| CPC G03F 7/0035 (2013.01) [G03F 7/2004 (2013.01); G03F 7/2026 (2013.01); G03F 7/22 (2013.01); G03F 7/36 (2013.01)] | 20 Claims |
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1. A method, comprising:
depositing a mask layer over a substrate;
directing first radiation reflected from a central collector section of a sectional collector of a lithography system toward the mask layer according to a pattern;
directing second radiation reflected from a peripheral collector section of the sectional collector toward the mask layer according to the pattern, wherein the peripheral collector section is vertically separated from the central collector section by a gap;
forming openings in the mask layer by removing first regions of the mask layer exposed to the first radiation and second regions of the mask layer exposed to the second radiation; and
removing material of a layer underlying the mask layer exposed by the openings;
wherein the peripheral collector section includes:
a first surface configured to reflect extreme ultraviolet (EUV) radiation toward a focal point, wherein the first surface of the peripheral collector section has no openings;
a second surface opposite the first surface and having substantially the same curvature as the first surface;
a third surface forming an outer edge of the peripheral collector section and being substantially perpendicular to the first surface and the second surface;
a hollow cavity formed within the peripheral collector section;
a first opening located in the second surface of the peripheral collector section; and
a second opening located opposite the third surface and adjacent to an inner edge of the peripheral collector section, wherein the first opening, the hollow cavity, and the second opening are in fluid communication with each other, and the method further comprises:
causing a flow of air into the first opening of the peripheral collector section, through the hollow cavity of the peripheral collector section, and out of the second opening of the peripheral collector section.
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