Method of fabricating diffraction gratings
A method of fabricating a blazed diffraction grating comprises providing a master template substrate and imprinting periodically repeating lines on the master template substrate in a plurality of master template regions. The periodically repeating lines in different ones of the master template regions extend in different directions. The method additionally comprises using at least one of the master template regions as a master template to imprint at least one blazed diffraction grating pattern on a grating substrate.
1. A method of fabricating a blazed diffraction grating, the method comprising:
providing a master template substrate;
imprinting periodically repeating lines on the master template substrate in a plurality of master template regions, wherein the periodically repeating lines in different ones of the master template regions extend in different radial directions with respect to a central axis of the master template substrate; and
using at least one of the master template regions as a master template to imprint at least one blazed diffraction grating pattern on a grating substrate.
2. The method of claim 1 , wherein the periodically repeating lines in different ones of the master template regions extend in non-orthogonal directions.
3. The method of claim 1 , wherein imprinting periodically repeating lines on the master template substrate comprises imprinting in at least four master template regions.
4. The method of claim 1 , wherein imprinting the periodically repeating lines comprises imprinting over a silicon surface of the master template substrate.
5. The method of claim 1 , wherein imprinting the periodically repeating lines comprises imprinting over a silicon oxide surface of the master template substrate.
6. The method of claim 1 , wherein imprinting the periodically repeating lines on the master template substrate comprises serially imprinting in different ones of the plurality of master template regions using the same primary master template.
7. The method of claim 1 , wherein the periodically repeating lines formed on the master template substrate has a sawtooth profile.
8. The method of claim 1 , wherein the periodically repeating lines formed on the master template substrate comprise symmetric opposing side surfaces forming similar angles with respect to a plane of the master template substrate.
9. The method of claim 1 , wherein the periodically repeating lines formed on the master template substrate comprise asymmetric opposing side surfaces forming different angles with respect to a plane of the master template substrate.
10. The method of claim 1 , wherein the periodically repeating lines formed on the master template substrate comprise a side surface having a stepped structure.
11. The method of claim 1 , wherein the periodically repeating lines formed on the master template substrate comprise a polymeric material.
12. The method of claim 1 , wherein the periodically repeating lines formed on the master template substrate comprise a dielectric material.
13. The method of claim 1 , further comprising coating the periodically repeating lines formed on the master template substrate with a dielectric material.
14. The method of claim 1 , further comprising coating the periodically repeating lines formed on the master template substrate with a metal oxide or a metal nitride.
15. The method of claim 1 , further comprising coating the periodically repeating lines formed on the master template substrate with a metal or a metal alloy.
16. The method of claim 1 , further comprising transferring a pattern corresponding to the periodically repeating lines into the master template substrate.
17. The method of claim 16 , wherein transferring the pattern comprises using the periodically repeating lines as a partial mask to dry etch the master template substrate.
18. The method of claim 17 , wherein dry etching comprises locally dry etching the master template regions.
19. The method of claim 1 , wherein imprinting the periodically repeating lines comprises imprinting using a primary master template comprising periodically repeating lines formed on a primary master substrate.
20. The method of claim 1 , wherein the different radial directions are not associated with crystallographic directions of the master template substrate.