EP-4740049-A1 - PATTERNED THIN FILMS AS ANTI-REFLECTION COATINGS FOR AUGMENTED REALITY WAVEGUIDE COMBINERS

Abstract

A waveguide is disclosed. The waveguide includes one or more gratings disposed over a substrate. The gratings include grating structures having a grating pitch. The waveguide includes a waveguide region disposed over the substrate between each grating and an edge of the substrate. The waveguide region includes auxiliary structures with an auxiliary pitch less than the grating pitch.

Inventors

• Wang, Evan
• SHASTRI, Kunal
• SELL, DAVID ALEXANDER
• MESSER, Kevin
• BHARGAVA, SAMARTH

Assignees

• Applied Materials, Inc.

Dates

Publication Date

20260513

Application Date

20240619

Claims (20)

1. 1. A waveguide, comprising: one or more gratings disposed over a substrate, each grating comprising grating structures having a grating pitch; and a waveguide region disposed over the substrate between each grating and an edge of the substrate, the waveguide region having auxiliary structures with an auxiliary pitch less than the grating pitch.
2. 2. The waveguide of claim 1 , wherein the grating pitch is a distance between a center of adjacent grating structures.
3. 3. The waveguide of claim 1 , wherein the one or more gratings further comprise a depth, the depth being 10 nanometers or greater.
4. 4. The waveguide of claim 3, wherein the one or more gratings further comprise a pitch to depth ratio of about 1 :1 to about 1 :5.
5. 5. The waveguide of claim 1 , wherein the auxiliary structures comprise one or more of silicon carbide (SiC), silicon oxycarbide (SiOC), titanium dioxide (TiC ), SiC>2, vanadium (IV) oxide (VOx), aluminum oxide (AI2O3), aluminum-doped zinc oxide (AZO), indium tin oxide (ITO), tin dioxide (SnO2), zinc oxide (ZnO), tantalum pentoxide (Ta2Os), silicon nitride (SisN4), zirconium dioxide (ZrO2), niobium oxide (Nb20s), cadmium stannate (Cd2SnO4), silicon mononitride (SiN), silicon oxynitride (SiON), barium titanate (BaTiOs), diamond like carbon (DLC), hafnium(IV) oxide (HfO2), lithium niobate (LiNbOs), or silicon carbon-nitride (SiCN).
6. 6. The waveguide of claim 1 , wherein the auxiliary structures comprise a refractive index of about 1 .5 to 2.0.
7. 7. The waveguide of claim 1 , wherein a refractive index of the substrate is about 1.5 to 2.0.
8. 8. The waveguide of claim 1 , wherein the auxiliary structures surround a respective grating.
9. 9. The waveguide of claim 8, wherein the grating structures in the waveguide region are shaped differently than the auxiliary structures in the waveguide region.
10. 10. A method, comprising: disposing a structure material over a surface of a substrate; forming a patterned photoresist over the structure material, the patterned photoresist disposed over: a grating region; and a waveguide region between the grating region and an edge of the substrate, wherein each grating region and each waveguide region exposes unmasked portions of the structure material; and etching the unmasked portions of structure material layer, wherein the etching the unmasked portions form: a grating comprising grating structures with a grating pitch; and auxiliary structures with an auxiliary pitch less than the grating pitch.
11. 11. The method of claim 10, wherein the grating pitch is a distance between a center of each adjacent grating structures.
12. 12. The method of claim 10, wherein etching the unmasked portions simultaneously forms the grating structures disposed in the grating region and the auxiliary structures disposed in the waveguide region.
13. 13. The method of claim 10, wherein a shape of the auxiliary structures is one of a cylindrical shape, a rectangular shape, a hexagonal pillar shape, a cone shape, or an one dimensional grating line shape.
14. 14. A method, comprising: imprinting a stamp into a structure material layer disposed over a surface of a substrate; curing the structure material layer to form: a grating comprising grating structures having a grating pitch; and auxiliary structures with an auxiliary pitch less than the grating pitch.
15. 15. The method of claim 14, wherein the auxiliary structures are sized and shaped to maintain a characteristic of a light passed through the substrate.
16. 16. The method of claim 14, wherein the grating structures are disposed in a grating region and the auxiliary structures are disposed in a waveguide region around the grating region.
17. 17. The method of claim 14, wherein the grating structures and the auxiliary structures have the same composition.
18. 18. The method of claim 16, wherein a refractive index of the waveguide region is greater than a refractive index of the grating region.
19. 19. The method of claim 14, wherein a shape of the grating structures is one of a cylindrical shape, a rectangular shape, a hexagonal pillar shape, a cone shape, or an one dimensional grating line shape.
20. 20. The method of claim 19, wherein the grating structures in a grating region are shaped differently than the auxiliary structures in a waveguide region.

