Patent Publication Number: US-2021170543-A1

Title: Top ring for holding a substrate and substrate processing apparatus

Description:
TECHNICAL FIELD 
     This application relates to a top ring for holding a substrate and a substrate processing apparatus. This application claims priority from Japanese Patent Application No. 2019-208865 filed on Nov. 19, 2019 and Japanese Patent Application No. 2020-167306 filed on Oct. 1, 2020. The entire disclosures including the descriptions, the claims, the drawings, and the abstracts in Japanese Patent Application No. 2019-208865 and Japanese Patent Application No. 2020-167306 are herein incorporated by reference. 
     BACKGROUND ART 
     Fabricating semiconductor devices employs a chemical mechanical polishing (CMP) device to planarize surfaces of substrates. The substrates used in the fabrication of the semiconductor devices are in a circular-plate shape in many cases. Additionally, not only for the semiconductor devices, but also when surfaces of quadrangular substrates, such as copper clad laminate substrates (CCL substrates), printed circuit board (PCB) substrates, photomask substrates, and display panels, are planarized, there is an increasing demand for flatness. Further, there is an increasing demand for planarizing surfaces of package substrates on which electronic devices such as PCB substrates are arranged. 
     A substrate processing apparatus, such as a chemical mechanical polishing device, contains atop ring for holding a substrate. For example, as described in PTL 1, the top ring includes a rotation shaft, a flange portion coupled to the rotation shaft, a porous suction plate fitted to the flange portion, and a shielding plate attached on an upper surface of the suction plate. This top ring is configured to suction the substrate via micropores of the suction plate by vacuum suction and press the substrate against a polishing pad by applying pressure to the shielding plate. 
     Additionally, a substrate processing apparatus, such as a chemical mechanical polishing device, contains a top ring for holding a substrate. For example, as described in PTL 1, the top ring includes a rotation shaft, a flange coupled to the rotation shaft, a porous suction plate fitted to an opening formed on a lower surface of the flange, and a shielding plate attached on an upper surface of the suction plate. This top ring is configured to suction the substrate via micropores of the suction plate by vacuum suction and press the substrate against a polishing pad by applying pressure to the shielding plate. 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: Japanese Patent No. 3668529 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     The technique described in PTL 1 has a room for improvement in ensuring a compact top ring that ensures uniformly pressing a substrate against a polishing pad. 
     That is, in a substrate processing apparatus, a surface plate on which the top ring or the polishing pad is attached may be tilted due to manufacturing tolerance of respective components. On the other hand, in the top ring described in PTL 1, a suction plate is fitted in the opening of a flange. Therefore, when the top ring or the surface plate is tilted, the surface of the substrate to be polished held to the top ring and the polishing surface of the polishing pad do not come into contact in parallel, and as a result, there is a possibility that the substrate cannot be uniformly pressed against the polishing pad. 
     In this respect, it is conceivable not to fit the suction plate to the opening of the flange, but to connect a frame-shaped member of the flange forming the opening to the suction plate via an elastic film. With this configuration, even if the top ring or the surface plate is tilted, it is considered that the suction plate can be aligned with the polishing surface of the polishing pad by the elasticity of the elastic film, and the substrate can be uniformly pressed against the polishing pad. 
     However, when an attempt is made to route a vacuum passage for vacuum suction from the suction plate through the frame-shaped member of the top ring, the plane size of the top ring becomes large due to space limitation of the frame-shaped member, thus hindering downsizing of the top ring. 
     Therefore, one object of this application is to provide the top ring and the substrate processing apparatus that can uniformly press the substrate against the polishing pad. 
     Solution to Problem 
     According to one embodiment, a top ring for holding a substrate is disclosed, the top ring includes a base member, an elastic film, and a substrate suction member. The base member is coupled to a rotary shaft. The elastic film is mounted to the base member and forms a pressurization chamber for pressurizing the substrate between the base member and the elastic film. The substrate suction member includes a porous member having a substrate suction surface for suctioning the substrate and a pressure reducing portion communicating with a pressure reducing unit. The substrate suction member is held to the elastic film. 
     According to one embodiment, a top ring for holding a substrate is disclosed, the top ring includes a base member, a substrate suction member, and an elastic member. The base member is coupled to a rotary shaft. The substrate suction member includes a porous member that includes a substrate suction surface for suctioning the substrate and a pressure reducing portion communicating with a pressure reducing unit. The shielding member is configured to shield a surface of the porous member on an opposite side of the substrate suction surface and a side surface. The framing member is disposed on the shielding member so as to surround at least a part of a periphery of the base member. The elastic member connects the at least a part of the base member surrounded by the framing member to the framing member. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a plan view illustrating an overall configuration of a substrate processing apparatus according to one embodiment: 
         FIG. 2  is a perspective view schematically illustrating a configuration of a polishing unit according to the one embodiment; 
         FIG. 3  is a cross-sectional view schematically illustrating a top ring according to the one embodiment: 
         FIG. 4  is a view illustrating a cross section taken along the line  5 - 5  of  FIG. 3 ; 
         FIG. 5  is a plan view schematically illustrating a substrate suction member according to the one embodiment: 
         FIG. 6  is a perspective view schematically illustrating a substrate suction member according to the one embodiment; 
         FIG. 7  is a view illustrating a modification of a substrate suction member; 
         FIG. 8  is a view illustrating a modification of a substrate suction member; 
         FIG. 9  is a plan view schematically illustrating a substrate suction member according to the one embodiment; 
         FIG. 10  is a cross-sectional view schematically illustrating a part of a top ring according to the one embodiment: 
         FIG. 11  is a cross-sectional view schematically illustrating a top ring according to the one embodiment; 
         FIG. 12  is a cross-sectional view schematically illustrating a top ring according to the one embodiment; 
         FIG. 13  is a plan view illustrating an overall configuration of a substrate processing apparatus according to one embodiment; 
         FIG. 14  is a perspective view schematically illustrating a configuration of a polishing unit according to the one embodiment; 
         FIG. 15  is a cross-sectional view schematically illustrating a top ring according to the one embodiment; 
         FIG. 16  is a cross-sectional perspective view schematically illustrating a top ring according to the one embodiment; 
         FIG. 17  is a cross-sectional view schematically illustrating a top ring according to the one embodiment: 
         FIG. 18  is an enlarged cross-sectional view schematically illustrating a part of a top ring according to the one embodiment: 
         FIG. 19A  is a plan view schematically illustrating a pattern area and a non-pattern area of a substrate of the one embodiment, and  FIG. 19B  is a plan view schematically illustrating a substrate suction member of the one embodiment: 
         FIG. 20  is a perspective view schematically illustrating a substrate suction member according to the one embodiment; and 
         FIG. 21  is an enlarged view of the area AA of  FIG. 20 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following describes an embodiment of a top ring and a substrate processing apparatus including the top ring according to the present invention together with accompanying drawings. In the accompanying drawings, the same or similar elements are denoted by the same or similar reference numerals, and duplicate description of the same or similar elements may be omitted in the description of each embodiment. Further, the features shown in each embodiment can be applied to other embodiments as long as they do not contradict each other. 
       FIG. 1  is a plan view illustrating an overall configuration of a substrate processing apparatus  1000  according to one embodiment. The substrate processing apparatus  10 ) illustrated in  FIG. 1  includes a loading unit  100 , a conveyance unit  200 , a polishing unit  300 , a drying unit  500 , and an unloading unit  600 . In the illustrated embodiment, the conveyance unit  200  includes two conveyance units  200 A and  200 B, and the polishing unit  300  includes two polishing units  300 A and  300 B. In the one embodiment, each of these units can be formed independently. By forming these units independently, arbitrarily combining the number of each unit can easily form the substrate processing apparatus  1000  having different configurations. Further, the substrate processing apparatus  1000  includes a control device  900 , and each component of the substrate processing apparatus  1000  is controlled by the control device  900 . In the one embodiment, the control device  900  can be constituted of a general computer including an input/output device, a computing device, a storage device, and the like. 
     &lt;Loading Unit&gt; 
     The loading unit  100  is a unit for introducing a substrate WF before processing, such as polishing and cleaning, is performed into the substrate processing apparatus  1000 . In the one embodiment, the loading unit  100  is configured to comply with Mechanical Equipment Interface Standard (IPC-SMEMA-9851) of Surface Mount Equipment Manufacturers Association (SMEMA). 
     In the illustrated embodiment, a conveyance mechanism of the loading unit  100  includes a plurality of conveyance rollers  202  and a plurality of roller shafts  204  to which the conveyance rollers  202  are mounted. In the embodiment illustrated in  FIG. 1 , three conveyance rollers  202  are mounted on each roller shaft  204 . The substrate WF is arranged on the conveyance rollers  202 , and the substrate WF is conveyed by rotation of the conveyance rollers  202 . The mounting positions of the conveyance rollers  202  on the roller shafts  204  can be arbitrary as long as the positions allow conveying the substrate WF stably. However, since the conveyance rollers  202  come into contact with the substrate WF, they should be arranged such that the conveyance rollers  202  come into contact with the area where no problem occurs even if coming into contact with the substrate WF to be processed. In the one embodiment, the conveyance rollers  202  of the loading unit  100  can be constituted of a conductive polymer. In the one embodiment, the conveyance rollers  202  are electrically grounded via the roller shafts  204  or the like. This avoids damage of the substrate WF due to being charged. Further, in the one embodiment, the loading unit  100  may be provided with an ionizer (not illustrated) to avoid charging of the substrate WF. 
     &lt;Conveyance Unit&gt; 
     The substrate processing apparatus  1000  illustrated in  FIG. 1  includes the two conveyance units  200 A and  200 B. Since the two conveyance units  200 A and  200 B can have the same configuration, they will be described collectively as the conveyance unit  200  below. 
     The illustrated conveyance unit  200  includes the plurality of conveyance rollers  202  for conveying the substrate WF. By rotating the conveyance rollers  202 , the substrate WF on the conveyance rollers  202  can be conveyed in a predetermined direction. The conveyance rollers  202  of the conveyance unit  200  may be formed of a conductive polymer or may be formed of a non-conductive polymer. The conveyance rollers  202  are driven by a motor (not illustrated). The substrate WF is conveyed to a substrate delivery position by the conveyance rollers  202 . 
     In the one embodiment, the conveyance unit  200  includes cleaning nozzles  284 . The cleaning nozzle  284  is connected to a supply source of a cleaning liquid (not illustrated). The cleaning nozzle  284  is configured to supply the cleaning liquid to the substrate WF conveyed by the conveyance rollers  202 . 
     &lt;Polishing Unit&gt; 
       FIG. 2  is a perspective view schematically illustrating a configuration of the polishing unit  300  according to the one embodiment. The substrate processing apparatus  1000  illustrated in  FIG. 1  includes two polishing units  300 A and  300 B. Since the two polishing units  300 A and  300 B can have the same configuration, they will be described collectively as the polishing unit  300  below. 
