WO2021044694A1 - Polishing device, polishing method and substrate processing device - Google Patents

Abstract

The present invention relates to a polishing device and a polishing method for polishing the back side of a substrate such as a wafer. The present invention further relates to a substrate processing device provided with the polishing device. This polishing device is provided with a substrate holding unit (10) which holds a substrate (W) in a state with the device surface (2) thereof facing upwards and which rotates the substrate (W); a polishing tool (31) which contacts a non-device surface (1) of the substrate (W) and polishes the non-device surface (1) of said substrate (W); and a contactless washing mechanism (30) which washes the device surface (2) of the substrate (W) while the non-device surface (1) of the substrate (W) is processed with the polishing tool (31).

Description

Polishing equipment, polishing method, and substrate processing equipment

The present invention relates to a polishing apparatus and a polishing method for polishing the back surface of a substrate such as a wafer. Furthermore, the present invention relates to a substrate processing apparatus provided with a polishing apparatus.

In recent years, devices such as memory circuits, logic circuits, and image sensors (for example, CMOS sensors) are becoming more integrated. In the process of forming these devices, foreign matter such as fine particles and dust may adhere to the device. Foreign matter adhering to the device causes short circuits between wires and circuit malfunctions. Therefore, in order to improve the reliability of the device, it is necessary to clean the substrate (for example, the wafer) on which the device is formed to remove foreign matter on the substrate.

Foreign substances such as fine particles and dust as described above may also adhere to the back surface (non-device surface) of the substrate. When such foreign matter adheres to the back surface of the substrate, the substrate is separated from the stage reference plane of the exposure apparatus, or the surface of the substrate (device surface) is tilted with respect to the stage reference plane, resulting in patterning deviation and focal length. Will occur. In order to prevent such a problem, it is necessary to remove the foreign matter adhering to the back surface of the substrate.

Therefore, a polishing device that polishes the back surface of the substrate to remove foreign substances adhering to the back surface has been conventionally used (see, for example, Patent Document 1). In this specification, the back surface of the substrate on which the device is not formed or the device is not planned to be formed is defined as the "non-device surface", and the device is formed or the device is planned to be formed. The surface of the substrate is defined as the "device surface".

In the polishing apparatus described in Patent Document 1, the entire non-device surface of the substrate is efficiently polished with the non-device surface of the substrate facing downward. Therefore, since it is not necessary to invert the substrate in order to polish the non-device surface of the substrate, it is possible to prevent impurities in the air from adhering to the substrate and reduce the processing time of the entire polishing apparatus. Further, such a polishing device is provided in, for example, a substrate processing device capable of performing a series of steps of polishing, cleaning, and drying the non-device surface of the substrate. In this case, since a reversing machine for reversing the substrate is not required, the configuration of the substrate processing device can be simplified and the cost can be reduced.

Japanese Unexamined Patent Publication No. 2019-077003

Even in a polishing device that polishes the non-device surface with the non-device surface of the substrate facing downward, foreign matter such as polishing debris generated during polishing of the substrate and / or a rinsing liquid containing the polishing debris is present on the substrate. There is a risk of wrapping around the device surface of the substrate and contaminating the device surface of the substrate. Therefore, the polishing apparatus described in Patent Document 1 has a protective liquid supply nozzle that supplies a protective liquid (for example, pure water) to the device surface during polishing of the non-device surface of the substrate. By covering the device surface with a protective liquid, it is possible to prevent the device surface of the substrate from being contaminated by foreign matter generated during polishing of the non-device surface.

However, in order to further improve the reliability of the device formed on the device surface of the substrate, the device surface of the substrate is not contaminated as much as possible during polishing of the non-device surface, that is, foreign matter can be formed on the device surface of the substrate. It is important not to adhere as much as possible. Further, if a large amount of foreign matter adheres to the device surface during polishing of the substrate, it becomes necessary to clean the substrate for a relatively long time in order to remove the foreign matter. For example, the cleaning unit of the substrate processing apparatus needs to clean the device surface of the substrate after polishing for a relatively long time, and as a result, the throughput of the substrate processing apparatus may decrease. Therefore, in order to reduce the burden of the substrate cleaning process performed after the substrate polishing process and improve the throughput of the substrate processing device, as much foreign matter as possible on the device surface during polishing of the non-device surface of the substrate It is important not to adhere.

Therefore, the present invention prevents the device surface of the substrate from being contaminated by foreign matter while holding the substrate with its device surface facing up and polishing the non-device surface of the substrate. It is an object of the present invention to provide a polishing apparatus capable of capable of polishing, and a polishing method. Another object of the present invention is to provide a substrate processing apparatus having such a polishing apparatus.

In one aspect, the substrate is held with its device surface facing up, and the substrate holding portion for rotating the substrate is brought into contact with the non-device surface of the substrate to polish the non-device surface of the substrate. Provided is a polishing apparatus comprising a polishing tool and a non-contact cleaning mechanism for cleaning the device surface of the substrate while polishing the non-device surface of the substrate with the polishing tool. To.

In one aspect, the non-contact cleaning mechanism comprises a cleaning fluid nozzle that ejects a cleaning fluid toward the device surface of the substrate and a nozzle moving mechanism that moves the cleaning fluid nozzle above the device surface of the substrate. Has.
In one aspect, the cleaning fluid nozzle is a two-fluid jet nozzle that ejects a two-fluid jet toward the device surface of the substrate.
In one aspect, the non-contact cleaning mechanism further comprises an ozone generator, the cleaning fluid nozzle ejecting ozone water, or ozone microbubble water, toward the device surface of the substrate.

In one aspect, the non-contact cleaning mechanism further comprises an electrolyzed water generator, the cleaning fluid nozzle ejecting electrolyzed water toward the device surface of the substrate.
In one aspect, the cleaning fluid nozzle ejects megasonic water or chemicals towards the device surface of the substrate.
In one aspect, the polishing apparatus further comprises a protective liquid supply nozzle that supplies the protective liquid to the device surface of the substrate.

In one aspect, the substrate is held with its device surface facing up, the substrate is rotated, and a polishing tool is pressed against the non-device surface of the rotating substrate to polish the non-device surface. A polishing method is provided, which comprises cleaning the device surface of the substrate with a non-contact cleaning mechanism while polishing the non-device surface of the substrate.

In one aspect, cleaning of the device surface of the substrate is performed by injecting cleaning fluid from the cleaning fluid nozzle onto the device surface of the substrate while moving the cleaning fluid nozzle above the device surface of the substrate.
In one aspect, the cleaning fluid nozzle ejects a two-fluid jet towards the device surface of the substrate.
In one aspect, the cleaning fluid nozzle injects ozone water or ozone microbubble water toward the device surface of the substrate.

In one aspect, the cleaning fluid nozzle ejects electrolyzed water toward the device surface of the substrate.
In one aspect, the cleaning fluid nozzle ejects megasonic water or chemicals towards the device surface of the substrate.
In one aspect, the protective liquid is further supplied to the device surface of the substrate while polishing the non-device surface of the substrate.

In one aspect, the substrate processing apparatus includes the polishing apparatus, a cleaning unit for cleaning the substrate polished by the polishing apparatus, and a drying unit for drying the substrate cleaned by the cleaning unit. Is provided.
In one aspect, the cleaning unit cleans only the non-device surface of the substrate.

According to the present invention, the device surface of the substrate is positively cleaned by the non-contact cleaning mechanism while the polishing tool is polishing the non-device surface of the substrate. Therefore, it is possible to effectively prevent the device surface of the substrate from being contaminated by foreign matter, and as a result, the reliability of the device is improved. Further, even after polishing the non-device surface of the substrate, almost no foreign matter adheres to the device surface of the substrate, so that the burden of the substrate cleaning process performed after the substrate polishing process can be reduced. , The time required for the cleaning process can be shortened.

