LENS REGULATING METHOD AND ITS APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a lens regulating method which enables even a lens with small NA to be highly precisely regulated, and to provide its apparatus. SOLUTION: The apparatus comprises: a light source emitting light; a device that is branched into four beams of light by adding two pieces of light having an inclination of a degree of±Ψ1 to an optical axis on a first plane including light on the optical axis, and two pieces of light having an inclination of a degree of±Ψ2 to the optical axis on a second plane orthogonal to the first plane including the optical axis; a regulating device for driving a second lens on a plane making the optical axis a normal line; a diffraction grating for diffracting and interfering condensed light from the first and second lenses; a slow motion stage for driving the diffracting grating in a direction including components of a groove direction and a vertical direction in the grating face; four interference image observation systems composed of an objective lens, an image formation lens and a CCD camera and for observing interference light; a processing device for detecting one aberration out of aberrations having a sensitivity for decentralization of the second lens by processing four interfering images; and a control device for calculating an amount of regulation from the detected aberration and driving the regulating device. COPYRIGHT: (C)2004,JPO&NCIPI