A double-side polishing method including: disposing a wafer between a polishing pad attached to an upper surface of a lower turn table and a polishing pad attached to a lower surface of an upper turn table provided above the lower turn table; and polishing both sides of the wafer. An absolute value of a difference between a gap at inner circumferential portions of the two polishing pads and a gap at outer circumferential portions thereof is defined as a pad gap. The pad gap is larger when the both sides of the wafer are polished than when the two polishing pads are dressed. This provides a double-side polishing method that simultaneously achieves enhancement of quality level (processing precision) and extension of cloth life.

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.

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 double-side polishing method, including: simultaneously polishing both surfaces of a semiconductor wafer by holding the semiconductor wafer in a carrier, interposing the held semiconductor wafer between an upper turn table and a lower turn table each having a polishing pad attached thereto, and bringing both surfaces of the semiconductor wafer into sliding contact with the polishing pads, wherein the semiconductor wafer is polished under a condition that a thickness A (mm) of the polishing pad attached to the upper turn table and a thickness B (mm) of the polishing pad attached to the lower turn table satisfy relations of 1.0≤A+B≤2.0 and A/B>1.0. This provides a double-side polishing method capable of obtaining a semiconductor wafer in which F-ZDD<0 while controlling the GBIR value to be equal to or smaller than a required value.

A double-side polishing method, including: simultaneously polishing both surfaces of a semiconductor wafer by holding the semiconductor wafer in a carrier, interposing the held semiconductor wafer between an upper turn table and a lower turn table each having a polishing pad attached thereto, and bringing both surfaces of the semiconductor wafer into sliding contact with the polishing pads, wherein the semiconductor wafer is polished under a condition that a thickness A (mm) of the polishing pad attached to the upper turn table and a thickness B (mm) of the polishing pad attached to the lower turn table satisfy relations of 1.0≤A+B≤2.0 and A/B>1.0. This provides a double-side polishing method capable of obtaining a semiconductor wafer in which F-ZDD<0 while controlling the GBIR value to be equal to or smaller than a required value.

Provided is a double-side polishing apparatus and a double-side polishing method which make it possible to terminate double-side polishing with timing allowing a work having been polished to have a target shape. A computing unit 13 performs a step of grouping the data of thicknesses measured using work thickness measuring devices 11 on a work basis; a step of extracting shape components of each work from the thickness data; a step of identifying a position of each of the shape components in the work radial direction; a step of computing a shape distribution of the work from the identified position ; a step of obtaining a shape index of the work from the computed shape distribution; and a step of determining timing of termination of the double-side polishing based on the obtained shape index, thus timing of termination of the double-side polishing is determined.

Provided is a double-side polishing apparatus and a double-side polishing method which make it possible to terminate double-side polishing with timing allowing a work having been polished to have a target shape. A computing unit 13 performs a step of grouping the data of thicknesses measured using work thickness measuring devices 11 on a work basis; a step of extracting shape components of each work from the thickness data; a step of identifying a position of each of the shape components in the work radial direction; a step of computing a shape distribution of the work from the identified position ; a step of obtaining a shape index of the work from the computed shape distribution; and a step of determining timing of termination of the double-side polishing based on the obtained shape index, thus timing of termination of the double-side polishing is determined.

The present invention provides an optical member including an organic polymer. This optical member includes a surface A which has an area of 1 mm.sup.2 or more, and in which the flatness of a region having an area of 1 mm.sup.2, as measured by a non-contact type optical flatness meter, is 80 μm or less.

The present invention provides an optical member including an organic polymer. This optical member includes a surface A which has an area of 1 mm.sup.2 or more, and in which the flatness of a region having an area of 1 mm.sup.2, as measured by a non-contact type optical flatness meter, is 80 μm or less.

A semiconductor wafer processing system for processing a set of semiconductor wafers includes a controller, a transfer robot controlled by the controller, a wet bath for containing a cleaning solution, and a cassette positioned in the wet bath for holding the set of wafers. The transfer robot transfers the wafer from a transfer location to the cassette and the controller controls the transfer robot during the transfer.