US 2008/0188162 Al  12  Aug. 7, 2008  substrate W, the polishing rate (removal rate) of the edge  portion can be controlled by making the pressure (pressing  force) of the retainer ring  3  high or low. When the pressurized  fluid is supplied to the pressure chambers  22  to  25,  the chuck› ing plate  6  receives an upward force. In this embodiment, the  pressurized fluid is supplied via the fluid passage  31  into the  pressure chamber  21  so as to prevent the chucking plate  6  from being elevated by the force applied from the pressure  chambers  22  to  25.  [0157]  Polishing of the substrate Wis thus performed while  appropriately adjusting the pressure applied by the head air  cylinder  111  to press the retainer ring  3  against the polishing  pad  101,  the pressures applied by the pressurized airs sup› plied to the pressure chambers  22  to  25  to press the divisional  portions of the substrate W against the polishing pad  101,  and  appropriately adjusting the currents flowing between the  divided electrodes  256a  to  256c  (the first electrode  256)  and  the conductive film, e.g., copper film, on the surface of the  substrate facing the divided electrodes  256a  to  256c  ( or the  voltages to be applied between the divided electrodes  256a  to  256c  and the conductive film on the surface of the substrate  facing the divided electrodes  256a  to  256c  ).  [0158]  In this embodiment, the polishing head  1  has the  pressure chambers  21  to  25  whose internal pressures can be  changed independently via the regulators RE2 to RE6 for fine  polishing control. Alternatively, it is possible to use a polish› ing head which is not provide with pressure chambers whose  internal pressures are independently variable, but is designed  to hold ( e.g., attract) a substrate and press the substrate  against the polishing surface of the polishing pad  101  uni› formly e.g., at polishing pressure of not more than 70 hPa  (about 1 psi).  [0159]  The operations of the substrate processing apparatus  will now be described.  [0160]  First, the substrate cassette  204,  which stores a large  number of substrates W shown in FIG.  1B  each having the  copper film  907  formed on the surface, is mounted on the  loading and unloading stage. One substrate is removed from  the substrate cassette  204  by the transfer robot  202  and placed  onto the substrate station  206.  The transfer robot  208  receives  the substrate from the substrate station  206  and, after revers› ing the substrate as necessary, transfers the substrate to the  rotary transporter  210.  The rotary transporter  210  is then  rotated horizontally, and the substrate, supported by the  rotary transporter  210,  is held by the polishing head  1  of one  of the two electrochemical mechanical polishing apparatuses  250.  [0161]  Thereafter, the substrate, held by the polishing head  1,  is moved to a polishing position above the polishing table  100.  The polishing head  1  is then lowered to press the sub› strate against the polishing surface of the polishing pad  101  at  predetermined pressure of not more than 70 hPa (1 psi). While  supplying an electrolytic solution to the polishing pad  101,  the voltages are applied by the power source  254  between the  divided electrodes  256a  to  256c  (the first electrode  256)  and  the conductive film of the substrate, i.e. the copper film  907,  facing the divided electrodes  256a  to  256c  to perform polish› ing (first polishing) of the conductive film. Holding of the  substrate, e.g., by vacuum attraction, may be released during  polishing of the substrate with the polishing pad  101.  [0162]  In the electrochemical mechanical polishing appa› ratus  250,  the first polishing is performed so as to remove the  conductive film, e.g., the copper film  907  (and the seed film  906),  until an average thickness of the remaining conductive  film is not more than 300 nm and a variation in thickness of  the remaining conductive film falls within not more than 150  nm. During polishing of the copper film  907  (and the seed  film  906),  the film-thickness detection sensor  274,  such as an  eddy-current sensor, detects an in-plane distribution of the  thickness of the copper film  907  (and the seed film  906),  and  the control section  280  controls and adjusts the polishing  pressures to be applied to the divisional portions (press areas)  Cl to C4 shown in FIG. 6. The control section280 also adjusts  the electric currents flowing ( or voltages applied) between the  divided electrodes  256a  to  256c  and the conductive film, via  the variable resistors  268a  to  268c  of the variable resistance  unit  270.  The electrochemical mechanical polishing gener› ally causes little damage to interconnects. Therefore, use of  the electrochemical mechanical polishing can significantly  reduce damage to an interconnect structure of the substrate.  For example, the electrochemical mechanical polishing can  be used for removing most part of an interconnect metal film  formed outside interconnect recesses. Since a portion of the  film outside of the interconnect recesses constitutes a major  part of a total amount of the film to be removed, use of the  electrochemical mechanical polishing can significantly  reduce damage to the interconnect structure.  [0163]  A speed of relative movement between the polishing  pad  101  and the substrate W may also be controlled. A rota› tional speed of the polishing pad  101  may be controlled, e.g.,  in a range of 20 to 40 rpm, and a rotational speed of the  substrate W may be controlled, e.g., in a range of 50 to 100  rpm.  It  is possible to rotate the substrate W in an opposite  direction to a rotational direction of the polishing pad  101,  if  necessity.  It  is also possible to move the substrate W repeat› edly in the radial direction of the polishing pad  101,  if neces› sity.  [0164]  After completion of the first polishing in one of the  electrochemical mechanical polishing apparatuses  250,  the  polished surface and the back surface of the substrate are  cleaned (rinsed) with a cleaning liquid, e.g., pure water, and  then dried, if necessary. The substrate is then transported via  the rotary transporter  210  to another of the electrochemical  mechanical polishing apparatuses  250,  and held by the pol› ishing head  1.  In the electrochemical mechanical polishing  apparatus  250  which performed the first polishing, on the  other hand, conditioning of the polishing surface of the pol› ishing pad  101  with the dresser  218  is performed so as to  prepare for the next polishing.  [0165]  In the second polishing, the substrate, held by the  polishing head  1,  is moved to a polishing position above the  polishing table  100.  The polishing head  1  is then lowered to  press the substrate against the polishing surface of the polish› ing pad  101.  While supplying an electrolytic solution to the  polishing pad  101,  voltages are applied by the power source  254  between the divided electrodes  256a  to  256c  (the first  electrode  256)  and the conductive film of the substrate to  perform the second polishing of the conductive film which  has not been removed by the first polishing. Specifically, the  second polishing is performed so as to remove the copper film  907  ( and the seed film  906)  remaining on the barrier film  905  to thereby expose the barrier film  905.  [0166]  The electrochemical mechanical polishing appara› tus  250  performs the second polishing under a condition such  that the polishing rate of the conductive film is decreased  from the center to the periphery of the substrate. With this  operation, the barrier film  905,  underlying the conductive  film, i.e., the copperfilm907 (and seed film  906),  is gradually 