be in contact with the polishing pad, and the contact portion is movable relative to the polishing pad at a relative speed of not more than 0.1 mis. 

[0046] The second electrode may have a roller as the con› tact portion (an electric supply contact). In this case, a rota› tional speed (a linear velocity of rotation) of the roller and a rotational speed of the polishing pad are adjusted such that a relative speed between the roller and the rotating pad is zero, for example. Alternatively, the roller may be rotatably sup› ported with its rotational friction being nearly zero, so that the roller can be rotated by friction between the roller and the polishing pad. These structures can reduce the friction between the electric supply contact (roller) and the polishing pad, and can thus prevent the polishing pad from being dam› aged and removed from the polishing table. Because the damage to the polishing pad is prevented, reliable current supply can be secured without deteriorating polishing prop› erties. 

[0047] Another aspect of the present invention is an elec› trochemical mechanical polishing apparatus including: a pol› ishing table adapted to hold a conductive polishing pad hav› ing a polishing surface, the polishing table having a first electrode coupled to one of poles of a power source; a pol› ishing head adapted to hold a workpiece having a conductive film and to press the workpiece against the polishing surface; a second electrode coupled to another of the poles of the power source, the second electrode being brought into contact with the polishing pad so as to supply an electric current to the conductive film via the polishing pad; an electrolytic-solution supply section for supplying an electrolytic solution to the polishing surface; and a moving mechanism for providing relative movement between the polishing pad and the work› piece held by the polishing head. The polishing surface of the polishing pad has a non-contact area which does not contact the conductive film during polishing. The polishing pad has through-holes therein. The non-contact area and at least a part of inner surfaces of the through-holes have been subjected to an insulating treatment. 

[0048] Since the non-contact area and the inner surface of the through-holes of the conductive polishing pad, which may be made of mainly carbon, have been subjected insulating treatment, an electrolytic reaction at the surface of the pol› ishing pad ( conductive pad) can be minimized. Therefore, formation of pits in the surface of the conductive film and a drop in polishing rate due to oxygen generated at the surface of the polishing pad can be prevented. 

[0049] Usable methods of insulating part of the conductive polishing pad include an insulating coating treatment and a surface modification treatment. Examples of such an insulat› ing coating treatment include coating of a surface with an ink, a paint, an adhesive, or the like. Examples of the surface modification treatment include modifying of a surface by means of a chemical treatment, graft polymerization, irradia› tion with a light, an electron beam or an ion beam, a plasma treatment, or plating. 

[0050] According to the present invention, the surface of the conductive film ( e.g., a copper film on a surface of a substrate) is not damaged, and reliable supply of an electric current can be performed with a uniform electric potential being provided over the surface of the conductive film, even when a rotary type is employed. Further, because the non› contact area (i.e., an area which is not used for polishing) of the conductive polishing pad is covered with the insulating material, an electrolytic reaction (production of oxygen) on 

the surface of the polishing pad can be minimized. As a result, production of a defect in the conductive film during polishing can be suppressed. 

[0051] Another aspect of the present invention is an elec› trochemical mechanical polishing apparatus including: a pol› ishing pad having vertically-extending through-holes and having an upper surface serving as a polishing surface; a polishing head adapted to press a substrate against the pol› ishing surface; a first electrode coupled to one of poles of a power source and arranged below the polishing pad; a second electrode coupled to another of the poles of the power source and adapted to supply an electric current to a conductive film on the substrate; an electrolytic-solution supply section for supplying an electrolytic solution to the polishing pad; an electrolytic-solution path for directing an electrolytic solu› tion, supplied from the electrolytic-solution supply section, to the through-holes from below the polishing pad; and a mov› ing mechanism for providing relative movement between the polishing pad and the substrate held by the polishing head. 

[0052] In a preferred aspect of the present invention, the electrolytic-solution path includes: an electrolytic-solution receiving section for receiving the electrolytic solution from the electrolytic-solution supply section; communication holes configured to communicate respectively with the through-holes; and communication grooves configured to communicate with the electrolytic-solution receiving section and to allow the communication holes to communicate with each other. 

[0053] In a preferred aspect of the present invention, the electrolytic-solution receiving section comprises an annular groove arranged concentrically with the polishing pad; and the annular groove has a larger radius than a distance between a center of the polishing pad and a circumferential surface of the polishing head in a polishing position. 

[0054] In a preferred aspect of the present invention, the electrochemical mechanical polishing apparatus further includes a weir surrounding a circumferential surface of the polishing pad. The weir has an outer wall and an inner wall, the outer wall has an upper end at a position higher than the polishing surface, and the inner wall has an upper end at a position lower than the polishing surface. 

[0055] In a preferred aspect of the present invention, the electrochemical mechanical polishing apparatus further includes: a deformable liquid-permeable member surround› ing a circumferential surface of the polishing pad; and a liquid recovery section provided below the liquid-permeable mem› ber. The liquid-permeable member has an upper surface at a position higher than the polishing surface. 

[0056] Another aspect of the present invention is an elec› trochemical mechanical polishing apparatus including: a pol› ishing pad having vertically-extending through-holes and having an upper surface serving as a polishing surface; at least one liquid-retaining member embedded in the polishing sur› face; a polishing head adapted to press a substrate against the polishing surface; a first electrode coupled to one of poles of a power source and arranged below the polishing pad; a second electrode coupled to another of the poles of the power source and adapted to supply an electric current to a conduc› tive film on the substrate; an electrolytic-solution supply sec› tion for supplying an electrolytic solution to the polishing pad; and a moving mechanism for providing relative move› ment between the polishing pad and the substrate held by the polishing head. 

