Kabushiki Kaisha Ohara

Ohara, Inc.

Toshihide Nakajima

Kousuke Nakajima

Takahisa Oonami

Masahiko Daimon

Osamu Okajima

Kazuyoshi Nakamura

Nobuo Kawasaki

A substrate having flatness of less than 230 nmPV and surface roughness at RMS of less than 0.20 nm. is obtained by a method comprising: a process of polishing an object to be polished with a polishing pad comprising at least one layer having compressibility of 5% or below in a base layer of the polishing pad.

Substrate and a method for polishing a substrate

A coefficient of linear expansion measuring apparatus includes: two reflection plates between which a sample is put, a container to house them, which is filled with a gas having known rate of a refractive index variation, a temperature regulating member to set a temperature in the container variably, a light source to irradiate an irradiating light to reflecting surfaces of the reflection plates, a light receiving element to receive reflected lights in which the lights interferes each other and detecting a light intensity thereof, and a calculating member to calculate a coefficient of linear expansion of the sample, wherein: the calculating member calculates an optical path length variation between the reflecting surfaces from an output variation of the light receiving element, and calculates a length variation of the sample by correcting a part of the optical path length variation derived from the refractive index variation of the gas caused by the temperature variation.

Coefficient of linear expansion measuring apparatus and coefficient of linear expansion measuring method

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Akishima, Japan

Toshihide Nakajima