US 2006/0139608 A1 · De-focus uniformity correction

Abstract

A system and method for uniformity correction such that a defined uniformity specification is met while minimizing a set of selected constraints is provided. The system includes illumination optics, an opto-mechanical correction system, a contrast device, projection optics and a correction module coupled to the correction system. The correction system includes a plurality of adjustable components such as fingers. The correction module is configured to determine adjustments to the components to correct uniformity. A method for discretizing the continuous intensity integral is also provided. The illumination slot is divided into a grid having multiple grid points. “pupils” are then superimposed onto the grid. Multiple second grids are also defined. Each ““pupil”” is mapped to a second grid such that the center of the second grid is coincident with the ““pupil”” center. The continuous intensity integral is then discretized using the first grid, plurality of second grids, and ““pupil”” mappings.

Claims20

Dependent claims

For use in connection with a lithography tool, a method for calculating an intensity integral, comprising:

(a) dividing an illumination slot into a first grid having a plurality of first grid points, wherein each first grid point is defined by a first and second direction coordinate;
(b) superimposing a plurality of pupils on the first grid, wherein each “pupil” has a center represented by a respective one of the first grid point;
(c) defining a plurality of second grids, each second grid having a plurality of second grid points, wherein each second grid point is defined by a third and fourth direction coordinate, and wherein the plurality of pupils maps to the plurality of second grids, one pupil per second grid, and a center of each second grid is coincident with the center of the pupil mapped to that second grid;
and
(d) discretizing the intensity integral using the results of steps (a), (b), and (c).

2 more elements

A method for calculating an intensity integral modified by a plurality of adjustable components of a uniformity correction system, comprising:

(a) dividing the illumination slot into a first grid having a plurality of first grid points, wherein each first grid point is defined by a first and second direction coordinate;
(b) superimposing a plurality of pupils on the first grid, wherein each pupil has a center represented by one of the first grid points;
(c) superimposing the plurality of adjustable component on the first grid;
(d) defining a plurality of second grids, each second grid having a plurality of second grid points, wherein each second grid point is defined by a third and fourth direction coordinate, and wherein the plurality of pupils maps to the plurality of second grids, one pupil per second grid, and a center of each second grid is coincident with the center of the pupil mapped to that second grid;
and
(e) discretizing the intensity integral modified by the plurality of adjustable components using the results of steps (a)-(d).

3 more elements

Dependencies are inferred from the claim text.

De-focus uniformity correction

Life of this patent

De-focus uniformity correction

Life of this patent

Abstract

Claims20