     As illustrated in  FIG. 2 , the polishing unit  300  includes a polishing table  350  and a top ring  302  constituting a polishing head that holds and presses the substrate to be polished against a polishing surface on the polishing table  350 . The polishing table  350  is coupled to a polishing table rotation motor (not illustrated), arranged below a table shaft  351 , via the table shaft  351  and is rotatable around the table shaft  351 . A polishing pad  352  is attached to an upper surface of the polishing table  350 , and a surface  352   a  of the polishing pad  352  constitutes a polishing surface that polishes the substrate. In the one embodiment, the polishing pad  352  may be attached via a layer for facilitating peeling from the polishing table  350 . Such a layer includes, for example, a silicone layer or a fluorine-based resin layer, and for example, those described in Japanese Unexamined Patent Application Publication No. 2014-176950 may be used. 
     A polishing liquid supply nozzle  354  is installed above the polishing table  350 , and the polishing liquid is supplied onto the polishing pad  352  on the polishing table  350  by the polishing liquid supply nozzle  354 . Further, as illustrated in  FIG. 2 , the polishing table  350  and the table shaft  351  are provided with a passage  353  for supplying the polishing liquid. The passage  353  communicates with an opening portion  355  on the surface of the polishing table  350 . A through hole  357  is formed in the polishing pad  352  at the position corresponding to the opening portion  355  of the polishing table  350 , and the polishing liquid passing through the passage  353  is supplied from the opening portion  355  of the polishing table  350  and the through hole  357  of the polishing pad  352  to the surface of the polishing pad  352 . Note that the numbers of the opening portion  355  of the polishing table  350  and the through hole  357  of the polishing pad  352  may be one or plural. Further, although the position of the opening portion  355  of the polishing table  350  and the through hole  357  of the polishing pad  352  is arbitrary, in the one embodiment, they are arranged near the center of the polishing table  350 . 
     Although not illustrated in  FIG. 2 , in the one embodiment, the polishing unit  300  includes an atomizer  358  for injecting a liquid or a mixed fluid of a liquid and a gas toward the polishing pad  352  (see  FIG. 1 ). The liquid injected from the atomizer  358  is, for example, pure water, and the gas is, for example, nitrogen gas. 
     The top ring  302  is connected to a top ring shaft  18 , and the top ring shaft  18  moves vertically with respect to a swing arm  360  by an up-and-down motion mechanism  319 . The vertical motion of the top ring shaft  18  causes the entire top ring  302  to move vertically with respect to the swing arm  360  for positioning. The top ring shaft  18  rotates by driving a top ring rotation motor (not illustrated). The rotation of the top ring shaft  18  causes the top ring  302  to rotate about the top ring shaft  18 . Note that a rotary joint  323  is mounted to the upper end of the top ring shaft  18 . 
     Note that there are various types of polishing pads available on the market, for example, SUBA800 (“SUBA” is a registered trademark), IC-1000, IC-1000/SUBA400 (double layer cloth) manufactured by Nitta Haas Co., Ltd., and Surfin xxx-5, Surfin 000, and the like (“Surfin” is a registered trademark) manufactured by Fujimi Incorporated are available. SUBA800, Surfin xxx-5, and Surfin 000 are non-woven fabrics in which fibers are hardened with urethane resin, and IC-1000 is a hard foamed polyurethane (single laver). The foamed polyurethane is porous and has a large number of fine dents or pores on its surface. 
     The top ring  302  can hold a quadrangular substrate on its lower surface. The swing arm  360  is configured to be turnable around a spindle  362 . The top ring  302  can move between the substrate delivery position of the above-described conveyance unit  200  and the upper side of the polishing table  350  by the turn of the swing arm  360 . By moving the top ring shaft  18  down, the top ring  302  can be moved down to press the substrate against the surface (polishing surface)  352   a  of the polishing pad  352 . At this time, the top ring  302  and the polishing table  350  are each rotated, and the polishing liquid is supplied from the polishing liquid supply nozzle  354  disposed above the polishing table  350  and/or from the opening portion  355  disposed in the polishing table  350  onto the polishing pad  352 . Thus, by pressing the substrate WF against the polishing surface  352   a  of the polishing pad  352 , the surface of the substrate WF can be polished. During polishing of the substrate WF, the arm  360  may be fixed or swung such that the top ring  302  passes through the center of the polishing pad  352  (so as to cover the through hole  357  of the polishing pad  352 ). 
     The up-and-down motion mechanism  319 , which vertically moves the top ring shaft  18  and the top ring  302 , includes a bridge  28  that rotatably supports the top ring shaft  18  via a bearing  321 , a ball screw  32  mounted to the bridge  28 , a support table  29  supported by a support column  130 , and an AC servo motor  38  disposed on the support table  29 . The support table  29  that supports the servo motor  38  is secured to the swing arm  360  via the support column  130 . 
     The ball screw  32  includes a screw shaft  32   a  coupled to the servo motor  38  and a nut  32   b  into which the screw shaft  32   a  is screwed. The top ring shaft  18  vertically moves integrally with the bridge  28 . Therefore, when the servomotor  38  is driven, the bridge  28  vertically moves via the ball screw  32 , whereby the top ring shaft  18  and the top ring  302  vertically move. The polishing unit  300  includes a ranging sensor  70  as a position detecting unit for detecting a distance to a lower surface of the bridge  28 , that is, the position of the bridge  28 . By detecting the position of the bridge  28  by the ranging sensor  70  the position of the top ring  302  can be detected. The ranging sensor  70  constitutes the up-and-down motion mechanism  319  together with the ball screw  32  and the servo motor  38 . Note that the ranging sensor  70  may be a laser type sensor, an ultrasonic sensor, an overcurrent type sensor, or a linear scale type sensor. Further, each equipment in the polishing unit including the ranging sensor  70  and the servo motor  38  is configured to be controlled by the control device  900 . 
     The polishing unit  300  according to the one embodiment includes a dressing unit  356  that dresses the polishing surface  352   a  of the polishing pad  352 . The dressing unit  356  includes a dresser  50  that is slidably in contact with the polishing surface  352   a , a dresser shaft  51  to which the dresser  50  is coupled, an air cylinder  53  disposed at an upper end of the dresser shaft  51 , and a swing arm  55  that rotatably supports the dresser shaft  51 . A lower portion of the dresser  50  is constituted by a dressing member  50   a , and needle-shaped diamond particles are attached to a lower surface of the dressing member  50   a . The air cylinder  53  is arranged on a support table  57  supported by support columns  56 , and these support columns  56  are secured to the swing arm  55 . 
     The swing arm  55  is configured to be driven by a motor (not illustrated) and turn around a spindle  58 . The dresser shaft  51  rotates by driving of a motor (not illustrated), and the rotation of the dresser shaft  51  causes the dresser  50  to rotate around the dresser shaft  51 . The air cylinder  53  vertically moves the dresser  50  via the dresser shaft  51  and presses the dresser  50  against the polishing surface  352   a  of the polishing pad  352  with a predetermined pressing force. 
     Dressing of the polishing surface  352   a  of the polishing pad  352  is performed in the following manner. The dresser  50  is pressed against the polishing surface  352   a  by the air cylinder  53 , and at the same time, pure water is supplied to the polishing surface  352   a  from a pure water supply nozzle (not illustrated). In this state, the dresser  50  rotates around the dresser shaft  51 , and the lower surface (diamond particles) of the dressing member  50   a  is brought into sliding contact with the polishing surface  352   a . Thus, the dresser  50  scrapes off the polishing pad  352  and dresses the polishing surface  352   a.    
     &lt;Drying Unit&gt; 
     The drying unit  500  is a device for drying the substrate WF. In the substrate processing apparatus  1000  illustrated in  FIG. 1 , the drying unit  500  dries the substrate WF which is cleaned by the cleaning unit of the conveyance unit  200  after being polished by the polishing unit  300 . As illustrated in  FIG. 1 , the drying unit  500  is arranged downstream of the conveyance unit  200 . 
     The drying unit  500  includes nozzles  530  for injecting gas toward the substrate WF being conveyed on the conveyance rollers  202 . The gas can be, for example, compressed air or nitrogen. The substrate WF can be dried by blowing off water droplets on the conveyed substrate WF with the drying unit  500 . 
     &lt;Unloading Unit&gt; 
     The unloading unit  600  is a unit for carrying out the substrate WF after processing, such as polishing and cleaning, is performed to outside of the substrate processing apparatus  1000 . In the substrate processing apparatus  1000  illustrated in  FIG. 1 , the unloading unit  600  receives the substrate after being dried by the drying unit  500 . As illustrated in  FIG. 1 , the unloading unit  600  is arranged downstream of the drying unit  500 . 
     In the one embodiment, the unloading unit  600  is configured to comply with Mechanical Equipment Interface Standard (IPC-SMEMA-9851) of Surface Mount Equipment Manufacturers Association (SMEMA). 
     &lt;Top Ring&gt; 
     Next, the top ring  302  in the polishing unit  300  according to the one embodiment will be described.  FIG. 3  is a cross-sectional view schematically illustrating the top ring  302  according to the one embodiment. As illustrated in  FIG. 3 , the top ring  302  includes a base member  301  coupled to the top ring shaft (rotary shaft)  18 . Specifically, the base member  301  is configured to include a flange  303  coupled to the top ring shaft (rotary shaft)  18 , a spacer  304  mounted to a lower surface of the flange  303 , a frame-shaped upper portion guiding member  305  mounted to a peripheral edge portion of a lower surface of the spacer  304 , and a frame-shaped lower portion guiding member  306  mounted to a lower surface of the upper portion guiding member  305 . The flange  303 , the spacer  304 , and the upper portion guiding member  305  are fastened by bolts  307 . The upper portion guiding member  305  and the lower portion guiding member  306  are fastened by bolts  308 . 
     The top ring  302  includes an elastic film  320  mounted to the base member  301  and a substrate suction member  330  held to the elastic film  320 . The lower portion guiding member  306  is arranged so as to surround the substrate suction member  330 . The elastic film  320  forms a pressurization chamber  322  for pressurizing the substrate WF between the base member  301  and the elastic film  320 . The spacer  304  is coupled to the upper portion guiding member  305  via a sealing material  309 , whereby air tightness of the pressurization chamber  322  is maintained. The elastic film  320  can be formed of a rubber material, for example but not limited to silicon rubber, ethylene propylene diene rubber (EPDM), or fluororubber (FKM). The elastic film  320  can be formed of a material which bears a load applied to the elastic film  320  due to weight of the substrate suction member  330  and the substrate WF when the substrate WF is conveyed, has a strength with which the elastic film  320  does not break in a range where motion of the substrate suction member  330  is limited by a stopper member  310  described later and the lower portion guiding member  306 , and has an elasticity that allows having the degree of freedom in angle of the substrate suction member  330  with respect to the base member  301 . 
