Abstract: Provided is a polishing composition which can polish a sapphire substrate having a non-polar plane or a semi-polar plane at a high polishing rate. The invention is a polishing composition used in an application to polish a sapphire substrate having a non-polar plane or a semi-polar plane, the polishing composition containing colloidal silica particles and water, in which a value obtained by dividing a specific surface area (unit: m2/g) of the colloidal silica particles by a number average particle diameter (unit: nm) of the colloidal silica particles, that is, (specific surface area/number average particle diameter) is 0.5 or more and 3.0 or less.

Abstract: Provided is a polishing composition which can polish a sapphire substrate having a non-polar plane or a semi-polar plane at a high polishing rate. The invention is a polishing composition used in an application to polish a sapphire substrate having a non-polar plane or a semi-polar plane, the polishing composition containing colloidal silica particles and water, in which a value obtained by dividing a specific surface area (unit: m2/g) of the colloidal silica particles by a number average particle diameter (unit: nm) of the colloidal silica particles, that is, (specific surface area/number average particle diameter) is 0.5 or more and 3.0 or less.

Abstract: A method is provided for manufacturing a microstructure on a substrate in which the substrate has thereon linear and parallel atomic steps. The microstructure includes linear elements that extend along the atomic steps. The method includes a step for preparing a substrate having atomic steps on its surface and a step for applying linear elements onto the substrate. Each linear element is oriented to extend along one of the atomic steps, with the result that a microstructure in which the linear elements extend along the atomic steps is formed on the substrate. The substrate can be prepared by subjecting a silicon carbide substrate, a sapphire substrate, or a zinc oxide substrate to an ultrasmoothing process. As the linear elements, peptide fibers can be employed that are made up of peptide molecules that form ?-sheet structures.

Abstract: A polishing composition contains a vanadate such as ammonium vanadate, sodium vanadate, and potassium vanadate and an oxygen donor such as hydrogen peroxide and ozone. It is preferable that the polishing composition further contains at least either one of abrasive grains and a pH adjusting agent. The polishing composition can be suitably used for polishing a silicon carbide wafer such as a hexagonal silicon carbide single crystal wafer.

Abstract: A method is provided for manufacturing a microstructure on a substrate in which the substrate has thereon linear and parallel atomic steps. The microstructure includes linear elements that extend along the atomic steps. The method includes a step for preparing a substrate having atomic steps on its surface and a step for applying linear elements onto the substrate. Each linear element is oriented to extend along one of the atomic steps, with the result that a microstructure in which the linear elements extend along the atomic steps is formed on the substrate. The substrate can be prepared by subjecting a silicon carbide substrate, a sapphire substrate, or a zinc oxide substrate to an ultrasmoothing process. As the linear elements, peptide fibers can be employed that are made up of peptide molecules that form ?-sheet structures.

Abstract: A first polishing composition includes abrasive grains and an iodine compound and has a pH of 6 or more. The first polishing composition can suitably polish the Si [0001] plane of a single crystal silicon carbide substrate. A second polishing composition includes an iodine compound and has a pH of 8 or less. The second polishing composition can suitably polish the C [000-1] plane of a single crystal silicon carbide substrate. A third polishing composition includes abrasive grains and an iodine compound and has a pH of 6 to 8, inclusive. The third polishing composition can suitably polish each of the Si [0001] and C [000-1] planes of a single crystal silicon carbide substrate.

Abstract: A polishing composition contains a vanadate such as ammonium vanadate, sodium vanadate, and potassium vanadate and an oxygen donor such as hydrogen peroxide and ozone. It is preferable that the polishing composition further contains at least either one of abrasive grains and a pH adjusting agent. The polishing composition can be suitably used for polishing a silicon carbide wafer such as a hexagonal silicon carbide single crystal wafer.

Abstract: A first polishing composition includes abrasive grains and an iodine compound and has a pH of 6 or more. The first polishing composition can suitably polish the Si [0001] plane of a single crystal silicon carbide substrate. A second polishing composition includes an iodine compound and has a pH of 8 or less. The second polishing composition can suitably polish the C [000-1] plane of a single crystal silicon carbide substrate. A third polishing composition includes abrasive grains and an iodine compound and has a pH of 6 to 8, inclusive. The third polishing composition can suitably polish each of the Si [0001] and C [000-1] planes of a single crystal silicon carbide substrate.

Abstract: To provide a wafer, made from a lithium tantalate single crystal or a lithium niobate single crystal, wafer which is charge restrained without impairing the piezoelectricity. Moreover, to provide a processing method and a processing apparatus therefor. It is characterized in that a wafer 50, made from a lithium tantalate single crystal or a lithium niobate single crystal, and a reducing agent 60, including an alkali metal or an alkali metal compound, are accommodated in a processing tank 2, and the inside of the processing tank 2 is held at a temperature of from 200° C. or more to less than a Curie temperature of the single crystal under decompression, thereby reducing the wafer 50.