A method of polishing a SiC substrate by supplying a polishing liquid and bringing a polishing pad into contact with the SiC substrate is provided. The polishing liquid contains a permanganate, inorganic salts having an oxidizing ability, and water. The method includes: a first polishing step of polishing the SiC substrate by use of a first polishing pad; and a second polishing step of polishing the SiC substrate by use of a second polishing pad softer than the first polishing pad after the first polishing step.

This invention provides a silicon wafer polishing composition used in the presence of an abrasive. The composition comprises a silicon wafer polishing accelerator, an amide group-containing polymer, and water. The amide group-containing polymer has a building unit A in its main chain. The building unit A comprises a main chain carbon atom constituting the main chain of the amide group-containing polymer and a secondary amide group or a tertiary amide group. The carbonyl carbon atom constituting the secondary amide group or tertiary amide group is directly coupled to the main chain carbon atom.

A method of a polishing a wafer includes: a first polishing step of polishing a surface of the wafer while supplying a rough polishing liquid onto a polishing surface of a rough polishing cloth; subsequent to the first polishing step, a protection film formation step of supplying a protection film formation solution containing a water-soluble polymer to the rough polishing cloth after being used in the first polishing step and bringing the protection film formation solution into contact with the polished surface of the wafer to form a protection film on the polished surface; and a second polishing step of polishing the surface of the wafer where the protection film is formed while supplying a finish polishing liquid to a polishing surface of a finish polishing cloth different from the rough polishing cloth.

Provided is a method that is for polishing a silicon wafer by a polishing device using a carrier holding the silicon wafer, and that can reduce wear on the carrier. In this polishing method, a polishing liquid used in the polishing device contains 0.1-5 mass %, in terms of the concentration of silica, silica particles comprising: silica particles (A) having an average primary particle size of 4-30 nm as measured by BET, and having an (X2/X1) ratio of 1.2-1.8, where X2 (nm) represents an average particle size along the major axis thereof as calculated from a perspective projection image obtained using an electron beam, and X1 (nm) represents the average primary particle size as measured by BET; and silica particles (B) having an average primary particle size of more than 30 nm but not more than 50 nm as measured by BET, and having a (X2/X1) ratio of 1.2-1.8, where X2 (nm) represents an average particle size along the major axis thereof as calculated from a perspective projection image obtained using an electron beam, and X1 (nm) represents the average primary particle size as measured by BET, wherein the mass ratio of the silica particles (A) to the silica particles (B) is 100:0 to 85:15.

A method of preheating a polishing pad of a semiconductor wafer polishing system includes heating a fluid to a first predetermined temperature. The method also includes applying the fluid to the polishing pad. The method further includes rotating the polishing pad such that the fluid covers the polishing pad. The fluid increases a polishing pad temperature to a second predetermined temperature.

An object of the present invention is to provide a silica particle having excellent polishing characteristics and storage stability. The present invention relates to a silica particle in which a proportion of silanol groups present on a surface represented by (x/y)×100% is 15% or less, where a content of silanol groups on the surface is x mass % and a content of bulk silanol groups is y mass %.

A method may include thinning a silicon wafer to a particular thickness. The particular thickness may be based on a passband frequency spectrum of an adjustable optical filter. The method may also include covering a surface of the silicon wafer with an optical coating. The optical coating may filter an optical signal and may be based on the passband frequency spectrum. The method may additionally include depositing a plurality of thermal tuning components on the coated silicon wafer. The plurality of thermal tuning components may adjust a passband frequency range of the adjustable optical filter by adjusting a temperature of the coated silicon wafer. The passband frequency range may be within the passband frequency spectrum. The method may include dividing the coated silicon wafer into a plurality of silicon wafer dies. Each silicon wafer die may include multiple thermal tuning components and may be the adjustable optical filter.

A method of producing a silicon wafer includes: a laser mark printing step of printing a laser mark having a plurality of dots on a silicon wafer; an etching step of performing etching on at least a laser-mark printed region in a surface of the silicon wafer; and a polishing step of performing polishing on both surfaces of the silicon wafer having been subjected to the etching step. In the laser mark printing step, each of the plurality of dots is formed by a first step of irradiating a predetermined position on a periphery of the silicon wafer with laser light of a first beam diameter thereby forming a first portion of the dot and a second step of irradiating the predetermined position with laser light of a second beam diameter that is smaller than the first beam diameter thereby forming a second portion of the dot.

An object of the present invention is to provide a silica particle having excellent polishing characteristics and storage stability, a method for producing the silica particle, a silica sol containing the silica particles, and a polishing composition containing the silica sol.

Another object of the present invention is to provide a polishing method, a method for producing a semiconductor wafer, and a method for producing a semiconductor device, which are excellent in productivity of an object to be polished. The silica particle in the present invention satisfies formula (1): y≥4.2 where a d value measured by wide-angle X-ray scattering is y ∪.

A wafer manufacturing method, an epitaxial wafer manufacturing method, and a wafer and epitaxial wafer manufactured thereby, are provided. The wafer manufacturing method enables the manufacture of a wafer with a low density of micropipe defects and minimum numbers of particles and scratches. The epitaxial wafer manufacturing method enables the manufacture of an epitaxial wafer that has low densities of defects such as downfall, triangular, and carrot defects, exhibits excellent device characteristics, and improves the yield of devices.