FIG. 1 is a schematic view showing an embodiment of a polishing apparatus. FIG. 2 is a schematic view showing details of the substrate holding portion. FIG. 3 is a plan view showing the roller rotation mechanism shown in FIG. FIG. 4 is a cross-sectional view taken along the line AA of FIG. FIG. 5 is a schematic view showing an enlarged example of the upper part of the roller. FIG. 6 is a plan view showing an example of the arrangement of the polishing heads. FIG. 7 is a view seen from the direction indicated by the arrow B in FIG. FIG. 8 is a schematic view showing an example of a non-contact cleaning mechanism. FIG. 9 is a schematic view showing how the cleaning fluid nozzle moves above the wafer. FIG. 10A is a graph showing an example of the supply timing of the cleaning fluid. FIG. 10B is a graph showing an example of the supply timing of the cleaning fluid. FIG. 10C is a graph showing an example of the supply timing of the cleaning fluid. FIG. 11 is a plan view schematically showing an embodiment of a substrate processing apparatus provided with a polishing apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an embodiment of a polishing apparatus. The polishing apparatus shown in FIG. 1 holds a wafer W, which is an example of a substrate, and holds a substrate holding portion 10 which rotates around the axis thereof and a polishing tape 31 which is an example of a polishing tool, in the substrate holding portion 10. A polishing head 50 that contacts the first surface 1 of the wafer W to polish the first surface 1 of the wafer W, a polishing tape supply mechanism 41 that supplies the polishing tape 31 to the polishing head 50, and a polishing head 50. It also includes a translational rotation movement mechanism 60 that causes the polishing tape supply mechanism 41 to perform translational rotation movement.

The substrate holding portion 10 includes a plurality of rollers 11 capable of contacting the peripheral edge portion of the wafer W. The polishing head 50 is arranged below the wafer W held by the substrate holding portion 10. The translational rotation movement mechanism 60 is arranged below the polishing head 50 and the polishing tape supply mechanism 41, and the polishing head 50 and the polishing tape supply mechanism 41 are connected to the translational rotation movement mechanism 60. In FIG. 1, a part of the substrate holding portion 10 is not shown.

In the present embodiment, the first surface 1 of the wafer W is the back surface of the wafer W on which the device is not formed or the device is not planned to be formed, that is, the non-device surface. The second surface 2 of the wafer W opposite to the first surface 1 is the surface on which the device is formed or is to be formed, that is, the device surface. Hereinafter, the first surface 1 of the wafer W will be referred to as a “non-device surface 1”, and the second surface 2 of the wafer W will be referred to as a “device surface 2”. In the present embodiment, the wafer W is horizontally held by the substrate holding portion 10 with its non-device surface 1 facing downward.

FIG. 2 is a schematic view showing the details of the substrate holding portion 10, and FIG. 3 is a plan view showing the roller rotation mechanism 12 shown in FIG. The substrate holding portion 10 includes a plurality of rollers 11 that can come into contact with the peripheral edge portion of the wafer W, and a roller rotation mechanism 12 that rotates these rollers 11 around their respective axes. In this embodiment, four rollers 11 are provided. Five or more rollers 11 may be provided. The plurality of rollers 11 when in contact with the peripheral edge portion of the wafer W (that is, when holding the wafer W) are at the same distance from the axial center CP of the substrate holding portion 10.

The roller rotation mechanism 12 includes a first belt 14A connecting two of the four rollers 11 and a first motor 15A connected to one of the two rollers 11 connected by the first belt 14A. A first motor support 25A that supports the first motor 15A, a first roller base 16A that rotatably supports two rollers 11 connected by a first belt 14A, and the other two of the four rollers 11. A second belt 14B connecting the two, a second motor 15B connected to one of the two rollers 11 connected by the second belt 14B, and a second motor support 25B supporting the second motor 15B. A second roller base 16B that rotatably supports two rollers 11 connected by a second belt 14B via a bearing 24B is provided. The first roller stand 16A includes an upper first roller stand 17A and a lower first roller stand 17B. The first motor 15A and the first belt 14A are arranged below the first roller stand 16A, and the second motor 15B and the second belt 14B are arranged below the second roller stand 16B. The first motor 15A is fixed to the first roller stand 16A via the first motor support 25A. The second motor 15B is fixed to the lower surface of the second roller stand 16B via the second motor support 25B.

FIG. 4 is a cross-sectional view taken along the line AA of FIG. As shown in FIG. 4, the first roller base 16A and the lower first roller base 17B that rotatably support the two rollers 11 connected by the first belt 14A via the bearing 24A (see FIG. 2). A pivot shaft 17C fixed to the lower first roller base 17B and an upper first roller base 17A that rotatably supports the pivot shaft 17C via a bearing 24C are provided. The upper first roller stand 17A and the lower first roller stand 17B are connected to each other via a pivot shaft 17C. As shown in FIG. 3, the pivot shaft 17C is located between the two rollers 11 connected by the first belt 14A. As shown in FIG. 2, the first motor 15A is fixed to the lower surface of the lower first roller stand 17B via the first motor support 25A. Therefore, the first belt 14A, the two rollers 11 connected by the first belt 14A, the lower first roller base 17B, the first motor 15A, and the first motor support 25A are integrally centered on the pivot shaft 17C. It is rotatable.

The roller rotation mechanism 12 is configured to rotate the four rollers 11 in the same direction and at the same speed. During polishing of the non-device surface 1 of the wafer W, the peripheral edge of the wafer W is gripped by the roller 11. The wafer W is held horizontally, and the rotation of the roller 11 causes the wafer W to rotate about its axis. During polishing of the non-device surface 1 of the wafer W, the four rollers 11 rotate around their respective axes, but the positions of the rollers 11 themselves are stationary.

Pulleys 22 are fixed to the lower parts of the four rollers 11. The first belt 14A is hung on a pulley 22 fixed to two of the four rollers 11, and the second belt 14B is hung on a pulley 22 fixed to the other two rollers 11. The first motor 15A and the second motor 15B are configured to rotate at the same speed and in the same direction. Therefore, the four rollers 11 can rotate in the same direction at the same speed.

As shown in FIG. 3, the roller rotation mechanism 12 further includes a first actuator 18A connected to the upper first roller stand 17A of the first roller stand 16A and a second actuator 18B connected to the second roller stand 16B. I have. The first actuator 18A moves the two rollers 11 supported by the first roller stand 16A in the horizontal direction as shown by arrows. Similarly, the second actuator 18B moves the other two rollers 11 supported by the second roller stand 16B in the horizontal direction as indicated by the arrows. That is, the first actuator 18A and the second actuator 18B are configured to move two sets of rollers 11 (each set includes two rollers 11 in this embodiment) in a direction toward and away from each other. .. The first actuator 18A and the second actuator 18B can be composed of an air cylinder, a motor-driven actuator, or the like. In the embodiment shown in FIGS. 2 and 3, the first actuator 18A and the second actuator 18B are composed of an air cylinder. The first actuator 18A and the second actuator 18B are fixed to the lower surface of the base plate 23.

The roller 11 penetrates the base plate 23 and extends upward. A first linear motion guide 26A and a second linear motion guide 26B are fixed to the lower surface of the base plate 23. The movable portion of the first linear motion guide 26A is connected to the upper first roller stand 17A, and the movable portion of the second linear motion guide 26B is connected to the second roller stand 16B. The two linear motion guides 26A and 26B limit the movement of the roller 11 to a linear motion in the horizontal direction.