       FIG. 4  is a view illustrating across section taken along the line  5 - 5  of  FIG. 3 .  FIG. 5  is a plan view schematically illustrating a substrate suction member according to the one embodiment.  FIG. 6  is a perspective view schematically illustrating a substrate suction member according to the one embodiment. As illustrated in  FIG. 3  to  FIG. 6 , the substrate suction member  330  includes a porous member  334  and a shielding member  332 . It is only necessary that the porous member  334  is a member that can perform vacuum suction of the substrate WF by vacuum drawing using a pressure reducing unit (vacuum source)  31 , and the porous member  334  can be constituted of, for example, a resin porous material. The porous member  334  is formed in a plate shape in this embodiment and includes a substrate suction surface  334   a  for suctioning the substrate WF and a pressure reducing portion  334   b  communicating with the pressure reducing unit (vacuum source)  31 . 
     It is only necessary that the shielding member  332  is an airtight member that can shield the flow of gas, and can be formed of, for example, a relatively soft resin plate, such as polyethylene (PE), polypropylene (PP), or polytetrafluoroethylene (PTFE). In this embodiment, the shielding member  332  is formed so as to shield a surface  334   c  of the porous member  334  on an opposite side of the substrate suction surface  334   a  and a side surface  334   d . However, it is only necessary that the shielding member  332  is formed so as to shield at least the surface  334   c  of the porous member  334  on the opposite side of the substrate suction surface  334   a . By providing the shielding member  332 , when the porous member  334  is vacuum drawn by the pressure reducing unit (vacuum source)  31 , negative pressure can be efficiently formed on the substrate suction surface  334   a . This allows the substrate WF to be reliably suctioned to the substrate suction member  330 , thus avoiding jumping out (slipping out) of the substrate WF to outside during polishing.  FIG. 7  and  FIG. 8  are views illustrating modifications of the substrate suction member  330 . As illustrated in  FIG. 7 , the substrate suction member  330  may include the porous member  334 , the shielding member  332  configured to shield the surface  334   c  of the porous member  334  on the opposite side of the substrate suction surface  334   a , and a sealing material  333  configured to shield the side surface  334   d  of the porous member  334 . The sealing material  333  may be a chemical resistant adhesive or the like and can fill a void on the side surface  334   d  for sealing. With this configuration, when the porous member  334  is vacuum drawn by the pressure reducing unit (vacuum source)  31 , negative pressure can be efficiently formed on the substrate suction surface  334   a , thus allowing suctioning the substrate WF reliably onto the substrate suction member  330 . Further, as illustrated in  FIG. 8 , the substrate suction member  330  may include the porous member  334 , the shielding member  332  configured to shield the surface  334   c  of the porous member  334  on the opposite side of the substrate suction surface  334   a , and the sealing material  333  configured to shield the peripheral edge portion of the side surface  334   d  of the porous member  334  and the substrate suction surface  334   a . With this configuration, when the porous member  334  is vacuum drawn by the pressure reducing unit (vacuum source)  31 , air short pass can be reduced, and thus, suction force of the substrate WF against the substrate suction member  330  can be improved. Note that, in this embodiment, although the example in which the substrate suction member  330  includes the shielding member  332  has been shown, the substrate suction member  330  can be formed only by the porous member  334 . In that case, it is preferred that the surfaces other than the substrate suction surface  334   a  of the porous member  334  or a hole  336  are treated by sealing similarly to the side surface  334   d  of the porous member  334  in  FIG. 7  and  FIG. 8 . 
     The shielding member  332  includes the hole  336  formed so as to expose the porous member  334 . The pressure reducing portion  334   b  of the porous member  334  is disposed at a position where the hole  336  is formed. Further, a plurality of holes  338  are formed at the end portion of the shielding member  332  along the circumferential direction. To the portions where the holes  338  are formed, the stopper members  310  described later are mounted. 
     The elastic film  320  includes a center portion  324  that covers a surface  332   c  of the substrate suction member  330  on the opposite side of the substrate suction surface  334   a , and an end portion  326  that projects from the center portion  324  to outside of the substrate suction member  330 . The end portion  326  is sandwiched between the upper portion guiding member  305  and the lower portion guiding member  306 . The elastic film  320  has the end portion  326  secured between the upper portion guiding member  305  and the lower portion guiding member  306  in the circumferential direction. This forms the pressurization chamber  322  between the spacer  304  with the upper portion guiding member  305  and the elastic film  320 . The pressurization chamber  322  communicates with a pressure adjustment portion  30 . The pressure adjustment portion  30  has a pressure adjustment function for adjusting pressure of pressurized fluid supplied to the pressurization chamber  322 . With this embodiment, the substrate WF is suctioned to the substrate suction surface  334   a  by making the porous member  334  negative pressure by using the pressure reducing unit  31 , and the substrate WF can be pressed against the polishing pad  352  by pressurizing the pressurization chamber  322  by the pressure adjustment portion  30 . 
     Further, the top ring  302  includes the plurality of stopper members  310  for restricting the movement in the vertical direction of the substrate suction member  330 . The stopper member  310  is a plate-shaped member that is coupled to the substrate suction member  330  with the elastic film  320  sandwiched at the end portion of the substrate suction member  330 . The stopper member  310  is coupled to the substrate suction member  330  by screwing a bolt  312  into the hole  338  of the shielding member  332 . The stopper member  310  includes a flange portion  311  that projects outward with respect to the substrate suction member  330 . 
     On the other hand, the upper portion guiding member  305  and the lower portion guiding member  306  have regulating surfaces  305   a  and  306   a  that restrict the movement in the vertical direction of the stopper member  310  by abutting on the flange portion  311  of the stopper member  310 . When the substrate suction member  330  moves in the upward direction, the flange portion  311  comes into contact with the regulating surface  305   a  to restrict the movement in the upward direction of the substrate suction member  330 . On the other hand, when the substrate suction member  330  moves in the downward direction, the flange portion  311  comes into contact with the regulating surface  306   a  to restrict the movement in the downward direction of the substrate suction member  330 . This allows restricting a range of the movement in the vertical direction of the substrate suction member  330  to a desired range. 
     With this embodiment, even when the top ring  302  or the polishing table  350  to which the polishing pad  352  is attached is tilted due to manufacturing tolerance or the like of each component constituting the substrate processing apparatus  1000 , the substrate WF can be uniformly pressed against the polishing pad  352 . That is, according to this embodiment, the substrate suction member  330  is not secured to the base member  301  but is held to the elastic film  320 . In view of this, even if the top ring  302  or the polishing table  350  is tilted and the substrate WF partially contacts the polishing pad  352 , the elasticity of the elastic film  320  causes the substrate suction member  330  to align with the polishing surface of the polishing pad  352 , and as a result, the substrate WF can be brought into contact with the polishing pad  352  in parallel. Therefore, with this embodiment, the substrate WF can be uniformly pressed against the polishing pad  352 . 
     Further, in this embodiment, the lower portion guiding member  306  is arranged around the substrate suction member  330 . Therefore, with this embodiment, the force laterally applied on the substrate suction member  330  during polishing of the substrate WF can be supported by the lower portion guiding member  306 . Further, with this embodiment, since the substrate WF can be suctioned by the substrate suction member  330 , without providing a retainer member for avoiding the jumping out (slipping out) of the substrate WF to outside during polishing, the slipping out of the substrate WF can be avoided. In particular, as the substrate WF has been thinned in recent years, there is a possibility that the substrate WF slips out during polishing even when the retainer member is provided. Further, when the shape of the substrate WF is quadrangular, there were a possibility that the corner portions of the substrate WF could come into contact with the retainer member during polishing, and the substrate WF or a top ring could be damaged. In contrast to this, with this embodiment, since the substrate WF can be pressed against the polishing pad  352  while being vacuum suctioned by the substrate suction member  330 , the slipping out of the substrate WF during polishing can be avoided and the substrate WF or the top ring  302  can be avoided from being damaged during polishing. 
     Next, a modification of the top ring  302  of this embodiment will be described.  FIG. 9  is a plan view schematically illustrating a substrate suction member according to the one embodiment. As illustrated in  FIG. 9 , the substrate suction member  330  may have a plurality of pressure reducing portions  334   b . Specifically, the substrate suction member  330  includes a plurality of porous members  334 , and the shielding member  332  configured to shield the surfaces  334   c  of the plurality of porous members  334  on the opposite side of the respective substrate suction surfaces  334   a . The shielding member  332  includes a plurality of holes  336  formed so as to expose the respective plurality of porous members  334 . The respective pressure reducing portions  334   b  are disposed at the positions where the plurality of holes  336  are formed. 
     By providing the substrate suction member  330  with the plurality of pressure reducing portions  334   b  in this way, the entire substrate suction member  330  can be decompressed by the pressure reducing unit (vacuum source)  31 . As a result, even when the substrate WF is large, the substrate WF can be firmly suctioned to the substrate suction member  330 , thus allowing the substrate WF to be avoided from slipping out of the top ring  302  during polishing. In this embodiment, an example in which one pressure reducing portion  334   b  and one hole  336  are provided for each of the plurality of porous members  334  is shown, but it is not limited this. For example, as illustrated in  FIG. 3 , in the substrate suction member  330  having one porous member  334 , a plurality of pressure reducing portions  334   b  may be provided for the one porous member  334  by forming a plurality of holes  336  in the shielding member  332 . With this configuration, even when the substrate WF is large and the porous member  334  is large, the substrate WF can be uniformly suctioned to the substrate suction member  330 . 
     Next, a modification of the top ring  302  of this embodiment will be described.  FIG. 10  is a cross-sectional view schematically illustrating a part of the top ring  302  according to the one embodiment. As illustrated in  FIG. 10 , in the top ring  302  of this embodiment, a frame-shaped first elastic film spacer  314  and a frame-shaped second elastic film spacer  316  are disposed between the upper portion guiding member  305  and the lower portion guiding member  306  in the vertical direction. Further, a frame-shaped or annular-shaped elastic film holder  318  is mounted to a lower surface of the center portion of the upper portion guiding member  305 . The first elastic film spacer  314 , the second elastic film spacer  316 , and the elastic film holder  318  can be regarded as members constituting the base member  301 . 
     On the other hand, the elastic film  320  includes a plurality of pieces of elastic films  320 - 1 ,  320 - 2 ,  320 - 3 , and  320 - 4 . The elastic films  320 - 1 ,  320 - 2 ,  320 - 3 , and  320 - 4  each include a center portion that is connected to the surface  332   c  of the substrate suction member  330  on the opposite side of the substrate suction surface  334   a , and an end portion that extends from the center portion and is secured to a different position of the base member  301 . 
