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.

Method for processing a semiconductor-wafer having a front surface, back surface, and chamfered-portion composed of a chamfered surface on the front surface side, a chamfered surface on the back surface side, and an end face at a peripheral end, including: mirror-polishing of each portion of the chamfered surface on the front surface side, the chamfered surface on the back surface side, the end face, and an outermost peripheral-portion on the front or back surface adjacent to the chamfered surface; wherein the end face mirror-polishing and mirror-polishing of the outermost peripheral-portion on the front or back surface are performed in one step, after step of mirror-polishing the chamfered surface on the front surface side and step of mirror-polishing the chamfered surface on the back surface side; roll-off amount of the outermost peripheral-portion on the front or back surface is adjusted by one step-performed mirror-polishing of the end face and outermost peripheral-portion.

According to the present invention, there is provided a slurry supply system including: a slurry mixing unit configured to mix slurry; a slurry supply unit in which the slurry mixed in the slurry mixing unit is stored and configured to supply the slurry to a polishing apparatus; a pipe configured to connect the slurry mixing unit and the slurry supply unit; and a slurry cooling unit installed in at least one of pipes configured to connect the slurry supply unit and the polishing apparatus to cool down the mixed slurry.

The present invention relates to a single-crystal silicon-carbide substrate provided with a principal surface having an atomic step-and-terrace structure containing atomic steps and terraces derived from a crystal structure, in which the atomic step-and-terrace structure has a proportion of an average line roughness of a front edge portion of the atomic step to a height of the atomic step being 20% or less.

A polishing composition eliminating protrusions around a laser mark in wafer polishing processes, the manufacturing method therefor and a polishing method using the composition. The polishing composition including silica particles and water, wherein: the composition includes a tetraalkylammonium ion such that the mass ratio of the ion to SiO.sub.2 of the silica particles is 0.400 to 1.500:1, and the mass ratio of SiO.sub.2 dissolved in the polishing composition to SiO.sub.2 is 0.100 to 1.500:1; the tetraalkylammonium ion is derived from a compound selected from the group made of an alkali silicate, a hydroxide, a carbonate, a sulfate, and a halide while the ion is contained in the polishing composition in 0.2% by mass to 8.0% by mass; and the dissolved SiO.sub.2 is derived from a tetraalkylammonium silicate, a potassium silicate, a sodium silicate, or a mixture of any of these.

Provided is a polishing composition capable of keeping a good polishing removal rate stably. The polishing composition includes silica particles as abrasives and a basic compound as a polishing removal accelerator. The silica particles have a density of silanol groups that is 1.5 to 6.0 pieces/nm.sup.2. The polishing composition has an adsorption ratio parameter A that is 1.2 or less, the adsorption ratio parameter representing concentration dependency of an amount of adsorption of the basic compound to the silica particles as the ratio of high-concentration adsorption amount/low-concentration adsorption amount.

A method for producing mirror-polished wafer, the method produces a plurality of mirror-polished wafers by performing, on plurality of silicon wafers obtained by slicing a silicon ingot, slicing strain removing step of removing strain on a surface caused by slicing, etching step of removing strain caused by the slicing strain removing step, and double-side polishing step of performing mirror polishing on both surfaces of the silicon wafers subjected to etching, each step being performed by batch processing, wherein silicon wafers which are processed in double-side polishing step by batch processing are selected from silicon wafers processed in same batch in the slicing strain removing step and the number of silicon wafers to be selected is made to be equal to the number of silicon wafers processed in the slicing strain removing step or submultiple thereof. As a result, a method that can produce mirror-polished wafers having high flatness is provided.

Disclosed is a method of chemically-mechanically polishing a substrate. The method comprises, consists of, or consists essentially of (a) contacting a substrate containing at least one Group III-V material, with a polishing pad and a chemical-mechanical polishing composition comprising water, abrasive particles having a negative surface charge, and an oxidizing agent for oxidizing the Group III-V material in an amount of from about 0.01 wt. %to about 5 wt. %, wherein the polishing composition has a pH of from about 2 to about 5; (b) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate; and (c) abrading at least a portion of the substrate to polish the substrate. In some embodiments, the Group III-V material is a semiconductor that includes at least one element from Group III of the Periodic Table and at least one element from Group V of the Periodic Table.

Containment and exhaust systems for substrate polishing components are disclosed. In one aspect, a substrate carrier head, includes a polishing pad, a substrate carrier head configured to retain a wafer against the polishing pad, an atomizer configured to atomize a liquid and spread a layer of the atomized liquid over a surface area of the polishing pad, and a chamber configured to contain and exhaust the atomized liquid.

The present disclosure relates to aqueous suspensions suitable for chemical mechanical planarization (CMP), the use of aqueous suspensions and a method of CMP using aqueous suspensions. The suspensions and method can be used for CMP of silicon carbide surfaces.