Method for forming a multiple depth optical device - Patents.com

Abstract

Optical devices and methods of forming the optical devices are provided having a multi-depth optical device structure with a refractive index of 2.0 or greater. The optical devices and methods include forming a first matrix stack structure and a second matrix stack structure. The adjacent first matrix stack structure forms a first via having a first depth and the adjacent second matrix stack structure forms a second via having a second depth. The first depth of the first via differs from the second depth of the second via resulting from the formation of the submicron multi-depth optical device structure when the vias are backfilled with device material.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure generally relate to optical devices for augmented reality, virtual reality, and mixed reality. More specifically, embodiments described herein relate to optical devices and methods for forming optical devices having multi-depth optical device structures with a refractive index of 2.0 or greater. [Background technology]

[0002] The optical device may be used to manipulate the propagation of light using structures of the optical device formed on a substrate. The optical device includes an array of structures with in-plane dimensions smaller than half the design wavelength of light. The structures have sub-micron critical dimensions, e.g., nano-sized dimensions, to modify the propagation of light by manipulating photons to induce localized phase discontinuities (i.e., abrupt changes in phase over distances shorter than the wavelength of light). In addition to having sub-micron critical dimensions, it is desirable for different sections of the optical device to have structures with different heights. It is also desirable to have a high contrast ratio between the refractive index of the structures and the refractive index of the areas between the structures to improve the performance of the optical device.

[0003] However, forming optical devices having submicron critical dimensions from high refractive index materials, i.e., materials having a refractive index greater than about 2.0, can be difficult. For example, etching a layer of high refractive index material to form structures of different heights can result in non-uniform critical dimensions. Thus, what is needed in the art are optical devices and methods for forming optical devices having multi-depth optical device structures with a refractive index of 2.0 or greater. Summary of the Invention

[0004] In one embodiment, a method is provided that includes disposing a matrix stack on a substrate, the substrate having at least a first section and a second section, forming a first patterned hard mask on the matrix stack, the first patterned hard mask having a first hard mask structure on the first section, removing an exposed first portion of the matrix stack of the first section to form a first matrix stack structure, the first matrix stack structure defining a first via, removing the exposed first portion of the matrix stack of the first section, and forming a second patterned hard mask on the matrix stack, the second patterned hard mask having a first hard mask structure on the first section. forming a second patterned hard mask having a second hard mask structure over the first section; removing an exposed second portion of the matrix stack of the second section to form a second matrix stack structure, the second matrix stack structure defining a second via; removing the first patterned hard mask and the second patterned hard mask; forming a first optical device structure on the first section and forming a second optical device structure on the second section, the forming the first optical device structure and the second optical device structure comprising disposing device material in the first via and the second via.

[0005] In another embodiment, a method is provided that includes disposing a matrix stack of a first matrix layer, an etch stop layer, and a second matrix layer on a substrate, the substrate having at least a first section and a second section, forming a first patterned hard mask on the matrix stack, the first patterned hard mask having a first hard mask structure on the first section, removing an exposed first portion of the second matrix layer in the first section to form a first matrix stack structure, the first matrix stack structure defining a first via, removing an exposed first portion of the second matrix layer in the first section to form a first matrix stack structure, the first matrix stack structure defining a first via, and forming a second patterned hard mask on the matrix stack, the second patterned hard mask having a second hard mask structure on the second section. forming a second patterned hard mask having a first depth from the etch stop layer to a first top surface of the first optical device structure and a second depth from the substrate to a second top surface of the second optical device structure; removing the exposed second portion of the second matrix layer, the etch stop layer, and the first matrix layer of the second section to form a second matrix stack structure, the second matrix stack structure defining a second via; forming a first optical device structure on the first section and forming a second optical device structure on the second section, the forming the first optical device structure and the second optical device structure comprising disposing device material in the first via and the second via;

[0006] In yet another embodiment, an optical device is provided. The optical device includes a first section of a first optical device structure, the first matrix stack structure defining the first optical device structure, the first matrix stack structure including a second matrix layer disposed on the first matrix layer, the first optical device structure having a first depth from the first matrix layer to a first top surface of the first optical device structure. The optical device also includes a second section of a second optical device structure, the second matrix stack structure defining a second optical device structure, the second matrix stack structure including the first matrix layer and a second matrix layer disposed on the first matrix layer, the second optical device structure having a second depth from the optical device substrate to a second top surface of the second optical device structure.

[0007] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the present disclosure briefly summarized above may be made by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings depict only exemplary embodiments and are therefore not intended to limit the scope of the invention, which may admit of other embodiments that are equally effective. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of a portion of an optical device according to one or more embodiments. [Diagram 2] 1 is a flow diagram of a method for forming an optical device according to one or more embodiments. [Figure 3A] 1 is a schematic cross-sectional view of a portion of an optical device substrate according to one or more embodiments. [Figure 3B] 1 is a schematic cross-sectional view of a portion of an optical device substrate according to one or more embodiments. [Figure 3C] 1 is a schematic cross-sectional view of a portion of an optical device substrate according to one or more embodiments. [Figure 3D]1 is a schematic cross-sectional view of a portion of an optical device substrate according to one or more embodiments. [Figure 3E] 1 is a schematic cross-sectional view of a portion of an optical device substrate according to one or more embodiments. [Figure 3F] 1 is a schematic cross-sectional view of a portion of an optical device substrate according to one or more embodiments. [Figure 3G] 1 is a schematic cross-sectional view of a portion of an optical device substrate according to one or more embodiments. [Figure 4A] FIG. 2 is a perspective front view of an optical device according to an embodiment described herein. [Figure 4B] 1 is a schematic top view of an optical device according to an embodiment described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] To facilitate understanding, the same reference numbers have been used wherever possible to designate identical elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0010] FIELD OF THE DISCLOSURE Embodiments of the present disclosure generally relate to optical devices for augmented reality, virtual reality, and mixed reality. More specifically, embodiments described herein relate to optical devices and methods for forming optical devices having multi-depth optical device structures with a refractive index of 2.0 or greater.