     Specifically, in the elastic film  320 - 1 , a center portion  320 - 1   a  is connected to the surface  332   c  of the substrate suction member  330  on the opposite side of the substrate suction surface  334   a , and an end portion  320 - 1   b  is sandwiched between the second elastic film spacer  316  and the lower portion guiding member  306 . In the elastic film  320 - 2 , a center portion  320 - 2   a  is connected to the center portion  320 - 1   a  of the elastic film  320 - 1 , and an end portion  320 - 2   b  is sandwiched between the first elastic film spacer  314  and the second elastic film spacer  316 . In the elastic film  320 - 3 , the center portion  320 - 3   a  is connected to the center portion  320 - 1   a  of the elastic film  320 - 1 , and the end portion  320 - 3   b  is sandwiched between the upper portion guiding member  305  and the first elastic film spacer  314 . In the elastic film  320 - 4 , the center portion  320 - 4   a  is connected to the center portion  320 - 1   a  of the elastic film  320 - 1 , and the end portion  320 - 4   b  is sandwiched between the upper portion guiding member  305  and the elastic film holder  318 . 
     With such a structure of the plurality of elastic films  320 - 1 ,  320 - 2 ,  320 - 3 , and  320 - 4 , a plurality of pressurization chambers  322   a ,  322   b ,  322   c , and  322   d  for pressurizing the substrate WF are formed between the base member  301  and the plurality of pieces of elastic films  320 - 1 ,  320 - 2 ,  320 - 3 , and  320 - 4 . 
     According to this embodiment, by forming the plurality of concentric pressurization chambers  322   a ,  322   b ,  322   c , and  322   d , the pressing force of the substrate WF against the polishing pad  352  can be controlled for each area. Further, according to this embodiment, since the substrate suction member  330  has a certain degree of elasticity (to the extent that the pressure difference of each pressurization chamber can be reflected in the substrate pressing pressure difference), profile control becomes possible by applying a different pressure to each pressurization chamber. 
       FIG. 11  is a cross-sectional view schematically illustrating the top ring  302  according to the one embodiment. As illustrated in  FIG. 11 , the top ring  302  of this embodiment includes the base member  301  coupled to the top ring shaft (rotary shaft)  18 . Specifically, the base member  301  is configured to include the flange  303  coupled to the top ring shaft (rotary shaft)  18 , the spacer  304  mounted to a lower surface of the flange  303 , the upper portion guiding member  305  including a plate-shaped member  305   a  mounted to a lower surface of the spacer  304  and a frame-shaped member  305   b  disposed on the peripheral edge portion of a lower surface of the plate-shaped member  305   a  and the frame-shaped lower portion guiding member  306  mounted to a lower surface of the frame-shaped member  305   b.    
     Further, the top ring  302  includes an elastic film  402  mounted to the base member  301 . The elastic film  402  includes abase film  402   a  disposed in a space formed by the upper portion guiding member  305 , and a plurality of partition walls  402   b  formed concentrically on the base film  402   a . The upper end portions of the plurality of partition walls  402   b  are secured to the plate-shaped member  305   a . This forms a plurality of concentric pressurization chambers  434 ,  436 , and  438  for pressurizing the substrate WF between the elastic film  402  and the base member  301 . By forming the pressurization chambers  434 ,  436 , and  438 , the pressing force of the substrate WF against the polishing pad  352  can be controlled for each area. 
     The top ring  302  includes a substrate holding member  430  held to the elastic film  402 . The substrate holding member  430  can be attached to a lower surface of the base film  402   a . The substrate holding member  430  includes an elastic plate-shaped member  431  in which a substrate holding surface  431   a  for holding the substrate WF is mirror-finished. The elastic plate-shaped member  431  can be formed of a rubber material, such as silicon rubber, ethylene propylene diene rubber (EPDM), or fluororubber (FKM). The substrate holding surface  431   a  is mirror-finished so as to hold the substrate WF. Here, the mirror-finished surface is a surface having an arithmetic mean roughness Ra of less than or equal to 5 μm. In one example, the substrate holding member  430  can be molded using a mold configured such that the arithmetic mean roughness Ra of the substrate holding surface  431   a  becomes less than or equal to 5 μm. Note that the elastic film  402  and the substrate holding member  430  can be integrally molded of the same material. In this case, it is not necessary to attach the elastic film  402  and the substrate holding member  430 . 
     According to this embodiment, by mirror-finishing the substrate holding surface  431   a  of the substrate holding member  430 , the friction force between the substrate WF and the substrate holding surface  431   a  is improved and the substrate WF can be held on the substrate holding surface  431   a . As a result, according to this embodiment, without using the retainer member for guarding the periphery of the substrate WF, the slipping out of the substrate WF during polishing can be avoided. 
     Further, in this embodiment, the lower portion guiding member  306  is arranged around the substrate holding member  430 . Therefore, with this embodiment, during polishing of the substrate WF, the force laterally applied on the substrate holding member  430  can be supported by the lower portion guiding member  306 . 
     In the substrate holding member  430 , a plurality of holes  432  passing through the substrate holding surface  431   a  and the surface on the opposite side of the substrate holding surface  431   a  are formed. By forming the holes  432 , the pressurization chamber  436  is switched to be negative pressure when the substrate WF is conveyed between the conveyance unit  200  and the polishing unit  300 , allowing the substrate WF to be chucked to the substrate holding member  430 . Further, after the substrate WF is polished and conveyed to the conveyance unit  200 , the substrate WF held to the substrate holding member  430  can be easily removed by applying, for example, air pressure from the holes  432 . 
       FIG. 12  is a cross-sectional view schematically illustrating the top ring  302  according to the one embodiment. The top ring  302  illustrated in  FIG. 12  is different in the structure of the elastic film, and identical in other structures, compared with the top ring  302  illustrated in  FIG. 11 . Therefore, only the structure different from the top ring  302  illustrated in  FIG. 11  will be described. 
     As illustrated in  FIG. 12 , the top ring  302  of this embodiment is provided with the frame-shaped first elastic film spacer  314  and the frame-shaped second elastic film spacer  316  between the upper portion guiding member  305  and the lower portion guiding member  306  in the vertical direction. Further, the frame-shaped or annular-shaped elastic film holder  318  is mounted to the lower surface of the center portion of the upper portion guiding member  305 . The first elastic film spacer  314 , the second elastic film spacer  316 , and the elastic film holder  318  can be regarded as the members constituting the base member  301 . 
     An elastic film  420  includes a plurality of pieces of elastic films  420 - 1 ,  420 - 2 ,  420 - 3 , and  420 - 4 . The elastic films  420 - 1 ,  420 - 2 ,  420 - 3 , and  420 - 4  include center portions that are connected to a surface  431   b  of the substrate holding member  430  on the opposite side of the substrate holding surface  431   a , and end portions that are secured to different positions of the base member  301 . 
     Specifically, in the elastic film  420 - 1 , a center portion  420 - 1   a  is connected to the surface  431   b  of the substrate holding member  430  on the opposite side of the substrate holding surface  431   a , and an end portion  420 - 1   b  is sandwiched between the second elastic film spacer  316  and the lower portion guiding member  306 . In the elastic film  420 - 2 , a center portion  420 - 2   a  is connected to the center portion  420 - 1   a  of the elastic film  420 - 1 , and an end portion  420 - 2   b  is sandwiched between the first elastic film spacer  314  and the second elastic film spacer  316 . In the elastic film  420 - 3 , the center portion  420 - 3   a  is connected to the center portion  420 - 2   a  of the elastic film  420 - 2 , and the end portion  420 - 3   b  is sandwiched between the upper portion guiding member  305  and the first elastic film spacer  314 . In the elastic film  420 - 4 , the center portion  420 - 4   a  is connected to the center portion  420 - 3   a  of the elastic film  420 - 3 , and the end portion  420 - 4   b  is sandwiched between the upper portion guiding member  305  and the elastic film holder  318 . Note that the elastic film  420 - 1  and the substrate holding member  430  can be integrally molded of the same material. In this case, it is not necessary to connect the elastic film  420 - 1  to the substrate holding member  430 . 
     With such a structure of the plurality of elastic films  420 - 1 ,  420 - 2 ,  420 - 3 , and  420 - 4 , a plurality of pressurization chambers  434 ,  436 ,  438 , and  440  for pressurizing the substrate WF are formed between the base member  301  and the plurality of pieces of elastic films  420 - 1 ,  420 - 2 ,  420 - 3 , and  420 - 4 . 
     According to this embodiment, by forming the plurality of concentric pressurization chambers  434 ,  436 ,  438 , and  440 , the pressing force of the substrate WF against the polishing pad  352  can be controlled for each area. Further, according to this embodiment, since the elastic plate-shaped member  431  has a certain degree of elasticity (to the extent that the pressure difference of each pressurization chamber can be reflected in the substrate pressing pressure difference) although having thickness, profile control is allowed by applying a different pressure to each pressurization chamber. 
       FIG. 13  is a plan view illustrating an overall configuration of a substrate processing apparatus  2 - 1000  according to the one embodiment. The substrate processing apparatus  2 - 1000  illustrated in  FIG. 13  includes a loading unit  2 - 100 , a conveyance unit  2 - 200 , a polishing unit  2 - 300 , a drying unit  2 - 500 , and an unloading unit  2 - 600 . In the illustrated embodiment, the conveyance unit  2 - 200  includes two conveyance units  2 - 200 A and  2 - 200 B, and the polishing unit  2 - 300  includes two polishing units  2 - 300 A and  2 - 300 B. In the one embodiment, each of these units can be formed independently. By forming these units independently, arbitrarily combining the number of each unit can easily form the substrate processing apparatus  2 - 1000  having different configurations. Further, the substrate processing apparatus  2 - 1000  includes a control device  2 - 900 , and each component of the substrate processing apparatus  2 - 1000  is controlled by the control device  2 - 9 ( x ). In the one embodiment, the control device  2 - 900  can be constituted of a general computer including an input/output device, a computing device, a storage device, and the like. 
     &lt;Loading Unit&gt; 
     The loading unit  2 - 100  is a unit for introducing a substrate WF before processing, such as polishing and cleaning, is performed into the substrate processing apparatus  2 - 1000 . In the one embodiment, the loading unit  2 - 100  is configured to comply with Mechanical Equipment Interface Standard (IPC-SMEMA-9851) of Surface Mount Equipment Manufacturers Association (SMEMA). 
     In the illustrated embodiment, a conveyance mechanism of the loading unit  2 - 100  includes a plurality of conveyance rollers  2 - 202  and a plurality of roller shafts  2 - 204  to which the conveyance rollers  2 - 202  are mounted. In the embodiment illustrated in  FIG. 13 , three conveyance rollers  2 - 202  are mounted on each roller shaft  2 - 204 . The substrate WF is arranged on the conveyance rollers  2 - 202 , and the substrate WF is conveyed by rotation of the conveyance rollers  2 - 202 . The mounting positions of the conveyance rollers  2 - 202  on the roller shafts  2 - 204  can be arbitrary as long as the positions allow conveying the substrate WF stably. However, since the conveyance rollers  2 - 202  come into contact with the substrate WF, they should be arranged such that the conveyance rollers  2 - 202  come into contact with the area where no problem occurs even if coming into contact with the substrate WF to be processed. In the one embodiment, the conveyance rollers  2 - 202  of the loading unit  2 - 100  can be constituted of a conductive polymer. In the one embodiment, the conveyance rollers  2 - 202  are electrically grounded via the roller shafts  2 - 204  or the like. This avoids damage of the substrate WT due to being charged. Further, in the one embodiment, the loading unit  2 - 100  may be provided with an ionizer (not illustrated) to avoid charging of the substrate WF. 
