Refractive projection objective for immersion lithography

A purely refractive projection objective suitable for immersion microlithography is designed as a one-waist system with five lens groups, in which a first lens group with negative refractive power, a second lens group with positive refractive power, a third lens group with negative refractive power, a fourth lens group with positive refractive power and a fifth lens group are provided with positive refractive power. In the area of ​​the waist there is a constriction of narrowest constriction of the radiation beam. Between the object plane and the constriction X there is a waist distance AT. For a distance ratio AT / L between the waist distance AT and an object image distance L of the projection lens, the following condition holds: AT / L ≦ 0.4.