When the two sets of rollers 11 move in the direction of approaching each other, the wafer W is held by the four rollers 11. Since two of the four rollers 11 are rotatable around the pivot shaft 17C, the positions of the two rollers 11 are automatically adjusted when the four rollers 11 hold the wafer W. .. When the two sets of rollers 11 move away from each other, the wafer W is released from the four rollers 11. In the present embodiment, four rollers 11 arranged around the axis CP of the substrate holding portion 10 are provided, but the number of rollers 11 is not limited to four. For example, three rollers 11 may be arranged around the axis CP at equal intervals of 120 degrees, and one actuator may be provided for each roller 11. In one embodiment, the three rollers 11 are arranged around the axis CP at equal intervals of 120 degrees, two of the three rollers 11 are connected by the first belt 14A, and the first belt 14A. One actuator may be provided for each of the two rollers 11 that are connected and the roller 11 that is not connected by the first belt 14A.

FIG. 5 is an enlarged schematic view showing an example of the upper part of the roller 11. The roller 11 has a cylindrical substrate holding surface 11a that can come into contact with the peripheral edge of the wafer W, and a tapered surface 11b that is connected to the substrate holding surface 11a and is inclined downward from the substrate holding surface 11a. The tapered surface 11b has a truncated cone shape and has a diameter larger than that of the substrate holding surface 11a. The wafer W is first placed on the tapered surface 11b by a transfer device (not shown), and then the peripheral edge portion of the wafer W is held on the substrate holding surface 11a by moving the roller 11 toward the wafer W. When the roller 11 releases the wafer W, the roller 11 moves away from the wafer W, so that the peripheral edge portion of the wafer W is separated from the substrate holding surface 11a and supported by the tapered surface 11b (dotted line in FIG. 5). reference). A transfer device (not shown) can take out the wafer W on the tapered surface 11b.

As shown in FIG. 1, below the wafer W held by the substrate holding portion 10, a rinse liquid supply nozzle 27 that supplies a rinse liquid (for example, pure water or an alkaline chemical liquid) to the non-device surface 1 of the wafer W. Is placed. The rinse liquid supply nozzle 27 is connected to a rinse liquid supply source (not shown). The rinse liquid supply nozzle 27 is arranged so as to face the center O1 of the non-device surface 1 of the wafer W. The rinse liquid is supplied from the rinse liquid supply nozzle 27 to the non-device surface 1 of the wafer W, and the rinse liquid spreads on the non-device surface 1 of the wafer W by centrifugal force. The rinsing liquid flows outward in the radial direction on the non-device surface 1 of the wafer W, whereby polishing debris can be removed from the non-device surface 1 of the wafer W.

In the present embodiment, a protective liquid supply nozzle 28 that supplies a protective liquid (for example, pure water) to the device surface 2 of the wafer W is arranged above the wafer W held by the substrate holding portion 10. The protective liquid supply nozzle 28 is connected to a protective liquid supply source (not shown). The protective liquid supply nozzle 28 is arranged so as to face the center of the device surface 2 of the wafer W. The protective liquid is supplied from the protective liquid supply nozzle 28 to the center of the device surface 2 of the wafer W, and the protective liquid spreads on the device surface 2 of the wafer W by centrifugal force. The protective liquid prevents the rinsing liquid containing polishing debris and foreign matter generated by polishing the wafer W from wrapping around the device surface 2 of the wafer W and adhering to the device surface 2 of the wafer W. As a result, the device surface 2 of the wafer W can be kept clean.

As will be described later, during polishing of the non-device surface 1 of the wafer W, the cleaning fluid is injected onto the device surface 2 of the wafer W from the cleaning fluid nozzle 33 of the non-contact cleaning mechanism 30. Therefore, the protective liquid supply nozzle 28 may be omitted depending on the polishing recipe for the non-device surface 1, particularly the rotation speed of the wafer W.

As shown in FIG. 1, the translational rotary motion mechanism 60 includes a motor 62, a crankshaft 70 fixed to the motor 62, a table 69, a base 71, and a plurality of eccentric joints 65. The motor 62 is arranged below the base 71 and is fixed to the lower surface of the base 71. The crankshaft 70 penetrates the base 71 and extends upward. The table 69 is connected to the base 71 via a plurality of eccentric joints 65 and a crankshaft 70. The table 69 is connected to a plurality of eccentric joints 65 via a plurality of bearings 67, and is further connected to a crankshaft 70 via a bearing 68. The base 71 is connected to a plurality of eccentric joints 65 via a plurality of bearings 75. Although only two eccentric joints 65 are drawn in FIG. 1, the translational rotary motion mechanism 60 includes at least two eccentric joints 65.

The tip of the crankshaft 70 is eccentric by a distance e from the axis of the motor 62. Therefore, when the motor 62 is operated, the table 69 makes a circular motion with a radius e. In the present specification, circular motion is defined as the motion of an object moving in a circular orbit. Since the table 69 is supported by a plurality of eccentric joints 65, the table 69 itself does not rotate when the table 69 is in a circular motion. The eccentricity of the plurality of eccentric joints 65 is the same as the eccentricity of the table 69. Such a motion of the table 69 is also called a translational rotational motion. In the present specification, the motion of the object moving in a circular orbit without rotating the object itself is defined as a translational rotational motion. The polishing head 50 and the polishing tape supply mechanism 41 are fixed to the table 69. Therefore, when the translational rotation movement mechanism 60 is activated, the polishing head 50 and the polishing tape supply mechanism 41 integrally (synchronously) perform translational rotation movement.

In this embodiment, a polishing tape 31 having abrasive grains on its surface is used as a polishing tool for polishing the non-device surface 1 of the substrate. An example of the polishing tape 31 is a polishing tape having a base material tape and a polishing layer covering the surface of the base material tape. The polishing layer has, for example, abrasive grains and a binder (resin) for holding the abrasive grains. Another example of the polishing tape 31 is a polishing tape having a base material tape, a polishing layer, and an elastic layer located between them. The elastic layer is composed of, for example, a non-woven fabric made of polypropylene, polyurethane, polyester, or nylon, or an elastic material such as silicone rubber.

As shown in FIG. 1, the polishing head 50 is arranged below the substrate holding surface 11a and is arranged upward. The polishing head 50 includes a polishing blade 55 that presses the polishing tape 31 against the non-device surface 1 of the wafer W, a pressurizing mechanism 52 that pushes up the polishing blade 55 upward, and a support member 79 that supports the pressurizing mechanism 52. ing. The support member 79 is fixed to the table 69 of the translational rotation movement mechanism 60, and the entire polishing head 50 can perform the translational rotation movement integrally with the table 69. The support member 79 has a through hole (not shown), and the polishing tape 31 extends through the through hole.

The polishing tape supply mechanism 41 includes a tape unwinding reel 43 for supplying the polishing tape 31 and a tape winding reel 44 for collecting the polishing tape 31. The tape winding reel 43 and the tape winding reel 44 are connected to tension motors 43a and 44a, respectively. These tension motors 43a and 44a are fixed to the reel base 42, and by applying a predetermined torque to the tape winding reel 43 and the tape winding reel 44, a predetermined tension can be applied to the polishing tape 31. The reel base 42 is fixed to the table 69 of the translational rotation movement mechanism 60, and the entire polishing tape supply mechanism 41 can perform the translational rotation movement integrally with the table 69.

A tape feeding device 46 for feeding the polishing tape 31 in the longitudinal direction is provided between the tape winding reel 43 and the tape winding reel 44. The tape feed device 46 includes a tape feed roller 48 that feeds the polishing tape 31, a nip roller 49 that presses the polishing tape 31 against the tape feed roller 48, and a tape feed motor 47 that rotates the tape feed roller 48. There is. The polishing tape 31 is sandwiched between the nip roller 49 and the tape feed roller 48. When the tape feed motor 47 rotates the tape feed roller 48 in the direction indicated by the arrow in FIG. 1, the polishing tape 31 is fed from the tape unwinding reel 43 to the tape winding reel 44 via the polishing blade 55. The speed at which the polishing tape 31 is fed can be changed by changing the rotation speed of the tape feed motor 47. In one embodiment, the direction in which the polishing tape 31 is fed may be opposite to the direction indicated by the arrow in FIG. 1 (the arrangement of the tape unwinding reel 43 and the tape winding reel 44 may be interchanged). In this case as well, the tape feeding device 46 is installed on the tape winding reel 44 side.

