Method of forming a plurality of gratings
Embodiments of the present application generally relate to methods for forming a plurality of gratings. The methods generally include depositing a material over one or more protected regions of a waveguide combiner disposed on a substrate, the material having a thickness inhibiting removal of a grating material disposed on the waveguide combiner when an ion beam is directed toward the substrate, and directing the ion beam toward the substrate. The methods disclosed herein allow for formation of a plurality of gratings in one or more unprotected regions, while no gratings are formed in the protected regions.
1. A method of forming a first plurality of gratings, comprising:
depositing a protective material between portions of a patterned hardmask, the patterned hardmask disposed over a grating material, the protective material having a thickness from a planar top surface of the grating material to an upper surface of the protective material, the thickness of the protective material varying along the planar top surface of the grating material such that the thickness of the protective material at least partially inhibits removal of the grating material when an ion beam is directed toward the grating material; and
directing the ion beam toward the grating material such that at least a portion of the grating material is removed such that the first plurality of gratings is formed having a depth profile that corresponds with the thickness of the protective material such that at least two gratings of the first plurality of gratings have different depths than each other, at least one of the gratings of the first plurality of gratings has an angle of about 5° to about 85°.
2. The method of claim 1 ,
wherein the depositing the protective material includes depositing the protective material over a first portion and a second portion of the grating material such that the protective material with the thickness totally inhibits removal of the grating material in the first portion; and
removing the protective material over the second portion.
3. The method of claim 2 , wherein
the protective material disposed over the first portion is thicker than the protective material disposed over the second portion.
4. The method of claim 1 , wherein the thickness of the protective material varies in two dimensions over the first plurality of gratings.
5. The method of claim 1 , wherein the thickness of the protective material varies linearly across the grating material.
6. The method of claim 1 , wherein at least one of the gratings of the first plurality of gratings has a different height than other gratings of the first plurality of gratings.
7. A method of forming a plurality of gratings, comprising:
depositing a protective material over a first portion of a grating material, the first portion adjacent to a second portion of the grating material, the protective material disposed between portions of a patterned hardmask on the first portion, the patterned hardmask disposed over the grating material, the protective material comprising:
a thickness from a planar top surface of the grating material to an upper surface of the protective material, the thickness of the protective material inhibiting removal of the first portion of the grating material when an ion beam is directed toward the grating material; and
directing the ion beam toward the first portion and the second portion of the grating material such that the plurality of gratings is formed, wherein:
a first plurality of gratings is formed in the first portion and a second plurality of gratings is formed in the second portion, the first plurality of gratings having a first depth that is less than a second depth of the second plurality of gratings, the first depth corresponding to the thickness of the protective material; and
at least one grating of the first plurality of gratings or the second plurality of gratings has an angle of about 5° to about 85°.
8. The method of claim 7 , further comprising:
depositing the protective material on the second portion of the grating material.
9. The method of claim 8 , wherein
the protective material disposed over the first portion is thicker than the protective material disposed over the second portion.
10. The method of claim 8 , wherein the protective material disposed over the second portion has a second thickness that varies across the grating material.
11. The method of claim 10 , wherein the thickness of the protective material disposed over the first portion varies linearly across the grating material.
12. The method of claim 7 , wherein at least one of the gratings of the first plurality of gratings has a different thickness than other gratings of the first plurality of gratings.
13. The method of claim 7 , wherein
the depositing the protective material, and the directing the ion beam is repeated.
14. A method of forming a first plurality of gratings, comprising:
depositing a protective material over a first portion and a second portion of a grating material, the first portion adjacent to the second portion of the grating material, the protective material disposed between portions of a patterned hardmask on the first portion and the second portion, the patterned hardmask disposed over the grating material, the protective material comprising:
a first thickness from a planar top surface of the first portion to an upper surface of the protective material, the first thickness of the protective material inhibiting removal of the first portion of the grating material when an ion beam is directed toward the first portion; and
a second thickness from the planar top surface of the second portion to the upper surface of the protective material, the second thickness of the protective material inhibiting removal of the second portion of the grating material when an ion beam is directed toward the second portion; and
directing the ion beam toward the first portion and the second portion of the grating material such that the first plurality of gratings and a second plurality of gratings is formed, wherein:
the first plurality of gratings is formed in the first portion and the second plurality of gratings is formed in the second portion, the first plurality of gratings having a first depth that is less than a second depth of the second plurality of gratings, the first depth corresponding to the first thickness and the second depth corresponding to the second thickness;
at least one grating of the first plurality of gratings or the second plurality of gratings has an angle of about 5° to about 85°; and
the depositing the protective material on the second portion comprises exposing the protective material to a plurality of heating pixels or light-emitting diodes (LEDs).
15. The method of claim 14 , wherein each of the plurality of the heating pixels or LEDs is individually controlled.
16. The method of claim 15 , wherein a temperature distribution corresponding to first portion is provided to a back-side of a substrate disposed under the orating material.
17. The method of claim 14 , wherein at least one of the gratings of the first plurality of gratings has a different thickness than other gratings of the first plurality of gratings.
18. The method of claim 14 , wherein the protective material comprises a photoresist.
19. The method of claim 18 , wherein the protective material comprises SU-8.
20. The method of claim 14 , wherein the depositing the protective material comprises inkjet printing or three-dimensional (3D) printing.