Reinforced thin-film semiconductor device and methods of making same
A reinforced thin-film device ( 100, 200, 500 ) including a substrate ( 101 ) having a top surface for supporting an epilayer; a mask layer ( 103 ) patterned with a plurality of nanosize cavities ( 102, 102 ′) disposed on said substrate ( 101 ) to form a needle pad; a thin-film ( 105 ) of lattice-mismatched semiconductor disposed on said mask layer ( 103 ), wherein said thin-film ( 105 ) comprises a plurality of in parallel spaced semiconductor needles ( 104, 204 ) of said lattice-mismatched semiconductor embedded in said thin-film ( 105 ), wherein said plurality of semiconductor needles ( 104, 204 ) are substantially vertically disposed in the axial direction toward said substrate ( 101 ) in said plurality of nanosize cavities ( 102, 102 ′) of said mask layer ( 103 ), and where a lattice-mismatched semiconductor epilayer ( 106 ) is provided on said thin-film supported thereby.
1. A reinforced thin-film device comprising;
a substrate having a top surface for supporting an epilayer;
a mask layer patterned with a plurality of nanosize cavities disposed on said substrate to form a needle pad;
a thin-film of, relative to the substrate, lattice-mismatched semiconductor disposed on said mask layer, wherein said thin-film comprises a plurality of in parallel spaced semiconductor needles of said lattice-mismatched semiconductor embedded in said thin-film, wherein said plurality of semiconductor needles are vertically disposed in the axial direction toward said substrate in said plurality of nanosize cavities of said mask layer; and
a, relative to the substrate, lattice-mismatched semiconductor epilayer provided on said thin-film and supported thereby, wherein the mask layer is in direct contact with the substrate,
and wherein said epilayer comprises a plurality of isolated islands of at least two different lattice-mismatched semiconductors, wherein each of the two different lattice-mismatched semiconductors comprise semiconductor material which is intentionally mismatched relative to the substrate.
2. The reinforced thin-film device according to claim 1 , wherein said plurality of in parallel spaced semiconductor needles of lattice-mismatched semiconductor are arranged in a close-packed structure, wherein said close-packed structure is a hexagonal pattern; and each individual semiconductor needle is disposed at a distance of 50-100 nm from each plurality of semiconductor needles.
3. The reinforced thin-film device according to claim 1 , wherein said plurality of nanosize cavities are nanosize holes configured with a hole diameter of 5-25 nm to provide said semiconductor needles of the same thickness in said nanosize holes.
4. The reinforced thin-film device according to claim 1 , wherein said thin-film is germanium and said epilayer is graphene.
5. The reinforced thin-film device of claim 1 , wherein said epilayer comprises semiconductor fins of the same semiconductor material as said epilayer.
6. The reinforced thin-film device according to claim 1 , wherein said plurality of islands is positioned at a distance of 200-500 nm to each other.
7. The reinforced thin-film device according to claim 1 , wherein said epilayer comprises at least one heterostructure of III-V semiconductor alloy with different bandgaps having a 1-10 nm thin middle layer, said middle layer having a smaller band gap than abutting semiconductor in said heterostructure.
8. The reinforced thin-film device of claim 7 , wherein the heterostructure comprises Ill-nitride nanowires having a light emitting diode (LED), and a structure of GaN core/AlGaN shell/GaN barrier shell/InGaN active layer shell/GaN barrier shell/GaN shell, and where the INGaN active layer shell acts as the middle layer.
9. The reinforced thin-film device of claim 1 , wherein said semiconductor needles have at least a portion which is wurtzite crystal structure.
10. The reinforced thin-film device of claim 1 , wherein said substrate is a silicon wafer.
11. The reinforced thin-film device of claim 1 , wherein the lattice-mismatched semiconductor epilayer and the thin-film of lattice-mismatched semiconductor are of the same semiconductor material which is intentionally mismatched relative to the substrate.