The polishing tape 31 is supplied to the upper surface of the polishing blade 55 so that the polishing surface 31a of the polishing tape 31 faces the non-device surface 1 of the wafer W. In the present specification, the polishing surface 31a of the polishing tape 31 is defined as a surface located above the polishing blade 55 and pressed against the non-device surface 1 of the wafer W.

The polishing device further includes a plurality of guide rollers 53a, 53b, 53c, 53d that support the polishing tape 31. The polishing tape 31 is guided by these guide rollers 53a, 53b, 53c, 53d so as to surround the polishing blade 55 and the pressurizing mechanism 52. The polishing head 50 polishes the non-device surface 1 of the wafer W by pressing the polishing tape 31 from the back side of the polishing tape 31 against the non-device surface 1 of the wafer W by the polishing blade 55. The guide rollers 53b and 53c arranged on the upper part of the polishing head 50 guide the polishing tape 31 so that the polishing tape 31 advances in the direction parallel to the non-device surface 1 of the wafer W.

The tape feeding device 46 and the guide rollers 53a, 53b, 53c, 53d are fixed to a holding member (not shown), and the holding member is fixed to the table 69 of the translational rotary motion mechanism 60. Therefore, when the translational rotation movement mechanism 60 operates, the polishing head 50, the polishing tape supply mechanism 41, the tape feeding device 46, and the guide rollers 53a, 53b, 53c, 53d integrally (that is, synchronously) perform translational rotation movement. Do.

FIG. 6 is a plan view showing an example of the arrangement of the polishing head 50, and FIG. 7 is a view seen from the direction indicated by the arrow B in FIG. As shown in FIG. 6, the polishing head 50 is arranged so that a part of the polishing blade 55 protrudes outward from the peripheral edge portion of the wafer W. That is, the distance d1 from the axial center CP of the substrate holding portion 10 to the outermost end of the polishing blade 55 is from the axial center CP when the roller 11 holds the wafer W to the substrate holding surface 11a of each roller 11. Longer than the distance d2. In the present embodiment, the polishing blade 55 is longer than the radius of the wafer W, and the upper edge of the polishing blade 55 has a rounded cross-sectional shape. More specifically, one end of the polishing blade 55 protrudes outward from the peripheral edge of the wafer W, and the other end exceeds the center O1 of the non-device surface 1 of the wafer W (that is, the axial CP of the substrate holding portion 10). Is extending. As a result, the polishing blade 55 can bring the polishing tape 31 into contact with the non-device surface 1 of the wafer W from the center O1 to the outermost side. The polishing blade 55 can be made of a resin material such as PEEK (polyetheretherketone). In one embodiment, the polishing blade 55 may be longer than the diameter of the wafer W.

During polishing of the wafer W, the wafer W is rotated by the roller 11. All the rollers 11 rotate around their respective axes, but the positions of these rollers 11 are fixed. Therefore, even if a part of the polishing blade 55 protrudes from the peripheral edge of the wafer W, the roller 11 does not come into contact with the polishing blade 55. During polishing of the wafer W, the polishing head 50 including the polishing blade 55 is moved in translational rotation by the translational rotation movement mechanism 60. By this translational rotational movement, the polishing head 50 makes a relative movement with respect to the wafer W, and the polishing tape 31 and the wafer W at the contact point between the polishing tape 31 and the non-device surface 1 of the wafer W (hereinafter referred to as the polishing point). Secure the relative speed with. In particular, the translational rotary motion mechanism 60 can increase the relative speed between the wafer W and the polishing tape 31 at the center of the wafer W. The polishing head 50 is arranged at a position where it does not come into contact with the roller 11 during the translational rotational movement. As a result, the polishing tape 31 can polish the entire non-device surface 1 of the wafer W including the outermost one.

As shown in FIG. 6, the polishing blade 55 extends obliquely with respect to the traveling direction (indicated by the arrow C) of the polishing tape 31. In the present embodiment, the traveling direction C of the polishing tape 31 coincides with the longitudinal direction of the polishing tape 31. Further, the polishing blade 55 extends over the entire width of the polishing tape 31 as long as it does not protrude from the polishing tape 31. By tilting the polishing blade 55 diagonally with respect to the traveling direction C (longitudinal direction of the polishing tape 31) of the polishing tape 31, the downstream side of the traveling direction of the polishing tape 31 (in the case of this embodiment, the outer peripheral side of the wafer W). However, the unused polishing tape 31 can be brought into contact with the wafer W. As a result, it is possible to prevent a decrease in the polishing rate due to the use of the polishing tape 31 deteriorated by polishing.

As shown in FIG. 7, the polishing blade 55 is provided on the surface of the holding pad 56 and projects upward. The holding pad 56 is fixed to the surface of the back plate 57. The pressurizing mechanism 52 is arranged below the back plate 57 and is connected to the lower surface of the back plate 57. The pressurizing mechanism 52 is configured to be able to integrally raise and lower the polishing blade 55, the holding pad 56, and the back plate 57. During polishing of the wafer W, the pressurizing mechanism 52 pushes up the polishing blade 55, the holding pad 56, and the back plate 57, and presses the polishing tape 31 against the non-device surface 1 of the wafer W at the upper edge of the polishing blade 55. Can be polished. Since the polishing blade 55 has a cross-sectional shape with a rounded upper edge, the contact resistance between the polishing tape 31 and the polishing blade 55 can be reduced. In the polishing standby state (non-polishing state), the pressurizing mechanism 52 lowers the polishing blade 55, the holding pad 56, and the back plate 57 to separate the polishing tape 31 from the non-device surface 1 of the wafer W.

In this embodiment, the pressurizing mechanism 52 is composed of an air cylinder. The pressurizing mechanism 52 composed of an air cylinder includes a piston rod 52a connected to the back plate 57, a first pressure chamber 52b that pushes down the piston rod 52a by supplying gas, and a piston rod by supplying gas. It is provided with a second pressure chamber 52c that pushes up 52a. The pressure of the gas supplied to the first pressure chamber 52b and the second pressure chamber 52c is controlled by a pressure regulator (not shown). An example of a pressure regulator is an electropneumatic regulator. A constant pressing force on the polishing tape 31 can be obtained by the pressure regulator.

In one embodiment, the polishing tool may be fixed abrasive grains such as a grindstone instead of the polishing tape 31. In this case, the fixed abrasive grains may be fixed to the surface of the back plate 57 or may be fixed to the surface of the polishing blade 55. The polishing head 50 can polish the non-device surface 1 of the wafer W by bringing the fixed abrasive grains into contact with the non-device surface 1 of the wafer W.

Further, in one embodiment, the fixed abrasive grains may be annularly fixed to the surface of the back plate 57. In this case, the polishing head 50 includes a rotation mechanism (not shown), the rotation mechanism is connected to the back plate 57, and the fixed abrasive grains and the back plate 57 are configured to be rotatable by the rotation mechanism. The polishing head 50 can polish the non-device surface 1 of the wafer W by bringing the fixed abrasive grains into contact with the non-device surface 1 of the wafer W while rotating them.

