Air-spaced encapsulated dielectric nanopillars for flat optical devices

Patent metadata

Field	Value
Publication number	US-12216243-B2
Application number	US-202016905703-A
Country	US
Kind code	B2
Filing date	Jun 18, 2020
Priority date	Jun 18, 2019
Publication date	Feb 4, 2025
Grant date	Feb 4, 2025

Abstract

Embodiments described herein relate to flat optical devices and methods of forming flat optical devices. One embodiment includes a substrate having a first arrangement of a first plurality of pillars formed thereon. The first arrangement of the first plurality of pillars includes pillars having a height h and a lateral distance d, and a gap g corresponding to a distance between adjacent pillars of the first plurality of pillars. An aspect ratio of the gap g to the height h is between about 1:1 and about 1:20. A first encapsulation layer is disposed over the first arrangement of the first plurality of pillars. The first encapsulation layer has a refractive index of about 1.0 to about 1.5. The first encapsulation layer, the substrate, and each of the pillars of the first arrangement define a first space therebetween. The first space has a refractive index of about 1.0 to about 1.5.

First claim

What is claimed is:

1. A flat optical device, comprising:
a substrate, the substrate having a first arrangement of a first plurality of pillars formed thereon, the first arrangement of the first plurality of pillars comprising:
pillars having a height h and a lateral distance d;
a gap g corresponding to a distance between adjacent pillars of the first plurality of pillars, and
a silica-containing aerogel material having an absorption coefficient less than 0.001 only disposed in each gap g; and

a first encapsulation layer disposed on the first arrangement of the first plurality of pillars, the first encapsulation layer is disposed on a top surface of each pillar of the first plurality of pillars and on the silica-containing aerogel material disposed in each gap g, the first encapsulation layer having a refractive index of about 1.0 to about 1.5.

2. The flat optical device of claim 1 , wherein the silica-containing aerogel material has nanoscale porosities formed therein.

3. The flat optical device of claim 2 , wherein the silica-containing aerogel material and the first encapsulation layer consist of substantially the same materials.

4. The flat optical device of claim 1 , wherein the gap g has an air gap disposed in a center opening of the silica-containing aerogel material.

5. The flat optical device of claim 1 , wherein a liner is disposed over the pillars.

6. The flat optical device of claim 5 , wherein the liner has a thickness of about 1 nanometer (nm) to about 200 nm.

7. The flat optical device of claim 1 , further comprising:
a second arrangement of a second plurality of pillars formed over the first encapsulation layer, the second arrangement of the second plurality of pillars comprising:
pillars having the height h and the lateral distance d;
the gap g corresponding to the distance between adjacent pillars of the second plurality of pillars, and
a silica-containing aerogel material having an absorption coefficient less than 0.001 only disposed in each gap g; and

a second encapsulation layer disposed on the second arrangement of the second plurality of pillars, the second encapsulation layer is disposed on a top surface of each pillar of the second plurality of pillars and on the silica-containing aerogel material disposed in each gap g, the second encapsulation layer having the refractive index of about 1.0 to about 1.5 .

8. The flat optical device of claim 1 , wherein the pillars comprise one or more of titanium dioxide (TiO 2 ), zinc oxide (ZnO), tin dioxide (SnO 2 ), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (FTO), cadmium stannate (tin oxide) (CTO), zinc stannate (tin oxide) (SnZnO 3 ), or silicon containing materials.

9. The flat optical device of claim 1 , wherein the fist encapsulation material comprises a lower surface, wherein the lower surface is disposed on a top surface of each pillar of the first plurality of pillars and each gap, and wherein the lower surface is planar over the top surface.

10. A flat optical device, comprising:
a substrate, the substrate having a first arrangement of a first plurality of pillars formed thereon, the first arrangement of the first plurality of pillars comprising:
pillars having a height h and a lateral distance d; and
a gap g corresponding to a distance between adjacent pillars of the first plurality of pillars, wherein each gap g is composed of only a silica-containing aerogel material with nanoscale porosities within the silica-containing material, the silica-containing aerogel material having:
an absorption coefficient less than 0.001; and

a first encapsulation layer disposed on the first arrangement of the first plurality of pillars, the first encapsulation layer is disposed on a top surface of each pillar of the first plurality of pillars and on the silica-containing aerogel material disposed in each gap g, the first encapsulation layer having a refractive index of about 1.0 to about 1.5.

11. The flat optical device of claim 10 , wherein the gap is less than 350 nanometers (nm).

12. The flat optical device of claim 10 , wherein the height h is about 1500 nm or less.

13. The flat optical device of claim 10 , wherein the first encapsulation layer has a thickness less than 50 micrometers (μm).

14. The flat optical device of claim 10 , further comprising:
a second arrangement of a second plurality of pillars formed over the first encapsulation layer, the second arrangement of the second plurality of pillars comprising:
pillars having the height h and the lateral distance d;
the gap g corresponding to the distance between adjacent pillars of the second plurality of pillars, and
a silica-containing aerogel material having an absorption coefficient less than 0.001 only disposed in each gap q; and

a second encapsulation layer disposed on the second arrangement of the second plurality of pillars, the second encapsulation layer is disposed over a top surface of each pillar of the second plurality of pillars and on the silica-containing aerogel material disposed in each gap g, the second encapsulation layer having the refractive index of about 1.0 to about 1.5 .

15. The flat optical device of claim 10 , wherein the pillars comprise one or more of titanium dioxide (TiO 2 ), zinc oxide (ZnO), tin dioxide (SnO 2 ), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (FTO), cadmium stannate (tin oxide) (CTO), zinc stannate (tin oxide) (SnZnO 3 ), or silicon containing materials.

Assignees

• Applied Materials Inc

Inventors

• Godet Ludovic
• Roy Tapashree
• Goradia Prerna Sonthalia
• Sen Srobona
• Visser Robert Jan
• Deepak Nitin
• Chakraborty Tapash

Classifications

• B32B3/20

  of hollow pieces, e.g. tubes; of pieces with channels or cavities · CPC title

• G02B2207/109

  Sols, gels, sol-gel materials · CPC title

• G02B2207/101

  Nanooptics · CPC title

• G02F1/13398

  Spacer materials; Spacer properties · CPC title

• C09K3/10

  {Materials in mouldable or extrudable form} for sealing or packing joints or covers (filling pastes C09D5/34) · CPC title