Method for adjusting a projection objective
First Claim
1. A method for adjusting a projection exposure machine used for microlithography in the fabrication of semiconductor components and having an illumination device for providing an illumination beam and a projection objective comprising a plurality of optical elements in the path of the illumination beam for projecting an image of structures on a reticle onto a substrate at an image plane, said method comprising the steps of:
- (a) measuring initial values for two or more parameters at each of a plurality of points in a field at the image plane, each parameter corresponding to a respective imaging property of the projection objective, wherein for each parameter there are one or more corresponding points in the field having an initial value that has a largest absolute value compared to the initial values of the other points in the field; and
;
(b) adjusting the reticle and/or at least one of the optical elements of the projection objective such that, for each of the parameters, the largest absolute value for the points in the field is reduced compared to the initial values.
2 Assignments
0 Petitions
Accused Products
Abstract
A projection objective having a number of adjustable optical elements is optimized with respect to a number of aberrations by specifying a set of parameters describing imaging properties of the objective, each parameter in the set having an absolute value at each of a plurality of field points in an image plane of the projection objective. At least one of the optical elements is adjusted such that for each of the parameters in the set, the field maximum of its absolute value is minimized.
42 Citations
13 Claims
-
1. A method for adjusting a projection exposure machine used for microlithography in the fabrication of semiconductor components and having an illumination device for providing an illumination beam and a projection objective comprising a plurality of optical elements in the path of the illumination beam for projecting an image of structures on a reticle onto a substrate at an image plane, said method comprising the steps of:
-
(a) measuring initial values for two or more parameters at each of a plurality of points in a field at the image plane, each parameter corresponding to a respective imaging property of the projection objective, wherein for each parameter there are one or more corresponding points in the field having an initial value that has a largest absolute value compared to the initial values of the other points in the field; and
;(b) adjusting the reticle and/or at least one of the optical elements of the projection objective such that, for each of the parameters, the largest absolute value for the points in the field is reduced compared to the initial values. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
Specification