As long as the non-device surface 1 of the wafer W can be polished, the configuration of the polishing head 50 is also arbitrary and is not limited to the above-described embodiment. For example, the pressurizing mechanism 52 of the polishing head 50 may be an airbag capable of moving the polishing blade 55 up and down. In this case, when gas (for example, air) is supplied to the airbag, the airbag expands and the polishing blade 55 can be pressed against the non-device surface 1 of the wafer W. When the gas is removed from the airbag, the polishing blade 55 separates from the non-device surface 1.

Alternatively, the polishing head 50 may have a plurality of polishing blades and a plurality of pressurizing mechanisms for pressing a polishing tool (for example, a polishing tape) against the non-device surface 1 of the wafer W via each polishing blade. Good. In this case, the plurality of polishing blades may be arranged side by side in a straight line, or may be arranged apart from each other in the circumferential direction of the wafer W. Of the plurality of polishing blades, one end of the polishing blades arranged on the peripheral edge of the wafer W protrudes outward from the peripheral edge of the wafer W, and a part of the polishing blades arranged in the center of the wafer W is the wafer W. Is arranged so as to overlap the center O1 of the first surface 1 of the wafer W during one rotation.

Further, as long as the non-device surface 1 of the wafer W can be polished, the configuration of the substrate holding portion 10 is also arbitrary. Although not shown, the substrate holding portion 10 may be composed of a combination of a first holding portion that holds the peripheral portion of the substrate and a second holding portion that holds the central portion of the substrate. In this case, the polishing of the wafer W is carried out by a first polishing step of polishing the central portion of the wafer W whose peripheral portion is held by the first holding portion with a first polishing tool and a first polishing step in which the central portion is held by the second holding portion. It is performed by combining the two polishing steps of the second polishing step of polishing the peripheral edge portion of the wafer W with the second polishing tool. The second polishing tool may be the same polishing tool as the first polishing tool, or may be a different polishing tool. Further, the second polishing step may be performed after the first polishing step, or the first polishing step may be performed after the second polishing step.

When a polishing tool (polishing tape 31 in the polishing apparatus shown in FIG. 1) is pressed against the non-device surface 1 of the wafer W to polish the non-device surface 1, the polishing debris of the wafer W and the rinsing liquid containing the polishing debris are obtained. Foreign matter such as foreign matter may wrap around the device surface 2 of the wafer W and contaminate the device surface 2. Therefore, the polishing apparatus shown in FIG. 1 includes a non-contact cleaning mechanism 30 that cleans the device surface 2 during polishing of the non-device surface 1 of the wafer (substrate) W. The non-contact cleaning mechanism 30 is a cleaning mechanism that does not have a cleaning member (for example, a cleaning brush or a cleaning sponge) that directly contacts the device surface 2 of the wafer W.

FIG. 8 is a schematic view showing an example of a non-contact cleaning mechanism. As shown in FIG. 8, the non-contact cleaning mechanism 30 according to the present embodiment moves the cleaning fluid nozzle 33 for injecting the cleaning fluid onto the device surface 2 of the wafer W and the cleaning fluid nozzle 33 above the wafer W. A nozzle moving mechanism 32 is provided. The nozzle moving mechanism 32 includes a nozzle arm 34 that supports the cleaning fluid nozzle 33, a nozzle swivel shaft 35 that swivels the nozzle arm 34, and a motor (drive source) 36 that swivels the nozzle swivel shaft 35. The motor 36 is electrically connected to the motion control unit 180, and rotates the nozzle swivel shaft 35 around the axis thereof based on a command from the motion control unit 180.

The cleaning fluid nozzle 33 is connected to one end of the nozzle arm 34 and has a tip pointed downward. In the present embodiment, the non-contact cleaning mechanism 30 has a cleaning fluid supply device 40, and the cleaning fluid is supplied to the cleaning fluid nozzle 33 via a cleaning fluid line 37 extending from the cleaning fluid supply device 40. To. The cleaning fluid nozzle 33 is configured to inject a cleaning fluid from the tip thereof onto the device surface 2 of the wafer W to clean the device surface 2. A nozzle swivel shaft 35 is connected to the other end of the nozzle arm 34, and when the nozzle swivel shaft 35 is rotated by the operation of the motor 36, the cleaning fluid nozzle 33 moves above the device surface 2 of the wafer W. Move horizontally.

FIG. 9 is a schematic view showing how the cleaning fluid nozzle 33 moves above the wafer W. As shown in FIG. 9, the cleaning fluid nozzle 33 is horizontally moved above the wafer W from the substantially central portion to the peripheral portion of the device surface 2 by the nozzle moving mechanism 32. When the cleaning fluid nozzle 33 is located at the center of the device surface 2 of the wafer W, the cleaning fluid ejected from the cleaning fluid nozzle 33 collides with a region including at least the center O2 of the device surface 2. By moving the cleaning fluid nozzle 33 from the substantially central portion to the peripheral portion of the device surface 2, the cleaning fluid collides with the entire device surface 2, and the entire device surface 2 is cleaned by the cleaning fluid. The cleaning fluid nozzle 33 that injects the cleaning fluid may be reciprocated once or more between the substantially central portion and the peripheral portion of the device surface 2.

Although not shown, the nozzle moving mechanism 32 may be configured by an air cylinder mechanism that moves the cleaning fluid nozzle 33 forward and backward in the radial direction of the wafer W. Alternatively, the nozzle moving mechanism 32 may be configured by a ball screw mechanism that moves the cleaning fluid nozzle 33 forward and backward in the radial direction of the wafer W.

The cleaning fluid supply device 40 is a device for supplying a predetermined cleaning fluid to the device 2 of the wafer W at a predetermined timing. The cleaning fluid supply device 40 may be arranged inside the polishing device or may be arranged outside the polishing device. The cleaning fluid supply device 40 is electrically connected to the operation control unit 180, and the operation of the cleaning fluid supply device 40 is controlled by the operation control unit 180. For example, the operation control unit 180 controls a flow rate regulator (not shown) such as a mass flow controller built in the cleaning fluid supply device 40 to supply the cleaning fluid from the cleaning fluid supply device 40 to the cleaning fluid nozzle 33. Controls the flow rate and supply timing of. As shown in FIG. 8, a flow rate regulator 38 such as a mass flow controller may be arranged on the cleaning fluid line 37. By controlling the operation of the flow rate regulator 38 by the operation control unit 180, the flow rate of the cleaning fluid supplied from the cleaning fluid supply device 40 and the supply timing are adjusted.

10A to 10C are graphs showing an example of the supply timing of the cleaning fluid, respectively. In FIGS. 10A to 10C, the vertical axis represents the operating state of the polishing head and the operating state of the non-contact cleaning mechanism 30, and the horizontal axis represents time. In FIGS. 10A to 10C, when the operating state of the polishing head 50 is turned on, the polishing tape (polishing tool) 31 is pressed against the non-device surface 1 of the wafer (substrate) W, and polishing of the non-device surface 1 is started. To. When the operating state of the polishing head 50 is turned off, the polishing tape 31 is separated from the non-device surface 1 of the wafer W, and polishing of the non-device surface 1 is stopped. When the operating state of the non-contact cleaning mechanism 30 is turned on, the cleaning fluid is ejected from the cleaning fluid nozzle 33 onto the device surface 2 of the wafer W, and cleaning of the device surface 2 is started. When the operating state of the non-contact cleaning mechanism 30 is turned off, the injection of the cleaning fluid from the cleaning fluid nozzle 33 is stopped, and the cleaning of the device surface 2 is stopped.

In the example shown in FIG. 10A, the time point Tc at which the cleaning of the device surface 2 is started is before the time point Ta at which the polishing of the non-device surface 1 of the wafer W with the polishing tape 31 is started. That is, the cleaning of the device surface 2 by the non-contact cleaning mechanism 30 is started before the polishing of the non-device surface 1 of the wafer W by the polishing tape 31. Further, in the example shown in FIG. 10A, the time point Td at which the cleaning of the device surface 2 is completed is later than the time point Tb at which the polishing of the non-device surface 1 of the wafer W with the polishing tape 31 is completed. That is, the cleaning of the device surface 2 by the non-contact cleaning mechanism 30 is completed after the polishing of the non-device surface 1 of the wafer W by the polishing tape 31 is completed.

