Patent Publication Number: US-2021183687-A1

Title: Edge ring arrangement with moveable edge rings

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present disclosure is a continuation of U.S. patent application Ser. No. 16/131,822, filed on Sep. 14, 2018, which is a continuation of U.S. patent application Ser. No. 14/705,430, filed on May 6, 2015, which is a continuation-in-part of U.S. patent application Ser. No. 14/598,943, filed on Jan. 16, 2015. The entire disclosures of the application referenced above are incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure relates to substrate processing systems, and more particularly to edge coupling rings of substrate processing systems. 
     BACKGROUND 
     The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
     Substrate processing systems may be used to perform etching and/or other treatment of substrates such as semiconductor wafers. A substrate may be arranged on a pedestal in a processing chamber of the substrate processing system. For example during etching in a plasma enhanced chemical vapor deposition (PECVD) process, a gas mixture including one or more precursors is introduced into the processing chamber and plasma is struck to etch the substrate. 
     Edge coupling rings have been used to adjust an etch rate and/or etch profile of the plasma near a radially outer edge of the substrate. The edge coupling ring is typically located on the pedestal around the radially outer edge of the substrate. Process conditions at the radially outer edge of the substrate can be modified by changing a position of the edge coupling ring, a shape or profile of an inner edge of the edge coupling ring, a height of the edge coupling ring relative to an upper surface of the substrate, a material of the edge coupling ring, etc. 
     Changing the edge coupling ring requires the processing chamber to be opened, which is undesirable. In other words, an edge coupling effect of the edge coupling ring cannot be altered without opening the processing chamber. When the edge coupling ring is eroded by plasma during etching, the edge coupling effect changes. Correcting erosion of the edge coupling ring requires the processing chamber to be opened in order to replace the edge coupling ring. 
     Referring now to  FIGS. 1-2 , a substrate processing system may include a pedestal  20  and an edge coupling ring  30 . The edge coupling ring  30  may include a single piece or two or more portions. In the example in  FIGS. 1-2 , the edge coupling ring  30  includes a first annular portion  32  arranged near a radially outer edge of a substrate  33 . A second annular portion  34  is located radially inwardly from the first annular portion below the substrate  33 . A third annular portion  36  is arranged below the first annular portion  32 . During use, plasma  42  is directed at the substrate  33  to etch the exposed portions of the substrate  33 . The edge coupling ring  30  is arranged to help shape the plasma such that uniform etching of the substrate  33  occurs. 
     In  FIG. 2 , after the edge coupling ring  30  has been used, an upper surface of a radially inner portion of the edge coupling ring  30  may exhibit erosion as identified at  48 . As a result, plasma  42  may tend to etch a radially outer edge of the substrate  33  at a faster rate than etching of radially inner portions thereof as can be seen at  44 . 
     SUMMARY 
     A substrate processing system includes a processing chamber and a pedestal arranged in the processing chamber. An edge coupling ring is arranged adjacent to a radially outer edge of the pedestal. A first actuator is configured to selectively move the edge coupling ring to a raised position relative to the pedestal to provide clearance between the edge coupling ring and the pedestal to allow a robot arm to remove the edge coupling ring from the processing chamber. 
     In other features, a lifting ring is arranged below at least part of the edge coupling ring. The first actuator biases the lifting ring and the lifting ring biases the edge coupling ring. A pillar is arranged between the first actuator and the lifting ring. A robot arm is configured to remove the edge coupling ring from the processing chamber when the edge coupling ring and the lifting ring are in a raised position. A holder is connected to the robot arm. The holder includes a self-centering feature that mates with a self-centering feature on the edge coupling ring. The edge coupling ring includes a self-centering feature that mates with a self-centering feature on the lifting ring. 
     In other features, a bottom edge coupling ring is arranged below at least part of the edge coupling ring and the lifting ring. The bottom edge coupling ring includes a self-centering feature that mates with a self-centering feature on the lifting ring. 
     In other features, the lifting ring includes a projection that extends radially outwardly. The projection includes a groove formed on a bottom facing surface thereof. The groove is biased by the pillar when the edge coupling ring is lifted. 
     In other features, the robot arm removes the edge coupling ring from the processing chamber without requiring the processing chamber to be opened to atmospheric pressure. A second actuator is configured to move the edge coupling ring relative to the lifting ring to alter an edge coupling profile of the edge coupling ring. A middle edge coupling ring is arranged between at least part of the edge coupling ring and the lifting ring. The middle edge coupling ring remains stationary when the second actuator moves the edge coupling ring relative to the lifting ring. 
