Patent Publication Number: US-10328546-B2

Title: Polishing cleaning mechanism, substrate processing apparatus, and substrate processing method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a Divisional Application of U.S. patent application Ser. No.: 14/533,133, filed Nov. 5, 2014, an application claiming benefit of Japanese Patent Application Nos. 2013-234788 and 2014-110836, filed on Nov. 13, 2013 and May 29, 2014, in the Japan Patent Office, the disclosure of which is incorporated herein in their entirety by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a polishing cleaning mechanism for polishing and cleaning, for example, a rear surface of a substrate, and a substrate processing apparatus and a substrate processing method provided with the polishing cleaning mechanism. 
     BACKGROUND 
     For example, in a photolithography process of a semiconductor device manufacturing method, a series of processes such as a resist application process for forming a resist film by applying a resist solution onto a wafer, an exposure process for exposing the resist film into a specified pattern, and a developing process for developing the exposed resist film is performed one after another to form a specified resist pattern on the wafer. The series of processes is performed by an application development system as a substrate processing system in which various kinds of processing units for processing the wafer and transfer units for transferring the wafer are installed. 
     In recent years, a circuit pattern formed on a wafer has been miniaturized and a defocus margin at the time of exposure has become more stringent. One of the causes for defocus includes, for example, adherence of particles to a stage of an exposure device. A major cause for generation of these particles is that the particles adhere to, particularly, a rear surface of a wafer transferred into the exposure device. For the above reason, prior to transferring the wafer into the exposure device, the rear surface of the wafer may be cleaned by a cleaning device installed within an application development system. 
     In the cleaning device, cleaning is performed by moving a brush pressed against the rear surface of the wafer while the rear surface of the wafer faces downward, for example, by attracting and holding the rear surface of the wafer. 
     In some cases, unevenness due to flaws and the like generated on the rear surface of the wafer may be a cause of defocus. Therefore, prior to transferring the wafer into the exposure device, the rear surface of the wafer may be polished by a polishing device as will be described below. 
     In the polishing device, polishing is performed by pressing a polishing pad against the wafer while supplying a polishing liquid to the wafer. The polishing pad is then retreated from above the wafer and a cleaning brush is moved onto the wafer. In order to remove polishing sludge or the like from the wafer, the wafer is cleaned by the cleaning brush while supplying a cleaning liquid. 
     Since the throughput in a photolithography process is typically dominated by the throughput of an exposure device, a throughput of the above described cleaning device and the like is required to be higher than that of the exposure device. However, the throughput of a typical cleaning device or a typical polishing device may be lower than that of the exposure device. Thus, for example, for one exposure device, a plurality of cleaning devices and the like may be installed within an application development system. 
     In addition, from the viewpoint of the running cost and the like of a clean room, the footprint of the application development system is required to be set as small as possible. Thus, a space for installation of a cleaning device or a polishing device may not be necessarily sufficient in the application development system. Thus, the polishing process or the cleaning process may be a bottleneck. 
     In this case, the polishing pad for the polishing process and the cleaning brush for the cleaning process may be installed within one device. In that case, however, controlling an arm for operating the polishing pad and an arm for operating the cleaning brush becomes complex. In addition, since drive devices for operating the arms are installed individually, the space required to install the drives devices becomes larger. Thus, space saving is not sufficient. 
     SUMMARY 
     The present disclosure provides a polishing cleaning mechanism, a substrate processing apparatus, and a substrate processing method for efficiently performing a polishing process and cleaning process on a wafer. 
     According to an aspect of the present disclosure, there is provided a polishing cleaning mechanism configured to be in contact with a rear surface of a substrate which is held in a substrate holding unit for holding the rear surface of the substrate and perform a polishing process and a cleaning process on the rear surface of the substrate, which includes: a polishing member configured to polish the rear surface of the substrate; a cleaning member configured to clean the rear surface of the substrate; and a support member configured to support the polishing member and the cleaning member to face the rear surface of the substrate held in the substrate holding unit, wherein a surface of the polishing member facing the substrate and a surface of the cleaning member facing the substrate differ in relative height from each other. 
     According to another aspect of the present disclosure, there is provided a polishing cleaning mechanism configured to be in contact with a rear surface of a substrate which is held in a substrate holding unit for holding the rear surface of the substrate and perform a polishing process and a cleaning process on the rear surface of the substrate, which includes: a polishing member including a polishing surface configured to polish the rear surface of the substrate; a cleaning member including a cleaning surface configured to clean the rear surface of the substrate; a first support member configured to support the polishing member and the cleaning member; and a relative movement mechanism configured to move each of the polishing surface of the polishing member and the cleaning surface of the cleaning member relative to the rear surface of the substrate held in the substrate holding unit by rotating the first support member. 
     According to still another aspect of the present disclosure, there is provided a substrate processing apparatus provided with the aforementioned polishing cleaning mechanism and configured to perform the polishing process and the cleaning process on the rear surface of the substrate held in the substrate holding unit for holding the rear surface of the substrate, which includes: a moving mechanism configured to relatively move the support member and the substrate held in the substrate holding unit; and a control unit configured to control the moving mechanism such that the relative height of the surface of the cleaning member facing the substrate and the surface of the polishing member facing the substrate is adjusted by relatively moving the support member and the substrate held in the substrate holding unit with the moving mechanism and pressing the cleaning member against the substrate to crush the cleaning member. 
     According to yet another aspect of the present disclosure, there is provided a substrate processing apparatus provided with the aforementioned polishing cleaning mechanism and configured to perform the polishing process and the cleaning process on the rear surface of the substrate held in the substrate holding unit for holding the rear surface of the substrate, which includes: a rotation drive mechanism configured to rotate the first support member about a vertical axis; a moving mechanism configured to relatively move the first support member and the substrate held in the substrate holding unit; and a control unit configured to execute a control operation such that while at least one of the cleaning member and the polishing member is pressed against the substrate by relatively moving the first support member and the substrate held in the substrate holding unit with the moving mechanism, the first support member is rotated by the rotation drive mechanism to move the polishing surface of the polishing member and the cleaning surface of the cleaning member relative to the rear surface of the substrate held in the substrate holding unit. 
     According to yet another aspect of the present disclosure, there is provided a substrate processing method for, using the aforementioned polishing cleaning mechanism, performing the polishing process and the cleaning process on the rear surface of the substrate held in the substrate holding unit for holding the rear surface of the substrate, which includes: performing the polishing process by bringing the polishing member into contact with the rear surface of the substrate while a height of a surface of the polishing member facing the substrate is made equal to or higher than a height of a surface of the cleaning member facing the substrate; and performing the cleaning process by bringing only the cleaning member into contact with the rear surface of the substrate while the height of the surface of the polishing member facing the substrate is made lower than the height of the surface of the cleaning member facing the substrate. 
