Air-gap encapsulation of nanostructured optical devices

Patent metadata

Field	Value
Publication number	US-2022011471-A1
Application number	US-202117354667-A
Country	US
Kind code	A1
Filing date	Jun 22, 2021
Priority date	Jul 9, 2020
Publication date	Jan 13, 2022
Grant date	—

Abstract

Embodiments described herein relate to encapsulated optical devices and methods of forming optical devices with controllable air-gapped encapsulation. In one embodiment, a plurality of openings are formed in a support layer surrounding the plurality of optical device structures to create a high refractive index contrast between the optical device structures, the support layer, and the openings. In another embodiment, sacrificial material is disposed in-between the optical device structures and then an encapsulation layer is disposed on the optical device structures. The sacrificial material is removed, forming a space bounded by the encapsulation layer, the substrate, and each of the optical device structures. In yet another embodiment, the encapsulation layer is disposed over the optical device structures forming a space bounded by the encapsulation layer, the substrate, and each of the optical device structures.

First claim

What is claimed is:

1 . An optical device comprising:
a plurality of optical device structures disposed in or on a substrate, each structure of the plurality of optical device structures comprising:
a critical dimension less than 2 microns corresponding to a width or a diameter of a cross section of each structure; and
a structure material having an optical device refractive index between about 1.7 and about 4.0; and
a support layer surrounding each optical device structure of the plurality of optical device structures, the support layer comprising:
a support material having a support layer refractive index of about 1.0 to about 1.5; and
a plurality of openings disposed therethrough, each opening of the plurality of openings abutting two or more optical device structures, the plurality of openings having a refractive index of about 1.0.

2 . The optical device of claim 1 , wherein the plurality of optical device structures have a structure height and the support layer has a support layer height, the support layer height greater than the structure height.

3 . The optical device of claim 1 , wherein the plurality of optical device structures have a structure height and the support layer has a support layer height, the support layer height equal to the structure height.

4 . The optical device of claim 1 , wherein the optical device structures comprise one or more of titanium dioxide (TiO 2 ), zinc oxide (ZnO), tin dioxide (SnO 2 ), niobium oxide (Nb 2 O 5 ), aluminum-doped zinc oxide (AZO), titanium nitride (TiN), and zirconium dioxide (ZrO 2 ), indium tin oxide (ITO), tantalum pentoxide (Ta 2 O 5 ), fluorine-doped tin oxide (FTO), vanadium (IV) oxide, aluminum oxide (Al 2 O 3 ), cadmium stannate (Cd 2 SnO 4 ), cadmium stannate (tin oxide) (CTO), zinc stannate (tin oxide) (SnZnO 3 ), silicon, silicon nitride (Si 3 N 4 ), silicon oxycarbide (SiOC), silicon oxynitride (SiON), or silicon dioxide (SiO 2 ).

5 . A method, comprising:
disposing a support layer on a substrate and between a plurality of optical device structures, the support layer is planar with a first hardmask layer disposed on the plurality of optical device structures; disposing a second hardmask layer over the support layer and the first hardmask layer; disposing a resist layer over the first hardmask layer; exposing a pattern in the resist layer, the pattern exposes exposed portions of the second hardmask layer, the pattern corresponding to an opening to be formed in the support layer; etching the exposed portions of the second hardmask layer; etching exposed portions of the support layer to form the opening therethrough; and removing the first hardmask layer and the second hardmask layer.

6 . The method of claim 5 , wherein the resist layer is a three layer stack comprising an organic planarization layer, an antireflective coating layer, and a photoresist layer.

7 . The method of claim 5 , the disposing the support layer on the substrate and between the plurality of optical device structures further comprising etching the support layer to be planar with the first hardmask layer.

8 . The method of claim 5 , further comprising etching the opening to enlarge a width or a diameter of the opening.

9 . The method of claim 5 , wherein the opening includes air having a refractive index of about 1.0, the plurality of optical device structures include a structure material having an optical device refractive index between about 1.7 and about 4.0, and the support layer includes a support material having a support layer refractive index of about 1.0 to about 1.6.

