INTERFERENCE TYPE DISPLACEMENT MEASURING SYSTEM AND LITHOGRAPHIC PROJECTION APPARATUS USING THE SAME

摘要

PURPOSE: Provided are an interference type displacement measuring system and a lithographic projection apparatus using the system having high accuracy under pressure and temperature of reference beam in light route. CONSTITUTION: The lithographic projection apparatus comprises a radiation system(Ex,IL,LA) for introducing radiation projection beam(PB); a programmable patterning unit for the projection beam depending on desired patterns; a mask table(MT) for fixing a substrate(W); a projection system(PL) for projecting the patterned beam on targeting part of the substrate; an interference measuring system for displacement of a targeting part; a secondary harmonic wave interference system; and a control system responding the secondary interference system.