A polishing agent regenerating method in which a component of a polished material is removed from polishing agent slurry and a polishing agent is collected and regenerated is shown. The method includes at least, polishing, polishing agent slurry supplying, polishing agent slurry collecting, and sedimenting/separating/concentrating, performed in the above order. In the polishing agent slurry collecting or the sedimenting/separating/concentrating, a K.sub.2O density in the polishing agent slurry after dilution by water is performed is to be within a range of 0.002-0.2 mass %.

A semiconductor wafer is adhered and fixed to a polishing head by means of a conductive adhesive, and the wafer is connected to a positive electrode of an external power supply through wires of the inner and outer rings of a conductive slip ring below the wafer. A polishing pad is adhered to the bottom of a counter electrode disc, the counter electrode disc is fixed at the bottom of a polishing disc and is processed with through holes at the position corresponding to the polishing disc, and the counter electrode disc is connected to a negative electrode of the external power supply through the wires of inner and outer rings of a conductive slip ring above the counter electrode disc. Ultraviolet light emitted by an ultraviolet light source can reach the surface of the wafer through the through holes, and a polishing solution can be sprayed through the through holes into a contact area between the wafer and the polishing pad.

An object of the present invention is to provide a polishing liquid which reduces the occurrence of dishing on a surface to be polished of an object to be polished having a cobalt-containing film after polishing in a case where the polishing liquid is applied to CMP of the object to be polished. In addition, another object of the present invention is to provide a chemical mechanical polishing method using the above-mentioned polishing liquid.

The polishing liquid of an embodiment of the present invention is a polishing liquid used for chemical mechanical polishing of an object to be polished having a cobalt-containing film, including colloidal silica, a nitrogen-containing aromatic heterocycle, and hydrogen peroxide, in which at least a specific nitrogen-containing aromatic heterocyclic compound (1), a specific nitrogen-containing aromatic heterocyclic compound (2) different from the nitrogen-containing aromatic heterocyclic compound (1) are included as the nitrogen-containing aromatic heterocyclic compound.

An aspect of the present invention is a polishing liquid containing abrasive grains, a copolymer, and a liquid medium, in which the copolymer has a structure unit derived from at least one styrene compound selected from the group consisting of styrene and a styrene derivative and a structure unit derived from acrylic acid, a content of the copolymer is more than 0.01% by mass and 0.2% by mass or less based on the total amount of the polishing liquid, and a pH of the polishing liquid is more than 4.5.

The present invention provides a polishing liquid which has a good polishing speed and can suppress the occurrence of corrosion and scratches on a surface to be polished in a case of being applied to CMP of an object to be polished having a cobalt-containing film. The present invention also provides a chemical mechanical polishing method using the polishing liquid. The polishing liquid of an embodiment of the present invention is a polishing liquid used for chemical mechanical polishing of an object to be polished having a cobalt-containing film, the polishing liquid including colloidal silica, a passivation film forming agent having a C log P value of 1.5 to 3.8, a polymer compound, and hydrogen peroxide, in which a pH is 2.0 to 4.0.

The present invention provides a polishing liquid which has a good polishing speed and reduces the occurrence of dishing on a surface to be polished of an object to be polished having a cobalt-containing film after polishing in a case where the polishing liquid is applied to CMP of the object to be polished, and makes it possible to manufacture a semiconductor product having excellent reliability. The present invention also provides a chemical mechanical polishing method using the polishing liquid. The polishing liquid of an embodiment of the present invention is a polishing liquid used for chemical mechanical polishing of an object to be polished having a cobalt-containing film, the polishing liquid including colloidal silica, one or more specific compounds selected from the group consisting of glycine, alanine, sarcosine, and iminodiacetic acid, a passivation film forming agent, hydrogen peroxide, sodium, and ammonia, in which a mass ratio of a content of ammonia to a content of sodium is 1×10.sup.3 to 1×10.sup.6, and a pH is 5.5 to 8.0.

An object of the present invention is to provide a polishing liquid which reduces the occurrence of erosion and scratches on a surface to be polished of an object to be polished having a cobalt-containing film after polishing in a case where the polishing liquid is applied to CMP of the object to be polished. In addition, another object of the present invention is to provide a chemical mechanical polishing method using the above-mentioned polishing liquid.

The polishing liquid of an embodiment of the present invention is a polishing liquid used for chemical mechanical polishing of an object to be polished having a cobalt-containing film, the polishing liquid including colloidal silica, an organic acid, a specific nitrogen-containing aromatic heterocyclic compound, and hydrogen peroxide, in which a pH is 8.5 to 12.

A polishing liquid used for chemical mechanical polishing includes colloidal silica, in which a zeta potential of the colloidal silica measured in a state where the colloidal silica is present in the polishing liquid is −20 mV or less, an electrical conductivity is 200 μS/cm or less, a pH is 2 to 6, and a transmittance is 70% to 99%.

A polishing liquid is a polishing liquid used for chemical mechanical polishing, the polishing liquid including colloidal silica; and a buffering agent excluding phosphoric acid, in which the buffering agent is a compound having a pKa within a range of X±1 in a case where a pH of the polishing liquid is denoted by X, a zeta potential of the colloidal silica measured in a state where the colloidal silica is present in the polishing liquid is −20 mV or less, an electrical conductivity is 200 μS/cm or more, and a pH is 2 to 6.

The present invention provides a polishing liquid which reduces the occurrence of dishing and erosion on a surface to be polished of an object to be polished having a cobalt-containing film after polishing in a case where the polishing liquid is applied to CMP of the object to be polished, and makes it possible to manufacture a semiconductor product having excellent reliability. The present invention also provides a chemical mechanical polishing method using the polishing liquid. The polishing liquid of an embodiment of the present invention is a polishing liquid used for chemical mechanical polishing of an object to be polished having a cobalt-containing film, and includes a colloidal silica, an organic acid, a passivation film forming agent, an anionic surfactant; hydrogen peroxide; potassium; and sodium, in which a value of a difference obtained by subtracting the C log P value of the passivation film forming agent from the C log P value of the anionic surfactant is more than 2.00 and less than 8.00, a mass ratio of a content of potassium to a content of sodium is 1×10.sup.6 to 1×10.sup.9, and the pH is 8.0 to 10.5.