     In other features, a controller is configured to move the edge coupling ring using the second actuator in response to erosion of a plasma-facing surface of the edge coupling ring. The controller is configured to automatically move the edge coupling ring using the second actuator after the edge coupling ring is exposed to a predetermined number of etching cycles. The controller is configured to automatically move the edge coupling ring using the second actuator after the edge coupling ring is exposed to a predetermined period of etching. 
     In other features, a sensor is configured to communicate with the controller and to detect the erosion of the edge coupling ring. A robot arm is configured to communicate with the controller and to adjust a position of the sensor. A controller is configured to move the edge coupling ring to a first position using the second actuator for a first treatment of the substrate using a first edge coupling effect and then to a second position using the second actuator for a second treatment of the substrate using a second edge coupling effect that is different than the first edge coupling effect. 
     A method for maintaining an edge coupling ring in a substrate processing system includes arranging an edge coupling ring adjacent to a radially outer edge of a pedestal in a processing chamber; using a first actuator to selectively move the edge coupling ring to a raised position relative to the pedestal; and replacing the edge coupling ring using a robot arm when the edge coupling ring is in the raised position. 
     In other features, the method includes arranging a lifting ring below at least part of the edge coupling ring. The actuator biases the lifting ring and the lifting ring biases the edge coupling ring. The method includes arranging a pillar between the first actuator and the lifting ring. The method includes attaching a holder to the robot arm. The holder includes a self-centering feature that mates with a self-centering feature on the edge coupling ring. The method includes using a self-centering feature on the edge coupling ring to mate with a self-centering feature on the lifting ring. 
     In other features, the method includes arranging a bottom edge coupling ring below at least part of the edge coupling ring and the lifting ring. The method includes using a self-centering feature on the bottom edge coupling ring to mate with a self-centering feature on the lifting ring. The lifting ring includes a projection that extends radially outwardly. The projection includes a groove formed on a bottom facing surface thereof. The groove is biased by the pillar when the edge coupling ring is lifted. 
     In other features, the method includes moving the edge coupling ring relative to the lifting ring using a second actuator to alter an edge coupling profile of the edge coupling ring. The method includes arranging a middle edge coupling ring between at least part of the edge coupling ring and the lifting ring, wherein the middle edge coupling ring remains stationary when the second actuator moves the edge coupling ring relative to the lifting ring. 
     In other features, the method includes moving the edge coupling ring using the second actuator in response to erosion of a plasma-facing surface of the edge coupling ring. The method includes automatically moving the edge coupling ring after the edge coupling ring is exposed to a predetermined number of etching cycles. The method includes automatically moving the edge coupling ring after the edge coupling ring is exposed to a predetermined period of etching. 
     In other features, the method includes detecting erosion of the edge coupling ring using a sensor. The method includes moving the edge coupling ring to a first position using the second actuator for a first treatment of the substrate using a first edge coupling effect and then to a second position using the second actuator for a second treatment of the substrate using a second edge coupling effect that is different than the first edge coupling effect. 
     Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a side cross-sectional view of a pedestal and an edge coupling ring according to the prior art; 
         FIG. 2  is a side cross-sectional view of a pedestal and an edge coupling ring according to the prior art after erosion of the edge coupling ring has occurred; 
         FIG. 3  is a side cross-sectional view of an example of a pedestal, an edge coupling ring and an actuator according to the present disclosure; 
         FIG. 4  is a side cross-sectional view of the pedestal, the edge coupling ring and the actuator of  FIG. 3  after erosion of the edge coupling ring has occurred; 
         FIG. 5  is a side cross-sectional view of the pedestal, the edge coupling ring and the actuator of  FIG. 3  after erosion of the edge coupling ring has occurred and the actuator is moved; 
         FIG. 6  is a side cross-sectional view of another example of a pedestal, an edge coupling ring and an actuator located in another position according to the present disclosure; 
         FIG. 7  is a side cross-sectional view of another example of a pedestal, an edge coupling ring and a piezoelectric actuator according to the present disclosure; 
         FIG. 8  is a side cross-sectional view of the pedestal, the edge coupling ring and the piezoelectric actuator of  FIG. 7  after erosion has occurred and the piezoelectric actuator is moved; 
         FIG. 9  is a functional block diagram of an example of a substrate processing chamber including a pedestal, an edge coupling ring and an actuator according to the present disclosure; 
         FIG. 10  is a flowchart illustrating steps of an example of a method for operating the actuator to move the edge coupling ring according to the present disclosure; 
         FIG. 11  is a flowchart illustrating steps of another example of a method for operating the actuator to move the edge coupling ring according to the present disclosure; 
         FIG. 12  is a functional block diagram of an example of a processing chamber including an edge coupling ring movable by actuators arranged outside of the processing chamber according to the present disclosure; 
         FIG. 13A and 13B  illustrates an example of side-to-side tilting of an edge coupling ring according to the present disclosure; 
         FIG. 14  illustrates an example of a method for moving an edge coupling ring during processing of a substrate; 
         FIG. 15  is a plan view of an example of a pedestal including an edge coupling ring and a lifting ring; 
         FIG. 16  is a side cross-sectional view of an example of the edge coupling ring and lifting ring; 
         FIG. 17  is a side cross-sectional view of an example of the edge coupling ring being lifted by the lifting ring and the edge coupling ring being removed by a robot arm; 
         FIG. 18  is a side cross-sectional view of an example of a movable edge coupling ring and a lifting ring; 
         FIG. 19  is a side cross-sectional view of the movable edge coupling ring of  FIG. 18  in a raised position; 
         FIG. 20  is a side cross-sectional view of the edge coupling ring of  FIG. 18  being lifted by the lifting ring and the edge coupling ring being removed by a robot arm; 
         FIG. 21  is a side cross-sectional view of an example of a movable edge coupling ring; 
         FIG. 22  is a side cross-sectional view of the edge coupling ring of  FIG. 21  being lifted by the actuator and removed by a robot arm; 
         FIG. 23  is an example of a method for replacing an edge coupling ring without opening a processing chamber; 
         FIG. 24  is an example of a method for moving an edge coupling ring due to erosion and replacing an edge coupling ring without opening a processing chamber; and 
         FIG. 25  is an example of a method for raising an edge coupling ring due to erosion and replacing the edge coupling ring without opening a processing chamber. 
       In the drawings, reference numbers may be reused to identify similar and/or identical elements. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure allows one or more portions of an edge coupling ring to be moved vertically and/or horizontally relative to a substrate or pedestal in a substrate processing system. The movement changes an edge coupling effect of the plasma relative to the substrate during etching or other substrate treatment without requiring the processing chamber to be opened. 
     Referring now to  FIGS. 3-5 , a substrate processing system includes a pedestal  20  and an edge coupling ring  60 . The edge coupling ring  60  may be made of a single portion or two or more portions may be used. In the example in  FIGS. 3-5 , the edge coupling ring  60  includes a first annular portion  72  arranged radially outside of the substrate  33 . A second annular portion  74  is located radially inwardly from the first annular portion  72  below the substrate  33 . A third annular portion  76  is arranged below the first annular portion  72 . 
     An actuator  80  may be arranged in various locations to move one or more portions of the edge coupling ring  60  relative to the substrate  33  as will be described further below. For example only, in  FIG. 3  the actuator  80  is arranged between the first annular portion  72  of the edge coupling ring  60  and the third annular portion  76  of the edge coupling ring  60 . In some examples, the actuator  80  may include a piezoelectric actuator, a stepper motor, a pneumatic drive, or other suitable actuator. In some examples, one, two, three, or four or more actuators are used. In some examples, multiple actuators are arranged uniformly around the edge coupling ring  60 . The actuator(s)  80  may be arranged inside or outside of the processing chamber. 
     During use, plasma  82  is directed at the substrate  33  to etch the exposed portions of the substrate  33 . The edge coupling ring  60  is arranged to help shape the plasma electric field such that uniform etching of the substrate  33  occurs. As can be seen at  84  and  86  in  FIG. 4 , one or more portions of the edge coupling ring  60  may be eroded by the plasma  82 . As a result of the erosion, non-uniform etching of the substrate  33  may occur near a radially outer edge of the substrate  33 . Normally, the process would need to be stopped, the processing chamber opened and the edge coupling ring replaced. 
