To provide modified colloidal silica capable of improving the stability of the polishing speed with time when used as abrasive grains in a polishing composition for polishing a polishing object that contains a material to which charged modified colloidal silica easily adheres, such as a SiN wafer, and to provide a method for producing the modified colloidal silica. Modified colloidal silica, being obtained by modifying raw colloidal silica, wherein the raw colloidal silica has a number distribution ratio of 10% or less of microparticles having a particle size of 40% or less relative to a volume average particle size based on Heywood diameter (equivalent circle diameter) as determined by image analysis using a scanning electron microscope.

The present disclosure describes an apparatus and a method for a chemical mechanical polishing (CMP) process that recycles used slurry as another slurry supply. The apparatus includes a pad on a rotation platen, a first feeder and a second feeder where each of the first and the second feeder is configured to dispense a slurry on the pad, and a flotation module configured to process a first fluid sprayed from the pad. The flotation module further includes an outlet fluidly connected to the second feeder and configured to output a second fluid, and a first tank configured to store a plurality of chemicals where the plurality of chemicals include a frother and a collector configured to chemically bond with chemicals in the first fluid.

The present disclosure describes an apparatus and a method for a chemical mechanical polishing (CMP) process that recycles used slurry as another slurry supply. The apparatus includes a pad on a rotation platen, a first feeder and a second feeder where each of the first and the second feeder is configured to dispense a slurry on the pad, and a flotation module configured to process a first fluid sprayed from the pad. The flotation module further includes an outlet fluidly connected to the second feeder and configured to output a second fluid, and a first tank configured to store a plurality of chemicals where the plurality of chemicals include a frother and a collector configured to chemically bond with chemicals in the first fluid.

A polishing pad includes a polishing layer, wherein the polishing layer includes zinc (Zn), and a concentration of the zinc (Zn) is 0.5 ppm to 40 ppm parts by weight based on the total weight of the polishing layer. In an exemplary embodiment, a polishing pad is provided wherein a concentration of the zinc (Zn) is 0.5 ppm to 40 ppm parts by weight based on the total weight of the polishing layer, a concentration of the iron (Fe) is 1 ppm to 50 ppm parts by weight based on the total weight of the polishing layer, and a concentration of the aluminum (Al) is 2 ppm to 50 ppm parts by weight based on the total weight of the polishing layer.

A grinding wheel jig includes a bottomed cylindrical grindstone accommodating section that accommodates the annular grindstone section, an annular base accommodating section that is located on a side opposite to a bottom portion of the grindstone accommodating section in a height direction of the grindstone accommodating section, has an outside diameter greater than an outside diameter of the grindstone accommodating section, and is capable of accommodating at least a part of the base, and a plurality of cylindrical bolt accommodating sections provided at bottom portions of the base accommodating sections and each capable of accommodating a head part of a bolt. In the grinding wheel jig, each bolt accommodating section is provided, at a bottom portion thereof, with an opening in which a fastening tool is insertable into the head part of the bolt.

A grinding wheel jig includes a bottomed cylindrical grindstone accommodating section that accommodates the annular grindstone section, an annular base accommodating section that is located on a side opposite to a bottom portion of the grindstone accommodating section in a height direction of the grindstone accommodating section, has an outside diameter greater than an outside diameter of the grindstone accommodating section, and is capable of accommodating at least a part of the base, and a plurality of cylindrical bolt accommodating sections provided at bottom portions of the base accommodating sections and each capable of accommodating a head part of a bolt. In the grinding wheel jig, each bolt accommodating section is provided, at a bottom portion thereof, with an opening in which a fastening tool is insertable into the head part of the bolt.

Various methods of cleaning a substrate are provided. In one aspect, method of cleaning a substrate, comprising: holding and rotating a substrate by a substrate holder; and supplying a chemical liquid to a chemical liquid nozzle and supplying two fluids to a two-fluid nozzle while moving the chemical-liquid nozzle and the two-fluid nozzle radially outwardly from the center to the periphery of the substrate, wherein the distance of the chemical-liquid nozzle from a rotating axis of the substrate holder is longer than the distance of the two-fluid nozzle from the rotating axis of the substrate holder while the chemical-liquid nozzle and the two-fluid nozzle are moved radially outwardly from the rotating axis of the substrate holder.

Various methods of cleaning a substrate are provided. In one aspect, method of cleaning a substrate, comprising: holding and rotating a substrate by a substrate holder; and supplying a chemical liquid to a chemical liquid nozzle and supplying two fluids to a two-fluid nozzle while moving the chemical-liquid nozzle and the two-fluid nozzle radially outwardly from the center to the periphery of the substrate, wherein the distance of the chemical-liquid nozzle from a rotating axis of the substrate holder is longer than the distance of the two-fluid nozzle from the rotating axis of the substrate holder while the chemical-liquid nozzle and the two-fluid nozzle are moved radially outwardly from the rotating axis of the substrate holder.

A slurry containing abrasive grains and a liquid medium, in which the abrasive grains include first particles and second particles in contact with the first particles, the first particles contain cerium oxide, the second particles contain a cerium compound, and in a case where a content of the abrasive grains is 2.0% by mass, a BET specific surface area of a solid phase obtained when the slurry is subjected to centrifugal separation for 30 minutes at a centrifugal acceleration of 1.1×10.sup.4 G is 24 m.sup.2/g or more.

Apparatus and systems are disclosed of a splash guard for a grinder/polisher having a base, a bowl, and a platen having an outer edge to prevent splashing during the grinding/polishing operation. The splash guard includes an inner sidewall, a lower rib, and outer sidewall, and an upper rib. The lower rib has an inner edge that is spaced at least 2.5 centimeters from the outer edge of the platen to prevent pinching of an operator's hands between the platen and the splash guard. The splash guard may also include a recess formed by the upper rib, outer sidewall, and lower rib, and at least a portion of an inner edge of the upper rib is extending further inwardly towards that platen than the inner edge of the lower rib.