     According to yet another aspect of the present disclosure, there is provided a substrate processing method for, using the aforementioned polishing cleaning mechanism, performing the polishing process and the cleaning process on the rear surface of the substrate held in the substrate holding unit for holding the rear surface of the substrate, which includes: performing one of the cleaning process and the polishing process by rotating the first support member in a specified direction while at least one of the polishing surface of the polishing member and the cleaning surface of the cleaning member is in contact with the rear surface of the substrate and by moving the polishing surface of the polishing member and the cleaning surface of the cleaning member relative to the rear surface of the substrate held in the substrate holding unit; and switching the polishing process and the cleaning process by rotating the first support member in a direction opposite to the specified direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure. 
         FIG. 1  schematically illustrates a configuration of a substrate processing apparatus in a horizontal sectional view, according to one embodiment of the present disclosure. 
         FIG. 2  schematically illustrates the configuration of the substrate processing apparatus in a vertical sectional view, according to one embodiment of the present embodiment. 
         FIG. 3  schematically illustrates a configuration of a polishing cleaning mechanism in a perspective view. 
         FIG. 4  schematically illustrates the configuration of the polishing cleaning mechanism is in a vertical sectional view. 
         FIG. 5  illustrates that the polishing cleaning mechanism is pressed against a wafer. 
         FIG. 6  illustrates delivery of the wafer to the substrate processing apparatus. 
         FIG. 7  illustrates that the wafer has been delivered to the substrate processing apparatus. 
         FIG. 8  illustrates that the polishing cleaning mechanism is brought into contact with the water. 
         FIG. 9  schematically illustrates a relative positional relationship between the water and the polishing cleaning mechanism during a polishing process and a cleaning process. 
         FIG. 10  illustrates that only a cleaning member is brought into contact with the wafer. 
         FIG. 11  schematically illustrates a relative positional relationship between the wafer and the polishing cleaning mechanism during the polishing process and the cleaning process. 
         FIG. 12  illustrates that the wafer has been delivered to a spin chuck. 
         FIG. 13  schematically illustrates a relative positional relationship between the wafer and the polishing cleaning mechanism during the polishing process and the cleaning process. 
         FIG. 14  schematically illustrates a configuration of a polishing cleaning mechanism in a perspective view, according to another embodiment of the present disclosure. 
         FIG. 15  schematically illustrates a configuration of a polishing cleaning mechanism in a perspective view, according to another embodiment of the present disclosure. 
         FIG. 16  schematically illustrates a configuration of a polishing cleaning mechanism in a perspective view, according to another embodiment of the present disclosure. 
         FIG. 17  schematically illustrates a configuration of a polishing cleaning mechanism in a perspective view, according to another embodiment of the present disclosure. 
         FIG. 18  schematically illustrates a configuration of a polishing cleaning mechanism in a perspective view, according to another embodiment of the present disclosure. 
         FIG. 19  schematically illustrates the configuration of the polishing cleaning mechanism in a plane view, according to the embodiment of the present disclosure. 
         FIG. 20  schematically illustrates a configuration of a polishing cleaning mechanism in a vertical sectional view, according to another embodiment of the present disclosure. 
         FIG. 21  schematically illustrates the configuration of the polishing cleaning mechanism in a vertical sectional view, according to the embodiment of the present disclosure. 
         FIG. 22  schematically illustrates a configuration of a polishing cleaning mechanism in a perspective view, according to another embodiment of the present disclosure. 
         FIG. 23  schematically illustrates a configuration of a support member in a perspective view, according to the embodiment of the present disclosure. 
         FIG. 24  schematically illustrates a configuration of a cleaning member in a perspective view, according to the embodiment of the present disclosure. 
         FIG. 25  schematically illustrates a configuration of a polishing member according to another embodiment. 
         FIGS. 26A and 26B  illustrate movement of the cleaning member. 
         FIGS. 27A and 27B  illustrate movement of the polishing member. 
         FIG. 28  schematically illustrates a configuration of a cam mechanism, according to another embodiment of the present disclosure. 
         FIG. 29  schematically illustrates a configuration of a polishing cleaning mechanism in a perspective view, according to another embodiment of the present disclosure. 
         FIG. 30  illustrates that a polishing surface or a cleaning surface is brought into contact with a wafer. 
         FIG. 31  illustrates that the polishing surface has been brought into contact with the wafer. 
         FIG. 32  illustrates that the cleaning surface has been brought into contact with the wafer. 
         FIG. 33  schematically illustrates a configuration of a polishing cleaning mechanism in a perspective view, according to another embodiment of the present disclosure. 
         FIG. 34  schematically illustrates a configuration of a substrate processing apparatus in a horizontal sectional view, according to another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, systems, and components have not been described in detail so as not to unnecessarily obscure aspects of the various embodiments. 
       FIG. 1  schematically illustrates a configuration of a substrate processing apparatus  1  in a horizontal sectional view  FIG. 2  schematically illustrates the configuration of the substrate processing apparatus  1  in a vertical sectional view. 
     The substrate processing apparatus  1  includes two attraction pads  10  configured to horizontally attract and hold a rear surface of a wafer W, a spin chuck  11  configured to horizontally attract and hold the rear surface of the wafer W received from the attraction pads  10 , a polishing cleaning mechanism  12  configured to perform a polishing process and a cleaning process on the rear surface of the wafer W, and a housing  13  with an upper surface opened. 
     As shown in  FIG. 1 , the two attraction pads  10  are formed in an elongated substantially-rectangular shape and are installed to be parallel to each other with the spin chuck  11  interposed therebetween, in a top view, such that the attraction pads  10  can hold peripheral edge portions of the rear surface of the wafer W. The attraction pads  10  are supported by substantially rectangular support plates  14 , respectively, which are longer than the attraction pads  10 . A frame  15 , which can be moved in a horizontal direction (i.e., a Y-axis direction in  FIG. 1 ) and a vertical direction (i.e., a Z-axis direction perpendicular to the drawing sheet surface of  FIG. 1 ) by a drive mechanism (not shown), is configured to support opposite ends of the support plates  14 . 
     An upper cup  16  is installed on an upper surface of the frame  15 . An opening portion  16   a  having a diameter larger than a diameter of the wafer W is formed on an upper surface of the upper cup  16 . Through the opening portion  16   a , the wafer W is conveyed between a transfer mechanism installed outside the substrate processing apparatus  1  and the attraction pads  10 . 
     As shown in  FIG. 2 , the spin chuck  11  is connected to a drive mechanism  21  via a shaft  20  and can be rotated and vertically moved by the drive mechanism  21 . For example, by adjusting a vertical position of the spin chuck  11 , it is possible to regulate a pressure exerted when the polishing cleaning mechanism  12  makes contact with the wafer W. 