     In  FIG. 5 , the actuator  80  is used to move one or more portions of the edge coupling ring  60  to alter the position of the one or more portions of the edge coupling ring  60 . For example, the actuator  80  may be used to move the first annular portion  72  of the edge coupling ring  60 . In this example, the actuator  80  moves the first annular portion  72  of the edge coupling ring  60  in an upward or vertical direction such that an edge  86  of the first annular portion  72  of the edge coupling ring  60  is higher relative to the radially outer edge of the substrate  33 . As a result, etch uniformity near the radially outer edge of the substrate  33  is improved. 
     Referring now to  FIG. 6 , as can be appreciated, the actuator may be arranged in one or more other locations and may move in other directions such as horizontal, diagonal, etc. Horizontal movement of the portion of the edge coupling ring may be performed to center the edge coupling effect relative to the substrate. In  FIG. 6 , an actuator  110  is arranged radially outside of the edge coupling ring  60 . In addition, the actuator  110  moves in a vertical (or an up/down) direction as well as in a horizontal (or side to side) direction. Horizontal repositioning may be used when etching of the substrates shows a horizontal offset of the edge coupling ring relative to the substrates. The horizontal offset may be corrected without opening the processing chamber. Likewise, tilting of the edge coupling ring may be performed by actuating some of the actuators differently than others of the actuators to correct or create side-to-side asymmetry. 
     Rather than locating the actuator  110  between annular portions of the edge coupling ring, the actuator  110  may also be attached to a radially outer wall or other structure identified at  114 . Alternately, the actuator  110  may be supported from below by a wall or other structure identified at  116 . 
     Referring now to  FIG. 7-8 , another example of an edge coupling ring  150  and a piezoelectric actuator  154  is shown. In this example, the piezoelectric actuator  154  moves the edge coupling ring  150 . The piezoelectric actuator  154  is mounted in the first annular portion  72  and the third annular portion  76  of the edge coupling ring  150 . In  FIG. 8 , the piezoelectric actuator  154  moves the first annular portion  72  of the edge coupling ring  150  to adjust a position of an edge  156  of the first annular portion  72 . 
     Referring now to  FIG. 9 , an example of a substrate processing chamber  500  for performing etching using RF plasma is shown. The substrate processing chamber  500  includes a processing chamber  502  that encloses other components of the substrate processing chamber  500  and contains the RF plasma. The substrate processing chamber  500  includes an upper electrode  504  and a pedestal  506  including a lower electrode  507 . An edge coupling ring  503  is supported by the pedestal  506  and is arranged around the substrate  508 . One or more actuators  505  may be used to move the edge coupling ring  503 . During operation, a substrate  508  is arranged on the pedestal  506  between the upper electrode  504  and the lower electrode  507 . 
     For example only, the upper electrode  504  may include a showerhead  509  that introduces and distributes process gases. The showerhead  509  may include a stem portion including one end connected to a top surface of the processing chamber. A base portion is generally cylindrical and extends radially outwardly from an opposite end of the stem portion at a location that is spaced from the top surface of the processing chamber. A substrate-facing surface or faceplate of the base portion of the showerhead includes a plurality of holes through which process gas or purge gas flows. Alternately, the upper electrode  504  may include a conducting plate and the process gases may be introduced in another manner. The lower electrode  507  may be arranged in a non-conductive pedestal. Alternately, the pedestal  506  may include an electrostatic chuck that includes a conductive plate that acts as the lower electrode  507 . 
     An RF generating system  510  generates and outputs an RF voltage to one of the upper electrode  504  and the lower electrode  507 . The other one of the upper electrode  504  and the lower electrode  507  may be DC grounded, AC grounded or floating. For example only, the RF generating system  510  may include an RF voltage generator  511  that generates the RF voltage that is fed by a matching and distribution network  512  to the upper electrode  504  or the lower electrode  507 . In other examples, the plasma may be generated inductively or remotely. 
     A gas delivery system  530  includes one or more gas sources  532 - 1 ,  532 - 2 , . . . , and  532 -N (collectively gas sources  532 ), where N is an integer greater than zero. The gas sources supply one or more precursors and mixtures thereof. The gas sources may also supply purge gas. Vaporized precursor may also be used. The gas sources  532  are connected by valves  534 - 1 ,  534 - 2 , . . . , and  534 -N (collectively valves  534 ) and mass flow controllers  536 - 1 ,  536 - 2 , . . . , and  536 -N (collectively mass flow controllers  536 ) to a manifold  540 . An output of the manifold  540  is fed to the processing chamber  502 . For example only, the output of the manifold  540  is fed to the showerhead  509 . 
