WAFER AND OPTICAL PATH MODIFYING DISC HOLDERS

摘要

A wafer holder and a disc holder respectively for holding a wafer (2) and disc (102) during rotation. The wafer holder comprises a peripheral portion (11) and the disc holder comprises a central hub portion (111), each of which are arranged for rotation about a central axis. The hub portion (111) and peripheral portion (11) each include resilient centring arms (3) which are arranged to provide centring forces on a carried disc or wafer in order to centre it about the axis of rotation. The arms (3) are disposed in , and movable in, planes which are substantially perpendicular to the axis of rotation.