to the distance between the two fluid nozzle and the designated axis of revolution.

In a preferred aspect of the invention, the substrate holding portion includes a plurality of slidable holding rollers, and the plurality of holding rollers hold a peripheral portion of the substrate.

A preferred aspect of the present invention is characterized by further comprising: a first substrate station for temporarily accommodating a substrate having a back surface cleaned; and a second substrate station for temporarily The substrate on the back side is not cleaned.

In a preferred aspect of the invention, the first substrate station and the second substrate station each include a container that forms a sealed space therein, and a pure water spray nozzle disposed in the container.

Another aspect of the present invention is a back cleaning apparatus, comprising: a plurality of back surface cleaning units for cleaning a back surface of a substrate; and a first substrate station for temporarily a substrate on which the back surface is cleaned; a second substrate station for temporarily accommodating a substrate on which the back surface is not cleaned; and a transfer device for removing the substrate having no back surface from the first substrate Transferring the two substrate stations to any one of the plurality of back surface cleaning units, and transferring the substrate having the back surface cleaned from any one of the plurality of back surface cleaning units to the first substrate station, the back surface cleaning The unit includes: a substrate holding portion that rotates the substrate while holding the substrate while the back surface of the substrate faces upward; the scrubbing device is configured to be rotatable; and the two-fluid nozzle is disposed in the two-fluid nozzle Above the substrate holding portion; and an outer casing forming a cleaning chamber for the substrate holding portion and the scrubbing device The two-fluid nozzle configuration.

According to another aspect of the invention, a substrate processing apparatus includes: a back surface polishing unit that polishes a back surface of the substrate; and the back surface cleaning device that cleans the back surface polishing unit The back side of the polished substrate.

According to still another aspect of the present invention, in a method of cleaning a back surface of a substrate, the substrate is placed in a cleaning chamber to hold the substrate, and the substrate held in the cleaning chamber is rotated to rotate the scrubbing device. The scrubbing device is in sliding contact with the back surface of the substrate in the cleaning chamber, and then the two-fluid jet is supplied to the back surface of the substrate in the cleaning chamber.

In a preferred aspect of the present invention, the step of slidingly contacting the scrubbing device with the back surface of the substrate is a step of rotating the scrubbing device while sliding the blade to the back surface of the substrate while rotating the scrubbing device. The rotating scrubbing implement is also moved back and forth between the center and the edge of the substrate.

In a preferred aspect of the present invention, the step of supplying the two-fluid jet to the back surface of the substrate is a step of supplying the two-fluid nozzle to the substrate while supplying the two-fluid jet from the two-fluid nozzle to the back surface of the substrate. The center and the edge move back and forth.

According to still another aspect of the present invention, in a method of cleaning a back surface of a substrate, the substrate is housed in a cleaning chamber to hold the substrate, and the held substrate is rotated to supply a two-fluid jet to the back surface of the substrate. The scrubbing device is rotated while the scrubbing device is in sliding contact with the back surface of the substrate.

According to the present invention, the first back surface cleaning step as either of the scrubbing and the two-fluid cleaning is performed, and then the second back surface cleaning step as the other of the scrubbing and the two-fluid cleaning is continuously performed. Since the back surface of the substrate is cleaned by a combination of scrubbing and two-fluid cleaning, particles such as polishing dust can be removed from the back surface of the substrate at a high removal rate. In particular, since the first back surface cleaning step and the second back surface cleaning step are continuously performed while the substrate in the same cleaning chamber is held by the substrate holding portion, it is possible to perform back cleaning with a high removal rate with a short cleaning time. Moreover, according to the present invention, it is possible to provide a substrate processing apparatus including a back surface cleaning unit that does not remain on the back surface of the substrate after cleaning after polishing the back surface of the substrate. Therefore, it is possible to prevent polishing debris from being applied to the substrate. This is the case on other substrates in the case.

5‧‧‧Loading

7‧‧‧Back grinding department

8‧‧‧First back grinding unit

9‧‧‧Second back grinding unit

10‧‧‧Back cleaning department

12‧‧‧Action Control Department

15‧‧‧Surface Cleaning Department

21‧‧‧Transfer robot

22‧‧‧ Temporary mounting platform

24‧‧‧Transfer robot

32‧‧‧First substrate holder

34‧‧‧First grinding head

37‧‧‧Substrate mounting table

37a‧‧‧ slot

39‧‧‧Moving table motor

40‧‧‧vacuum pipeline

42‧‧‧grinding tape

43‧‧‧ Roll

44‧‧‧ Pressing members

45‧‧‧ cylinder

51‧‧‧ release reel

52‧‧‧Reel

55‧‧‧ Grinding head moving mechanism

57, 58‧‧‧ Liquid supply nozzle

60A, 60B‧‧‧ temporary placement table

61‧‧‧Transfer robot

62‧‧‧Second substrate holder

64‧‧‧ grinding equipment

66‧‧‧Second grinding head

68‧‧‧ chuck

69‧‧‧ fixture

71‧‧‧ hollow motor

72‧‧‧Substrate support

75‧‧‧ head arm

76‧‧‧Swing axis

77‧‧‧ drive

79‧‧‧Liquid supply nozzle

80‧‧‧Back cleaning unit

81‧‧‧First Wafer Station (First Substrate Station)

82‧‧‧Second wafer station (second substrate station)

85‧‧‧Transfer robot

87‧‧‧ Container

87a‧‧‧First wall

87b‧‧‧ second wall

87c‧‧‧First opening

87d‧‧‧second opening

91‧‧‧First switch

92‧‧‧Second switch

94‧‧‧ pillar

96‧‧‧pure water spray nozzle

97‧‧‧Pure water supply pipe

99‧‧‧cleaning room

100‧‧‧ Shell

100a‧‧‧ side wall

100b‧‧‧ openings

101‧‧‧Opener

105‧‧‧ wafer holding unit (substrate holding unit)

