Patent ID: 6897956
Filing Date: 2005-05-24
Classification: G01B,H05K

Abstract:
1. An apparatus for measuring alignment accuracy for measuring an alignment accuracy between alignment mark of the lower layer and alignment mark of the upper layer formed to each of alignment mark portions on every plural chip units or exposure units arranged on a substrate to be measured, comprising: an XY stage running in a direction x and in a direction y while mounting the substrate; an illumination optical system for illuminating the alignment mark portions in a state where the XY stage runs in a direction x which is a direction of arranging the chips; a detecting optical system having an objective lens for collecting a reflection light in the running state obtained from the alignment mark of the lower layer and the alignment mark of the upper layer on each of the alignment mark portions irradiated by the illumination optical system, a focusing optical system for focusing reflection light in the running state obtained by collecting the reflection light from the objective lens, a scanning optical system for scanning reflection light image in the running state focused by the focusing optical system in a direction opposite to that of the running and a linear image sensor receiving reflection light image substantially in a static state being scanned in the opposite direction by the scanning optical system and converting them into image signal;, and an alignment accuracy calculation device for measuring alignment accuracy between the alignment mark of the lower layer and the alignment mark of the upper layer at least for a direction perpendicular to the running direction based on the image signal converted by the linear image sensor of the detecting optical system.