In the example shown in FIG. 10B, the time point Tc at which the cleaning of the device surface 2 is started is the same as the time point Ta at which the polishing of the non-device surface 1 of the wafer W with the polishing tape 31 is started. That is, the cleaning of the device surface 2 by the non-contact cleaning mechanism 30 is started at the same time as the polishing of the non-device surface 1 of the wafer W by the polishing tape 31. Further, in the example shown in FIG. 10B, the time point Td at which the cleaning of the device surface 2 is completed is the same as the time point Tb at which the polishing of the non-device surface 1 of the wafer W with the polishing tape 31 is completed. That is, the cleaning of the device surface 2 by the non-contact cleaning mechanism 30 is completed at the same time as the polishing of the non-device surface 1 of the wafer W by the polishing tape 31 is completed.

As shown in FIGS. 10A and 10B, by cleaning the device surface 2 at least while polishing the non-device surface 1 of the wafer W with the polishing tape 31, the contamination of the device surface 2 by foreign matter is maximized. It can be prevented to the limit.

On the other hand, in the example shown in FIG. 10C, the time point Tc at which the cleaning of the device surface 2 is started is started after a predetermined time Int has elapsed from the start of polishing the non-device surface 1 of the wafer W by the polishing tape 31. To. That is, the cleaning of the device surface 2 by the non-contact cleaning mechanism 30 is started after the non-device surface 1 of the wafer W is polished by the polishing tape 31. In this case, since the consumption of the cleaning fluid is reduced, the running cost of the polishing apparatus can be reduced. Further, in the example shown in FIG. 10C, the time point Td at which the cleaning of the device surface 2 is completed is later than the time point Tb at which the polishing of the non-device surface 1 of the wafer W with the polishing tape 31 is completed. In one embodiment, the time point Td at which the cleaning of the device surface 2 is completed may be set to be the same as the time point Tb at which the polishing of the non-device surface 1 of the wafer W with the polishing tape 31 is completed. As described above, it is preferable to clean the device surface 2 at least until the time point Tb at which the polishing of the non-device surface 1 of the wafer W by the polishing tape 31 is completed.

In the present embodiment, the cleaning fluid nozzle 33 is a two-fluid jet nozzle that injects a two-fluid jet toward the device surface 2. The two-fluid jet nozzle is a nozzle configured to be able to inject a mixed fluid of gas and liquid supplied from the cleaning fluid supply device 40 at high speed. The cleaning fluid nozzle 33, which is a two-fluid jet nozzle, causes, for example, a minute droplet (mist) placed on a high-speed gas to collide with the device surface 2 of the wafer W, and the shock wave generated by this collision is used to make the device surface 2 The upper foreign matter is removed, that is, the device surface 2 is cleaned.

The cleaning fluid injected from the cleaning fluid nozzle 33 onto the device surface 2 of the wafer W is not limited to the two-fluid jet. For example, the cleaning fluid may be ozone water in which ozone gas is dissolved in pure water (or ultrapure water), or ozone in which minute bubbles of ozone gas are contained in pure water (or ultrapure water). It may be micro bubble water (or ozone nano bubble water). In these cases, the cleaning fluid supply device 40 of the non-contact cleaning mechanism 30 includes an ozone generator 85 that produces ozone gas.

When the cleaning fluid is ozone water, the organic substances and metals adhering to the device surface 2 of the wafer W are dissolved in ozone water by the strong oxidizing action of ozone and removed from the device surface 2. When the cleaning fluid is ozone microbubble water (or ozone nanobubble water), foreign substances are decomposed and removed by using a large amount of OH radicals generated when the ozone microbubbles disappear.

In one embodiment, the cleaning fluid may be electrolyzed water. In this case, the cleaning fluid supply device 40 of the non-contact cleaning mechanism 30 has an electrolyzed water generator 86. The electrolyzed water generated by the electrolyzed water generator 86 is supplied to the cleaning fluid nozzle 33, and is injected from the cleaning fluid nozzle 33 onto the device surface 2. Further, the cleaning fluid injected from the cleaning fluid nozzle 33 onto the device surface 2 of the wafer W may be megasonic water excited by ultrasonic vibration or a chemical solution capable of dissolving foreign matter. Further, in one embodiment, the cleaning fluid injected from the cleaning fluid nozzle 33 onto the device surface 2 of the wafer W is a cleaning gas capable of reacting with foreign matter on the device surface 2 and removing the foreign matter from the device surface. May be good.

Next, the operation of the polishing apparatus according to this embodiment will be described. The operation of the polishing apparatus described below, that is, the polishing process of the wafer W, is controlled by the operation control unit 180 shown in FIG. The operation control unit 180 is electrically connected to a substrate holding unit 10, a non-contact cleaning mechanism 30, a polishing head 50, a polishing tape supply mechanism 41, a tape feeding device 46, a translational rotary motion mechanism 60, and the like. Controls the behavior of components. For example, the operation control unit 180 includes a substrate holding unit 10, a rinse liquid supply nozzle 27, a protective liquid supply nozzle 28, a motor 36, a flow rate regulator 38, a cleaning fluid supply device 40, a polishing head 50, a polishing tape supply mechanism 41, and a tape. It controls the operation of the feeder 46, the translational rotary motion mechanism 60, and the ozone generator 85 (or the electrolyzed water generator 86). The operation control unit 180 is composed of a dedicated computer or a general-purpose computer.

The wafer W to be polished is held by the roller 11 of the substrate holding portion 10 with the non-device surface 1 facing downward (that is, the device surface 2 facing upward), and is further rotated about the axis of the wafer W. To. Specifically, in the substrate holding portion 10, the plurality of rollers 11 are brought into contact with the peripheral edge portion of the wafer W while the non-device surface 1 of the wafer W is facing downward, and the plurality of rollers 11 are centered on their respective axes. By rotating, the wafer W is rotated. Next, the rinse liquid is supplied from the rinse liquid supply nozzle 27 to the non-device surface 1 of the wafer W, and the protective liquid is supplied from the protective liquid supply nozzle 28 to the device surface 2 of the wafer W. The rinsing liquid flows outward in the radial direction on the non-device surface 1 of the wafer W, and the protective liquid spreads over the entire device surface 2 of the wafer W by centrifugal force.

Further, as described with reference to FIG. 10A, cleaning of the device surface 2 of the wafer W by the non-contact cleaning mechanism 30 is started before the polishing of the non-device surface 1 of the wafer W is started. More specifically, the cleaning fluid is supplied to the cleaning fluid nozzle 33 from the cleaning fluid supply device 40 of the non-contact cleaning mechanism 30, and the cleaning fluid is injected from the cleaning fluid nozzle 33 onto the device surface 2 of the wafer W. At the same time, the nozzle moving mechanism 32 of the non-contact cleaning mechanism 30 moves the cleaning fluid nozzle 33 horizontally above the wafer W.

As described with reference to FIG. 10B, cleaning of the device surface 2 of the wafer W by the non-contact cleaning mechanism 30 may be performed at the same time as the start of polishing of the non-device surface 1 of the wafer W. Alternatively, as described with reference to FIG. 10C, cleaning of the device surface 2 of the wafer W by the non-contact cleaning mechanism 30 starts after a predetermined time Int has elapsed from the start of polishing the non-device surface 1 of the wafer W. You may.

