title: Position sensing of a grating mark by heterodyne detection using a Zeeman laser.
abstract: A way to detect with high resolution the position of a wafer and a mask is proposed and evaluated. In this method, a grating mark on a wafer or a mask is detected by heterodyne interference using a He-Ne Zeeman laser. Experiments show that the position of a wafer or a mask could be detected with a resolution of approximately 0.01 microm.
authors.forename: K
authors.initials: K
authors.lastname: Kataoka
authors.forename: S
authors.initials: S
authors.lastname: Katagiri
authors.forename: T
authors.initials: T
authors.lastname: Kurosaki