A magnetic-disk glass substrate of the present invention includes a pair of main surfaces, a side wall surface, and a chamfered surface between the main surfaces and the side wall surface. Regarding surface properties of at least one of the side wall surface and the chamfered surface of the glass substrate, an arithmetic average roughness (Ra) is 0.015 m or less, and a bearing factor of a roughness cross-sectional area when a roughness percentage is 60% is 95% or more in a bearing curve of a roughness cross-sectional area.

A magnetic-disk glass substrate of the present invention includes a pair of main surfaces, a side wall surface, and a chamfered surface between the main surfaces and the side wall surface. Regarding surface properties of at least one of the side wall surface and the chamfered surface of the glass substrate, an arithmetic average roughness (Ra) is 0.015 m or less, and a bearing factor of a roughness cross-sectional area when a roughness percentage is 60% is 95% or more in a bearing curve of a roughness cross-sectional area.

A carrier for a double-side polishing apparatus configured to double-side polish providing a semiconductor silicon wafer. The carrier being disposed between upper and lower turn tables have a polishing pad attached, and includes a holding hole formed to hold the semiconductor silicon wafer between the upper and lower turn tables during polishing. The carrier for a double-side polishing apparatus is made of a resin. An average contact angle with pure water of front and back surfaces of the carrier, which come into contact with the polishing pads, is 45 or more and 60 or less, and a difference in average contact angles between the front surface and the back surface is 5 or less, which provides a carrier for a double-side polishing apparatus capable of enhancing the polishing rate for a semiconductor silicon wafer by using a resinous carrier; and a double-side polishing apparatus and method which employ the carrier.

A carrier for a double-side polishing apparatus configured to double-side polish providing a semiconductor silicon wafer. The carrier being disposed between upper and lower turn tables have a polishing pad attached, and includes a holding hole formed to hold the semiconductor silicon wafer between the upper and lower turn tables during polishing. The carrier for a double-side polishing apparatus is made of a resin. An average contact angle with pure water of front and back surfaces of the carrier, which come into contact with the polishing pads, is 45 or more and 60 or less, and a difference in average contact angles between the front surface and the back surface is 5 or less, which provides a carrier for a double-side polishing apparatus capable of enhancing the polishing rate for a semiconductor silicon wafer by using a resinous carrier; and a double-side polishing apparatus and method which employ the carrier.

An indium phosphide substrate, a method of inspecting thereof and a method of producing thereof are provided, by which an epitaxial film grown on the substrate is rendered excellently uniform, thereby allowing improvement in PL characteristics and electrical characteristics of an epitaxial wafer formed using this epitaxial film. The indium phosphide substrate has a first main surface and a second main surface, a surface roughness Ra1 at a center position on the first main surface, and surface roughnesses Ra2, Ra3, Ra4, and Ra5 at four positions arranged equidistantly along an outer edge of the first main surface and located at a distance of 5 mm inwardly from the outer edge. An average value m1 of the surface roughnesses Ra1, Ra2, Ra3, Ra4, and Ra5 is 0.5 nm or less, and a standard deviation 1 of the surface roughnesses Ra1, Ra2, Ra3, Ra4, and Ra5 is 0.2 nm or less.

An indium phosphide substrate, a method of inspecting thereof and a method of producing thereof are provided, by which an epitaxial film grown on the substrate is rendered excellently uniform, thereby allowing improvement in PL characteristics and electrical characteristics of an epitaxial wafer formed using this epitaxial film. The indium phosphide substrate has a first main surface and a second main surface, a surface roughness Ra1 at a center position on the first main surface, and surface roughnesses Ra2, Ra3, Ra4, and Ra5 at four positions arranged equidistantly along an outer edge of the first main surface and located at a distance of 5 mm inwardly from the outer edge. An average value m1 of the surface roughnesses Ra1, Ra2, Ra3, Ra4, and Ra5 is 0.5 nm or less, and a standard deviation 1 of the surface roughnesses Ra1, Ra2, Ra3, Ra4, and Ra5 is 0.2 nm or less.

Semiconductor wafers are polished on both sides between polishing pads of a Shore A hardness of at least 80 and a compressibility of less than 3%, attached to upper and lower polishing plates, the polishing pads attached to the upper and lower polishing plates by bonding the polishing pads to the plates, and positioning an intermediate pad having a compressibility of at least 3% between the two bonded polishing pads as an intermediate layer and then pressing together the two polishing pads with the intermediate pad situated therebetween for a period of time.

Provided is a method of double-side polishing a semiconductor wafer, which can suppress variation in the polishing quality by providing for changes in the polishing environment during polishing. The method of double-side polishing of a semiconductor wafer includes: a step of predetermining a criterion function for determining polishing tendencies of double-side polishing; a first step of starting double-side polishing of the semiconductor wafer under initial polishing conditions; a second step of while performing double-side polishing on the semiconductor wafer under the initial polishing conditions, calculating a value of the criterion function using the apparatus log data in a predetermined period of polishing in the first step, and setting on the double-side polishing apparatus polishing conditions obtained by adjusting the initial polishing conditions based on the value of the criterion function; and a third step of performing double-side polishing of the semiconductor wafer under the adjusted polishing conditions.

A method includes: polishing a semiconductor wafer by a polishing device; measuring a form of the semiconductor wafer by a measuring device before a polished surface of the semiconductor wafer becomes hydrophilic; and setting polishing conditions for the polishing based on a measurement result of the form of the semiconductor wafer by a polishing condition setting unit.

A double-sided polishing apparatus includes: a lower surface plate; an upper surface plate; and a carrier disposed between the lower surface plate and the upper surface plate and holding a disk-shaped workpiece, wherein the carrier is configured to rotate about a center of the lower surface plate and the upper surface plate and to rotate about a center of the carrier, the double-sided polishing apparatus includes a thickness measuring sensor at a fixed position above the upper surface plate or below the lower surface plate or at a movable position in an upper portion of the upper surface plate or a lower portion of the lower surface plate, the carrier includes circular perforations each holding the workpiece at a position eccentric to the center of the carrier, when a central position of any of the perforations preset by a user is defined as a first reference position, with a distance between a center of the upper surface plate or the lower surface plate and a center of any of the perforations preset by the user being shortest or longest, and a position apart from the first reference position by half of a first distance in a direction of the center of the carrier is defined as a second reference position, with the first distance being a predetermined length within 30% of a radius of the perforation, then the thickness measuring sensor is provided in a range of the first distance about the second reference position in a plan view, and the thickness measuring sensor is configured to measure a thickness of the workpiece in a state in which the workpiece is held in the perforation, through a measuring hole provided on the upper surface plate or the lower surface plate closer to a side on which the thickness measuring sensor is disposed.