10 . A method comprising:
disposing a sacrificial material on a substrate and between optical device structures of a plurality of optical device structures, the plurality of optical device structures comprising:
a critical dimension less than 2 microns corresponding to a width or a diameter of a cross section of optical device structures; and
a structure material having an optical device refractive index between about 1.7 and about 4.0;
disposing an encapsulation layer over the plurality of optical devices structures and the sacrificial material, the encapsulation layer including an encapsulation material having an encapsulation refractive index of about 1.0 to about 1.6; and removing the sacrificial material with an etch process, wherein:
the encapsulation layer, the substrate, and each of the optical device structures of the plurality of optical devices structures bound a space therebetween, the space having a refractive index of about 1.0.

11 . The method of claim 10 , wherein the encapsulation layer may further comprise a plurality of openings disposed therethrough.

12 . The method of claim 11 , further comprising depositing material in the plurality of openings after the sacrificial material has been removed.

13 . The method of claim 10 , the etch process further comprises utilizing an etch chemistry that etches the sacrificial material at a higher rate than the encapsulation layer.

14 . An optical device comprising:
a plurality of optical device structures disposed in or on a substrate, the plurality of optical device structures comprising:
a critical dimension less than 2 microns corresponding to a width or a diameter of a cross section of optical device structures; and
a structure material having an optical device refractive index between about 1.7 and about 4.0; and
an encapsulation layer comprising:
an encapsulation refractive index of about 1.0 to about 1.6;
first portions of a first material, the first portions surrounding a top surface of the plurality of optical device structures, the first portions of the first material comprising:
gaps defined between the first portions; and

second portions of a second material at least disposed in the gaps; wherein:
the encapsulation layer, the substrate, and each of the optical device structures of the plurality of optical devices structures bound a space therebetween, the space having a refractive index of about 1.0.

15 . The optical device of claim 14 , wherein the encapsulation layer is planar.

16 . The optical device of claim 14 , wherein a second plurality of optical device structures may be disposed on the encapsulation layer to create a multi-layered optical device.

17 . The optical device of claim 14 , wherein the optical device structures comprise one or more of titanium dioxide (TiO 2 ), zinc oxide (ZnO), tin dioxide (SnO 2 ), niobium oxide (Nb 2 O 5 ), aluminum-doped zinc oxide (AZO), titanium nitride (TiN), and zirconium dioxide (ZrO 2 ), indium tin oxide (ITO), tantalum pentoxide (Ta 2 O 5 ), fluorine-doped tin oxide (FTO), vanadium (IV) oxide, aluminum oxide (Al 2 O 3 ), cadmium stannate (Cd 2 SnO 4 ), cadmium stannate (tin oxide) (CTO), zinc stannate (tin oxide) (SnZnO 3 ), silicon, silicon nitride (Si 3 N 4 ), silicon oxycarbide (SiOC), silicon oxynitride (SiON), or silicon dioxide (SiO 2 ).

18 . A method comprising:
disposing first portions of an encapsulation layer, the first portions of the encapsulation layer surrounding a top surface of a plurality of optical device structures, the plurality of optical device structures disposed in or on a substrate, the plurality of optical device structures comprising:
a critical dimension less than 2 micron corresponding to a width or a diameter of a cross section of optical device structures; and
a structure material having an optical device refractive index between about 1.7 and about 4.0, the first portions of the encapsulation layer comprising:
a first material

Assignees

• Applied Materials Inc

Inventors

• Doshay Sage Toko Garrett
• Ohno Kenichi
• Meyer Timmerman Thijssen Rutger
• Teo Russell Chin Yee
• Guo Jinrui

Classifications

• G02B1/002 Primary

  made of materials engineered to provide properties not available in nature, e.g. metamaterials · CPC title

• C03C15/00

  Surface treatment of glass, not in the form of fibres or filaments, by etching (etching or surface-brightening compositions, in general C09K13/00) · CPC title

• G02B3/08 Primary

  with discontinuous faces, e.g. Fresnel lens {(diffractive Fresnel lenses G02B5/1876)} · CPC title

• G02B5/1809

  with pitch less than or comparable to the wavelength · CPC title

• G02B5/1871

  Transmissive phase gratings · CPC title