107‧‧‧Drug supply nozzle

106‧‧‧ rinse liquid supply nozzle

108‧‧‧ pen type cleaning device (scrub device)

109‧‧‧Two-fluid nozzle

111‧‧‧ Keep roll

112‧‧‧ Roller motor

113‧‧‧Torque transmission mechanism

115‧‧‧ Arm

116‧‧‧Actuator

118‧‧‧Support shaft

120‧‧‧Slewing motor

121‧‧‧Nozzle holder

122‧‧‧Two-fluid supply line

131‧‧‧One cleaning unit

132‧‧‧Second cleaning unit

133‧‧‧ three cleaning units

135‧‧‧ drying unit

141, 142, 143‧‧‧Transfer robot

W‧‧‧ wafer (substrate)

The first drawing is a schematic view of a substrate processing apparatus for polishing the back surface of a substrate such as a wafer and cleaning the back surface.

The second (a) and second (b) are cross-sectional views of the wafer.

The third diagram is a schematic view showing a first back grinding unit for polishing the outer peripheral side region of the back surface of the wafer.

The fourth figure is a view showing a state in which the first polishing head shown in the third figure moves.

The fifth drawing is a schematic view showing a second back grinding unit for polishing the center side region of the back surface of the wafer.

The sixth drawing is a plan view of the second back grinding unit.

The seventh diagram is a schematic view showing the entire back surface cleaning unit.

The eighth figure is a horizontal cross-sectional view of the first wafer station.

The ninth drawing is a perspective view showing the details of the back surface cleaning unit.

The tenth view is a top view of the arm, the pen type cleaning device, and the two-fluid nozzle.

The eleventh diagram is a flowchart showing an embodiment of the entire processing of the wafer.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The first drawing is a schematic view of a substrate processing apparatus for polishing the back surface of a substrate such as a wafer and cleaning the back surface. In the embodiment described below, a wafer is used as an example of the substrate. As shown in the first figure, the substrate processing apparatus includes a loading cassette 5 on which a wafer cassette (or a substrate cassette) containing a plurality of wafers is placed, and a back surface polishing unit that polishes the back surface of the wafer. 7; a back surface cleaning unit 10 that cleans the back surface of the wafer polished by the back surface polishing unit 7; and a surface cleaning unit 15 that cleans the surface of the wafer to dry the surface of the wafer. The substrate processing apparatus further includes an operation control unit 12 that controls the operations of the respective transfer robots, such as the back surface polishing unit 7, the back surface cleaning unit 10, and the surface cleaning unit 15, and the following description.

The transfer robot 21 is disposed between the loading cassette 5 and the back surface polishing unit 7. The transport robot 21 operates to take out a wafer accommodated in one of the plurality of wafer cassettes and mount the wafer on the temporary mounting table 22 disposed adjacent to the back surface polishing unit 7 . The transfer robot 24 is disposed adjacent to the back surface polishing unit 7 and the temporary stage 22 .

The back surface polishing unit 7 includes two first back surface polishing units 8 and two second back surface polishing units 9. The two first back grinding units 8 are disposed adjacent to the transfer robot 24. The wafer on the temporary mounting table 22 is transported by the transfer robot 24 to either of the two first back grinding units 8.

The back surface polishing of the wafer is composed of a first polishing step and a second polishing step. The first polishing step is a step of polishing the outer peripheral side region of the back surface of the wafer, and the second polishing step is a step of polishing the center side region of the back surface of the wafer. The center side region is a region including the center of the wafer, and the outer peripheral side region is a region located radially outward of the center side region. The center side area and the outer side side area are adjacent to each other, and the area where the center side area and the outer circumference side area are combined is spread over the entire back surface of the wafer.

The second (a) and second (b) are cross-sectional views of the wafer. More specifically, the second diagram (a) is a cross-sectional view of a so-called linear wafer, and the second diagram (b) is a cross-sectional view of a so-called circular wafer. In the present specification, the surface of the wafer (substrate) is referred to as a surface on which the element and the wiring circuit are formed, and the back surface of the wafer (substrate) is referred to as a flat surface opposite to the surface on which the element and the wiring circuit are formed. surface. The outermost surface of the wafer is called a bevel. The back surface of the wafer is a flat surface located on the inner side in the radial direction of the inclined surface. The outer peripheral side area of the back side of the wafer is adjacent to the inclined surface. As an example, the width of the outer peripheral side region is an annular region of a few ten millimeters, and the central side region is a circular region of the inner side of the outer peripheral side region.

The third diagram is a schematic view showing the first back grinding unit 8 for polishing the outer peripheral side region of the back surface of the wafer. The first back surface polishing unit 8 includes a first substrate holding portion 32 that holds a wafer (substrate) W and rotates the wafer (substrate) W, and a polishing device that presses the polishing tool to the crystal held by the first substrate holding portion 32. The first polishing head 34 on the back side of the circle W. The first substrate holding portion 32 includes a substrate mounting table 37 that holds the wafer W by vacuum suction, and a mounting table motor 39 that rotates the substrate mounting table 37.

The wafer W is placed on the substrate stage 37 with its back surface facing downward. A groove 37a is formed on the upper surface of the substrate stage 37, and the groove 37a communicates with the vacuum line 40. The vacuum line 40 is connected to a vacuum source (for example, a vacuum pump) not shown. When a vacuum is formed in the groove 37a of the substrate stage 37 via the vacuum line 40, the wafer W is held by the substrate stage 37 by vacuum suction. In this state, the stage motor 39 rotates the substrate stage 37 to rotate the wafer W around its axis. The diameter of the substrate stage 37 is smaller than the diameter of the wafer W, and the center side area of the back surface of the wafer W is held by the substrate stage 37. The outer peripheral side region of the back surface of the wafer W extends beyond the substrate stage 37 to the outside.

