Abstract: There is provided a polishing composition for use in polishing of a surface of a polishing object including at least one of an oxide of a metal or a semimetal or a composite material of oxides of one or more metals and/or semimetals, and the polishing composition includes at least water and silica. The silica includes small-particle diameter silica having a particle diameter of 20 nm or more to 70 nm or less and large-particle diameter silica having a particle diameter of 100 nm or more to 200 nm or less, 2 mass % or more of the small-particle diameter silica is included in the polishing composition, 2 mass % or more of the large-particle diameter silica is included in the polishing composition, and a value obtained by dividing an average particle diameter of the large-particle diameter silica by an average particle diameter of the small-particle diameter silica is 2 or more.

Abstract: A polishing composition contains abrasive grains and water. 50% by mass or more of the abrasive grains consists of particles A having particle sizes between 40 nm and 80 nm inclusive, and 10% by mass or more of the abrasive grains consists of particles B having particle sizes between 150 nm and 300 nm inclusive. The polishing composition is used to polish a surface of a compound semiconductor substrate.

Abstract: To provide a polishing composition which can polish a polishing object composed of a hard brittle material having the Vickers hardness of greater than 1,500 HV at a high polishing rate under a condition of a high polishing load (polishing pressure) of 150 g/cm2 or more and can suppress the generation of a defect such as scratches on the surface of the polishing object or the generation of scratches on a polishing pad, a holding jig or the like when polishing a polishing object composed of a hard brittle material using a polishing apparatus having the polishing pad. The polishing composition contains abrasive grains, water and an additive agent that is adsorbed on the surface of the polishing pad to decrease unnecessary frictional resistance between the polishing pad and the polishing object.

Abstract: A polishing composition contains abrasive grains, a surface adsorptive agent, and water, and is used for polishing an object formed of a crystalline metallic compound. The polishing composition reduces defects on a polished surface of the object compared to a composition obtained by excluding the surface adsorptive agent from the polishing composition.

Abstract: A polishing composition contains abrasive grains and water. 50% by mass or more of the abrasive grains consists of particles A having particle sizes between 40 nm and 80 nm inclusive, and 10% by mass or more of the abrasive grains consists of particles B having particle sizes between 150 nm and 300 nm inclusive. The polishing composition is used to polish a surface of a compound semiconductor substrate.

Abstract: A polishing composition containing at least water and silica and satisfying all of the following conditions (a) through (d) is provided. Condition (a) The specific surface area of the silica contained in the polishing composition is 30 m2/g or more. Condition (b) Silica having a particle size of 10 to 50 nm is contained in the amount of 2% by mass or more. Condition (c) Silica having a particle size of 60 to 300 nm is contained in the amount of 2% by mass or more. Condition (d) The value obtained by dividing the average particle size of the silica specified in the condition (c) by the average particle size of the silica specified in the condition (b) is 2 or more.