Novel method for fabrication of euv photomask fiducials
AssigneeIntel Corporation
InventorsJohn MAGANA, Guojing ZHANG
Life of this patent
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Abstract
Embodiments disclosed herein include reticles for extreme ultraviolet (EUV) lithography and methods of forming such reticles. In an embodiment, the reticle may comprise a substrate and a mirror layer over the substrate. In an embodiment, the mirror layer includes alternating layers of a first mirror layer and a second mirror layer. In an embodiment, a fiducial may be formed into the mirror layer. In an embodiment, the fiducial comprises constituents of the first mirror layer and the second mirror layer. In an embodiment, an absorber layer may be formed over the mirror layer.
Claims25
A reticle, comprising:
- a substrate;
- a mirror layer over the substrate, wherein the mirror layer comprises alternating layers of a first mirror layer and a second mirror layer;
- a fiducial formed into the mirror layer, wherein the fiducial comprises constituents of the first mirror layer and the second mirror layer;
- and
- an absorber layer over the mirror layer.
A method of forming a fiducial for an extreme ultra violet (EUV) reticle, comprising:
- providing an EUV reticle, wherein the EUV reticle comprises:
- a substrate;
- and
- a mirror layer over the substrate, wherein the mirror layer comprises a plurality of alternating layers of a first mirror layer and a second mirror layer;
- and
- irradiating the mirror layer with femtosecond laser radiation to form a fiducial in the mirror layer.
A method of using fiducials to fabricate an extreme ultraviolet (EUV) reticle, comprising:
- forming a mirror layer over a substrate, wherein the mirror layer comprises a plurality of alternating layers of a first mirror layer and a second mirror layer;
- forming a plurality of fiducials in the mirror layer, wherein the fiducials are formed with a femtosecond laser;
- inspecting the mirror layer, wherein inspecting the mirror layer comprises detecting defects in the mirror layer and recording positions of the defects relative to the fiducials;
- forming an absorber layer over the mirror layer;
- calculating an absorber layer pattern shift that minimizes the printing of the defects;
- and
- patterning the absorber layer with the absorber layer pattern shift.
Dependencies are inferred from the claim text.