     A heater  542  may be connected to a heater coil (not shown) arranged in the pedestal  506 . The heater  542  may be used to control a temperature of the pedestal  506  and the substrate  508 . A valve  550  and pump  552  may be used to evacuate reactants from the processing chamber  502 . A controller  560  may be used to control components of the substrate processing chamber  500 . The controller  560  may also be used to control the actuator  505  to adjust a position of one or more portions of the edge coupling ring  503 . 
     A robot  570  and a sensor  572  may be used to measure erosion of the edge coupling ring. In some examples, the sensor  572  may include a depth gauge. The robot  570  may move the depth gauge in contact with the edge coupling ring to measure erosion. Alternately, a laser interferometer (with or without the robot  570 ) may be used to measure erosion without direct contact. The robot  570  may be omitted if the laser interferometer can be positioned with a direct line of sight to the edge coupling ring. 
     Another robot arm  573  may be used to deliver and remove substrates onto the pedestal  506 . Additionally, the robot arm  573  may be used to deliver unused edge coupling rings onto a lifting ring and to replace used edge coupling rings after sufficient wear as will be described further below in conjunction with  FIGS. 15-23 . While the same robot arm  573  may be used for both substrates and edge coupling rings, dedicated robot arms may also be used. 
     Referring now to  FIG. 10 , an example of a method  600  for operating the actuator to move the edge coupling ring is shown. At  610 , at least part of an edge coupling ring is positioned in a first location relative to the substrate. At  614 , the substrate processing system is operated. The operation may include etching or other treatment of a substrate. At  618 , control determines whether a predetermined period of etching or a predetermined number etching cycles have occurred. If the predetermined period or number of cycles is not exceeded as determined at  618 , control returns to  614 . 
     When the predetermined period or number of cycles are up, control determines at  624  whether a maximum predetermined etching period is up, a maximum number of etching cycles has occurred and/or a maximum # of actuator moves have occurred. 
     If  624  is false, control moves at least part of the edge coupling ring using the actuator. Movement of the edge coupling ring can be performed automatically, manually or a combination thereof without opening the processing chamber. If  624  is true, control sends a message or otherwise indicates that the edge coupling ring should be serviced/replaced. 
     Referring now to  FIG. 11 , an example of a method  700  for operating the actuator to move the edge coupling ring is shown. At  710 , at least part of an edge coupling ring is positioned in a first location relative to the substrate. At  714 , the substrate processing system is operated. The operation may include etching or other treatment of a substrate. At  718 , control determines whether a predetermined amount of erosion of the edge coupling ring has occurred using a sensor such as a depth gauge or laser interferometer. If  718  is false, control returns to  714 . 
     When the predetermined amount of erosion has occurred, control determines at  724  whether a maximum amount of erosion has occurred. If  724  is false, control moves at least part of the edge coupling ring using the actuator. Movement of the edge coupling ring can be performed automatically, manually or a combination thereof without opening the processing chamber. If  724  is true, control sends a message or otherwise indicates that the edge coupling ring should be serviced/replaced. 
     In addition to the foregoing, a determination of whether or not the edge coupling ring needs to be moved may be based on inspection of etching patterns of the substrates after processing. The actuator may be used to adjust the edge coupling profile of the edge coupling ring without opening the chamber. 
     Referring now to  FIG. 12 , a processing chamber  800  includes an edge coupling ring  60  arranged on a pedestal  20 . The edge coupling ring  60  includes one or more portions that are movable by one or more actuators  804  arranged outside of the processing chamber  800 . In this example, the first annular portion  72  is movable. The actuators  804  may be connected by mechanical linkage  810  to the first annular portion  72  of the edge coupling ring  60 . For example, the mechanical linkage  810  may include a rod member. The mechanical linkage  810  may pass through a hole  811  in a wall  814  of the processing chamber  800 . A seal  812  such as an “O”-ring may be used. The mechanical linkage  810  may pass through holes  815  in one or more structures such as the third annular portion  76  of the edge coupling ring  60 . 