The first polishing head 34 is disposed adjacent to the substrate stage 37. More specifically, the first polishing head 34 is disposed to face the exposed outer peripheral side region. The first polishing head 34 includes a plurality of rollers 43 that support the polishing tape 42 as a polishing tool, a pressing member 44 that presses the polishing tape 42 against the back surface of the wafer W, and a cylinder that applies a pressing force to the pressing member 44 as an actuator. 45. The cylinder 45 applies a pressing force to the pressing member 44, whereby the pressing member 44 presses the polishing tape 42 against the back surface of the wafer W. Further, as the grinding tool, a grindstone may be used instead of the polishing tape.

One end of the polishing tape 42 is connected to the discharge reel 51, and the other end is connected to the take-up reel 52. The polishing tape 42 is fed from the discharge reel 51 to the take-up reel 52 at a predetermined speed via the first polishing head 34. Examples of the polishing tape 42 to be used include a belt in which abrasive grains are fixed on the surface, or a belt composed of a hard nonwoven fabric. The first polishing head 34 is coupled to the polishing head moving mechanism 55. The polishing head moving mechanism 55 is configured to move the first polishing head 34 to the outside in the radial direction of the wafer W. The polishing head moving mechanism 55 is constituted by, for example, a combination of a ball screw and a servo motor.

The liquid supply nozzles 57 and 58 that supply the polishing liquid to the wafer W are disposed above and below the wafer W held on the substrate stage 37. As the polishing liquid, pure water is preferably used. The reason for this is that if a chemical liquid containing a chemical component having an etching action is used, the concave portion formed on the back surface may expand.

The outer peripheral side region of the back surface of the wafer W is polished as follows. The wafer W held by the substrate stage 37 is rotated about the axis thereof by the stage motor 39, and the polishing liquid is supplied from the liquid supply nozzles 57 and 58 to the front and back surfaces of the rotating wafer W. In this state, the first polishing head 34 presses the polishing tape 42 against the back surface of the wafer W. The polishing tape 42 is in sliding contact with the outer peripheral side region of the back surface of the wafer W, whereby the outer peripheral side region is polished. The polishing head moving mechanism 55 presses the polishing tape 42 against the back surface of the wafer W on the first polishing head 34, and specifies the first polishing head 34 to the outer side in the radial direction of the wafer W as indicated by the arrow in the fourth drawing. The speed of movement. As a result, the entire outer peripheral side region of the back surface of the wafer W is polished by the polishing tape 42. During the polishing process, the polishing liquid flows from the inside to the outside of the wafer W, and the polishing dust is removed from the wafer W by the polishing liquid.

As shown in the first figure, between the first back grinding unit 8 and the second back grinding unit 9, two temporary placement stages 60A and 60B are disposed. The upper temporary mounting table 60A is for temporarily placing the cleaned wafer, and the lower temporary mounting table 60B is for temporarily placing the wafer to be cleaned. The wafer polished by the first back surface polishing unit 8 is transported by the transfer robot 24 to the lower temporary stage 60B.

The transport robot 61 is disposed adjacent to the temporary mounts 60A and 60B and the two second backgrinding units 9. This transfer robot 61 has a function of inverting the wafer. The transport robot 61 takes out the wafer on the lower temporary stage 60B, inverts the wafer, and faces the upper side, and transports the wafer to either of the two second back grinding units 9.

The fifth drawing is a schematic view showing the second back grinding unit 9 for polishing the center side region of the back surface of the wafer W, and the sixth drawing is a plan view of the second back grinding unit 9. The second back surface polishing unit 9 includes a second substrate holding portion 62 that holds the wafer W to rotate the wafer W, and a second polishing head 66 that presses the polishing tool 64 against the back surface of the wafer W. The second substrate holding portion 62 includes a plurality of chucks 68 that hold the inclined surface portion of the wafer W and a hollow motor 71 that rotates the chucks 68 around the axis of the wafer W. Each of the chucks 8 is provided with a jig 69 at its upper end, and the inclined surface portion of the wafer W is held by the jig 69. In a state where the jig 69 grips the inclined surface portion of the wafer W, the chuck 68 is rotated by the hollow motor 71, and the wafer W is rotated about its axis as indicated by an arrow A in the sixth drawing.

In the second back grinding unit 9, the wafer W is held by the second substrate holding portion 62 with its back surface facing upward. The lower surface (the surface on the opposite side to the back surface) of the wafer W held by the chuck 68 is supported by the substrate supporting portion 72. The substrate supporting portion 72 is coupled to the hollow motor 71 by a connecting member 73, and the substrate supporting portion 72 and the second substrate holding portion 62 are integrally rotated by the hollow motor 71. The substrate supporting portion 72 has a circular upper surface that is in contact with the lower surface of the wafer W. The upper surface of the substrate supporting portion 72 is made of a sheet material made of an elastic material such as a nonwoven fabric or a backing film, and does not damage the elements formed on the lower surface of the wafer W. The substrate supporting portion 72 supports only the lower surface of the wafer W, and the wafer W is not held by vacuum suction or the like. The wafer W and the substrate supporting portion 72 are integrally rotated, and the relative speed of the two is zero.

The second polishing head 66 is disposed above the wafer W and presses the polishing tool 64 against the back surface of the wafer W. Examples of the polishing tool 64 to be used include a nonwoven fabric in which abrasive grains are fixed on the surface, a hard nonwoven fabric, a grindstone, or a polishing tape used in the first back surface polishing unit 8 described above. For example, the polishing tool 64 may be composed of a plurality of polishing tapes arranged around the axis of the second polishing head 66.

