MIRROR FOR POSITION MEASUREMENT AND MEMBER FOR MIRROR

摘要

PROBLEM TO BE SOLVED: To provide mirrors for position measurement having a low coefficient of thermal expansion and a high Young's modulus and high measurement accuracy and a member for the mirrors. SOLUTION: The mirrors 4 and 5 for position measurement are disposed on a sample stage for horizontally holding a sample and obtain reflected light for position measurement by reflecting reflected light. The mirrors have mirror bodies 11 comprising a composite material of low-thermal expansion ceramics and high-Young's modulus ceramics and reflection films 12 disposed on the surfaces thereof, in which the surface roughness RA of the surfaces of the mirror bodies 11 formed with reflection films 12 is≤10 nm. COPYRIGHT: (C)2004,JPO