Transfer of optical element patterns on a same side of a substrate already having a feature thereon
View Patent ↗A passive optical element is transferred into a substrate already having features with a vertical dimension thereon. The features may be another passive optical element, an active optical element, a dichroic layer, a dielectric layer, alignment features, metal portions. A protective layer is provided over the feature during the transfer of the optical element. One or more of these processes may be performed on a wafer level.
1. A method of forming a refractive optical element on a first surface of a substrate already having diffractive optical element thereon, the method comprising:
creating a pattern for the refractive optical element on the first surface of the substrate, in a separate portion of the substrate from the diffractive optical element;
providing a protective layer over the diffractive optical element;
transferring the pattern into the substrate using an analog etch to form the refractive optical element, the protective layer protecting the diffractive optical element during the transferring; and
removing the protective layer.
2. The method as claimed in claim 1 , wherein the providing the protective layer includes providing a layer more resistant to the analog etch than the pattern.
3. The method as claimed in claim 1 , wherein the providing the protective layer includes providing a layer of a same material as the pattern that is thicker than the pattern.
4. The method as claimed in claim 1 , wherein the providing the protective layer includes providing a layer less resistant to the analog etch than the pattern, the layer being thicker than the pattern.
5. The method as claimed in claim 1 , wherein the providing the protective layer includes providing a layer having a same material as the substrate.
6. The method as claimed in claim 1 , wherein the creating and providing are simultaneous.
7. The method as claimed in claim 1 , wherein the creating occurs after the providing.
8. The method as claimed in claim 1 , wherein the removing occurs during the transferring.
9. The method as claimed in claim 1 , further comprising stabilizing the pattern.
10. The method as claimed in claim 1 , wherein the creating the pattern for the refractive optical element includes reflowing photoresist.
11. The method as claimed in claim 10 , wherein the providing the protective layer includes providing a layer which maintains substantially all of its vertical dimension during the reflowing.
12. The method as claimed in claim 1 , wherein the providing a protective layer includes providing a lift off layer over a region in which the refractive optical element is to be formed, providing the protective layer over the first surface, and lifting off the protective layer in the region.
13. The method as claimed in claim 1 , further comprising alignment feature on the first surface.
14. The method as claimed in claim 1 , further comprising electro-optical elements on the first surface.
15. The method as claimed in claim 1 , further comprising metal portions on the first surface.
16. The method as claimed in claim 1 , further comprising one of dichroic portions and dielectric portions on the first surface.
17. The method as claimed in claim 1 , wherein the providing the protective layer includes die bonding protective portions over the diffractive optical element.
18. A method of making different optical elements on a first surface of a substrate, the method comprising:
forming a refractive optical element on the first surface of the substrate;
creating a pattern for a diffractive optical element on the first surface of the substrate, in a separate portion of the substrate from the refractive optical element;
providing a protective layer over the refractive optical element;
transferring the pattern into the substrate to form the diffractive optical element, the protective layer protecting the refractive optical element during the transferring; and
removing the protective layer.
19. The method as claimed in claim 18 , wherein the providing the protective layer includes providing a layer more resistant to the etch than the pattern.
20. The method as claimed in claim 18 , wherein the providing the protective layer includes providing a layer of a same material as the pattern that is thicker than the pattern.
21. The method as claimed in claim 18 , wherein the providing the protective layer includes providing a layer less resistant to the etch than the pattern, the layer being thicker than the pattern.
22. The method as claimed in claimed 18 , wherein the providing the protective layer includes providing a layer having a same material as the substrate.
23. The method as claimed in claim 18 , wherein the creating occurs after the providing.
24. The method as claimed in claim 18 , wherein the removing occurs during the transferring.
25. The method as claimed in claim 18 , further comprising stabilizing the pattern.
26. The method as claimed in claim 18 , wherein the creating the pattern for the diffractive optical element includes coating the first surface with a photoresist.
27. The method as claimed in claim 26 , wherein the providing the protective layer is achieved with the coating.
28. The method as claimed in claim 26 , wherein the coating includes one of spray coating and solvent assisted coating.
29. The method as claimed in claim 26 , wherein the providing the protective layer includes die bonding protective portions over the refractive optical element.
30. A method of making different optical elements on a first surface of a substrate, the method comprising:
forming a diffractive optical element on the first surface of the substrate;
creating a pattern for a refractive optical element on the first surface of the substrate, in a separate portion of the substrate from the diffractive optical element;
providing a protective layer over the diffractive optical element;
transferring the pattern into the substrate to form the refractive optical element, the
protective layer protecting the diffractive optical element during the transferring; and removing the protective layer.
31. The method as claimed in claim 30 , wherein the creating the pattern for the refractive optical element includes reflowing photoresist.