     For example, three lifter pins  22  which can be moved up and down by an elevator mechanism (not shown) are installed around the spin chuck  11 . Thus, the wafer W can be conveyed between the lifter pins  22  and the transfer mechanism (not shown) installed outside the substrate processing apparatus  1 . 
     In the substrate processing apparatus  1 , a cleaning nozzle  30  configured to supply a cleaning liquid to a front surface of the wafer W held by the spin chuck  11  and a gas nozzle  31  configured to spray a drying gas to the front surface of the wafer W are installed above the wafer W. For example, pure water is used as the cleaning liquid. For example, a nitrogen gas or clean air is used as the drying gas. A common nozzle arm  32  supports the cleaning nozzle  30  and the gas nozzle  31 . A drive mechanism  33  configured to move the nozzle arm  32  in the vertical direction (i.e., the Z-axis direction perpendicular to the drawing sheet surface in  FIG. 1 ) is connected to the nozzle arm  32 . The drive mechanism  33  is connected to the housing  13  and can be horizontally moved in the Y-axis direction along the housing  13 . 
     In a bottom portion of the housing  13 , there are installed a drain pipe  40  for draining the cleaning liquid and an exhaust pipe  41  for forming a downward airflow within the substrate processing apparatus  1  and exhausting the airflow. 
     As shown in  FIGS. 1 and 2 , an ultraviolet lamp  43  disposed within an accommodation box  42  having an open upper surface is installed, for example, in a sidewall of the housing  13  and, for example, in a route through which the transfer mechanism (not shown) installed outside the substrate processing apparatus  1  passes when moving onto the opening portion  16   a  of the upper cup  16 . Thus, the ultraviolet lamp  43  can irradiate the rear surface of the wafer W with ultraviolet rays when the wafer W is transferred into and out of the substrate processing apparatus  1  by the transfer mechanism (not shown). For example, even if particles originating from a polymer remain on the rear surface of the cleaned wafer W, the particles are shrunken and removed by the ultraviolet rays. 
     Next, description will be made on the polishing cleaning mechanism  12  that performs a polishing process and a cleaning process for the rear surface of the wafer W. For example, as shown in  FIGS. 3 and 4 , the polishing cleaning mechanism  12  includes a polishing member  50  having polishing surfaces  50   a  made of, for example, foamed urethane, non-woven fabric, or the like, a plurality of cleaning members  51  made of an flexible material, for example, polyvinyl alcohol, polypropylene, nylon, or the like, and a support member  52  configured to support the polishing member  50  and the cleaning members  51 . Each of the polishing surfaces  50   a  of the polishing member  50  is configured, for example, by bonding a sheet formed of foamed urethane or non-woven fabric to an upper surface of a substantially ring-shaped member  50   b , which has a diameter smaller than a diameter of the wafer W, for example, equal to about one fourth of the diameter of the wafer W. As an example of the shape of the polishing member  50 .  FIG. 3  illustrates that eight arc-shaped polishing surfaces  50   a  having a specified width are concentrically arranged at a predetermined interval. 
     The cleaning members  51  are formed for example, in a fan shape, and are disposed inside the annular polishing member  50  to be concentric with the polishing member  50 .  FIG. 3  illustrates an example where four fan-shaped cleaning members  51  are disposed inside the polishing member  50 . 
     Surfaces of the polishing member  50  and the cleaning members  51 , which are opposite to the support member  52 , include, respectively, the polishing surfaces  50   a  and cleaning surfaces  51   a  installed to face the wafer W. For example, as shown in  FIG. 4 , the cleaning surfaces  51   a  of the cleaning members  51  may be formed to protrude upward beyond the polishing surfaces  50   a  of the polishing member  50 . Therefore, when the polishing cleaning mechanism  12  is vertically moved, for example, by using a moving mechanism  61 , which will be described below, such that a distance between the polishing cleaning mechanism  12  and the rear surface of the wafer W is shortened gradually, the cleaning members  51  initially make contact with the rear surface of the wafer W. The cleaning members  51  are made of a flexible material. Thus, when the polishing cleaning mechanism  12  is pressed further against the wafer W by the moving mechanism  61  after the cleaning members  51  make contact with the wafer W, the cleaning members  51  are crushed as shown in  FIG. 5  and the polishing member  50  comes into contact with the rear surface of the wafer W and can polish the wafer W. 
     A shaft  53  is installed on a surface of the support member  52 , which is opposite to the other surface supporting the polishing member  50  and the cleaning members  51 . A belt  55  connected to a motor  54  is installed in a lower end portion of the shaft  53 . Driving the belt  55  with the motor  54  can rotate, via the shaft  53 , the support member  52 , and ultimately, the polishing surfaces  50   a  of the polishing member  50  and the cleaning surfaces  51   a  of the cleaning members  51 . Thus, a polishing process and a cleaning process can be performed on the rear surface of the wafer W by rotating the support member  52  in a state in which the polishing surfaces  50   a  of the polishing member  50  and the cleaning surfaces  51   a  of the cleaning members  51  are in contact with the rear surface of the wafer W. 
     The moving mechanism  61  is connected to the polishing cleaning mechanism  12  via a support body  60 . The moving mechanism  61  is connected to the housing  13  and can be horizontally moved, for example, in the X-axis direction in  FIG. 1 , along the housing  13 . Moving the moving mechanism  61  in the X-axis direction can move the polishing cleaning mechanism  12  in the X-axis direction in  FIG. 1 . 
     Installed at an end portion of the support body  60  are a cleaning liquid nozzle  60   a , which supplies a cleaning liquid for washing away the particles removed by the cleaning members  51  and the polishing sludge generated when the polishing process is performed by the polishing member  50 , and a purge nozzle  60   b , which supplies a gas, for example, a nitrogen gas, for drying the cleaning liquid adhering to the rear surface of the cleaned wafer W. Pure water in which a carbon dioxide gas is dissolved may be used as the cleaning liquid supplied from the cleaning liquid nozzle  60   a.    
     As shown in  FIG. 1 , a control unit  200  is installed in the substrate processing apparatus  1  described above. The control unit  200  is, for example, a computer, and is provided with a program storage unit (not shown). A program for controlling the processing of the wafer W performed in the substrate processing apparatus  1  is stored in the program storage unit. Also stored in the program storage unit is a program for implementing the polishing process and the cleaning process in the substrate processing apparatus  1  by controlling the operation of a drive system such as various kinds of drive devices and moving devices described above and various kinds of nozzles. The aforementioned programs may be recorded in a computer-readable storage medium H such as a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magneto-optical disk (MO), a memory card, and the like, and may be installed in the control unit  200  from the storage medium H. 
