CHEMICAL MECHANICAL FABRICATION (CMF) FOR FORMING TILTED SURFACE FEATURES
A method of chemical-mechanical fabrication (CMF) for forming articles having tilted surface features. A substrate is provided having a patterned surface including two different layer compositions or a non-planar surface having at least one protruding or recessed feature, or both. The patterned surface are contacted with a polishing pad having a slurry composition, wherein a portion of surface being polished polishes at a faster polishing rate as compared to another portion to form at least one tilted surface feature. The tilted surface feature has at least one surface portion having a surface tilt angle from 3 to 85 degrees and a surface roughness<3 nm rms. The tilted surface feature includes a post-CMF high elevation portion and a post-CMF low elevation portion that defines a maximum height (h), wherein the tilted surface feature defines a minimum lateral dimension (r), and h/r is ≧0.05.
1 . A method of chemical-mechanical fabrication (CMF) for forming articles having tilted surface features, comprising:
contacting a substrate having a patterned surface with a polishing pad having a slurry composition therebetween, and
moving said slurry composition relative to said patterned surface to form at least one tilted surface feature,
wherein said tilted surface feature comprises at least one surface portion having (i) a surface tilt angle from 3 to 85 degrees, and (ii) a surface roughness<5 nm rms, and
wherein said tilted surface feature has a post-CMF high elevation portion and a post-CMF low elevation portion that defines a maximum height (h), and wherein said tilted surface feature defines a minimum lateral dimension (r), further wherein h/r is ≧0.05.
2 . The method in claim 1 , wherein said patterned surface comprises at least one protruding or recessed feature, said protruding or recessed feature comprising a first composition and having a pre-CMF high portion and a pre-CMF low portion, wherein a vertical distance between said pre-CMF high portion and said pre-CMF low portion is ≧10 nm, said pre-CMF high portion including a center portion and an edge portion.
3 . The method in claim 1 , wherein said patterned surface comprises two or more layers of different compositions.
4 . The method of claim 1 , wherein said h/r ratio is ≧0.1.
5 . The method of claim 2 , wherein said protruding or recessed feature comprises a protruding rectangular feature.
6 . The method of claim 3 , wherein said two or more layers of different compositions provide a polishing selectivity of >1.5.
7 . The method in claim 1 , wherein said two or more layers of different compositions provide a polishing selectivity of >20.0.
8 . The method of claim 1 , wherein said patterned surface comprises a plurality of protruding features, wherein a top surface of said plurality of protruding features have a polishing stop layer on a portion of said top surface.
9 . The method of claim 8 , wherein said polishing stop layer is positioned proximate to said center portion of said top surface.
10 . The method of claim 8 , wherein said polishing stop layer is positioned proximate to an edge portion of said top surface.
11 . An article, comprising:
a substrate having a patterned surface;
wherein said patterned surface comprises:
a plurality of protruding or recessed tilted surface features, said plurality of surface features having (i) a surface tilt angle from 3 to 85 degrees, and (ii) a surface roughness<5 nm rms, and
wherein said tilted surface features includes a high elevation portion and a low elevation portion that defines a height (h)>100 nm, and wherein said tilted surface feature defines a minimum lateral dimension (r), and wherein h/r is ≧0.05.
12 . The article of claim 11 , wherein said h/r ratio is ≧0.1.
13 . The article of claim 11 , wherein said surface roughness is <0.5 nm rms.
14 . The article of claim 11 , wherein said substrate comprises a single crystal substrate and said surface roughness is <0.3 nm rms.
15 . The article of claim 11 , wherein said patterned surface and said substrate comprise the same material.
16 . The article of claim 11 , wherein said tilted surface features are microlens shaped.
17 . The article of claim 11 , wherein said patterned surface comprises a metal, semiconductor, ceramic or a dielectric.
18 . The article of claim 11 , wherein said patterned surface comprises a glass, SiC, GaN, a carbide, a nitride, sapphire, an oxide, an optically transparent electrically conducting oxide, or a phosphor.
19 . The article of claim 11 , wherein said tilted surface features provide a positive curvature.
20 . The article of claim 11 , wherein said tilted surface features provide a negative curvature.