摘要 |
An EUV optical projection system includes at least six mirrors (M1, M2, M3, M4, M5, M6) for imaging an object (OB) to an image (IM). At least one mirror pair is preferably configured as an at least phase compensating mirror pair. The system is preferably configured to form an intermediate image (IMI) along an optical path from the object (OB) to the image (IM) between a second mirror (M2) and a third mirror (M3), such that a first mirror (M1) and the second mirror (M2) form a first optical group (G1) and the mirror (3), a fourth mirror (M4), a fith mirror (M5) and a sith mirror (M6) form a second optical group (G1). The system also preferably includes an aperture stop (APE located along the optical path from the object (OB) to the image (IM) between the first mirror (M1) and the second mirror (M2). The second mirror (M2) is preferably convex, and the third mirror (M3) is preferably concave. The system preferably forms an image (IM) with a numerical aperture greater than 0.18. |