     The substrate processing apparatus  1  according to the present embodiment is configured as described above. Next, description will be made on the polishing process and the cleaning process of the wafer W which are performed in the substrate processing apparatus  1 . In this embodiment, description will be made on an example where the wafer W is first subjected to the polishing process and then to the cleaning process. 
     When the wafer W is processed, the wafer W is transferred above the upper cup  16  by a transfer mechanism  90  installed outside the substrate processing apparatus  1 , as shown in  FIG. 6 . The lifter pins  22  are then moved upward and the wafer W is delivered to the lifter pins  22 . In this case, the attraction pads  10  wait at a position where the upper surfaces of the attraction pads  10  are higher than the upper surface of the polishing cleaning mechanism  12 . The spin chuck  11  retreats to a position lower than the upper surface of the polishing cleaning mechanism  12 . Thereafter, the lifter pins  22  move downward. As shown in  FIG. 7 , the wafer W is delivered to the attraction pads  10 , which in turn attract and hold the wafer W. 
     Next, as shown in  FIG. 8 , the attraction pads  10  move downward to bring the polishing cleaning mechanism  12  into contact with an outer peripheral portion of the rear surface of the wafer W. In this case, the cleaning members  51  of the polishing cleaning mechanism  12  initially make contact with the rear surface of the wafer W. When the attraction pads  10  continue to move downward after the wafer W and the cleaning members  51  make contact with each other, the cleaning members  51  are crushed. Thus, as shown in  FIG. 5 , the polishing member  50  comes into contact with the outer peripheral portion of the rear surface of the wafer W. In one embodiment, instead of moving the attraction pads  10  downward, the polishing cleaning mechanism  12  may be moved upward by the moving mechanism  61  such that the polishing cleaning mechanism  12  is pressed against the wafer W. Also, it may be possible to move both the attraction pads  10  and the moving mechanism  61 . A load for pressing the polishing cleaning mechanism  12  may be determined by a test conducted in advance. For example, a load measuring instrument for measuring the load may be installed between the support member  52  and the cleaning members  51 . The load may be adjusted based on the measurement result of the load measuring instrument. 
     Next, the cleaning liquid is supplied from the cleaning liquid nozzle  60   a  and the support member  52  of the polishing cleaning mechanism  12  is rotated. Subsequently, for example, as shown in  FIG. 9 , the polishing cleaning mechanism  12  reciprocates in the X-axis direction while the attraction pads  10  and the wafer W are moved toward the negative side of the Y-axis direction. As such, a region A in the rear surface of the wafer W between the attraction pads  10  is polished. In this process, the cleaning liquid is also supplied from the cleaning nozzle  30  to clean the front surface of the wafer W concurrently. The origin O shown in  FIG. 9  indicates a position when the moving mechanism  61  is moved toward a center of the wafer W over the frame  15 . In  FIGS. 9 and 11 , the origins O are illustrated to show a relative positional relationship between the polishing cleaning mechanism  12  and the wafer W. 
     Next, as shown in  FIG. 10 , the polishing cleaning mechanism  12  is slightly moved away from the rear surface of the wafer W so that only the cleaning members  51  make contact with the rear surface of the wafer W. In this case, only the attraction pads  10  may be moved up and down, only the moving mechanism  61  may be moved up and down, or both the attraction pads  10  and the moving mechanism  61  may be moved up and down. Subsequently, as shown in  FIG. 11 , while the polishing cleaning mechanism  12  reciprocates in the X-axis direction, the wafer W is moved toward the positive side of the Y-axis direction to clean the rear surface of the wafer W. Thus, the region A in the rear surface of the wafer W between the attraction pads  10 , which is illustrated in  FIG. 9 , is cleaned. Accordingly, the region A can be polished and cleaned while the wafer W reciprocates along the Y-axis direction. 
     Next, a central portion of the rear surface of the wafer W is cleaned by supplying the cleaning liquid from the cleaning liquid nozzle  60   a  and rotating the support member  52 . In this case, the support body  60  reciprocates in the X-axis direction in  FIG. 1  and the frame  15  reciprocates in the Y-axis direction. Thus, the central portion of the rear surface of the wafer W may be evenly cleaned. In this process, electric charges of the wafer W that are charged by electrostatic induction may be removed by using pure water in which a carbon dioxide gas is dissolved as the cleaning liquid supplied from the cleaning liquid nozzle  60   a . As a result, the particles having adhered to the rear surface of the wafer W, for example, by a Coulomb&#39;s force may be easily washed away. In addition, although the particles themselves are electrically charged, electric charges of the particles can be removed, and thus, the rear surface of the wafer W may be efficiently cleaned. In this case, the cleaning liquid nozzle  60   a  serves as an electric charge removal mechanism for removing electric charges of the wafer W. The method of removing electric charges of the wafer W is not limited to the present embodiment. As an alternative example, the purge nozzle  60   b  may be used as an ionizer for supplying ionized air. 
     Upon finishing the polishing process and the cleaning process on the region A in the rear surface of the wafer W, the frame  15  moves horizontally, as illustrated in  FIG. 12 , such that the center of the wafer W and the center of the spin chuck  11  coincide with each other when seen in a top view. Subsequently, the spin chuck  11  is moved upward and the wafer W is delivered from the attraction pads  10  to the spin chuck  11 . As shown in  FIG. 13 , the wafer W is then moved toward the negative side of the Y-axis direction so that the polishing cleaning mechanism  12  can make contact with the outer peripheral portion of the wafer W. Then, the distance between the wafer W and the polishing cleaning mechanism  12  is shortened to bring the polishing member  50  and the cleaning members  51  into contact with the wafer W. 
     Subsequently, the wafer W is rotated by the spin chuck  11  in such a state that the polishing member  50  and the cleaning members  51  are pressed against the rear surface of the wafer W. The polishing cleaning mechanism  12  is slidingly moved in the X-axis direction by the moving mechanism  61 . As such, the outer peripheral portion of the rear surface of the wafer W is polished. Thereafter, the polishing cleaning mechanism  12  is slightly moved away from the rear surface of the wafer W such that only the cleaning members  51  make contact with the rear surface of the wafer W. The water W is then rotated to clean the outer peripheral portion of the rear surface of the wafer W. 
     Upon finishing the cleaning process of the rear surface of the wafer W, the rotation of the polishing cleaning mechanism  12  and the supply of the cleaning liquid are stopped. The spin chuck  11  is rotated at a high speed to thereby centrifugally remove and dry the cleaning liquid adhering to the rear surface of the wafer W. In this process, the purge using the gas nozzle  31  and the purge nozzle  60   b  is performed concurrently. 
     If the drying process of the wafer W is finished, the wafer W is delivered to the transfer mechanism  90  in an order opposite to the order in which the wafer W is transferred into the substrate processing apparatus  1 . As such, the polishing process and the cleaning process on the wafer W are finished. 