     Referring now to  FIG. 13A and 13B , side-to-side tilting of an edge coupling ring  830  is shown. Side-to-side tilting may be used to correct side-to-side misalignment. In  FIG. 13A , portions  830 - 1  and  830 - 2  of an edge coupling ring  830  on opposite sides of the substrate are arranged in a first arrangement  840 . The portions  830 - 1  and  830 - 2  may be generally aligned with portions  832 - 1  and  832 - 2  of the edge coupling ring  830 . Actuators  836 - 1  and  836 - 2  are arranged between the portions  830 - 1  and  832 - 1  and  830 - 2  and  832 - 2 , respectively. 
     In  FIG. 13B , the actuators  836 - 1  and  836 - 2  move the respective portions of the edge coupling ring  830  such that the edge coupling ring  830  moves to a second arrangement  850  that is different than the first arrangement  840  shown in  FIG. 13A . As can be appreciated, the substrates may be inspected after treatment and the tilt relative to the substrate may be adjusted as needed without opening the processing chamber. 
     Referring now to  FIG. 14 , a method  900  for moving an edge coupling ring during processing of a substrate is shown. In other words, different treatments may be performed on a single substrate in the same processing chamber. The edge coupling effect of the edge coupling ring may be adjusted between the multiple treatments performed on the substrate in the same processing chamber before proceeding to a subsequent substrate. At  910 , a substrate is positioned on a pedestal and a position of the edge coupling ring is adjusted if needed. At  914 , treatment of the substrate is performed. If processing of the substrate is done as determined at  918 , the substrate is removed from the pedestal at  922 . At  924 , control determines whether another substrate needs to be processed. If  924  is true, the method returns to  910 . Otherwise the method ends. 
     If  918  is false and the substrate needs additional treatment, the method determines whether adjustment of the edge coupling ring is required at  930 . If  930  is false, the method returns to  914 . If  930  is true, at least part of the edge coupling ring is moved using one or more actuators at  934  and the method returns to  914 . As can be appreciated, the edge coupling ring can be adjusted between treatments of the same substrate in the same processing chamber. 
     Referring now to  FIG. 15 , an edge coupling ring  1014  and a lifting ring  1018  are arranged adjacent to and around an upper surface of a pedestal  1010 . The edge coupling ring  1014  includes a radially inner edge that is arranged adjacent to the substrate during etching as described above. The lifting ring  1018  is arranged below at least part of the edge coupling ring  1014 . The lifting ring  1018  is used to raise the edge coupling ring  1014  above a surface of the pedestal  1010  when removing the edge coupling ring  1014  using a robot arm. The edge coupling ring  1014  can be removed without requiring the processing chamber to be opened to atmospheric pressure. In some examples, the lifting ring  1018  may optionally include an open portion  1019  between circumferentially spaced ends  1020  to provide clearance for a robot arm to remove the edge coupling ring  1014  as will be described below. 
     Referring now to  FIGS. 16-17 , an example of the edge coupling ring  1014  and lifting ring  1018  are shown in further detail. In the example shown in  FIG. 16 , the pedestal may include an electrostatic chuck (ESC) generally identified at  1021 . The ESC  1021  may include one or more stacked plates such as ESC plates  1022 ,  1024 ,  1030  and  1032 . The ESC plate  1030  may correspond to a middle ESC plate and the ESC plate  1032  may correspond to an ESC baseplate. In some examples, an O-ring  1026  may be arranged between the ESC plates  1024  and  1030 . While a specific pedestal  1010  is shown, other types of pedestals may be used. 
     A bottom edge coupling ring  1034  may be arranged below the edge coupling ring  1014  and the lifting ring  1018 . The bottom edge coupling ring  1034  may be arranged adjacent to and radially outside of the ESC plates  1024 ,  1030  and  1032  and the O-ring  1026 . 
     In some examples, the edge coupling ring  1014  may include one or more self-centering features  1040 ,  1044  and  1046 . For example only, the self-centering features  1040  and  1044  may be triangular-shaped, female self-centering features, although other shapes may be used. The self-centering feature  1046  may be a sloped surface. The lifting ring  1018  may include one or more self-centering features  1048 ,  1050  and  1051 . For example only, the self-centering features  1048  and  1050  may be triangular-shaped, male self-centering features, although other shapes may be used. The self-centering feature  1051  may be a sloped surface having a complementary shape to the self-centering feature  1046 . The self-centering feature  1048  on the lifting ring  1018  may mate with the self-centering feature  1044  on the edge coupling ring  1014 . The self-centering feature  1050  on the lifting ring  1018  may mate with a self-centering feature  1052  of the bottom edge coupling ring  1034 . 