The second polishing head 66 is supported by the head arm 75. A rotation mechanism (not shown) is incorporated in the head arm 75, and the second polishing head 66 is rotated about its axis as indicated by an arrow B by the rotation mechanism. The end of the head arm 75 is fixed to the swing shaft 76. The swing shaft 76 is coupled to a driver 77 such as a motor. The swing shaft 76 is rotated by a predetermined angle by the actuator 77, so that the second polishing head 66 moves between the polishing position above the wafer W and the standby position outside the wafer W.

A liquid supply nozzle 79 that supplies a polishing liquid to the back surface of the wafer W is disposed adjacent to the second polishing head 66. As the polishing liquid, pure water is preferably used.

The center side region of the wafer W was polished as follows. In a state where the back surface of the wafer W faces upward, the inclined surface portion of the wafer W is held by the chuck 68. The wafer W is rotated about the axis by the hollow motor 71, and the polishing liquid is supplied from the liquid supply nozzle 79 to the back surface of the rotating wafer W. In this state, the second polishing head 66 presses the polishing tool 64 against the center side region including the center of the back surface of the wafer W while rotating the polishing tool 64. The polishing tool 64 is in sliding contact with the center side region, whereby the center side region is polished. The second polishing head 66 may be oscillated along the substantially radial direction of the wafer W while maintaining the state in which the polishing tool 64 is in contact with the center of the wafer W during the polishing process. As a result, the center side region of the back surface of the wafer W is polished by the polishing tool 64. During the polishing process, the polishing liquid flows from the inside to the outside of the wafer W, and the polishing dust is removed from the wafer W by the polishing liquid.

In the above-described embodiment, the outer peripheral side region of the back surface of the wafer W is first polished, and then the center side region of the back surface is polished. In one embodiment, after the center side region of the back surface of the wafer W is polished, the outer peripheral side region of the back surface may be polished.

As shown in the first figure, the back surface cleaning unit 10 is disposed adjacent to the back surface polishing unit 7. The wafer polished on the back surface by the first back surface polishing unit 8 and the second back surface polishing unit 9 is transported to the back surface cleaning unit 10 by the transport robot 61.

The seventh diagram is a schematic view showing the entire back surface cleaning unit 10. The back surface cleaning unit 10 is a device for cleaning the back surface after the back surface of the wafer is polished. As shown in FIG. 7 , the back surface cleaning unit 10 includes a plurality of (four in the present embodiment) back surface cleaning units 80 and a first crystal for temporarily accommodating the wafers whose back surface is cleaned by the back surface cleaning unit 80. a circular station (first substrate station) 81; a second wafer station (second substrate station) 82 for temporarily accommodating a wafer whose back surface is not cleaned; and a first wafer station 81 and a second wafer The transfer robot 85 that transfers the wafer between the station 82 and the back surface cleaning unit 80. The operations of the back surface cleaning unit 80 and the transport robot 85 are controlled by the motion control unit 12 shown in the first figure.

The wafer whose back surface is polished but has not been cleaned is transported to the second wafer station 82 by the transfer robot 61 (see the first drawing) with the back surface facing upward. The wafer whose back surface is polished and cleaned is transported to the first wafer station 81 by the transfer robot 85 of the back surface cleaning unit 10 with the back surface facing upward. In the present embodiment, the first wafer station 81 is disposed above the second wafer station 82, but the first wafer station 81 may be disposed below the second wafer station 82.

In the present embodiment, the two back surface cleaning units 80 are arranged up and down, and the other two back surface cleaning units 80 are arranged up and down. However, the arrangement of the back surface cleaning unit 80 is not limited to the embodiment. For example, the four backside cleaning units 80 may also be arranged in a row along the longitudinal or lateral direction.

The transport robot 85 is disposed at a position where the four back surface cleaning units 80 can be accessed. The first wafer station 81 and the second wafer station 82 are disposed between the two back surface cleaning units 80 arranged one above the other. The first wafer station 81 and the second wafer station 82 have the same structure, and therefore, the first wafer station 81 will be described below.

The eighth figure is a horizontal cross-sectional view of the first wafer station 81. As shown in FIG. 8, the first wafer station (first substrate station) 81 includes a box-shaped container 87 capable of accommodating the wafer W therein, and a first opening and closing device attached to the first wall portion 87a constituting the container 87. The second switch 92 is attached to the second wall portion 87b constituting the container 87; and a plurality of pillars 94 for the wafer W are placed. In the present embodiment, the four pillars 94 are disposed in the container 87, but five or more pillars may be disposed.

The first opening portion 87c through which the wafer W can pass is formed in the first wall portion 87a, and the first shutter 91 covers the first opening portion 87c. Similarly, the second opening portion 87d through which the wafer W can pass is formed in the second wall portion 87b, and the second shutter 92 covers the second opening portion 87d. These first shutters 91 and second shutters 92 are normally closed.

In a state where the first shutter 91 and the second shutter 92 are closed, a sealed space is formed in the container 87. This is to prevent drying of the wafer W. In order to maintain the wafer W in the container 87 in a wet state, a plurality of pure water spray nozzles 96 are disposed in the container 87. Each of the pure water spray nozzles 96 is connected to the pure water supply pipe 97. In the present embodiment, the three pure water spray nozzles 96 are disposed toward the lower surface (the surface on the opposite side to the back surface) of the wafer W. Two or more pure water spray nozzles can be configured, or more than four pure water spray nozzles can be configured.