As the cleaning fluid ejected from the cleaning fluid nozzle 33, an appropriate cleaning fluid is selected according to the foreign matter that may adhere to the device surface 2. The cleaning fluid can be, for example, a two-fluid jet, ozone water, ozone microbubble water, electrolyzed water, megasonic water, and a chemical solution. In one embodiment, the cleaning fluid may be a cleaning gas.

Next, the operation control unit 180 drives the polishing tape supply mechanism 41 and the tape feeding device 46, and advances the polishing tape 31 in the longitudinal direction at a predetermined speed while applying a predetermined tension. Then, the translational rotation movement mechanism 60 moves the polishing head 50, the polishing tape supply mechanism 41, the guide rollers 53a, 53b, 53c, 53d, and the tape feeding device 46 in translational rotation movement, while the polishing head 50 wafers the polishing tape 31. The non-device surface 1 of the wafer W is polished in the presence of the rinsing liquid by contacting the non-device surface 1 of the W. Specifically, the pressurizing mechanism 52 pushes up the polishing blade 55 upward, and the polishing blade 55 presses the polishing surface 31a of the polishing tape 31 against the non-device surface 1 of the wafer W, whereby the non-device surface 1 of the wafer W is pressed. Polish the whole of. The polishing apparatus constantly supplies the rinse liquid and the protective liquid to the wafer W during the polishing of the wafer W. Further, the polishing apparatus preferably continues to supply the cleaning fluid to the wafer W during the polishing of the wafer W.

In the present embodiment, during polishing of the wafer W, the protective liquid is supplied from the protective liquid supply nozzle 28 to the central portion of the device surface 2 of the wafer W. Therefore, even if the cleaning liquid supply nozzle 33 is moved to the vicinity of the peripheral edge portion of the wafer W, the central portion of the wafer W remains covered with the protective liquid. In particular, even if the rotation speed of the wafer W is set high, at least the entire device surface 2 including the central portion of the wafer W can be covered with the protective liquid. As a result, foreign matter is effectively prevented from adhering to the device surface 2 of the wafer W.

As described above, one end of the polishing blade 55 protrudes outward from the peripheral edge of the wafer W, and the other end extends beyond the center O1 of the non-device surface 1 of the wafer W, so that the polishing blade 55 is polished. The tape 31 can be brought into contact with the non-device surface 1 of the wafer W from the center O1 to the outermost side. Since the position of the roller 11 is stationary during the polishing of the wafer W, the roller 11 does not come into contact with the polishing blade 55. Further, since the polishing head 50 including the polishing blade 55 moves in translational rotation, the relative speed between the polishing tape 31 and the wafer W can be increased even in the central portion of the wafer W. As a result, the polishing tape 31 can polish the entire non-device surface 1 of the wafer W including the outermost surface at a high polishing rate.

After the preset time has elapsed, the pressurizing mechanism 52 lowers the polishing blade 55 and separates the polishing tape 31 from the non-device surface 1 of the wafer W. After that, the operation control unit 180 stops the operation of the components such as the substrate holding unit 10, the non-contact cleaning mechanism 30, the polishing head 50, the polishing tape supply mechanism 41, the tape feeding device 46, and the translational rotary motion mechanism 60. , Finish the polishing process of the wafer W. As described with reference to FIGS. 10A to 10C, the motion control unit 180 is after the polishing of the non-device surface 1 of the wafer W is completed (that is, after the polishing tape 31 is separated from the non-device surface 1). The non-contact cleaning mechanism 30 may be stopped, or the non-contact cleaning mechanism 30 may be stopped at the same time as the polishing of the non-device surface 1 of the wafer W is completed.

According to the present embodiment, while the polishing tape 31, which is an example of a polishing tool for polishing the non-device surface 1 of the wafer (substrate) W, is polishing the non-device surface 1, the device is polished by the non-contact cleaning mechanism 30. Surface 2 is actively cleaned. Further, the protective liquid supplied from the protective liquid supply nozzle 28 covers the device surface 2 to prevent foreign matter from reaching the device surface 2. Therefore, it is possible to effectively prevent the device surface 2 of the wafer W from being contaminated by foreign matter such as polishing debris, and as a result, the reliability of the device formed on the device surface 2 is improved.

Here, as a method of cleaning the surface of the substrate (for example, the device surface 2), a contact-type cleaning method (for example, a scrub cleaning method) in which a cleaning member such as a cleaning brush or a cleaning sponge is brought into direct sliding contact with the surface of the substrate is conventionally used. Known from. This contact-type cleaning method has an advantage that relatively large foreign matters adhering to the surface of the substrate can be efficiently removed.

However, since the contact-type cleaning method requires ancillary equipment such as a pressing mechanism that presses the cleaning member against the device surface 2 with a predetermined force, the configuration of the polishing apparatus becomes complicated as compared with the non-contact-type cleaning method. .. Further, in the contact type cleaning method, there is a possibility that foreign matter removed from the surface of the substrate accumulates on the cleaning member, and the foreign matter accumulated on the cleaning member reattaches to the device surface 2 so-called back pollution problem. Therefore, it is necessary to regularly maintain or replace the cleaning member. In the present embodiment, the device surface 2 is cleaned by a non-contact cleaning method using a cleaning fluid selected from two-fluid jet, ozone water, ozone microbubble water, megasonic water, chemical solution, cleaning gas, and the like. Therefore, the problem of back pollution does not occur. Therefore, the non-contact cleaning method can reduce the maintenance frequency and the running cost as compared with the contact cleaning method.

Further, according to the present embodiment, since almost no foreign matter adheres to the device surface 2 of the wafer W after polishing the non-device surface 1 of the wafer W, cleaning of the wafer W performed after the polishing process of the wafer W is performed. The processing time can be shortened. As a result, as will be described later, the throughput of the substrate processing apparatus in which the polishing apparatus is arranged can also be improved.

FIG. 11 is a plan view schematically showing an embodiment of the substrate processing apparatus provided with the above-mentioned polishing apparatus. In the present embodiment, the substrate processing apparatus has a load / unload portion 121 having a plurality of load ports 122 on which a wafer cassette (board cassette) accommodating a large number of wafers W is placed. The load port 122 can be equipped with an open cassette, a SMIF (Standard Manufacturing Interface) pod, or a FOUP (Front Opening Unified Pod). SMIF and FOUP are airtight containers that can maintain an environment independent of the external space by storing the wafer cassette inside and covering it with a partition wall.

The load / unload section 121 is provided with a first transfer robot (loader) 123 that can move along the arrangement direction of the load ports 122. The first transfer robot 123 can access the wafer cassette mounted on the load port 122 and take out the wafer W from the wafer cassette.

The substrate processing apparatus includes a second transfer robot 126 that can move in the horizontal direction, a first temporary placement table 140 and a second temporary placement table 141 on which the wafer W is temporarily placed, a polishing unit 127, and a substrate processing device. It further includes a system controller 133 that controls the overall operation, a cleaning unit 172 that cleans the polished wafer W, and a drying unit 173 that dries the cleaned wafer W. A third transfer robot 150 for transporting the wafer W is arranged between the second temporary stand 141 and the cleaning unit 172, and the wafer W is located between the cleaning unit 172 and the drying unit 173. A fourth transfer robot 151 for transporting the wafer is arranged. The polishing unit 127 is the above-mentioned polishing device. The above-mentioned operation control unit 180 may be used as the system controller 133, or may be built in the system controller 133.

Next, the transfer route of the wafer W when polishing the wafer W using the polishing unit 127 will be described. A plurality of (for example, 25) wafers W are housed in the wafer cassette (board cassette) of the load port 122 with the device surface 2 facing upward. The first transfer robot 123 takes out one wafer W from the wafer cassette and places the wafer W on the first temporary storage table 140. The second transfer robot 126 takes out the wafer W from the first temporary stand 140 and transfers the wafer W to the polishing unit 127 with the non-device surface 1 of the wafer W facing downward. As described above, the non-device surface 1 of the wafer W is polished by the polishing unit 127. The second transfer robot 126 takes out the polished wafer W from the polishing unit 127 and places it on the second temporary storage table 141. The third transfer robot 150 takes out the wafer W from the second temporary storage table 141 and transfers it to the cleaning unit 172.

