LITHOGRAPHIC APPARATUS, DEVICE MANUFACTURING METHOD, AND DEVICE MANUFACTURED THEREBY

摘要

Lithographic Apparatus, Device Manufacturing Method, and Device Manufactured Thereby. During device manufacturing a projection beam is projected onto a substrate through a mask. The substrate is aligned with the mask using an alignment structure on the substrate. Properties of the light reflected from the alignment structure are used to determine the relative position of the substrate. Preceding processing of the substrate potentially causes errors in the position determined from the reflected light measurement of properties of the reflected light are used to determine the size of a correction that is needed to correct for the errors caused by processing of the substrate. Preferably parameters of a physical model of the alignment structure are estimated from the reflected light and used to determine the correction. Preferably, the amplitudes of a plurality of different diffraction peaks are measured to determine the correction.