When the transfer robot 85 (see FIG. 7) carries the wafer cleaned by the back surface cleaning unit 80 into the first wafer station 81, the second shutter 92 is opened. When the transport robot 61 (see the first figure) takes out the cleaned wafer from the first wafer station 81, the first shutter 91 is opened. On the other hand, when the transfer robot 61 (refer to the first drawing) carries the wafer before cleaning into the second wafer station 82, the first shutter 91 of the second wafer station 82 is opened. When the transfer robot 85 (see FIG. 7) takes out the wafer before cleaning from the second wafer station 82, the second shutter 92 of the second wafer station 82 is opened.

As shown in the seventh figure, the transport robot 85 of the back surface cleaning unit 10 is configured to be movable in the vertical direction. The conveyance robot 85 conveys the wafer to one of the four back surface cleaning units 80 in a state where the back surface of the wafer faces upward. The four back cleaning units 80 have the same structure. Each of the back surface cleaning units 80 has a casing 100 in which a cleaning chamber 99 is formed inside. An opening 100b through which a wafer can pass is formed in the side wall 100a of the casing 100, and a shutter 101 that covers the opening 100b is provided in the side wall 100a. When the wafer is carried into the cleaning chamber 99 of the back surface cleaning unit 80 and the wafer is carried out from the cleaning chamber 99 of the back surface cleaning unit 80, the shutter 101 is opened.

The ninth diagram is a perspective view showing the details of the back surface cleaning unit 80. In the ninth figure, the illustration of the outer casing 100 and the shutter 101 is omitted. The back surface cleaning unit 80 includes a wafer holding portion (substrate holding portion) 105 that holds the wafer W and rotates the wafer W around the axis of the wafer W, and a back surface of the wafer W held by the wafer holding portion 105. (upper surface) the chemical solution supply nozzle 107 that supplies the chemical solution; the rinse liquid supply nozzle 106 that supplies the pure water as the rinse liquid to the back surface of the wafer W; and the back surface of the wafer W while rotating around the axis of the wafer W The pen-type cleaning device 108 as a scrubbing device is contacted; and a two-fluid nozzle 109 that supplies a two-fluid jet to the back surface of the wafer W. The pen type cleaning device 108 is made of a porous material such as a sponge. A pen-type cleaning device 108 composed of a sponge is also referred to as a sponge pen.

The wafer holding portion (substrate holding portion) 105 includes a plurality of holding rolls 111 that hold the peripheral edge portion of the wafer W, and a roll motor 112 that rotates the holding rolls 111. In the present embodiment, four holding rolls 111 are provided. The wafer W to be cleaned is placed on the holding roller 111 by the transport robot 85 with its back surface facing upward, and is rotated by the holding roller 111. The back surface cleaning of the wafer W described below is performed with the back surface facing upward.

Two of the four holding rolls 111 are coupled by the torque transmitting mechanism 113, and the other two are also coupled by another torque transmitting mechanism 113. The torque transmitting mechanism 113 is composed of, for example, a combination of a pulley and a belt. In the present embodiment, two roller motors 112 are provided. One of the two roller motors 112 is coupled to two holding rollers 111 that are coupled to each other by a torque transmitting mechanism 113, and the other roller motor 112 and the other two holding rollers 111 that are coupled to each other by another torque transmitting mechanism 113. link.

The wafer holding portion (substrate holding portion) 105 is not limited to the embodiment, and other embodiments may be applied. For example, in one embodiment, one roller motor may be coupled to all of the holding rollers 111 by a torque transmitting mechanism. Further, in the present embodiment, all of the holding rollers 111 are coupled to the roller motor 112, but a plurality of the plurality of holding rollers 111 may be coupled to the roller motor 112. Preferably, at least two of the plurality of holding rolls 111 are coupled to the roll motor 112.

In the present embodiment, two of the four holding rolls 111 can be moved in a direction in which they are close to the other two holding rolls 111 and in a direction away from each other by a moving mechanism (not shown). After the wafer W is placed on the upper end of the four holding rolls 111 by the transfer robot 85, the two holding rolls 111 are moved toward the other two holding rolls 111, and the four holding rolls 111 hold the peripheral edge portion of the wafer W. After the back surface of the wafer W is cleaned, the two holding rolls 111 move in a direction away from the other two holding rolls 111, so that the four holding rolls 111 release the peripheral portion of the wafer W. In one embodiment, all of the holding rolls 111 may be configured to be movable by a moving mechanism (not shown). Since the holding roller 111 is a mechanism that does not hold the entire peripheral edge portion of the wafer W, the pen-type cleaning tool 108 can clean the entire back surface including the edge portion (the outermost peripheral portion of the back surface) of the wafer W.

The back surface cleaning unit 80 further includes an arm 115 to which the pen type cleaning device 108 and the two-fluid nozzle 109 are fixed, an actuator 116 coupled to the pen type cleaning device 108, a support shaft 118 that supports the arm 115, and a support shaft 118 connected swing motor 120. The arm 115, the pen-type cleaning device 108, and the two-fluid nozzle 109 are disposed at a position higher than the holding roller 111. The actuator 116 is configured to be able to rotate the pen-type cleaning tool 108 (for example, a sponge pen) about its axis, and to move the rotating pen-type cleaning tool 108 in the direction of its axis. In other words, the actuator 116 is configured to be able to press the pen-type cleaning tool 108 against the back surface of the wafer W held by the holding roller 111 while rotating the pen-type cleaning tool 108 around its axis. The axis of the pen-type cleaning tool 108 is perpendicular to the back surface of the wafer W held by the holding roller 111. In the present embodiment, the axis of the pen-type cleaning tool 108 extends in the vertical direction, and the wafer W is horizontally held by the holding roller 111.