     According to the above described embodiment, the cleaning members  51  are made of a flexible material. By pressing the polishing cleaning mechanism  12  against the wafer W, it is possible to adjust a relative height of the polishing surfaces  50   a  of the polishing member  50  and the cleaning surfaces  51   a  of the cleaning members  51  supported on the support member  52 . Accordingly, the polishing process can be performed by bringing the polishing member  50  into contact with the wafer W. Subsequently, only the cleaning members  51  can keep contact with the rear surface of the wafer W by adjusting the position of the polishing cleaning mechanism  12  such that the cleaning members  51  are positioned higher than the polishing member  50 . In this manner, the polishing process and the cleaning process can be performed within the substrate processing apparatus  1 . 
     Since the polishing member  50  and the cleaning members  51  are installed in one support body  60 , it is possible to minimize the moving mechanism  61  for moving the support body  60 , which may reduce a size of the substrate processing apparatus  1 . Furthermore, there is no need to install the support body  60  individually for polishing member  50  and the cleaning members  51 . Therefore, the control for moving the polishing member  50  and the cleaning members  51  may not be complicated. 
     In the above described embodiment, the cleaning members  51  are disposed inside the substantially ring-shaped polishing member  50 . However, the shape and arrangement of the polishing member  50  and the cleaning members  51  are not limited to the above embodiment. For example, as illustrated in  FIG. 14 , the diameter of the support member  52  may be increased and an additional cleaning member  70  may be installed outside the polishing member  50 . Moreover, as depicted in  FIG. 15 , an annular cleaning member  70  may be installed only outside the polishing member  50 . As shown in  FIG. 16 , an annular cleaning member  71  may be installed only inside the polishing member  50 . Further, the polishing member  50  and the cleaning members  51 ,  70 , and  71  need not be necessarily installed concentrically. 
     In addition, the cleaning surfaces of the cleaning members  51 ,  70 , and  71  need not be necessarily flat. For example, as illustrated with a cleaning member  72  in  FIG. 17 , the cleaning surfaces of the cleaning members  51 ,  70 , and  71  may be formed in an uneven shape of a specified pattern as long as the cleaning members  51 ,  70 , and  71  can be crushed by pressing the polishing cleaning mechanism  12  against the wafer W. In such a case, the cleaning surface of the cleaning member  70  or the cleaning member  72  is installed to protrude upward beyond the polishing surfaces of the polishing member  50 . The inventors of the present disclosure found that as the pressing load increases when the polishing cleaning mechanism  12  is pressed against the wafer W to crush the cleaning member, the wafer W is bent to hinder maintaining a proper contact between the cleaning member and the wafer W. As such, if an area of the cleaning surfaces of the cleaning members is increased to enhance efficiency of cleaning, a load for crushing the cleaning member is also increased in proportion thereto, which may result in reducing the efficiency of cleaning. Therefore, a surface area of the cleaning surface of the cleaning member may need to be properly set in view of the load for pressing the polishing cleaning mechanism  12  against the wafer W. The shape of the cleaning member may be, for example, an annular shape as illustrated with the cleaning members  70  and  71  in  FIGS. 15 and 16 , or an uneven shape as illustrated with the cleaning member  72  in  FIG. 17 . Further, the shape of the cleaning member may be configured to reduce the crushing load as the contact area between the cleaning surface and the wafer W is reduced. 
     Particularly, since the polishing cleaning mechanism  12  is moved relative to the wafer W in the polishing process and the cleaning process of the wafer W, if the shape of the cleaning member is an annular shape as illustrated with the cleaning members  70  and  71 , the extent for cleaning may reach to the outer diameter of the cleaning member  70  or  71 . In addition, if the width, i.e., the difference between the inner diameter and the outer diameter, of the cleaning member  70  or  71  is decreased, it is possible to reduce the area of the cleaning surface which governs the area making contact with the wafer W, while maintaining the extent for cleaning. Accordingly, the shape of the cleaning members may have an annular cleaning surface as illustrated with the cleaning members  70  and  71 . 
     In the above described embodiment, the polishing surfaces  50   a  of the polishing member  50  are formed, for example, in a circular arc shape having a specified width. The shape of the polishing surfaces  50   a  may have no corner in their outer circumference in a toy view.  FIGS. 18 and 19  illustrate an example of a perspective view and a plane view of the polishing cleaning mechanism  12  that has polishing surfaces  50   c  in an exemplary shape. The inventors of the present disclosure discovered that if corners exist in outer circumferences of the polishing surfaces  50   a , the corners of the polishing surfaces  50   a  may make contact with the water W and may scratch the water W. Thus, if the polishing surfaces  50   c  each having an outer circumference shape defined by a curve with no corner as shown in  FIGS. 18 and 19  are formed, for example, by round-chamfering the corners of the polishing surfaces  50   a  shown in  FIG. 3 , the generation of scratches on the wafer W can be suppressed when the polishing surfaces  50   c  are in contact with the wafer W. 
     When the load for pressing the polishing cleaning mechanism  12  against the wafer W is constant, the surface pressure that is applied when the polishing surfaces make contact with the wafer W increases as the contact area between the polishing surfaces and the wafer W decreases. In this case, the polishing power is increased. Therefore, the arc-shaped polishing surfaces  50   c  which are divided into eight sections in  FIG. 19  may be divided into, for example, sixteen sections or thirty two sections, to reduce the total sum of the surface areas of the polishing surfaces  50   c.    
     In the above described embodiment, the descriptions have been made by taking, as an example, a case where the polishing member  50  is brought into contact with the wafer W by pressing the polishing cleaning mechanism  12  against the wafer W. However, the method of changing the relative height of the polishing surfaces  50   a  of the polishing member  50  and the cleaning surfaces  51   a  of the cleaning members  51  is not limited to the present embodiment. For example, as illustrated in  FIG. 20 , a polishing cleaning mechanism  82  may be configured to be equipped with an elevator mechanism  81  between a support member  80  and the cleaning member  51  such that the cleaning member  51  is moved up and down by the elevator mechanism  81 .  FIG. 20  illustrates an example where the support member  80  is formed in a cylindrical shape with an upper opening, and the elevator mechanism  81  formed of, for example, a spring and a support plate, is installed to close the opening of the support member  80 . Further,  FIG. 20  illustrate a state in which the cleaning member  51  is positioned lower than the polishing member  50  and the polishing process is performed by the polishing cleaning mechanism  82 . 
     As illustrated in  FIG. 21 , for example, when compressed air is supplied into a space surrounded by the support member  80  and the elevator mechanism  81  so that the elevator mechanism  81  is moved upward, the cleaning member  51  protrudes upward beyond the polishing surface  50   a  of the polishing member  50 . As such, the polishing cleaning mechanism  82  comes into a state in which the polishing cleaning mechanism  82  can perform the cleaning process. In this case, the polishing process and the cleaning process may be performed efficiently within the substrate processing apparatus  1 , like the case where the cleaning member  51  is crushed. 
