Post arrays and methods of making the same
View Patent ↗In general, in one aspect, the invention features a method that includes forming layer of a mask material on a surface of a first layer, patterning the layer of the mask material to obtain a mask feature, the mask feature having a surface comprising a depression, inducing mass transport of the mask material of the mask feature to obtain a modified mask feature, and transferring a profile of the modified mask feature into the first layer to form a first structure. In general, in another aspect, the invention features a method that includes forming layer of a mask material on a surface of a first layer, patterning the layer of the mask material to obtain a mask feature, inducing mass transport of the mask material of the mask feature to obtain a modified mask feature, and transferring a profile of the modified mask feature into the first layer to form a first structure. The first layer is composed of an amorphous material and the first structure is a post having a base side-wall angle of in a range from about 60 degrees to about 80 degrees.
1. A method of manufacturing an optically transmissive material, comprising:
forming layer of a mask material on a surface of a first layer;
patterning the layer of the mask material to obtain a mask feature, the mask feature having a surface comprising a depression;
inducing mass transport of the mask material of the mask feature to obtain a modified mask feature;
transferring a profile of the modified mask feature into the first layer to form a post array, in which individual posts have: (a) a top portion having an indentation resulting from the depression; and (b) angled or curved sides resulting from induction of the mass transport; and
forming a layer of a second material on a surface of at least an individual one of the posts to form a lens.
2. The method according to claim 1 , wherein inducing mass transport of the mask feature comprises inducing reflow of the mask feature.
3. The method according to claim 2 , wherein inducing reflow of the mask feature comprises heating the mask feature above a glass transition temperature of the mask material.
4. The method according to claim 3 , wherein inducing reflow of the mask feature reduces a contact angle of the mask feature to between 60 and 80 degrees.
5. The method according to claim 4 , further comprising cooling the modified mask feature to inhibit reflow prior to transferring the profile of the modified mask feature.
6. The method according to claim 1 , wherein transferring the profile into the first layer comprises etching the first layer.
7. The method according to claim 6 , wherein transferring the profile into the first layer comprises anisotropically etching the first layer.
8. The method according to claim 7 , wherein the anisotropic etching comprises reactive ion etching.
9. The method according to claim 1 , wherein the layer of the second material is formed using atomic layer deposition.
10. The method according to claim 9 , wherein the lens comprises multiple layers of different dielectric materials.
11. The method of claim 1 , wherein the first layer is composed of an amorphous material.
12. The method of claim 11 , wherein the amorphous material is an inorganic, amorphous material.
13. The method of claim 11 , wherein the amorphous material is a glass.
14. The method according to claim 1 , further comprising applying a hydrophobic monolayer to the surface of the first layer prior to depositing the mask material.
15. The method according to claim 1 , further comprising applying a hydrophilic monolayer to the surface of the first layer prior to depositing the mask material.
16. The method according to claim 1 , wherein patterning the mask material comprises applying photolithography to the mask material.
17. The method according to claim 16 , wherein applying photolithography comprises using a brightfield mask between a light source and the mask material.
18. The method according to claim 1 , wherein patterning the mask material further comprises pre-shaping the mask feature.
19. The method according to claim 18 , wherein pre-shaping the mask feature comprises plasma etching the mask feature.
20. A method of manufacturing an optically transmissive material, comprising:
forming a layer of a mask material on a surface of a first layer;
patterning the layer of the mask material to obtain a mask feature;
inducing mass transport of the mask material of the mask feature to obtain a modified mask feature;
transferring a profile of the modified mask feature into the first layer to form a post array, and
forming a layer of a second material on a surface of at least an individual one of the posts to form a lens;
wherein each of the posts has (a) a base side-wall angle in a range from about 60 degrees to about 80 degrees, and (b) a top portion having a depression.