The two-fluid nozzle 109 is adjacent to the pen-type cleaning appliance 108. More specifically, the dual fluid nozzle 109 extends downward from the nozzle holder 121 fixed to the side surface of the arm 115. The two-fluid nozzle 109 is connected to the two-fluid supply line 122 by means of the nozzle holder 121. The pen type cleaning device 108 is located below the top end of the arm 115. The swing motor 120 is configured to be capable of rotating the support shaft 118 by a predetermined angle in the clockwise direction and the counterclockwise direction. When the swing motor 120 rotates the support shaft 118, the arm 115, the pen-type cleaning tool 108, and the two-fluid nozzle 109 are rotated at a predetermined angle in the clockwise direction and the counterclockwise direction about the rotation axis P of the support shaft 118.

The tenth view is a plan view of the arm 115, the pen-type cleaning device 108, and the two-fluid nozzle 109. As shown in the tenth diagram, the holding roller 111, the arm 115, the pen-type cleaning device 108, and the two-fluid nozzle 109 are disposed in the cleaning chamber 99 formed by the outer casing 100. The wafer W is transported to the cleaning chamber 99 by the transfer robot 85 with the back surface facing upward, and placed on the holding roller 111. The holding roller 111 holds the peripheral portion of the wafer W and also rotates the wafer W. The back surface of the wafer W is cleaned while rotating the wafer W.

As the arm 115 rotates, the pen-type cleaning tool 108 and the two-fluid nozzle 109 are integrally moved by an arc-shaped track held by the center O of the wafer W of the holding roller 111. The distance between the pen-type cleaning device 108 and the axis of rotation P of the support shaft 118 is equal to the distance between the two-fluid nozzle 109 and the axis of rotation P of the support shaft 118. Thus, as the arm 115 rotates, the pen-type cleaning device 108 and the two-fluid nozzle 109 move the same track. More specifically, in the back surface cleaning process of the wafer W, the pen-type cleaning tool 108 and the two-fluid nozzle 109 are between the center O of the wafer W and the edge portion of the wafer W (the outermost peripheral portion of the back surface) Move back and forth. In addition, the wafer holding portion (substrate holding portion) 105 is not limited to the holding roller method. For example, the wafer holding portion can be horizontally adsorbed and held in the vicinity of the center portion of the surface of the wafer W whose back surface faces upward. Rotate.

The back surface cleaning unit 80 of the present embodiment can continuously perform the cleaning by the pen type cleaning device 108 in the same cleaning chamber 99 while the wafer W is rotated by the holding roller 111 of the wafer holding portion (substrate holding portion) 105. Scrubbing and two-fluid cleaning by the two-fluid nozzle 109. Both the scrubbing and the two-fluid cleaning are performed with the back side of the wafer W facing upward. By performing physical scrubbing and two-fluid cleaning in a time-continuous manner, it is possible to perform cleaning of the wafer W by utilizing the characteristics of each cleaning process.

The scrubbing is performed by supplying the chemical liquid to the wafer W from the chemical liquid supply nozzle 107 while the wafer W is rotated about the axis by the holding roller 111 of the wafer holding portion (substrate holding portion) 105. On the back side, the pen-type cleaning device 108 (i.e., the scrubbing device) is brought into sliding contact with the back surface of the wafer W in the presence of the chemical liquid. During the scrubbing process, the pen-type cleaning device 108 is rotated by the actuator 116 while being pressed against the back surface of the wafer W. Further, in the scrubbing process, the pen-type cleaning tool 108 is pressed against the back surface of the wafer W, at the center O of the rotating wafer W and the edge portion of the wafer W (the outermost peripheral portion of the back surface) Move back and forth between the specified number of times. The two-fluid nozzle 109 does not supply the two-fluid jet to the back side of the wafer W during the scrubbing process. After the end of the scrubbing, the pen-type cleaning tool 10 is separated from the back surface of the wafer W in order to prevent the dripping of the chemical solution from the pen-type cleaning device 108. Further, in order to prevent dripping of the chemical liquid, a cover member (not shown) that can be positioned below the retracted pen-type cleaning device 108 can be provided on the arm 115 or the like.

The two-fluid cleaning is performed by supplying the two-fluid jet from the two-fluid nozzle 109 to the wafer while the wafer W is rotated about the center of the axis by the holding roller 111 of the wafer holding portion (substrate holding portion) 105. The back of W. A two-fluid jet is a mixture of a liquid (eg, carbonated water) and a gas (eg, nitrogen). In the two-fluid cleaning process, the two-fluid nozzle 109 is reciprocated a predetermined number of times between the center O of the rotating wafer W and the edge portion of the wafer W. In the two-fluid cleaning process, the pen-type cleaning device 108 is not in contact with the back surface of the wafer W, and the chemical liquid is not supplied to the back surface of the wafer W.

Further, in order to prevent the two-fluid jet jetted to the wafer W from scattering and returning to the front surface of the wafer W, a rotating cup (not shown) may be provided outside the holding roller 111. The rotating cup can be configured to rotate at the same rotational speed as the rotating wafer W and in the same direction. In this way, since there is no relative speed between the wafer W and the rotating cup, it is possible to prevent the droplet acceleration from being applied to the rotating cup, and as a result, the scattering of the droplet can be prevented.

In one embodiment, the back surface cleaning unit 80 performs a first back surface cleaning step of scrubbing the back surface of the wafer W by the pen type cleaning device 108, and then performs a second back surface cleaning step of cleaning the back surface of the wafer W by the two-fluid jet. After the wafer W is cleaned by the two-fluid jet, the rinse liquid (usually pure water) may be supplied from the rinse liquid supply nozzle 106 to the back surface of the wafer W. In one embodiment, the back surface cleaning unit 80 may perform the first back surface cleaning step of cleaning the back surface of the wafer W by the two-fluid jet, and then the second surface of the wafer W may be scrubbed by the pen type cleaning tool 108. Back cleaning process. In this case, after the scrubbing, the rinse liquid is supplied from the rinse liquid supply nozzle 106 to the back surface of the wafer W, and the chemical liquid is washed from the back surface of the wafer W.