     In  FIGS. 20 and 21 , the elevator mechanism  81  is moved upward by supplying compressed air. Alternatively, the spring constituting the elevator mechanism  81  may be configured to push up the cleaning member  51  to protrude upward beyond the polishing surface  50   a  of the polishing member  50  in a normal state. The spring may be compressed by evacuating the inside of the space surrounded by the support member  80  and the elevator mechanism  81 . Alternatively, by disposing the polishing member  50  above the elevator mechanism  81  and the cleaning member  51  on the upper surface of the support member  80 , the polishing member  50  may be moved up and down. 
     As another method of changing the relative height of the polishing surfaces  50   a  of the polishing member  50  and the cleaning surfaces  51   a  of the cleaning members  51 , for example, a cam mechanism for converting rotating movement to reciprocating movement may be installed in the support member  52  that supports the polishing member  50  and the cleaning members  51 . In this case, the contact state of the polishing member  50  and the cleaning members  51  with the wafer W may be changed by rotating the polishing cleaning mechanism. 
       FIG. 22  illustrates an example of a polishing cleaning mechanism  100 , which is provided with a cam mechanism, according to another embodiment. The polishing cleaning mechanism  100  includes a cleaning member  101  having an opening formed in a central portion of the cleaning member  101  and a polishing member  102  installed within the opening of the cleaning member  101 . As illustrated in  FIG. 23 , in the polishing cleaning mechanism  100 , for example, first lower slant members  103  and second lower slant members  104 , each of which has a slope extending along a circumferential direction of the support member  52  at a predetermined angle, are concentrically formed at a predetermined pitch in an outer peripheral portion and a central portion of an upper surface of the support member  52 . The first lower slant members  103  and the second lower slant members  104  have slopes extending in opposite directions to each other.  FIG. 23  illustrates an example where the first lower slant members  103  and the second lower slant members  104  are installed such that, for example, when the support member  52  is rotated clockwise, vertical positions of upper surfaces of the first lower slant members  103  installed in the outer peripheral portion is configured to get gradually higher and the vertical positions of upper surfaces of the second lower slant members  104  installed in the central portion is configured to get gradually lower. For example, a locking portion  103   a  is formed on a top portion at the slope of each of the first lower slant members  103  to extend vertically upward by a predetermined height, and a locking portion  104   a  is formed on a top portion at the slope of each of the second lower slant portions  104  to extend vertically upward by a predetermined height. 
     As illustrated in  FIG. 24 , for example, a lower surface of the cleaning member  101  is supported by a first rotating member  110  of a substantial disc shape which is substantially identical to the shape of the cleaning member  101  in a top view. A diameter of the first rotating member  110  is substantially equal to that of the support member  52 . A cylindrical partition plate  111  extending vertically downward is installed on an outer side surface of the first rotating member  110 . An inner diameter of the partition plate  111  is slightly larger than the diameter of the support member  52  such that the support member  52  can be accommodated in the partition plate  111 . 
     A plurality of first upper slant members  112 , each of which has a slope extending in a circumferential direction of the first rotating member  110  at a predetermined angle, is formed in an outer peripheral portion of a rear surface of the first rotating member  110 , i.e., a surface of the first rotating member  110  opposite to the cleaning member  101 . The first upper slant members  112  are formed, respectively, substantially on the same circumference as the first lower slant members  103  installed in the outer peripheral portion of the support member  52  and are disposed at the same pitch as the first lower slant members  103 . Lower surfaces of the slopes of the first upper slant members  112  are set to be substantially parallel to the slopes of the facing first lower slant members  103 . In other words, the slant surfaces of the first upper slant members  112  are formed to have the same angle as that of the slant surfaces of the first lower slant members  103  in a case where, for example, the first lower slant members  103  are rotated 180 degrees about a horizontal axis. For example, a locking portion  112   a  is formed on a top portion at the slope of each of the first upper slant members  112  to extend vertically downward by a predetermined height such that the locking portions  112   a  engage with the locking portions  103   a  of the first lower slant members  103 , respectively. 
     As illustrated in  FIG. 25 , for example, a lower surface of the polishing member  102  is supported by a second rotating member  120  having a substantially disc-shape which is substantially identical to the shape of the polishing member  102  in a top view. A diameter of the second rotating member  120  is smaller than that of the central opening of the cleaning member  101 . 
     A plurality of second upper slant members  121 , each of which has a slope extending in the circumferential direction of the second rotating member  120  at a predetermined angle, is formed in an outer peripheral portion of a rear surface of the second rotating member  120 , i.e., a surface of the second rotating member  120  opposite to the polishing member  102 . The second upper slant members  121  are formed, respectively, substantially on the same circumference as the second lower slant members  104  installed in the central portion of the support member  52  and are disposed at the same pitch as the second lower slant members  104 . Lower surfaces of the slopes of the second upper slant members  121  are set to be substantially parallel to the slopes of the facing second lower slant members  104 . In other words, the slant surfaces of the second upper slant members  121  are formed to have the same angle as that of the slant surfaces of the second lower slant members  104  in a case where, for example, the second lower slant members  104  are rotated 180 degrees about a horizontal axis. For example, a locking portion  121   a  is formed on a top portion of each of the slopes of the second upper slant members  121  to extend vertically downward by a predetermined height such that the locking portions  121   a  engage with the locking portions  104   a  of the second lower slant members  104 . A friction coefficient between each of the lower slant members  103  and  104  and each of the upper slant members  112  and  121  is set to be smaller than a friction coefficient between the cleaning member  101  and the rear surface of the wafer W and a friction coefficient between the polishing member  102  and the rear surface of the wafer W. In other words, each of the lower slant members  103  and  104  and each of the upper slant members  112  and  121  are formed of a member having a friction coefficient smaller than the friction coefficient between the cleaning member  101  and the rear surface of the wafer W and the friction coefficient between the polishing member  102  and the rear surface of the wafer W. The cam mechanism of the polishing cleaning mechanism  100  is configured by the support member  52  provided with the lower slant members  103  and  104 , the first rotating member  110  provided with the first upper slant members  112 , and the second rotating member  120  provided with the second upper slant members  121 . 
     A cylindrical partition plate  122  extending vertically downward is installed on an outer side surface of the second rotating member  120 . An outer diameter of the partition plate  122  is smaller than a diameter of the opening formed in the central portion of the cleaning member  101  and is set such that the partition plate  122  surrounds the second upper slant members  121 . 
