Rutile phase tiox deposition with preferred crystal orientations
Embodiments of the present disclosure generally relate to optical devices. More specifically, embodiments described herein relate to an optical device layer stack, an optical device formed from the optical device layer stack, and a method of forming an optical device layer stack.
1 . A method of forming an optical device layer stack, comprising:
depositing a titanium containing layer on a substrate;
thermally treating the titanium containing layer to form an orientation liner on the substrate; and
depositing an optical device layer of titanium oxide over the orientation liner, wherein a rutile phase of titanium oxide is about 100 percent of the optical device layer.
2 . The method of claim 1 , wherein the titanium containing layer is formed of pure titanium or titanium oxide.
3 . The method of claim 1 , wherein the titanium oxide of the optical device layer is selected from the group consisting of titanium(IV) oxide (TiO 2 ), titanium monoxide (TiO), dititanium trioxide (Ti 2 O 3 ), Ti 3 O, Ti 2 O, b-TiO x , where x is 0.68 to 0.75, and Ti n O 2n-1 , where n is 3 to 9.
4 . The method of claim 1 , wherein thermally treating the titanium containing layer comprises perform a thermal annealing processing process, wherein an annealing temperature is between about 400 degrees Celsius and about 1500 degree Celsius.
5 . The method of claim 1 , wherein thermally treating the titanium containing layer comprises flowing an annealing gas, wherein the annealing gas is selected from the group consisting of air, O 2 , N 2 , Ar, Kr, Xe, H 2 O, H 2 , and combinations thereof.
6 . The method of claim 1 , wherein thermally treating the titanium containing layer comprises perform a thermal annealing processing process for an annealing time between about 1 minute and about 72 hours.
7 . The method of claim 1 , wherein the deposition used to deposit the titanium containing layer is one of a physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), low pressure chemical vapor deposition (LPCVD), electron-beam evaporation, or thermal evaporation process.
8 . The method of claim 1 , wherein the deposition used to deposit the optical device layer is one of a physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), low pressure chemical vapor deposition (LPCVD), electron-beam evaporation, or thermal evaporation process.
9 . The method of claim 1 , wherein the titanium containing layer comprises a thickness less than about 20 nm.
10 . The method of claim 1 , wherein the optical device layer comprises a thickness less than about 1000 nm.
11 . An optical device layer stack comprising:
a substrate having a first surface;
an orientation liner disposed over the first surface of the substrate; and
an optical device layer disposed over the orientation liner, wherein:
the orientation liner is formed of a titanium containing material;
the optical device layer is formed of titanium oxide, the titanium oxide selected from the group consisting of titanium(IV) oxide (TiO 2 ), titanium monoxide (TiO), dititanium trioxide (Ti 2 O 3 ), Ti 3 O, Ti 2 O, δ-TiO x , where x is 0.68 to 0.75, and Ti n O2n−1, where n is 3 to 9; and
a rutile phase of the titanium oxide is about 100 percent of the optical device layer.
12 . The optical device of claim 11 , wherein a crystal orientation of the titanium oxide in the optical device layer is one of (211), (110), (101), (200), (111), (210), (220), (002), (221), (301), (311), (320), (202), (212), (321), (400), or (410).
13 . The optical device of claim 11 , wherein a crystal orientation of the titanium oxide in the optical device layer is (211).
14 . The optical device of claim 11 , wherein the orientation liner and the optical device layer are crystalline.
15 . The optical device of claim 11 , wherein the orientation liner and the optical device layer are polycrystalline.
16 . The optical device of claim 11 , wherein a crystal orientation of the optical device layer is matched to the orientation liner.
17 . The optical device of claim 11 , wherein a crystal phase of the optical device layer is matched to the orientation liner.
18 . The optical device of claim 11 , wherein an optical loss of visible range light transmitted through the optical device layer is about 0.03%.
19 . An optical device comprising:
a substrate having a first surface;
a plurality of optical device structures disposed over the first surface of the substrate, the plurality of optical device structures spaced apart from each other in a direction parallel to the first surface, wherein
each optical device structure of the plurality of optical device structures is formed from an orientation liner and an optical device layer disposed on the substrate,
the orientation liner is formed of a titanium containing material;
the optical device layer is formed of titanium oxide;
the titanium oxide in the optical device layer is selected from the group consisting of titanium(IV) oxide (TiO 2 ), titanium monoxide (TiO), dititanium trioxide (Ti 2 O 3 ), Ti 3 O, Ti 2 O, b-TiO x , where x is 0.68 to 0.75, and Ti n O 2n-1 , where n is 3 to 9; and
a rutile phase of the titanium oxide is about 100 percent of the optical device layer.
20 . The optical device of claim 19 , wherein an optical loss of visible range light transmitted through the plurality of optical device structures is about 0.03%.