Apparatus and methods of electrically conductive optical semiconductor coating
A method of coating an optical substrate with a transparent, electrically conductive coating includes depositing a semiconductor coating over a surface of an optical substrate, wherein the semiconductor coating has broadband optical transmittance. A doped semiconductor is applied in a pattern over the semiconductor coating. The doped semiconductor in the pattern is activated for electrical conductivity in the doped semiconductor.
1. A method of coating an optical substrate, comprising:
depositing a semiconductor coating over a surface of an optical substrate, wherein the semiconductor coating has broadband optical transmittance, wherein the semiconductor coating has broadband optical transmittance in at least visible and infrared spectra; and
doping portions of the semiconductor coating to form a pattern of doped semiconductor in the semiconductor coating, wherein the pattern is configured to provide electromagnetic interference (EMI) shielding to the optical substrate.
2. A method as recited in claim 1 , wherein doping the semiconductor coating to form a pattern includes:
applying a photoresist over the semiconductor coating;
selectively exposing the photoresist;
developing the photoresist in the pattern;
doping the semiconductor coating through openings in the photoresist; and
removing the photoresist to leave the doped semiconductor in the pattern on the semiconductor coating.
3. A method as recited in claim 1 , wherein the pattern includes a grid.
4. A method as recited in claim 1 , further comprising applying a protective coating over the semiconductor coating and doped semiconductor before activating the doped semiconductor.
5. A method as recited in claim 4 , further comprising depositing a broadband anti-reflection coating over the protective coating.
6. A method as recited in claim 1 , further comprising depositing a broadband anti-reflection coating over the semiconductor coating and doped semiconductor.
7. A method as recited in claim 1 , wherein activating the doped semiconductor includes at least one of heat-treating or laser annealing the doped semiconductor.
8. A method as recited in claim 1 , wherein the semiconductor coating includes at least one of In 2 O 3 or ZnO.
9. A method as recited in claim 1 , wherein doping the semiconductor to form a pattern includes at least one of applying dopant by ion implantation or applying dopant by thin film coating.
10. A method as recited in claim 1 , wherein the doped semiconductor includes at least one of Sn, Mo, W, Ti, Al, or Ga.
11. A method as recited in claim 1 , wherein depositing the semiconductor coating includes depositing the semiconductor coating with the semiconductor coating undoped.
12. A method as recited in claim 1 , wherein doping the semiconductor coating and activating the doped semiconductor include diffusing the doped semiconductor through the semiconductor coating to the optical substrate.
13. A method as recited in claim 1 , wherein depositing a semiconductor coating includes depositing the semiconductor coating over a surface of the optical substrate in its entirety.
14. A method as recited in claim 1 , wherein doping the semiconductor coating to form a pattern includes doping a surface of the semiconductor coating so a surface of the semiconductor coating is covered in its entirety with the pattern.
15. A method as recited in claim 1 , wherein the activated doped semiconductor, semiconductor coating, and optical substrate are formed into a window without etching.
16. A method as recited in claim 1 , wherein the activated doped semiconductor, semiconductor coating, and optical substrate are formed into a window without polishing or post-process planarization.
17. A method as recited in claim 1 , wherein the activated doped semiconductor and semiconductor coating have closely matched indices of refraction to mitigate light scattering.
18. A method as recited in claim 1 , further comprising making the doped semiconductor electrically conductive.