     The lifting ring  1018  further includes a projection  1054  that extends radially outwardly. A groove  1056  may be arranged on a bottom-facing surface  1057  of the projection  1054 . The groove  1056  is configured to be biased by one end of a pillar  1060  that is connected to and selectively moved vertically by an actuator  1064 . The actuator  1064  may be controlled by the controller. As can be appreciated, while a single groove, pillar and actuator are shown, additional grooves, pillars and actuators may be circumferentially arranged in a spaced relationship around the lifting ring  1018  to bias the lifting ring  1018  in an upward direction. 
     In  FIG. 17 , the edge coupling ring  1014  is shown raised in an upward direction by the lifting ring  1018  using the pillar(s)  1060  and the actuator(s)  1064 . The edge coupling ring  1014  can be removed from the processing chamber by a robot arm. More particularly, a robot arm  1102  is connected to the edge coupling ring  1014  by a holder  1104 . The holder  1104  may include a self-centering feature  1110  that mates with the self-centering feature  1040  on the edge coupling ring  1014 . As can be appreciated, the robot arm  1102  and the holder  1104  may bias the edge coupling ring upwardly to clear the self-centering feature  1048  on the lifting ring  1018 . Then, the robot arm  1102 , the holder  1104  and the edge coupling ring  1014  can be moved out of the processing chamber. The robot arm  1102 , the holder  1104  and a new edge coupling ring can be returned and positioned on the lifting ring  1018 . Then, the lifting ring  1018  is lowered. The opposite operation may be used to deliver a new edge coupling ring  1014  onto the lifting ring  1018 . 
     Alternately, instead of lifting the robot arm  1102  and holder  1104  upwardly to lift the edge coupling ring  1014  off of the lifting ring  1018 , the robot arm  1102  and holder  1104  can be positioned below and in contact with the raised edge coupling ring  1014 . Then, the lifting ring  1018  is lowered and the edge coupling ring  1014  remains on the robot arm  1102  and holder  1104 . The robot arm  1102 , the holder  1104  and the edge coupling ring  1014  can be removed from the processing chamber. The opposite operation may be used to deliver a new edge coupling ring  1014  onto the lifting ring  1018 . 
     Referring now to  FIGS. 18-20 , a movable edge coupling ring  1238  and a lifting ring  1018  are shown. In  FIG. 18 , one or more pillars  1210  are moved up and down by one or more actuators  1214  through bores  1220 ,  1224  and  1228  in the ESC baseplate  1032 , the bottom edge coupling ring  1034  and the lifting ring  1018 , respectively. In this example, a middle edge coupling ring  1240  or spacer is arranged between the movable edge coupling ring  1238  and the lifting ring  1018 . The middle edge coupling ring  1240  may include self-centering features  1244  and  1246 . A corresponding self-centering feature  1248  may be provided on the movable edge coupling ring  1238 . The self-centering feature  1248  mates with the self-centering feature  1246  on the middle edge coupling ring  1240 . 
     As is described in detail above, erosion of an upwardly facing surface of the movable edge coupling ring  1238  may occur during use. This, in turn, may alter the profile of the plasma. The movable edge coupling ring  1238  may be selectively moved in an upward direction using the pillars  1210  and the actuators  1214  to alter the profile of the plasma. In  FIG. 19 , the movable edge coupling ring  1238  of  FIG. 18  is shown in a raised position. The middle edge coupling ring  1240  may remain stationary. Eventually, the movable edge coupling ring  1238  may be moved one or more times and then the edge coupling ring  1238  and the middle edge coupling ring  1240  may be replaced. 
     In  FIG. 20 , the actuator  1214  is returned to a lowered state and the actuator  1064  is moved to a raised state. The edge coupling ring  1238  and the middle edge coupling ring  1240  are lifted by the lifting ring  1018  and the movable edge coupling ring  1238  may be removed by the robot arm  1102  and the holder  1104 . 
     As can be appreciated, the actuators can be arranged in the processing chamber or outside of the processing chamber. In some examples, the edge coupling rings may be supplied to the chamber via a cassette, loadlock, transfer chambers and the like. Alternatively, the edge coupling rings may be stored outside of the processing chamber but inside of the substrate processing tool. 