Further, in one embodiment, after the wafer W is rinsed, the wafer W may be rotated for a predetermined period of time, and droplets on the wafer W may be scattered by centrifugal force to perform spin drying. Further, in one embodiment, after the back surface of the cleaned wafer W is first rinsed, the rinse liquid may be supplied to the nozzle 106, for example, to rinse the liquid flowing back to the front surface of the wafer W. The oscillating liquid is supplied from the center of the back surface of the wafer W toward the outer peripheral portion, and then the rinsing liquid is supplied to at least the inclined surface portion or the edge portion of the surface of the wafer W, and then the wafer W is rotated for a predetermined time by centrifugal force. The droplets on the wafer W are scattered to perform spin drying.

According to the above-described embodiment, the first back surface cleaning step as one of the scrubbing and the two-fluid cleaning is performed, and then the second back surface cleaning step as the other of the scrubbing and the two-fluid cleaning is continuously performed. Since the back surface of the wafer W is cleaned by a combination of scrubbing and two-fluid cleaning, particles such as polishing dust can be removed from the back surface of the wafer W at a high removal rate. Further, when the chemical liquid is used for cleaning, for example, when the back surface of the wafer W is scrubbed, the cleaning process of the chemical corresponding to the state of the back surface of the wafer W can be performed. Since the first back surface cleaning step and the second back surface cleaning step are continuously performed in the same cleaning chamber 99 while the wafer W is held by the wafer holding portion (substrate holding portion) 105, the cleaning can be performed with a short cleaning time. The back side cleaning of the removal rate.

The operations of the first back surface cleaning step and the second back surface cleaning step are controlled by the motion control unit 12 shown in the first figure. The back surface cleaning unit 80 may further include a surface monitoring device that monitors the state of the back surface of the wafer W. The surface monitoring device is a device that irradiates, for example, infrared rays onto a wafer surface to measure the number of particles on the wafer surface, or a device that generates an image of the wafer surface and determines the state of the wafer surface based on the image. And other known devices. The surface monitoring device transmits data indicating the state of the back surface of the wafer W to the operation control unit 12, and the operation control unit 12 controls the operations of the first back surface cleaning step and the second back surface cleaning step based on the data. For example, the operation control unit 12 may determine the timing of switching from the first back surface cleaning step to the second back surface cleaning step based on the data transmitted from the surface monitoring device, or may determine the first back surface cleaning step and the second back surface cleaning step. The respective time of the process.

The wafer W cleaned by the back surface cleaning unit 80 on the back surface is taken out from the back surface cleaning unit 80 by the transfer robot 85 and transported to the first wafer station 81.

Returning to the first figure, the wafer that has been cleaned on the back side is taken out from the first wafer station 81 of the back surface cleaning unit 10 by the transfer robot 61, turned upside down, and then sent to the upper temporary stage 60A. The wafer is next cleaned by the surface cleaning unit 15. The surface cleaning unit 15 includes a primary cleaning unit 131, a secondary cleaning unit 132, and a tertiary cleaning unit 133 that clean the surface (surface on the front side) of the wafer, and further includes a drying unit 135 that dries the cleaned wafer. In the present embodiment, the primary cleaning unit 131 and the secondary cleaning unit 132 are roller-type cleaning machines that clean the wafer by sliding the sponge roller against the upper and lower surfaces of the wafer, and the three-time cleaning unit 133 uses the two-fluid A two-fluid type cleaner that supplies a jet to the upper surface of the wafer. It is also possible to use a sponge pen type cleaner that has been used with a sponge pen instead of a two-fluid type cleaner.

The transport robot 141 is disposed between the primary cleaning unit 131 and the secondary cleaning unit 132, and the transport robot 142 is disposed between the secondary cleaning unit 132 and the tertiary cleaning unit 133. The transport robot 142 is disposed adjacent to the upper temporary mount 60A. A transfer robot 143 is disposed between the third cleaning unit 133 and the drying unit 135.

The wafer whose back surface has been cleaned is taken out by the transfer robot 142 from the upper temporary stage 60A. Then, the conveyance robot 142 and the conveyance robot 141 are conveyed to the primary cleaning unit 131 via the secondary cleaning unit 132. The surface of the wafer is cleaned by the primary cleaning unit 131, the secondary cleaning unit 132, and the tertiary cleaning unit 133. The wafer cleaned by the third cleaning unit 133 is transported to the drying unit 135 by the transfer robot 143, and the wafer is dried in the drying unit 135. The dried wafer is transported by the transport robot 21 from the drying unit 135 to the cassette on the loading cassette 5.

Next, an embodiment of the entire processing of the wafer will be described with reference to the flowchart of the eleventh drawing. In step 1, the outer peripheral side region of the back surface of the wafer is polished by the first back grinding unit 8. In step 2, the wafer is inverted by the transfer robot 61 so that the back side of the wafer faces upward. In step 3, the center side region of the back surface of the wafer is ground by the second back grinding unit 9. Further, polishing of the center side region of the back surface of the wafer may be performed as step 1, and polishing of the outer peripheral side region of the back surface of the wafer may be performed as step 3.