     &lt;Conveyance Unit&gt; 
     The substrate processing apparatus  2 - 1000  illustrated in  FIG. 13  includes the two conveyance units  2 - 200 A and  2 - 200 B. Since the two conveyance units  2 - 200 A and  2 - 200 B can have the same configuration, they will be described collectively as the conveyance unit  2 - 200  below. 
     The illustrated conveyance unit  2 - 200  includes the plurality of conveyance rollers  2 - 202  for conveying the substrate WF. By rotating the conveyance rollers  2 - 202 , the substrate WF on the conveyance rollers  2 - 202  can be conveyed in a predetermined direction. The conveyance rollers  2 - 202  of the conveyance unit  2 - 200  may be formed of a conductive polymer or may be formed of a non-conductive polymer. The conveyance rollers  2 - 202  are driven by a motor (not illustrated). The substrate WF is conveyed to a substrate delivery position by the conveyance rollers  2 - 202 . 
     In the one embodiment, the conveyance unit  2 - 200  includes cleaning nozzles  2 - 284 . The cleaning nozzle  2 - 284  is connected to a supply source of a cleaning liquid (not illustrated). The cleaning nozzle  2 - 284  is configured to supply the cleaning liquid to the substrate WF conveyed by the conveyance rollers  2 - 202 . 
     &lt;Polishing Unit&gt; 
       FIG. 14  is a perspective view schematically illustrating a configuration of the polishing unit  2 - 300  according to the one embodiment. The substrate processing apparatus  2 - 1000  illustrated in  FIG. 13  includes two polishing units  2 - 300 A and  2 - 300 B. Since the two polishing units  2 - 300 A and  2 - 300 B can have the same configuration, they will be described collectively as the polishing unit  2 - 300  below. 
     As illustrated in  FIG. 14 , the polishing unit  2 - 300  includes a polishing table  2 - 350  and a top ring  2 - 302  constituting a polishing head that holds and presses the substrate to be polished against a polishing surface on the polishing table  2 - 350 . The polishing table  2 - 350  is coupled to a polishing table rotation motor (not illustrated), arranged below a table shaft  2 - 351 , via the table shaft  2 - 351  and is rotatable around the table shaft  2 - 351 . A polishing pad  2 - 352  is attached to an upper surface of the polishing table  2 - 350 , and a surface  2 - 352   a  of the polishing pad  2 - 352  constitutes a polishing surface that polishes the substrate. In the one embodiment, the polishing pad  2 - 352  may be attached via a layer for facilitating peeling from the polishing table  2 - 350 . Such a layer includes, for example, a silicone layer or a fluorine-based resin layer, and for example, those described in Japanese Unexamined Patent Application Publication No. 2014-176950 may be used. 
     A polishing liquid supply nozzle  2 - 354  is installed above an upper side of the polishing table  2 - 350 , and the polishing liquid is supplied onto the polishing pad  2 - 352  on the polishing table  2 - 350  by the polishing liquid supply nozzle  2 - 354 . Further, as illustrated in  FIG. 14 , the polishing table  2 - 350  and the table shaft  2 - 351  are provided with a passage  2 - 353  for supplying the polishing liquid. The passage  2 - 353  communicates with an opening portion  2 - 355  on the surface of the polishing table  2 - 350 . A through hole  2 - 357  is formed in the polishing pad  2 - 352  at the position corresponding to the opening portion  2 - 355  of the polishing table  2 - 350 , and the polishing liquid passing through the passage  2 - 353  is supplied from the opening portion  2 - 355  of the polishing table  2 - 350  and the through hole  2 - 357  of the polishing pad  2 - 352  to the surface of the polishing pad  2 - 352 . Note that the numbers of the opening portion  2 - 355  of the polishing table  2 - 350  and the through hole  2 - 357  of the polishing pad  2 - 352  may be one or plural. Further, although the position of the opening portion  2 - 355  of the polishing table  2 - 350  and the through hole  2 - 357  of the polishing pad  2 - 352  is arbitrary, in the one embodiment, they are arranged near the center of the polishing table  2 - 350 . 
     Although not illustrated in  FIG. 14 , in the one embodiment, the polishing unit  2 - 300  includes an atomizer  2 - 358  for injecting a liquid or a mixed fluid of a liquid and a gas toward the polishing pad  2 - 352  (see  FIG. 13 ). The liquid injected from the atomizer  2 - 358  is, for example, pure water, and the gas is, for example, nitrogen gas. 
     The top ring  2 - 302  is connected to a top ring shaft  2 - 18 , and the top ring shaft  2 - 18  moves vertically with respect to a swing arm  2 - 360  by an up-and-down motion mechanism  2 - 319 . The vertical motion of the top ring shaft  2 - 18  causes the entire top ring  2 - 302  to move vertically with respect to the swing arm  2 - 360  for positioning. The top ring shaft  2 - 18  rotates by driving a top ring rotation motor (not illustrated). The rotation of the top ring shaft  2 - 18  causes the top ring  2 - 302  to rotate about the top ring shaft  2 - 18 . 
     The top ring  2 - 302  can hold a quadrangular substrate on its lower surface. The swing arm  2 - 360  is configured to be turnable around a spindle  2 - 362 . The top ring  2 - 302  can move between the substrate delivery position of the above-described conveyance unit  2 - 200  and the upper side of the polishing table  2 - 350  by the turn of the swing arm  2 - 360 . By moving the top ring shaft  2 - 18  down, the top ring  2 - 302  can be moved down to press the substrate against the surface (polishing surface)  2 - 352   a  of the polishing pad  2 - 352 . At this time, the top ring  2 - 302  and the polishing table  2 - 350  are each rotated, and the polishing liquid is supplied from the polishing liquid supply nozzle  2 - 354  disposed above the polishing table  2 - 350  and/or from the opening portion  2 - 355  disposed in the polishing table  2 - 350  onto the polishing pad  2 - 352 . Thus, by pressing the substrate WF against the polishing surface  2 - 352   a  of the polishing pad  2 - 352 , the surface of the substrate WF can be polished. During polishing of the substrate WF, the arm  2 - 360  may be fixed or swung such that the top ring  2 - 302  passes through the center of the polishing pad  2 - 352  (so as to cover the through hole  2 - 357  of the polishing pad  2 - 352 ). 
     The up-and-down motion mechanism  2 - 319 , which vertically moves the top ring shaft  2 - 18  and the top ring  2 - 302 , includes a bridge  2 - 28  that rotatably supports the top ring shaft  2 - 18  via a bearing  2 - 321 , a ball screw  2 - 32  mounted to the bridge  2 - 28 , a support table  2 - 29  supported by a support column  2 - 130 , and an AC servo motor  2 - 38  disposed on the support table  2 - 29 . The support table  2 - 29  that supports the servo motor  2 - 38  is secured to the swing arm  2 - 360  via the support column  2 - 130 . 
     The ball screw  2 - 32  includes a screw shaft  2 - 32   a  coupled to the servo motor  2 - 38  and a nut  2 - 32   b  into which the screw shaft  2 - 32   a  is screwed. The top ring shaft  2 - 18  vertically moves integrally with the bridge  2 - 28 . Therefore, when the servo motor  2 - 38  is driven, the bridge  2 - 28  vertically moves via the ball screw  2 - 32 , whereby the top ring shaft  2 - 18  and the top ring  2 - 302  vertically move. 
     The polishing unit  2 - 300  according to the one embodiment includes a dressing unit  2 - 356  that dresses the polishing surface  2 - 352   a  of the polishing pad  2 - 352 . The dressing unit  2 - 356  includes a dresser  2 - 50  that is slidably in contact with the polishing surface  2 - 352   a , a dresser shaft  2 - 51  to which the dresser  2 - 50  is coupled, an air cylinder  2 - 53  disposed at an upper end of the dresser shaft  2 - 51 , and a swing arm  2 - 55  that rotatably supports the dresser shaft  2 - 51 . A lower portion of the dresser  2 - 50  is constituted by a dressing member  2 - 50   a , and needle-shaped diamond particles are attached to a lower surface of the dressing member  2 - 50   a . The air cylinder  2 - 53  is arranged on a support table  2 - 57  supported by support columns  2 - 56 , and these support columns  2 - 56  are secured to the swing arm  2 - 55 . 
     The swing arm  2 - 55  is configured to be driven by a motor (not illustrated) and turn around a spindle  2 - 58 . The dresser shaft  2 - 51  rotates by driving of a motor (not illustrated), and the rotation of the dresser shaft  2 - 51  causes the dresser  2 - 50  to rotate around the dresser shaft  2 - 51 . The air cylinder  2 - 53  vertically moves the dresser  2 - 50  via the dresser shaft  2 - 51  and presses the dresser  2 - 50  against the polishing surface  2 - 352   a  of the polishing pad  2 - 352  with a predetermined pressing force. 
     Dressing of the polishing surface  2 - 352   a  of the polishing pad  2 - 352  is performed in the following manner. The dresser  2 - 50  is pressed against the polishing surface  2 - 352   a  by the air cylinder  2 - 53 , and at the same time, pure water is supplied to the polishing surface  2 - 352   a  from a pure water supply nozzle (not illustrated). In this state, the dresser  2 - 50  rotates around the dresser shaft  2 - 51 , and the lower surface (diamond particles) of the dressing member  2 - 50   a  is brought into sliding contact with the polishing surface  2 - 352   a . Thus, the dresser  2 - 50  scrapes off the polishing pad  2 - 352  and dresses the polishing surface  2 - 352   a.    
     &lt;Drying Unit&gt; 
     The drying unit  2 - 500  is a device for drying the substrate WF. In the substrate processing apparatus  2 - 1000  illustrated in  FIG. 13 , the drying unit  2 - 500  dries the substrate WF which is cleaned by the cleaning unit of the conveyance unit  2 - 200  after being polished by the polishing unit  2 - 300 . As illustrated in  FIG. 13 , the drying unit  2 - 500  is arranged downstream of the conveyance unit  2 - 200 . The drying unit  2 - 500  includes nozzles  2 - 530  for injecting gas toward the substrate WF being conveyed on the conveyance rollers  2 - 202 . The gas can be, for example, compressed air or nitrogen. The substrate WF can be dried by blowing off water droplets on the conveyed substrate WF with the drying unit  2 - 500 . 