     The polishing cleaning mechanism  100  in this embodiment provided with the cam mechanism is configured as above. Next, descriptions will be made on the operation of the polishing cleaning mechanism  100 . As shown in  FIGS. 26A and 27A , for example, the motor  54  is stopped and the polishing cleaning mechanism  100  is not rotated. In this state, the polishing cleaning mechanism  100  is rotated by, e.g., the motor  54 , clockwise in a top view (i.e., in the direction indicated by arrows in  FIGS. 26A and 27A ) with the cleaning member  101  and the polishing member  102  pressed against the rear surface of the wafer W. As described above, the friction coefficient between the first lower slant members  103  and the first upper slant members  112  is set to be smaller than the friction coefficient between the cleaning member  101  and the rear surface of the wafer W and the friction coefficient between the polishing member  102  and the rear surface of the wafer W. Therefore, as shown in  FIG. 26B , the first upper slant members  112  slide along the upper surfaces of the first lower slant members  103  and move obliquely upward along the slopes of the first lower slant members  103  until the locking portions  103   a  and  112   a  engage with each other. On the other hand, the second lower slant members  104  and the second upper slant members  121  have the slant surfaces inclined in the opposite direction to the slant surfaces of the first upper slant members  112  and the first lower slant members  103 . Thus, the second lower slant members  104  and the second upper slant members  121  are not changed from the state shown in  FIG. 274 . The second lower slant members  104  and the second upper slant members  121  are paused relative to each other when the polishing cleaning mechanism  100  is rotated clockwise. Therefore, if the polishing cleaning mechanism  100  is rotated clockwise when seen in a top view, the cleaning member  101  is moved upward with respect to the support member  52  but the polishing member  102  is not moved with respect to the support member  52 . As such, the cleaning member  101  is moved upward relative to the polishing member  102 . Thus, by rotating the polishing cleaning mechanism  100  clockwise, it is possible to bring only the cleaning member  101  of the polishing cleaning mechanism  100  into contact with the rear surface of the wafer W, thereby performing a cleaning process. 
     On the other hand, if the polishing cleaning mechanism  100  is rotated counterclockwise when in a top view, the first upper slant members  112  are paused relative to the first lower slant members  103  and are not changed from the state shown in  FIG. 26A . As shown in  FIG. 27B , the second upper slant members  121  move obliquely upward along the slopes of the second lower slant members  104  until the locking portions  104   a  and  121   a  engage with each other. In this case, the polishing member  102  is moved upward with respect to the support member  52  but the cleaning member  101  is not moved with respect to the support member  52 . Therefore, the polishing member  102  is moved upward relative to the cleaning member  101 . Thus, by rotating the polishing cleaning mechanism  100  counterclockwise, it is possible to bring only the polishing member  102  of the polishing cleaning mechanism  100  into contact with the rear surface of the wafer W, thereby performing a polishing process. 
     In the above described embodiment, the slant members  103 ,  104 ,  112 , and  121  are installed in the support member  52 , the first rotating member  110 , and the second rotating member  120 . However, the configuration of the cam mechanism is not limited to this embodiment. In order to provide the function as the cam mechanism, for example, the slant surface may be formed in one of the support member  52  and the first rotating member  110  as shown in  FIG. 28 , as long as the locking portions are formed in both of the support member  52  and the first rotating member  110 .  FIG. 28  illustrates that the first upper slant member  112  is installed at the first rotating member  110  and only the locking portion  103   a  is installed in the support member  52 . Alternatively, the slant member may be formed only at the support member  52 . Although the slant members are illustrated to be formed on the entire surfaces of the support member  52  and the rotating members  110  and  120 , the function as the cam mechanism is secured if a slant member is formed in at least one location. Therefore, the number and arrangement of the slant members can be set in a suitable manner. 
     In the embodiment described above, the state of contact of the polishing surfaces and the cleaning surfaces with the rear surface of the wafer W is changed by changing the relative height of the polishing surface of the polishing member  102 , the cleaning surface of the cleaning member  101 , and the rear surface of the wafer W through the use of the cam mechanism. However, the method of changing the state of contact of the polishing surface and the cleaning surface with the rear surface of the wafer W is not limited to this embodiment. 
     For example, it may be possible to use another polishing cleaning mechanism  130  shown in  FIG. 29 . The polishing cleaning mechanism  130  is configured as described below. A polishing member  150  and a cleaning member  160  are disposed on each of the support members  140  having a substantially rectangular parallelepiped shape such that an angle between a polishing surface  150   a  of the polishing member  150  and a cleaning surface  160   a  of the cleaning member  160  is at a right angle. The support members  140  are supported on the opposite ends of each support shaft  170  which extends in a horizontal direction such that the polishing surface and the cleaning surface  160   a  make a right angle when seen in the extending direction of each support shaft  170  and such that the support member  140  can rotate about each support shaft  170 . For example, bearings (not shown) are interposed between the support members  140  and the support shafts  170 . 
     The support shafts  170  are connected to another support member  171  having, for example, a substantially rectangular parallelepiped shape. The support member  171  is configured such that it can be horizontally rotated about a vertical axis by a rotational drive mechanism including, for example, the motor  54 , the shaft  53 , and the belt  55 . The arrangement of each of the support shafts  170  is adjusted such that the support member  140  having the polishing member  150  and the cleaning member  160  is positioned on a circumference of a circle centered at the support member  171 .  FIG. 29  illustrates that the two support shafts  170  carrying the support members  140  at the opposite ends thereof are connected to the support member  171 . However, the number, length, and shape of the support shafts  170  are not limited to this embodiment. It is only necessary that the support members  140  are disposed on the same circumference. 
     In the polishing cleaning mechanism  130 , as shown in  FIG. 30 , if the support member  171  is rotated, for example, counterclockwise (in the direction indicated by an arrow in  FIG. 30 ) in a top view, while at least one of the polishing member  150  and the cleaning member  160  makes contact with the rear surface of the wafer W, the at least one of the polishing member  150  and the cleaning member  160  making contact with the wafer W receives a frictional force from the wafer W. Then, each of the support members  140  is rotated counterclockwise about each of the support shafts  170  as shown in  FIG. 31 , whereby the polishing surface  150   a  of the polishing member  150  comes into contact with the rear surface of the wafer W. Thus, the wafer W can be polished by another polishing cleaning mechanism  130 . 
     Further, as illustrated in  FIG. 31 , for example, if the support member  171  is rotated clockwise while the polishing surface  150   a  makes contact with the rear surface of the wafer W, each of the support members  140  is rotated about each of the support shafts  170  by the frictional force between the polishing member  150  and the wafer W. Therefore, as shown in  FIG. 32 , the cleaning surface  160   a  of the cleaning member  160  comes into contact with the rear surface of the wafer W. Thus, the water W can be cleaned by the polishing cleaning mechanism  130 . 
