US 2008/0259308 A1 · PROJECTION OBJECTIVE FOR MICROLITHOGRAPHY

Abstract

A projection objective or microlithography for imaging a pattern arranged in an object plane on a substrate arranged in an image plane is disclosed. The projection objective has an arrangement of optical elements between the object plane and the image plane. The projection objective can have a first pupil plane arranged at the reticle side and at least a second pupil plane. The projection objective also includes at least one aperture diaphragm. The diaphragm aperture of which is variable and which is traversed only once by the imaging light. The at least one aperture diaphragm can be arranged within the arrangement of the optical elements at least optically close to the first pupil plane arranged at the reticle side. The projection objective further includes a pupil filter situated in immediate vicinity of the aperture diaphragm.

Claims20

Dependent claims

A projection objective configured to image a pattern in an object plane onto an article in an image plane, the projection objective comprising:

an arrangement of optical elements between the object plane and the image plane, the arrangement of optical elements having a first pupil plane at a reticle side of the projection objective and a second pupil plane;
an aperture diaphragm having a variable diaphragm aperture, the aperture diaphragm being configured so that, during use of the projection objective, the aperture diaphragm is traversed only once by imaging light;
and
a pupil filter in immediate vicinity of the aperture diaphragm,
wherein the aperture diaphragm is within the arrangement of optical elements at least optically close to the first pupil plane, and the projection objective is configured to be used in microlithography.

2 more elements

Dependencies are inferred from the claim text.

Projection objective for microlithography

Life of this patent

Projection objective for microlithography

Life of this patent

Abstract

Claims20