     &lt;Unloading Unit&gt; 
     The unloading unit  2 - 600  is a unit for carrying out the substrate WF after processing, such as polishing and cleaning, is performed to outside of the substrate processing apparatus  2 - 1000 . In the substrate processing apparatus  2 - 1000  illustrated in  FIG. 13 , the unloading unit  2 - 600  receives the substrate after being dried by the drying unit  2 - 500 . As illustrated in  FIG. 13 , the unloading unit  2 - 600  is arranged downstream of the drying unit  2 - 500 . In the one embodiment, the unloading unit  2 - 600  is configured to comply with Mechanical Equipment Interface Standard (IPC-SMEMA-9851) of Surface Mount Equipment Manufacturers Association (SMEMA). 
     &lt;Top Ring&gt; 
     Next, the top ring  2 - 302  in the polishing unit  2 - 300  according to the one embodiment will be described.  FIG. 15  is a cross-sectional view schematically illustrating the top ring  2 - 302  according to the one embodiment. As illustrated in  FIG. 15 , the top ring  2 - 302  includes a base member  2 - 301  coupled to the top ring shaft (rotary shaft)  2 - 18 . Specifically, the base member  2 - 301  includes a flange  2 - 303  coupled to the top ring shaft  2 - 18 , an upper portion guiding member  2 - 305  disposed at a lower portion of the flange  2 - 303 , and a lower portion guiding member  2 - 306  disposed at a lower portion of the upper portion guiding member  2 - 305 . The upper portion guiding member  2 - 305  has a smaller plane size than a plane size of the flange  2 - 303 , and projects downward from a lower surface of the flange  2 - 303 . The lower portion guiding member  2 - 306  is disposed in a frame shape on a peripheral edge portion of a lower surface of the upper portion guiding member  2 - 305 . Note that the plane size of the upper portion guiding member  2 - 305  or the flange  2 - 303  is the size of the upper portion guiding member  2 - 305  or the flange  2 - 303  when the upper portion guiding member  2 - 305  or the flange  2 - 303  is viewed in the plan view (viewed in the direction along the top ring shaft  2 - 18 ). 
     Further, the top ring  2 - 302  includes a substrate suction member  2 - 330  for suctioning the back surface of the substrate WF in a state where the surface to be polished faces downward. The substrate suction member  2 - 330  is arranged below the base member  2 - 301 . The substrate suction member  2 - 330  includes a porous member  2 - 334 . It is only necessary that the porous member  2 - 334  is a member that can perform vacuum-suction of the substrate WF by vacuum drawing using a pressure reducing unit (vacuum source)  2 - 31 , and can be constituted of, for example, a resin porous material in which many pores are formed in a resin, such as polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE), or polyvinyl chloride (PVC). The porous member  2 - 334  is formed in a plate shape in this embodiment and includes a substrate suction surface  2 - 334   a  for suctioning the substrate WF and a pressure reducing portion  2 - 334   b  communicating with the pressure reducing unit (vacuum source)  2 - 31 . 
     Further, the substrate suction member  2 - 330  includes a shielding member  2 - 332 . It is only necessary that the shielding member  2 - 332  is an airtight member that can shield the flow of gas, and can be formed of, for example, a relatively soft resin plate, such as polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE), or polyvinyl chloride (PVC). In this embodiment, the shielding member  2 - 332  is formed so as to shield a surface  2 - 334   c  of the porous member  2 - 334  on the opposite side of the substrate suction surface  2 - 334   a  and a side surface  2 - 334   d . The shielding member  2 - 332  includes a vacuum hole  2 - 336  formed so as to communicate with the porous member  2 - 334 . The pressure reducing portion  2 - 334   b  is disposed at a position where the vacuum hole  2 - 336  is formed. In this embodiment, the vacuum hole  2 - 336  is formed in the shielding member  2 - 332  so as to communicate with the side surface  2 - 334   d  of the porous member  2 - 334 , and the pressure reducing portion  2 - 334   b  is disposed on the side surface  2 - 334   d . One end portion of the vacuum hole  2 - 336  is connected to the side surface  2 - 334   d  of the porous member  2 - 334 , and the other end portion is connected to the pressure reducing unit  2 - 31  via a vacuum passage  2 - 312 . 
     By providing the shielding member  2 - 332 , when the porous member  2 - 334  is vacuum drawn by the pressure reducing unit (vacuum source)  2 - 31 , negative pressure can be efficiently formed on the substrate suction surface  2 - 334   a . Since this allows the substrate WF to be reliably suctioned to the substrate suction member  2 - 330 , jumping out (slipping out) of the substrate WF to outside during polishing can be avoided without providing a retainer member in the periphery of the substrate WF. In particular, as the substrate WF has been thinned in recent years, there is a possibility that the substrate WF slips out during polishing even when the retainer member is provided. Further, when the shape of the substrate WF is quadrangular, there is a possibility that the corner portions of the substrate WF come into contact with the retainer member during polishing, and the substrate WF or the top ring is damaged. In contrast to this, with this embodiment, since the substrate WF can be pressed against the polishing pad  2 - 352  while being vacuum suctioned by the substrate suction member  2 - 330 , the slipping out of the substrate WF during polishing can be avoided and the damage of the substrate WF or the top ring  2 - 302  can be avoided during polishing. 
     Further, in this embodiment, since the pressure reducing portion  2 - 334   b  is disposed on the side surface  2 - 334   d  of the porous member  2 - 334 , polishing profile of the substrate WF can be made uniform. That is, the position where the pressure reducing portion  2 - 334   b  is disposed is vacuum drawn by the pressure reducing unit  2 - 31 , thereby locally having negative pressure. Here, when the pressure reducing portion  2 - 334   b  is disposed on the surface  2 - 334   c  of the porous member  2 - 334  on the opposite side of the substrate suction surface  2 - 334   a , the position locally has negative pressure, and thus, the pressing force on the substrate WF becomes difficult to act as compared with other positions. As a result, there is a possibility that the polishing profile possibly becomes non-uniform. In contrast to this, in this embodiment, since the pressure reducing portion  2 - 334   b  is disposed on the side surface  2 - 334   d  of the porous member  2 - 334 , local negative pressure is unlikely to occur on the surface  2 - 334   c  of the porous member  2 - 334  on the opposite side of the substrate suction surface  2 - 334   a , and thus, the polishing profile of the substrate WF can be made uniform. 
     As illustrated in  FIG. 15 , the substrate suction member  2 - 330  includes a framing member  2 - 344  disposed on the shielding member  2 - 332  so as to surround at least a part of the periphery of the base member  2 - 301  (specifically, the upper portion guiding member  2 - 305  and the lower portion guiding member  2 - 306 ). The framing member  2 - 344  includes a lower portion framing member  2 - 343  disposed in a frame shape on the peripheral edge portion of an upper surface of the shielding member  2 - 332 , and a frame-shaped upper portion framing member  2 - 342  disposed on the lower portion framing member  2 - 343 . The lower portion framing member  2 - 343  is coupled to the shielding member  2 - 332  via a sealing material  2 - 341 . Note that in this embodiment, although the sealing material  2 - 341  is formed in a film shape covering an upper surface of the substrate suction member  2 - 330 , it is not limited to this. The sealing material  2 - 341  may be a frame shape having only the peripheral edge portion for sealing the lower portion framing member  2 - 343  and the shielding member  2 - 332 . 
     The upper portion framing member  2 - 342  includes a framing member protrusion  2 - 342   a  projecting in a direction toward the base member  2 - 301  (specifically, the upper portion guiding member  2 - 305 ). Further, the upper portion guiding member  2 - 305  includes a guiding member protrusion  2 - 305   a  projecting in a direction toward the upper portion framing member  2 - 342  at a height position different from that of the framing member protrusion  2 - 342   a . The framing member protrusion  2 - 342   a  and the guiding member protrusion  2 - 305   a  mutually overlap in a predetermined area when the top ring  2 - 302  is viewed in the plan view. Therefore, the movement in the height direction of the substrate suction member  2 - 330  can be restricted by the contact between the framing member protrusion  2 - 342   a  and the guiding member protrusion  2 - 305   a.    
     The substrate suction member  2 - 330  includes an elastic member  2 - 340  that connects at least a part of the base member  2 - 301  surrounded by the framing member  2 - 344  to the framing member  2 - 344 . Specifically, the elastic member  2 - 340  is a frame-shaped plate member that includes an inner end portion  2 - 340   a  sandwiched between the upper portion guiding member  2 - 305  and the lower portion guiding member  2 - 306  and an outer end portion  2 - 340   b  sandwiched between the lower portion framing member  2 - 343  and the upper portion framing member  2 - 342 . The elastic member  2 - 340  can be formed of a rubber material, for example but not limited to silicon rubber, ethylene propylene diene rubber (EPDM), or fluororubber (FKM). 
     As illustrated in  FIG. 15 , the top ring  2 - 302  includes an elastic film  2 - 320  configured to form a plurality of pressurization chambers for pressurizing the substrate WF between the base member  2 - 301  and the substrate suction member  2 - 330 . Specifically, the elastic film  2 - 320  includes a plurality of pieces of elastic films  2 - 320 - 1 ,  2 - 320 - 2 , and  2 - 320 - 3  that have different areas and are laminated. The elastic films  2 - 320 - 1 ,  2 - 320 - 2 , and  2 - 320 - 3  each include a center portion that is in contact with the upper surface of the shielding member  2 - 332 , and an end portion that extends from the center portion and is secured to a different position of the lower surface of the upper portion guiding member  2 - 305 . With the plurality of elastic films  2 - 320 - 1 ,  2 - 320 - 2 , and  2 - 320 - 3 , a plurality of concentric pressurization chambers for pressurizing the substrate WF are formed between the base member  2 - 301  and the plurality of pieces of elastic films  2 - 320 - 1 ,  2 - 320 - 2 , and  2 - 320 - 3 . The plurality of pressurization chambers each communicate with a pressure adjustment portion  2 - 30  via a pressurization passage  2 - 313 . The pressure adjustment portion  2 - 30  has a pressure adjustment function for adjusting the pressure of pressurized fluid supplied to each pressurization chamber. By forming the plurality of pressurization chambers, the pressing force of the substrate WF against the polishing pad  2 - 352  can be controlled for each area via the substrate suction member  2 - 330 . With this embodiment, while the substrate WF is suctioned to the substrate suction surface  2 - 334   a  by making the porous member  2 - 334  to have negative pressure by using the pressure reducing unit  2 - 31 , the substrate WF can be pressed against the polishing pad  2 - 352  via the substrate suction member  2 - 330  by pressurizing the pressurization chambers by the pressure adjustment portion  2 - 30 . 