The wafer W is cleaned by the cleaning unit 172 with its polished non-device surface 1 facing downward. In one embodiment, the cleaning unit 172 includes an upper cleaning tool (for example, an upper roll sponge) and a lower cleaning tool (for example, a lower roll sponge) arranged so as to sandwich the wafer W, and the cleaning liquid is transferred to the wafer. Both sides of the wafer are cleaned with these cleaning tools while supplying both sides of W.

As described above, the device surface 2 of the wafer W polished by the polishing unit 127 has already been cleaned by the non-contact cleaning mechanism 30. Therefore, the burden of the cleaning process of the wafer W in the cleaning unit 172 is reduced, and the cleaning process can be completed in a relatively short time. For example, it is possible to shorten the cleaning time of the device surface 2 by the upper cleaning tool, and further, it is expected that the cleaning time of both sides of the wafer W by the upper cleaning tool and the lower cleaning tool can be shortened. As a result, the throughput of the substrate processing apparatus can be improved, and the running cost in the cleaning unit 172 can be reduced. In one embodiment, the cleaning unit 172 may clean only the non-device surface 1 of the wafer W with the lower cleaning tool. In this case, since the upper cleaning tool can be omitted, the configuration of the cleaning unit 172 can be simplified, and the running cost of the cleaning unit 172 can be further reduced.

The fourth transfer robot 151 takes out the cleaned wafer W from the cleaning unit 172 and transfers it to the drying unit 173. The wafer W is dried by the drying unit 173 with its washed non-device surface 1 facing downward. In the present embodiment, the drying unit 173 is configured to spin-dry the wafer W by rotating the wafer W around its axis at high speed. In one embodiment, the drying unit 173, while moving the water nozzle and IPA nozzle in the radial direction of the wafer W, (a mixture of isopropyl alcohol and N ₂ gas) from the pure water nozzle and IPA nozzle pure water and the IPA vapor May be an IPA type that dries the wafer W by supplying the above surface to the upper surface of the wafer W.

The dried wafer W is returned to the wafer cassette of the load port 122 by the first transfer robot 123 with its non-device surface 1 facing downward. In this way, the substrate processing apparatus can perform a series of steps of polishing, cleaning, drying, and transferring the wafer W to the load / unload portion while the non-device surface 1 of the wafer W is facing downward. ..

According to this substrate processing apparatus, the entire non-device surface 1 of the wafer W can be efficiently polished while the non-device surface 1 of the wafer W is facing downward. As a result, it is not necessary to invert the wafer W, so that it is possible to prevent impurities in the air from adhering to the wafer W and reduce the overall processing time. Further, a reversing machine for reversing the wafer W is not required, the configuration of the substrate processing apparatus can be simplified, and the cost can be reduced. In one embodiment, the substrate processing apparatus may further include another polishing unit 127. When the substrate processing apparatus includes a plurality of polishing units 127, the number of processed sheets can be doubled and the throughput of the substrate processing apparatus can be improved.

The above-described embodiment is described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention belongs to carry out the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, 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, but is construed in the broadest range according to the technical idea defined by the claims.

The present invention can be used in a polishing device and a polishing method for polishing the back surface of a substrate such as a wafer. Furthermore, the present invention can be applied to a substrate processing apparatus provided with a polishing apparatus.

10 Board holding part 11 Roller 12 Roller rotation mechanism 27 Rinse liquid supply nozzle 28 Protective liquid supply nozzle 30 Non-contact cleaning mechanism 31 Polishing tape 32 Nozzle moving mechanism 33 Cleaning fluid nozzle 34 Nozzle arm 35 Nozzle swivel shaft 36 Motor (driving machine)
37 Cleaning fluid line 38 Flow regulator 40 Cleaning fluid supply device 41 Polishing tape supply mechanism 46 Tape feeding device 50 Polishing head 52 Pressurizing mechanism 53a, 53b, 53c, 53d, 53e, 53f, 53g Guide roller 55 Polishing blade 56 Polishing pad 57 Back plate 60 Translational rotary motion mechanism 85 Ozone generator 86 Electrolyzed water generator 127 Polishing unit (polishing device)
133 System controller 140 1st temporary stand 141 2nd temporary stand 150 3rd transfer robot 151 4th transfer robot 172 Cleaning unit 173 Drying unit 180 Operation control unit

Claims (16)

1. A substrate holding portion that holds the substrate with its device surface facing up and rotates the substrate,
   A polishing tool that comes into contact with the non-device surface of the substrate and polishes the non-device surface of the substrate.
   A polishing apparatus including a non-contact cleaning mechanism for cleaning the device surface of the substrate while polishing the non-device surface of the substrate with the polishing tool.
2. The non-contact cleaning mechanism
   A cleaning fluid nozzle that injects cleaning fluid toward the device surface of the substrate, and
   The polishing apparatus according to claim 1, further comprising a nozzle moving mechanism for moving the cleaning fluid nozzle above the device surface of the substrate.
3. The polishing apparatus according to claim 2, wherein the cleaning fluid nozzle is a two-fluid jet nozzle that injects a two-fluid jet toward a device surface of the substrate.
4. The non-contact cleaning mechanism further includes an ozone generator.
   The polishing apparatus according to claim 2, wherein the cleaning fluid nozzle injects ozone water or ozone microbubble water toward the device surface of the substrate.
5. The non-contact cleaning mechanism further includes an electrolyzed water generator.
   The polishing apparatus according to claim 2, wherein the cleaning fluid nozzle injects electrolyzed water toward the device surface of the substrate.
6. The polishing apparatus according to claim 2, wherein the cleaning fluid nozzle ejects megasonic water or a chemical solution toward the device surface of the substrate.
7. The polishing apparatus according to any one of claims 1 to 6, further comprising a protective liquid supply nozzle for supplying a protective liquid to the device surface of the substrate.
8. Hold the board with its device side facing up and rotate the board.
   A polishing tool is pressed against the non-device surface of the rotating substrate to polish the non-device surface.
   A polishing method comprising cleaning the device surface of the substrate with a non-contact cleaning mechanism while polishing the non-device surface of the substrate.
9. The device surface of the substrate is cleaned by injecting a cleaning fluid from the cleaning fluid nozzle onto the device surface of the substrate while moving the cleaning fluid nozzle above the device surface of the substrate. The polishing method according to claim 8.
10. The polishing method according to claim 9, wherein the cleaning fluid nozzle injects a two-fluid jet toward the device surface of the substrate.
11. The polishing method according to claim 9, wherein the cleaning fluid nozzle injects ozone water or ozone microbubble water toward the device surface of the substrate.
12. The polishing method according to claim 9, wherein the cleaning fluid nozzle injects electrolyzed water toward the device surface of the substrate.
13. The polishing method according to claim 9, wherein the cleaning fluid nozzle sprays megasonic water or a chemical solution toward the device surface of the substrate.
14. The polishing method according to any one of claims 8 to 13, wherein a protective liquid is further supplied to the device surface of the substrate while the non-device surface of the substrate is being polished.
15. The polishing apparatus according to any one of claims 1 to 7.
    A cleaning unit that cleans the substrate polished by the polishing device, and
    A substrate processing apparatus including a drying unit for drying a substrate cleaned by the cleaning unit.
16. The substrate processing apparatus according to claim 15, wherein the cleaning unit cleans only the non-device surface of the substrate.

Images