In step 4, the wafer whose back surface has been polished is transferred to the second wafer station 82 of the back surface cleaning unit 10 (see FIG. 7). In step 5, the back side of the wafer is scrubbed and two-fluid cleaned by the backside cleaning unit 80. The sequence of scrubbing and two-fluid cleaning is predetermined by the cleaning recipe. In step 6, the wafer whose back surface has been cleaned is transported to the first wafer station 81 of the back surface cleaning unit 10 (see FIG. 7). In step 7, the wafer is transported by the transport robot 61 from the first wafer station 81, and the wafer is also inverted by the transport robot 61 so that the back side faces downward. In step 8, the surface of the wafer is cleaned and dried by the surface cleaning unit 15. In this way, the substrate processing apparatus continuously performs a series of processes such as back surface polishing, back surface cleaning, surface cleaning, and wafer drying of the wafer. These actions are controlled by the motion control unit 12.

The above-described embodiments are described for the purpose of enabling the present invention to be carried out by a person having ordinary knowledge in the technical field to which the present invention pertains. As long as it is a person skilled in the art, various modifications of the above-described embodiments can be made, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, and is to be construed as the broadest scope of the scope of the invention.

Claims (16)

 An apparatus for cleaning a back surface of a substrate, comprising: a substrate holding portion that rotates the substrate while holding the substrate while the back surface of the substrate faces upward; and the scrubbing device configured to be capable of a two-fluid nozzle disposed above the substrate holding portion; and an outer casing forming a cleaning chamber for the substrate holding portion, the scrubbing device, and the two-fluid nozzle configuration .    An apparatus for cleaning a back surface of a substrate according to claim 1, further comprising: an arm to which the scrubbing device and the two-fluid nozzle are fixed; and a swing motor that enables the swing motor The arm, the scrubbing appliance, and the two-fluid nozzle rotate clockwise and counterclockwise at a specified angle centering on a designated axis of revolution.    The apparatus for cleaning the back surface of a substrate according to claim 2, wherein a distance between the scrubbing fixture and the designated rotation axis is equal to the two-fluid nozzle and the designated rotation axis. the distance between.    The apparatus for cleaning a back surface of a substrate according to any one of claims 1 to 3, wherein the substrate holding portion includes a plurality of rotatably held holding rollers, and the plurality of holding rollers hold the substrate Peripheral department.    The device for use according to any one of claims 1 to 3, further comprising: a first substrate station for temporarily accommodating a substrate on which the back surface is cleaned; A second substrate station for temporarily accommodating a substrate whose back surface is not cleaned.    The device of claim 4, further comprising: a first substrate station for temporarily accommodating the substrate on which the back surface is cleaned; and a second substrate station, the second substrate The station is for temporarily accommodating the substrate on the back side that has not been cleaned.    The apparatus according to claim 5, wherein the first substrate station and the second substrate station respectively have: a container that forms a sealed space therein; and a pure water spray disposed in the container nozzle.    The apparatus according to claim 6, wherein the first substrate station and the second substrate station respectively have: a container that forms a sealed space therein; and a pure water spray disposed in the container nozzle.    A back surface cleaning device characterized by comprising: a plurality of back surface cleaning units for cleaning a back surface of a substrate; and a first substrate station for temporarily accommodating a substrate having a back surface cleaned a second substrate station that temporarily accommodates a substrate on the back side that is not cleaned; and a transfer device that transports the substrate that has not been cleaned from the second substrate station to the plurality of substrates Any one of the back surface cleaning units transports the substrate having the back surface cleaned from any one of the plurality of back surface cleaning units to the first substrate station, and the back surface cleaning unit includes a substrate holding portion, the substrate The holding portion rotates the substrate while holding the substrate while the back surface of the substrate faces upward; the scrubbing device is configured to be rotatable; and the two-fluid nozzle is disposed above the substrate holding portion; An outer casing forming a cleaning chamber for the substrate holding portion, the scrubbing device, and the two-fluid nozzle Set.    A substrate processing apparatus comprising: a back surface polishing unit that polishes a back surface of the substrate; and a back surface cleaning device according to claim 9, wherein the back surface cleaning device is used for cleaning by the back surface polishing The back surface of the polished substrate.    A method for cleaning a back surface of a substrate, wherein the substrate is taken into the cleaning chamber to hold the substrate, and the substrate held in the cleaning chamber is rotated, and the scrubbing device is rotated while the scrubbing device is cleaned The back surface of the substrate is slidably contacted, and then a two-fluid jet is supplied to the back surface of the substrate in the cleaning chamber.    The method for cleaning the back surface of a substrate according to claim 11, wherein the step of slidingly contacting the scrubbing device with the back surface of the substrate is a step of rotating the scrubbing device while rotating the scrubbing device. The scrubbing device is in sliding contact with the back surface of the substrate, and the rotating scrubbing device is reciprocated between the center and the edge portion of the substrate.    The method for cleaning a back surface of a substrate according to claim 11 or 12, wherein the step of supplying the two-fluid jet to the back surface of the substrate is a step of supplying a two-fluid from the two-fluid nozzle to the back surface of the substrate. The two-fluid nozzle is reciprocated between the center and the edge of the substrate while jetting.    A method for cleaning a back surface of a substrate, wherein the substrate is housed in a cleaning chamber to hold the substrate, the held substrate is rotated, and a two-fluid jet is supplied to a back surface of the substrate, and then the scrubbing device is rotated While the scrubbing device is in sliding contact with the back surface of the substrate.    The method for cleaning the back surface of a substrate according to claim 14, wherein the step of slidingly contacting the scrubbing device with the back surface of the substrate is a step of rotating the scrubbing device while rotating the scrubbing device. The scrubbing device is in sliding contact with the back surface of the substrate, and the rotating scrubbing device is reciprocated between the center and the edge portion of the substrate.    A method for cleaning a back surface of a substrate according to claim 14 or 15, wherein the step of supplying the two-fluid jet to the back surface of the substrate is a step of supplying a two-fluid from the two-fluid nozzle to the back surface of the substrate. The two-fluid nozzle is reciprocated between the center and the edge of the substrate while jetting.