     Further, as illustrated in  FIG. 15 , the top ring  2 - 302  further includes a band  2 - 345  connecting an outer side surface of the portion of the base member  2 - 301  that is not surrounded by the framing member  2 - 344  (specifically, the flange  2 - 303 ) to an outer side surface of the framing member  2 - 344 . The band  2 - 345  is mounted from the outer side surface of the flange  2 - 303  to the outer side surface of the upper portion framing member  2 - 342 . The band  2 - 345  allows displacement of the substrate suction member  2 - 330  relative to the base member  2 - 301  while avoiding polishing liquid or the like from penetrating into a space between the substrate suction member  2 - 330  and the base member  2 - 301 . 
     According to this embodiment, even when the top ring  2 - 302  or the polishing table  2 - 350 , to which the polishing pad  2 - 352  is attached, is tilted due to manufacturing tolerances or the like of respective components constituting the substrate processing apparatus  2 - 1000 , the substrate WF can be uniformly pressed against the polishing pad  2 - 352 . That is, according to this embodiment, the substrate suction member  2 - 330  is not secured to the base member  2 - 301  but is held to the elastic member  2 - 340 . In view of this, even if the top ring  2 - 302  or the polishing table  2 - 350  is tilted and the substrate WF partially contacts the polishing pad  2 - 352 , the elasticity of the elastic member  2 - 340  causes the substrate suction member  2 - 330  to align with the polishing surface of the polishing pad  2 - 352 , and as a result, the substrate WF can be brought into contact with the polishing pad  2 - 352  in parallel. Therefore, with this embodiment, the substrate WF can be uniformly pressed against the polishing pad  2 - 352 . 
     In addition to this, with this embodiment, a compact top ring can be realized. That is, when the substrate suction member is supported to the base member via the elastic member, it is conceivable to, for example, provide an opening in the center of the lower surface of the base member, install the substrate suction member at the opening, and connect the frame-shaped member on the peripheral edge portion forming the opening to the substrate suction member with the elastic member. However, with such a configuration, when an attempt is made to route the vacuum passage for vacuum suction from the porous member through the frame-shaped member of the top ring, the plane size of the top ring becomes large due to space limitation of the frame-shaped member, which possibly hinders downsizing of the top ring. 
     In contrast to this, in the top ring  2 - 302  of this embodiment, the substrate suction member  2 - 330  includes the framing member  2 - 344  that surrounds at least a part of the base member  2 - 301 , and connects the framing member  2 - 344  to the base member  2 - 301  with the elastic member  2 - 340 . Therefore, as in this embodiment, even when the pressure reducing portion  2 - 334   b  is disposed on the side surface  2 - 334   d  of the porous member  2 - 334  and the vacuum passage  2 - 312  is routed through the outer peripheral portion of the top ring  2 - 302 , the plane size of the framing member  2 - 344  does not have to be increased, and as a result, the top ring  2 - 302  can be manufactured compactly. Note that the plane size of the top ring  2 - 302  or the framing member  2 - 344  is the size of the top ring  2 - 302  or the framing member  2 - 344  when the top ring  2 - 302  or the framing member  2 - 344  is viewed in the plan view (viewed in the direction along the top ring shaft  2 - 18 ). 
     Next, another aspect of the top ring  2 - 302  of this embodiment will be described.  FIG. 16  is a cross-sectional perspective view schematically illustrating a top ring according to the one embodiment.  FIG. 17  is a cross-sectional view schematically illustrating a top ring according to the one embodiment.  FIG. 18  is an enlarged cross-sectional view schematically illustrating a part of a top ring according to the one embodiment. In the embodiments illustrated in  FIG. 16  to  FIG. 18 , the description of duplicate configuration of the embodiment of  FIG. 15  will be omitted. 
     As illustrated in  FIG. 16  and  FIG. 17 , the base member  2 - 301  is configured to include the flange  2 - 303  coupled to the top ring shaft  2 - 18 , a spacer  2 - 304  mounted to the lower surface of the flange  2 - 303 , the upper portion guiding member  2 - 305  mounted to a lower surface of the spacer  2 - 304 , and the frame-shaped lower portion guiding member  2 - 306  mounted to the lower surface of the upper portion guiding member  2 - 305 . The flange  2 - 303 , the spacer  2 - 304 , and the upper portion guiding member  2 - 305  are fastened by bolts  2 - 307 . The upper portion guiding member  2 - 305  and the lower portion guiding member  2 - 306  sandwich the elastic member  2 - 340  and are fastened by bolts  2 - 326  (in the view, the form of fastening is schematically simplified). The shielding member  2 - 332 , the upper portion framing member  2 - 342 , and the lower portion framing member  2 - 343  are fastened by bolts  2 - 308 . The respective end portions of the elastic films  2 - 320 - 1 ,  2 - 320 - 2 , and  2 - 320 - 3  are fastened by bolts  2 - 325  to different positions on the lower surface of the upper portion guiding member  2 - 305  via respective holders (in the view, the form of fastening is schematically simplified). 
     As illustrated in  FIG. 18 , the shielding member  2 - 332  includes a frame-shaped lower portion shielding member  2 - 332 - 1  that surrounds the periphery of the side surface  2 - 334   d  of the porous member  2 - 334  and an upper portion shielding member  2 - 332 - 2  that covers the lower portion shielding member  2 - 332 - 1  and an upper surface of the porous member  2 - 334  (the surface  2 - 334   c  on the opposite side of the substrate suction surface  2 - 334   a ). Further, in this embodiment, the pressure reducing portion  2 - 334   b  of the porous member  2 - 334  is disposed on the peripheral edge portion of the upper surface of the porous member  2 - 334 . The vacuum hole  2 - 336  includes one end portion that is connected to the pressure reducing portion  2 - 334   b , extends in an outer peripheral direction between the lower portion shielding member  2 - 332 - 1  and the upper portion shielding member  2 - 332 - 2 , and passes through the lower portion framing member  2 - 343  and the upper portion framing member  2 - 342  to extend in the upward direction. The vacuum hole  2 - 336  includes the other end portion that is connected to a vacuum port  2 - 314  disposed on the upper portion framing member  2 - 342 . 
       FIG. 19A  is a plan view schematically illustrating a pattern area and a non-pattern area of a substrate of the one embodiment, and  FIG. 19B  is a plan view schematically illustrating a substrate suction member of the one embodiment.  FIG. 19A  schematically illustrates a pattern area and a non-pattern area of a substrate of the one embodiment. As illustrated in  FIG. 19A , the substrate WF of this embodiment has a pattern area  2 - 10  on which wiring, functional chips, or the like are disposed and a non-pattern area  2 - 20  on which wiring, functional chips, or the like are not disposed. As illustrated in  FIG. 19A , the non-pattern area  2 - 20  is disposed on the peripheral edge portion of the substrate WF and is disposed in a straight line so as to split the area excluding the peripheral edge portion into two upper and lower parts. The pattern area  2 - 10  is disposed in an area surrounded by the non-pattern area  2 - 20 . As illustrated in  FIG. 19B , the pressure reducing portion  2 - 334   b  of the porous member  2 - 334  is disposed corresponding to the non-pattern area  2 - 20  of the substrate WF. In this embodiment, the pressure reducing portion  2 - 334   b  is connected to the vacuum holes  2 - 336  disposed at four positions. In this embodiment, since the pressure reducing portion  2 - 334   b  is disposed corresponding to the non-pattern area  2 - 20  of the substrate WF, the position where the pressure reducing portion  2 - 334   b  is disposed locally becomes to have negative pressure. Even if the pressing force on the substrate WF become difficult to act, the polishing profile on the pattern area  2 - 10  of the substrate WF is not affected. 
       FIG. 20  is a perspective view schematically illustrating a substrate suction member according to the one embodiment.  FIG. 21  is an enlarged view of AA area of  FIG. 20 . As illustrated in  FIG. 20 , according to this embodiment, the vacuum ports  2 - 314  are disposed at four positions corresponding to the vacuum holes  2 - 336 . Each vacuum port  2 - 314  is connected to the pressure reducing unit  31  (not illustrated) via the vacuum passage  2 - 312  and a vacuum connector  2 - 311 . 
     As illustrated in  FIG. 20  and  FIG. 21 , the upper portion framing member  2 - 342  includes stoppers  2 - 346  disposed at the respective four corners of the upper portion framing member  2 - 342 . The stopper  2 - 346  is configured to connect different positions of the upper portion framing member  2 - 342  over an inside of the frame in an arch shape, and in this embodiment, is configured to connect two sides forming a corner of the upper portion framing member  2 - 342  in an arch shape. On the other hand, the upper portion guiding member  2 - 305  includes pads  2 - 309  disposed at the respective four corners of the upper portion guiding member  2 - 305 . The pad  2 - 309  is disposed at the position corresponding to the stopper  2 - 346 . The pad  2 - 309  is formed in a disk shape at a corner of the upper portion framing member  2 - 342  at a height position different from that of the stopper  2 - 346 . The stopper  2 - 346  and the pad  2 - 309  mutually overlap in a predetermined area when the top ring  2 - 302  is viewed in the plan view. Therefore, the movement of the substrate suction member  2 - 330  in the height direction can be restricted by the contact between the stopper  2 - 346  and the pad  2 - 309 . 
     According to the embodiments illustrated in  FIG. 16  to  FIG. 21 , similarly to the embodiment illustrated in  FIG. 15 , the substrate suction member  2 - 330  is not secured to the base member  2 - 301  but is held to the elastic member  2 - 340 . In view of this, even if the top ring  2 - 302  or the polishing table  2 - 350  is tilted and the substrate WF partially contacts the polishing pad  2 - 352 , the elasticity of the elastic member  2 - 340  causes the substrate suction member  2 - 330  to align with the polishing surface of the polishing pad  2 - 352 , and as a result, the substrate WF can be uniformly pressed against the polishing pad  2 - 352 . In addition to this, according to the embodiments illustrated in  FIG. 16  to  FIG. 21 , similarly to the embodiment illustrated in  FIG. 15 , the substrate suction member  2 - 330  includes the framing member  2 - 344  surrounding at least a part of the base member  2 - 301 , and connects the framing member  2 - 344  to the base member  2 - 301  with the elastic member  2 - 340 . Therefore, even when the vacuum passage  2 - 312  is routed through the outer peripheral portion of the top ring  2 - 302 , the plane size of the framing member  2 - 344  does not have to be increased, and as a result, the top ring  2 - 302  can be manufactured compactly. 
     In the above description, some embodiments of this invention are explained; and the above embodiments of this invention are those used for facilitating understanding of this invention and are not those for limiting this invention. It is obvious that this invention can be changed or modified without departing from the scope of the gist thereof, and that the scope of this invention includes equivalents thereof. Further, it is possible to arbitrarily combine components or omit a component (components) disclosed in the claims and the specification, within the scope that at least part of the above-stated problems can be solved and/or within the scope that at least part of advantageous effect can be obtained. 
