Patent ID: 6590670
Filing Date: 2003-07-08
Classification: G01B,H01L

Abstract:
A method for measuring a height of a test part of an object to be measured, said method comprising the steps of:placing said object on a table; projecting a spot beam of a measurement light flux to said object on said table from an upper direction of said object, said measurement light flux being emitted by a light source and focused into the spot beam by an optical member for focusing; receiving a reflected light of the spot beam reflected by said object with a photosensor to detect a focused state of said measurement light flux on said object; receiving said reflected light of the spot beam by a camera; forming, with said camera, an image of said object using said reflected light; determining X-Y coordinate data for said image including contour data on a contour of said image; setting a trajectory along which the optical axis is to be moved in said contour data of said image; driving said light source and said optical member relatively to said table in a way of scanning in a horizontal direction such that said measurement light flux moves along a periphery of said object while reciprocating said optical member vertically at a high speed; and determining said height of said test part on the basis of a vertical position of said optical member when said measurement light flux is focused on said test part by said optical member.