Meta-lens structure and method of fabricating the same
Various embodiments may provide a method of fabricating a meta-lens structure. The method may include forming a first dielectric layer in contact with a silicon wafer. The method may also include forming a second dielectric layer in contact with the first dielectric layer. A refractive index of the second dielectric layer may be different from a refractive index of the first dielectric layer. The method may further include, in patterning the second dielectric layer. The method may additionally include removing at least a portion of the silicon wafer to expose the first dielectric layer.
1. A method of fabricating a meta-lens structure, the method comprising:
forming a first dielectric layer in contact with a silicon wafer;
forming a second dielectric layer in contact with the first dielectric layer, a refractive index of the second dielectric layer different from a refractive index of the first dielectric layer;
patterning the second dielectric layer; and
removing at least a portion of the silicon wafer to expose the first dielectric layer,
wherein the silicon wafer is entirely removed;
wherein the method further comprises forming a layer of silicon oxide in contact with the second dielectric layer after the second dielectric layer is patterned and before the silicon wafer is entirely removed; and
wherein the method also comprises bonding a wafer to the silicon oxide layer after the silicon oxide layer is formed, and before the silicon wafer is entirely removed.
2. The method according to claim 1 , wherein the refractive index of the second dielectric layer is greater than the refractive index of the first dielectric layer.
3. The method according to claim 1 , wherein the first dielectric layer includes one or more first sub-layers of a first material and one or more second sublayers of a second material.
4. The method according to claim 3 , wherein a first sub-layer of the one or more first sub-layers has a first surface in contact with a second sub-layer of the one or more second sub-layers, and a second surface opposite the first in contact with another second sub-layer of the one or more second sub-layers.
5. The method according to claim 3 , wherein the first material is silicon oxide, and the second material is silicon nitride.
6. The method according to claim 1 , wherein the first dielectric layer comprises any one material selected from a group consisting of silicon oxide, silicon nitride, and aluminum nitride.
7. The method according to claim 1 , wherein the second dielectric layer comprises any one material selected from a group consisting of titanium oxide, amorphous silicon, silicon nitride, and aluminum nitride.
8. The method according to claim 1 , wherein patterning the second dielectric layer comprises forming or providing a mask over the second dielectric layer, and removing the exposed portions of the second dielectric layer via etching.
9. The method according to claim 1 , further comprising:
forming a patterned layer on a surface of the silicon wafer opposite another surface of the silicon wafer the first dielectric layer is in contact with; and
removing the portion of the silicon wafer exposed through the patterned layer while a further portion of the silicon wafer covered by the patterned layer remains in contact with the first dielectric layer.
10. The method according to claim 9 , wherein removing the portion of the silicon wafer exposes a portion of the first dielectric layer.
11. The method according to claim 9 , wherein the portion of the silicon wafer is removed via etching.
12. The method according to claim 1 , wherein the layer of silicon oxide is also in contact with exposed portions of the first dielectric layer.
13. The method according to claim 1 , wherein the wafer is configured to allow visible light to pass through.
14. The method according to claim 1 , wherein the wafer comprises glass, silica, or quartz.
15. The method according to claim 1 , wherein bonding the wafer to the silicon oxide layer comprises anodic bonding or fusion bonding.
16. The method according to claim 1 , further comprising:
removing a portion of the first dielectric layer to planarize a surface of the first dielectric layer via chemical mechanical polishing to form a meta-lens layer.
17. The method according to claim 16 , further comprising:
forming one or more further meta-lens layers over the meta-lens layer.
18. The method according to claim 16 ,
wherein the meta-lens layer is in contact with a first surface of the wafer; and
wherein the method also comprises forming a further meta-lens layer in contact with a second surface of the wafer opposite the first surface.