     Referring now to  FIGS. 21-22 , the lifting ring can be omitted in some examples. An edge coupling ring  1310  is arranged on the bottom edge coupling ring  1034  and a radially outer edge of the pedestal. The edge coupling ring  1310  may include one or more self-centering features  1316  and  1320 . The edge coupling ring  1310  may further include a groove  1324  for receiving a top surface of the pillar  1210 , which is biased by the actuator  1214 . The self-centering feature  1320  may be arranged against a corresponding self-centering feature  1326  of the bottom edge coupling ring  1034 . In some examples, the self-centering features  1320  and  1326  are inclined planes. 
     In  FIG. 22 , the actuator  1214  and the pillar  1210  bias the edge coupling ring  1310  upwardly to remove the edge coupling ring  1310  or to adjust a plasma profile after erosion has occurred. The robot arm  1102  and the holder  1104  can be moved into position below the edge coupling ring  1310 . The self-centering feature  1316  may be engaged by the self-centering feature  1110  on the holder  1104  connected to the robot arm  1102 . Either the robot arm  1102  moves in an upward direction to provide clearance between the groove  1324  and the pillar  1210  or the pillar  1210  is moved downwardly by the actuator  1214  to provide clearance for the groove  1324 . 
     Referring now to  FIG. 23 , a method  1400  for replacing an edge coupling ring without opening a processing chamber to atmospheric pressure is shown. At  1404 , the method determines whether the edge coupling ring is located on the lifting ring. If  1404  is false, the method moves an edge coupling ring into position on the lifting ring using a robot arm at  1408 . After the edge coupling ring is located on the lifting ring in the processing chamber, the process is run at  1410 . At  1412 , the method determines whether the edge coupling ring is worn using any of the criteria described above. If  1412  is false, the method returns to  1410  and the process may be run again. If the edge coupling ring is determined to be worn at  1412 , the edge coupling ring is replaced at  1416  and the method continues at  1410 . 
     Referring now to  FIG. 24 , a method  1500  adjusts a position of the movable edge coupling ring as needed to offset for erosion and selectively replaces the movable edge coupling ring when the movable edge coupling ring is determined to be worn. At  1502 , the method determines whether a movable edge coupling ring is located on the lifting ring. If  1502  is false, an edge coupling ring is moved into position on the lifting ring at  1504  and the method continues at  1502 . 
     If  1502  is true, the method determines whether a position of the movable edge coupling ring needs to be adjusted at  1506 . If  1506  is true, the method adjusts a position of the movable edge coupling ring using an actuator and returns to  1506 . When  1506  is false, the method runs the process at  1510 . At  1512 , the method determines whether the movable edge coupling ring is worn. If false, the method returns to  1510 . 
     If  1512  is true, the method determines whether the movable edge coupling ring is in a highest (or fully adjusted) position at  1520 . If  1520  is false, the method adjusts a position of the movable edge coupling ring using the actuator  1214  at  1524  and the method returns to  1510 . If  1520  is true, the method replaces the movable edge coupling ring using the actuator  1064 , the lifting ring  1018  and the robot arm  1102 . 
     Referring now to  FIG. 25 , a method  1600  for replacing the edge coupling ring without opening the process chamber to atmospheric pressure is shown. At  1610 , the lifting ring and edge coupling ring are biased upwardly using an actuator. At  1620 , the robot arm and the holder are moved underneath the edge coupling ring. At  1624 , the robot arm is moved upwardly to clear self-centering features of the edge coupling ring or the lifting ring is moved downwardly. At  1628 , the robot arm with the edge coupling ring is moved out of the processing chamber. At  1632 , the edge coupling ring is detached from the robot arm. At  1636 , a replacement edge coupling ring is picked up by the robot arm. At  1638 , the edge coupling ring is positioned on the lifting ring and aligned using one or more self-centering features. At  1642 , the robot arm is lowered to allow sufficient clearance for the self-centering feature and the robot arm is removed from the chamber. At  1646 , the lifting ring and the edge coupling ring are lowered into position. 
     The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.” It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. 
     In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can comprise semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and/or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and/or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and/or load locks connected to or interfaced with a specific system. 
     Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, and/or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or dies of a wafer. 
     The controller, in some implementations, may be a part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and/or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber. 
     Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and/or manufacturing of semiconductor wafers. 
     As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and/or load ports in a semiconductor manufacturing factory.