Description

PATTERNED THIN FILMS AS ANTI-REFLECTION COATINGS FOR AUGMENTED REALITY WAVEGUIDE COMBINERS BACKGROUND Field [0001] Embodiments of the present disclosure generally relate to waveguide combiners for augmented, virtual, and mixed reality. More specifically, embodiments described herein provide waveguides having auxiliary structures between one or more gratings and methods of fabrication. Description of the Related Art [0002] Virtual reality is generally considered to be a computer generated simulated environment in which a user has an apparent physical presence. A virtual reality experience can be generated in 3D and viewed with a head-mounted display (HMD), such as glasses or other wearable display devices that have near-eye display panels as lenses to display a virtual reality environment that replaces an actual environment. [0003] Augmented reality, however, enables an experience in which a user can still see through the display lenses of the glasses or other HMD device to view the surrounding environment, yet also see images of virtual objects that are generated for display and appear as part of the environment. Augmented reality can include any type of input, such as audio and haptic inputs, as well as virtual images, graphics, and video that enhance or augment the environment that the user experiences. As an emerging technology, there are many challenges and design constraints with augmented reality [0004] Augmented reality, however, enables an experience in which a user can still see through the display lenses of the glasses or other HMD device to view the surrounding environment, yet also see images of virtual objects that are generated for display and appear as part of the environment. Augmented reality can include any type of input, such as audio and haptic inputs, as well as virtual images, graphics, and video that enhance or augment the environment that the user experiences. As an emerging technology, there are many challenges and design constraints with augmented reality. Accordingly, what is needed in the art are waveguides having auxiliary structures between one or more gratings. SUMMARY [0005] The present disclosure generally relates to waveguides, including waveguides with gratings having a grating pitch and auxiliary structures having an auxiliary pitch. [0006] In one embodiment, a waveguide includes one or more gratings disposed over a substrate. The gratings include grating structures having a grating pitch. The waveguide includes a waveguide region disposed over the substrate between each grating and an edge of the substrate. The waveguide region includes auxiliary structures with an auxiliary pitch less than the grating pitch. [0007] In one embodiment, a method includes disposing a structure material over a surface of a substrate. The method includes forming a patterned photoresist over the structure material. The patterned photoresist is disposed over a grating region and a waveguide region between the grating region and an edge of the substrate. Each grating region and each waveguide region exposes unmasked portions of the structure material. The method includes etching the unmasked portions of structure material layer. Etching the unmasked portions forms a grating having grating structures with a grating pitch, and auxiliary structures with an auxiliary pitch less than the grating pitch. [0008] In one embodiment, a method includes imprinting a stamp into a structure material layer disposed over a surface of a substrate. The method includes curing the structure material layer to form a grating having grating structures with a grating pitch, and auxiliary structures with an auxiliary pitch that is less than the grating pitch. BRIEF DESCRIPTION OF THE DRAWINGS [0009] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments of the present disclosure and are therefore not to be considered limiting of its scope, and may admit to other equally effective embodiments. [0010] Figure 1A is a schematic, top view of a waveguide according to embodiments described herein. [0011] Figure 1 B is a cross-sectional view of a portion of a waveguide according to embodiments described herein. [0012] Figure 2A and 2B are schematic, cross-sectional views of a substrate during a first method according to embodiments described herein. [0013] Figures 3A and 3B are schematic, cross-sectional views of substrate during a second method according to embodiments described herein. [0014] Figure 4A is a schematic, top sectional view of a portion of a waveguide according to embodiments described herein. [0015] Figure 4B is a k-space diagram representative of a waveguide according to embodiments described he