     For example, a rotation limiting member  180  which extends along the extension direction of each of the support shafts  170  is installed in the support member  171  as shown in  FIGS. 31 and 32 . The rotation of each of the support members  140  is limited by the rotation limiting member  180  so that the angle between the cleaning surface  160   a  and the rear surface of the wafer W should not become more than 90 degrees when the polishing surface  150   a  makes contact with the rear surface of the wafer W. By installing the rotation limiting member  180 , it is possible to prevent each of the support members  140  from being further rotated and to prevent the polishing surface  150   a  and the rear surface of the wafer W from getting out of contact. In addition, a rotation limiting member  181  for limiting the rotation of each of the support members  140  is also installed in the support member  171  so that the angle between the polishing surface  150   a  and the rear surface of the wafer W should not become more than 90 degrees when the cleaning surface  160   a  makes contact with the rear surface of the wafer W. The shape and arrangement of the rotation limiting members  180  and  181  are not limited to the present embodiment and can be configured in a suitable manner. 
     In the above described embodiment, the support shafts  170  are connected to another support member  171 . Alternatively, as shown in  FIG. 33 , the support members  140  may be connected to the end portions of another support shaft  190  having, e.g., a cross shape when seen in a top view. 
     In the above described embodiment, a member made of polypropylene or the like is used as the cleaning member. When cleaning the rear surface of the water W after the polishing process, it is not necessarily required to perform the cleaning process by bringing the cleaning member into contact with the rear surface of the wafer W. For example, as shown in  FIG. 34 , another cleaning nozzle  210  for supplying a cleaning liquid on the rear surface of the wafer W may be additionally installed such that the cleaning process can be performed by injecting the cleaning liquid from the cleaning nozzle  210  toward the rear surface of the wafer W. The cleaning nozzle  210  is configured such that it can be swung, for example, by a moving mechanism  201 . 
     The inventors of the present disclosure discovered that in the cleaning process performed after the polishing process, desired cleaning performance can be secured by injecting the cleaning liquid toward the rear surface of the wafer W. Furthermore, it is necessary that only another moving mechanism  201  be installed in the cleaning nozzle  210 . For example, there is no need to employ the rotating mechanism such as motor  54  or the like which is employed in the polishing cleaning mechanism  12 . Therefore, only the cleaning nozzle  210  can be disposed in the substrate processing apparatus  1 . 
     For example, in the polishing cleaning mechanism  12 , after performing the polishing process with the polishing members  50 , the cleaning process is performed by the cleaning members  51  via the same route as that of the polishing process. It is therefore necessary for the polishing cleaning mechanism  12  to move twice along the same route. However, for example, if the cleaning process is performed by the cleaning nozzle  210  concurrently with the polishing process, it is possible to finish the cleaning process while the polishing cleaning mechanism  12  moves along the route of the polishing process. Therefore, it is sufficient for the polishing cleaning mechanism  12  to move once along a specified route on the wafer W. 
     In  FIG. 34 , the cleaning nozzle  210  is provided with the moving mechanism  201  which differs from the moving mechanism  61 . However, for example, the cleaning nozzle  210  may be connected to the moving mechanism  61  such that the cleaning nozzle  210  moves synchronously with the polishing cleaning mechanism  12 . 
     In the above described embodiment, pure water as a cleaning liquid is supplied from the cleaning nozzle  30  or the cleaning liquid nozzle  60   a . As an alternative example, a polishing fluid such as ammonia-added water or the like may be supplied in place of the cleaning liquid. In this case, for example, a cleaning liquid supply source for supplying a cleaning liquid to the cleaning nozzle  30  or the cleaning liquid nozzle  60   a  and a polishing liquid supply source for supplying a polishing liquid may be connected so that they can be switched by a valve. For example, when the polishing process is performed by the polishing members  50 , the polishing liquid may be supplied individually from the nozzles  30  and  60   a . When the cleaning process is performed by the cleaning members  51 , the cleaning liquid may be supplied individually from the nozzles  30  and  60   a.    
     In the above described embodiment, the central portion of the wafer W, namely the region A existing between the attraction pads  10 , is first polished and cleaned while the wafer W is attracted and held by the attraction pads  10 . Thereafter, the wafer W is delivered to the spin chuck  11  where the outer peripheral portion of the wafer W is polished and cleaned. Depending on the state of the rear surface of the wafer W, for example, only the region A of the wafer W may be polished and cleaned or only the outer peripheral portion of the wafer W may be polished and cleaned. For example, when the wafer W is subjected to a photolithography process, it is sometimes the case that a resist solution enters a so-called bevel portion of the outer periphery of the wafer W, which may be a source of generation of particles. Therefore, for example, the region A, i.e., the central portion of the wafer W may be subjected to only the cleaning process and the outer peripheral portion of the wafer W may be subjected to the polishing process and the cleaning process. 
     In this case, for example, when the region A of the wafer W is processed as shown in  FIG. 9 , for example, the cleaning process may be continuously performed while the wafer W reciprocates in the Y-axis direction. As an alternative example, the cleaning process may be performed when the wafer W is moved toward the negative side in the Y-axis direction. When the wafer W is moved toward the positive side in the Y-axis direction, the cleaning process may be stopped and the wafer W may be rapidly moved. By doing so, it is possible to improve the wafer processing throughput in the substrate processing apparatus  1 . 
     For example, when performing the polishing process and the cleaning process on the wafer W, the rear surface of the wafer W may be first inspected. Based on the inspection result, a portion to be subjected to the polishing process or the cleaning process may be selected. The movement of the moving mechanism  61  or the frame  15  may be controlled by the control unit  200  such that the selected portion is polished or cleaned. In this case, for example, only the polishing process may be performed on a specified portion or only the cleaning process may be performed on the specified portion. A processing range may be suitably decided depending on the inspection result of the wafer W and the polishing process or the cleaning process is selectively performed on the range thus decided. In the inspection of the wafer W, it may be possible to use, for example, a well-known inspection device. 
     While certain preferred embodiments of the present disclosure have been described with reference to the accompanying drawings, the present disclosure is not limited to these embodiments. It will be apparent to those skilled in the art that different modifications and changes can be conceived without departing from the scope of the idea recited in the claims. It is to be understood that these modifications and changes may well belong to the technical scope of the present disclosure. The present disclosure is not limited to these examples and may employ many different forms. The present disclosure may be applied to a case where the substrate is not a wafer but is other substrate such as a FPD (Flat Panel Display), a mask reticle for a photo mask or the like. 
     The present disclosure is useful in polishing and cleaning a rear surface of a substrate such as a semiconductor wafer or the like. 
     According to the present disclosure, it is possible to efficiently perform a polishing process and a cleaning process on a wafer. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosures. Indeed, the embodiments described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the disclosures. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosures.