Template defect inspection method
View Patent ↗A template defect inspection method using an optical system includes emitting linearly polarized light to a template having a metal film formed on at least part of a concave-convex structure that is formed on a substrate and that has a line-and-space pattern, acquiring information on a polarization-rotated component, which is different from linearly polarized light incident on the template, of light reflected by the template in accordance with the emission thereto, converting the acquired information on the polarization-rotated component into an electrical signal, and processing the electrical signal.
1. A template defect inspection method comprising:
emitting first light including a linearly polarized component to a template having a concave-convex structure in which a metal film is disposed on at least a part of the concave-convex structure to reflect second light including the linearly polarized component and a polarization-rotated component;
emitting the second light to a polarization beam splitter to output third light including the polarization-rotated component; and
detecting the third light including the polarization-rotated component.
2. The method of claim 1 , wherein the concave-convex structure has a line-and-space pattern, and the metal film has a thickness that is 5% to 20% of a half pitch of the line-and-space pattern, on an upper surface of the concave-convex structure and on at least a part of side and bottom surfaces of the concave-convex structure.
3. The method of claim 1 , wherein the metal film has a surface roughness equal to or less than 3 nm.
4. The method of claim 1 , wherein the metal film includes at least one metal of W, Ta, Ti and Ni, or includes an alloy of the at least one metal.
5. The method of claim 1 , wherein the concave-convex structure is disposed on a substrate, and the substrate and the concave-convex structure comprise either one of quartz, Si and glass.
6. The method of claim 1 , wherein the concave-convex structure is disposed on a substrate, the substrate comprises either one of quartz, Si and glass, and the concave-convex structure comprises a resin.
7. The method of claim 1 , wherein the concave-convex structure is disposed on a substrate, and the substrate and the concave-convex structure comprise a resin.
8. The method of claim 1 , wherein the concave-convex structure is disposed on a substrate, the substrate comprises a resin, wherein the method comprises stretching the substrate to enlarge a defect.
9. The method of claim 1 , wherein the first light is emitted by a light source, and the first light is focused to the template by an objective lens.
10. The method of claim 9 , wherein the second light is emitted to the polarization beam splitter through a half wave plate and a Faraday rotator.
11. The method of claim 1 , wherein the metal film is formed by a sputtering, a vacuum deposition or a chemical vapor deposition.
12. The method of claim 6 , wherein the resin includes at least one of a silicon polymer, silsesquioxane, a cyclic olefin polymer, a norbornene resin that is a raw material of the cyclic olefin polymer, an oxazole resin, and a block copolymer of amid acid and a silicon resin.
13. The method of claim 7 , wherein the resin includes at least one of a silicon polymer, silsesquioxane, a cyclic olefin polymer, a norbornene resin that is a raw material of the cyclic olefin polymer, an oxazole resin, and a block copolymer of amid acid and a silicon resin.
14. The method of claim 8 , wherein the substrate includes at least one of polymethyl methacrylate, polyethylene, polypropylene, polyvinyl alcohol, polyethylene terephthalate, and a fluorine-based resin.