     This application discloses, as one embodiment, a top ring for holding a substrate that includes a base member, an elastic film, and a substrate suction member. The base member is coupled to a rotary shaft. The elastic film is mounted to the base member and forms a pressurization chamber for pressurizing the substrate between the base member and the elastic film. The substrate suction member includes a porous member having a substrate suction surface for suctioning the substrate and a pressure reducing portion communicating with a pressure reducing unit. The substrate suction member is held to the elastic film. 
     With this top ring, since the substrate suction member is held to the elastic film, even if the substrate partially contacts a polishing pad, the elasticity of the elastic film allows the substrate to come into contact with the polishing pad in parallel, and as a result, an effect that the substrate can be uniformly pressed against the polishing pad is provided as one example. 
     Additionally, this application discloses, as the one embodiment, a top ring for holding a substrate that includes a base member, an elastic film, and a substrate holding member. The base member is coupled to a rotary shaft. The elastic film is mounted to the base member and forms a pressurization chamber for pressurizing the substrate between the base member and the elastic film. The substrate holding member includes an elastic plate-shaped member mirror-finished such that an arithmetic mean roughness Ra of the substrate holding surface for holding the substrate becomes less than or equal to 5 μm. The substrate holding member is held to the elastic film. 
     With this top ring, by mirror-finishing the substrate holding surface of the substrate holding member, a friction force between the substrate and the substrate holding surface improves to allow the substrate to be adhered and held on the substrate holding surface. As a result, with this embodiment, an effect that slipping out of the substrate can be avoided during polishing without using a retainer member to guard a periphery of the substrate is provided as one example. 
     Additionally, this application discloses, as the one embodiment, the top ring in which the substrate suction member includes the porous member and a shielding member configured to shield a surface of the porous member on an opposite side of the substrate suction surface and a side surface of the porous member. 
     With this top ring, when the porous member is vacuum drawn by a pressure reducing unit (vacuum source), negative pressure can be efficiently formed on the substrate suction surface, and therefore, the substrate can be suctioned reliably to the substrate suction member and an effect that slipping out of the substrate from the substrate suction member can be avoided during polishing is provided as one example. 
     Additionally, this application discloses, as the one embodiment, the top ring in which the shielding member includes a hole formed so as to expose the porous member, and the pressure reducing portion is disposed at a position where the hole is formed. 
     With this top ring, since the porous member can be decompressed via the hole formed in the shielding member, the substrate can be reliably suctioned to the substrate suction member, and an effect that slipping out of the substrate from the substrate suction member can be avoided during polishing is provided as one example. 
     Additionally, this application discloses, as the one embodiment, the top ring in which the substrate suction member includes a plurality of the porous members and a shielding member configured to shield respective surfaces of the plurality of the porous members on an opposite side of the substrate suction surfaces, the shielding member includes a plurality of holes formed to expose the respective plurality of the porous members, and the respective pressure reducing portions are disposed at positions where the plurality of holes are formed. 
     With this top ring, since the whole substrate suction member can be decompressed by the pressure reducing unit (vacuum source), even if a substrate is large, the substrate can be firmly suctioned to the substrate suction member. As a result, an effect that slipping out of the substrate from the top ring can be avoided during polishing is provided as one example. 
     Additionally, this application discloses, as the one embodiment, the top ring in which the base member includes a lower portion guiding member disposed so as to surround a periphery of the substrate suction member and an upper portion guiding member disposed on an upper portion of the lower portion guiding member, and the elastic film includes a center portion covering a surface of the substrate suction member on an opposite side of the substrate suction surface and an end portion sandwiched between the upper portion guiding member and the lower portion guiding member. 
     With this top ring, since the substrate suction member is held to the elastic film, the end portion of which is sandwiched between the upper portion guiding member and the lower portion guiding member, even if the substrate partially contacts the polishing pad, the elasticity of the elastic film allows the substrate to come into contact with the polishing pad in parallel, and as a result, an effect that the substrate can be uniformly pressed against the polishing pad is provided as one example. 
     Additionally, this application discloses, as the one embodiment, the top ring in which the elastic film includes a plurality of pieces of elastic films, the plurality of pieces of elastic films include center portions connected to a surface of the substrate suction member on an opposite side of the substrate suction surface and end portions secured to different positions on the base member, the plurality of pieces of elastic films are configured to form a plurality of pressurization chambers for pressurizing the substrate between the base member and the plurality of pieces of elastic films. 
     With this top ring, an effect that the pressing force of the substrate against the polishing pad can be controlled for each area by forming the plurality of pressurization chambers is provided as one example. 
     Additionally, this application discloses, as the one embodiment, the top ring that further includes a plurality of stopper members. The plurality of stopper members are coupled to the substrate suction member with the elastic film sandwiched at an end portion of the substrate suction member and have flange portions that project outward with respect to the substrate suction member. The base member includes a lower portion guiding member disposed so as to surround a periphery of the substrate suction member and an upper portion guiding member disposed on an upper portion of the lower portion guiding member, and the upper portion guiding member and the lower portion guiding member have regulating surfaces that regulate movement of the flange portions of the stopper members in a vertical direction. 
     With this top ring, an effect that a range of the movement in the vertical direction of the substrate suction member can be restricted to a desired range is provided as one example. 
     Additionally, this application discloses, as the one embodiment, a substrate processing apparatus that includes any of the above-described top ring and a polishing table configured to hold a polishing pad. 
     In this substrate processing apparatus, since the substrate suction member is held to the elastic film, even if the substrate partially contacts the polishing pad, the elasticity of the elastic film allows the substrate to come into contact with the polishing pad in parallel, and as a result, an effect that the substrate can be uniformly pressed against the polishing pad is provided as one example. 
     This application discloses, as the one embodiment, the top ring for holding a substrate that includes a base member, a substrate suction member, and an elastic member. The base member is coupled to a rotary shaft. The substrate suction member includes a porous member, a shielding member, and a framing member. The porous member includes a substrate suction surface for suctioning the substrate and a pressure reducing portion communicating with a pressure reducing unit. The shielding member is configured to shield a surface of the porous member on an opposite side of the substrate suction surface and a side surface. The framing member is disposed on the shielding member so as to surround at least a part of a periphery of the base member. The elastic member connects the at least a part of the base member surrounded by the framing member to the framing member. 
     Additionally, this application discloses, as the one embodiment, the top ring in which the shielding member includes a vacuum hole formed so as to communicate with the porous member, and the pressure reducing portion is disposed at a position where the vacuum hole is formed. 
     Additionally, this application discloses, as the one embodiment, the top ring in which the vacuum hole is formed in the shielding member so as to communicate with a peripheral edge portion of an upper surface of the porous member or the side surface of the porous member. 
     Additionally, this application discloses, as the one embodiment, the top ring in which the framing member includes a lower portion framing member disposed on a peripheral edge portion of an upper surface of the shielding member and an upper portion framing member disposed above the lower portion framing member, the base member includes a flange coupled to the rotary shaft, an upper portion guiding member disposed on a lower portion of the flange and having a smaller plane size than a plane size of the flange, and a frame-shaped lower portion guiding member disposed on a lower portion of the upper portion guiding member, and the elastic member is a plate-shaped member that includes an inner end portion sandwiched between the upper portion guiding member and the lower portion guiding member and an outer end portion sandwiched between the lower portion framing member and the upper portion framing member. 
     Additionally, this application discloses, as the one embodiment, the top ring in which the upper portion framing member or the lower portion framing member includes a framing member protrusion projecting in a direction toward the base member, and the upper portion guiding member or the lower portion guiding member includes a guiding member protrusion that projects in a direction toward the upper portion framing member or the lower portion framing member at a height position different from a height position of the framing member protrusion and overlaps the framing member protrusion. 
     Additionally, this application discloses, as the one embodiment, the top ring in which the upper portion framing member or the lower portion framing member includes a stopper connecting different positions of the upper portion framing member or the lower portion framing member over an inside of the frame in an arch shape, and the upper portion guiding member or the lower portion guiding member includes a pad overlapping the stopper at a height position different from a height position of the stopper. 
     Additionally, this application discloses, as the one embodiment, the top ring that further includes a plurality of pieces of elastic films configured to form a plurality of pressurization chambers for pressurizing the substrate between the base member and the substrate suction member. 
     Additionally, this application discloses, as the one embodiment, the top ring that further includes a band connecting an outer side surface of a portion of the base member that is not surrounded by the framing member and an outer side surface of the framing member. 
     Additionally, as the one embodiment, this application discloses a substrate processing apparatus that includes any of the above-described top ring and a polishing table configured to hold a polishing pad. 
     REFERENCE SIGNS LIST 
     
         
         
           
               18  . . . top ring shaft (rotary shaft) 
               31  . . . pressure reducing unit (vacuum source) 
               300  . . . polishing unit 
               301  . . . base member 
               302  . . . top ring 
               303  . . . flange 
               304  . . . spacer 
               305  . . . upper portion guiding member 
               305   a ,  306   a  . . . regulating surface 
               306  . . . lower portion guiding member 
               320 . 402 . 420  . . . elastic film 
               322  . . . pressurization chamber 
               330  . . . substrate suction member 
               332  . . . shielding member 
               334  . . . porous member 
               334   a  . . . substrate suction surface 
               334   b  . . . pressure reducing portion 
               352  . . . polishing pad 
               430  . . . substrate holding member 
               431  . . . elastic plate-shaped member 
               431   a  . . . substrate holding surface 
               1000  . . . substrate processing apparatus 
               2 - 18  . . . top ring shaft (rotary shaft) 
               2 - 31  . . . pressure reducing unit (vacuum source) 
               2 - 301  . . . base member 
               2 - 302  . . . top ring 
               2 - 303  . . . flange 
               2 - 305  . . . upper portion guiding member 
               2 - 305   a  . . . guiding member protrusion 
               2 - 306  . . . lower portion guiding member 
               2 - 309  . . . pad 
               2 - 312  . . . vacuum passage 
               2 - 314  . . . vacuum port 
               2 - 320  . . . elastic film 
               2 - 330  . . . substrate suction member 
               2 - 332  . . . shielding member 
               2 - 332 - 1  . . . lower portion shielding member 
               2 - 332 - 2  . . . upper portion shielding member 
               2 - 334  . . . porous member 
               2 - 334   a  . . . substrate suction surface 
               2 - 334   b  . . . pressure reducing portion 
               2 - 334   c  . . . surface on opposite side of substrate suction surface  2 - 334   a    
               2 - 334   d  . . . side surface 
               2 - 336  . . . vacuum hole 
               2 - 340  . . . elastic member 
               2 - 340   a  . . . inner end portion 
               2 - 340   b  . . . outer end portion 
               2 - 342  . . . upper portion framing member 
               2 - 342   a  . . . framing member protrusion 
               2 - 343  . . . lower portion framing member 
               2 - 344  . . . framing member 
               2 - 345  . . . band 
               2 - 346  . . . stopper 
               2 - 1000  . . . substrate processing apparatus 
             WF . . . substrate