PROJECTION OBJECTIVE OF MICROLITHOGRAPHY FOR PROJECTING PATTERN OF OBJECT PLANE ONTO IMAGE PLANE, AND METHOD FOR ADJUSTING A PROJECTION OBJECTIVE

摘要

PURPOSE: A projection objective of microlithography for projecting a pattern of an object plane onto an image plane, and a method for adjusting a projection objective are provided to perform a function of an immersion objective as well as a function of a dry objective by adjusting easily the dry objective. CONSTITUTION: A projection objective of microlithography includes a plurality of optical elements. The optical elements include a first group(14) of optical elements following an object plane(11) and a last optical element(15) following the first group for defining an exit surface(16) of the projection objective(10). The last optical element is substantially without refracting power and has no curvature or only slight curvature. The projection object is used for filling up an operational distance by using an immersion medium(18) having a refractive index more than 1 by considering aberration.