[0011] FIG. 1 is a schematic cross-sectional view of a portion 100 of an optical device substrate 102 according to one or more embodiments. In one embodiment, which can be combined with other embodiments described herein, the optical device 150 is a planar optical device, such as a metasurface. In another embodiment, which can be combined with other embodiments described herein, the optical device 150 is a waveguide combiner, such as an extended waveguide combiner. The portion 100 may correspond to a portion of a planar optical device or a portion of a waveguide combiner. In one example, the portion 100 corresponds to a grating of a waveguide combiner, such as one or more of an input coupling grating, an intermediate grating, or an output coupling grating. The portion 100 may correspond to a cross-section as shown in FIG. 4A and FIG. 4B.

[0012] The optical device 150 includes a plurality of optical device structures 109 disposed on the optical device substrate 102. A first section 130 of the portion 100 of the optical device substrate 102 includes a plurality of first optical device structures 109a. A second section 140 of the portion 100 of the optical device substrate 102 includes a plurality of second optical device structures 109b. Although the portion 100 of the optical device substrate 102 shows the first section 130 and the second section 140, the optical device 150 may include additional sections of optical device structures 109.

[0013] The optical device structures 109 have a depth and a critical dimension. More specifically, the first optical device structure 109a has a depth 113a and a critical dimension 125a, and the second optical device structure 109b has a depth 113b and a critical dimension 125b. The critical dimension 125a corresponds to a width or diameter of the first optical device structure 109a, and the critical dimension 125b corresponds to a width or diameter of the second optical device structure 109b. In other embodiments, the critical dimension 125a and the critical dimension 125b are the same. In some embodiments, the critical dimension 125a and the critical dimension 125b are different. The critical dimension 125a and the critical dimension 125b are less than 1 micrometer (μm). In one embodiment, which may be combined with other embodiments described herein, the critical dimension 125a and the critical dimension 125b are from about 100 nanometers (nm) to about 1000 nm. Depth 113a is the distance from the optional etch stop layer 106 to the first top surface 110a of the first optical device structure 109a. Depth 113b is the distance from the substrate to the second top surface 110b of the second optical device structure 109b. Depth 113a and depth 113b are different. Etch stop layer 106 is an optional layer. In embodiments without optional etch stop layer 106, depth 113a corresponds to the thickness of second matrix layer 104b.

[0014] The first optical device structure 109a may have a first aspect ratio defined by the ratio of the depth 113a to the critical dimension 125a. The second optical device structure 109b may have a second aspect ratio defined by the ratio of the depth 113b to the critical dimension 125b. The first aspect ratio and the second aspect ratio are from about 1:1.5 to about 1:20, such as from about 1:10 to about 1:15. The first aspect ratio and the second aspect ratio may be different from each other.

[0015] The optical device structures 109 have a device refractive index. The device refractive index is greater than about 2.0. The optical device structures 109 include one or more of the following materials including, but not limited to, silicon (e.g., amorphous silicon), silicon carbide (SiC), silicon oxycarbide (SiOC), titanium dioxide (TiO2), silicon dioxide (SiO2), vanadium (IV) oxide (VOx), aluminum oxide (Al2O3), aluminum doped zinc oxide (AZO), indium tin oxide (ITO), tin dioxide (SnO2), zinc oxide (ZnO), tantalum pentoxide (Ta2O5), silicon nitride (Si3N4), zirconium dioxide (ZrO2), niobium oxide (Nb2O5), cadmium stannate (Cd2SnO4), or silicon carbonitride (SiCN).

[0016] The optical device 150 includes a plurality of matrix stack structures 123. Adjacent matrix stack structures 123 include an optical device structure 109 disposed therebetween. Each of the matrix stack structures 123 includes at least a first matrix layer 104a disposed on the optical device substrate 102, an optional etch stop layer 106 disposed on the first matrix layer 104a, and a second matrix layer 104b disposed on the optional etch stop layer 106. A first section 130 of the portion 100 of the optical device substrate 102 includes a plurality of first matrix stack structures 123a, and a second section 140 of the portion 100 of the optical device substrate 102 includes a plurality of second matrix stack structures 123b. Adjacent first optical device structures 109a include a first matrix stack structure 123a disposed therebetween. Adjacent second optical device structures 109b include a second matrix stack structure 123b disposed therebetween.

[0017] Each of the plurality of first optical device structures 109a includes a bottom surface in contact with the optional etch stop layer 106 and a side surface in contact with an adjacent first matrix stack structure 123a. A first top surface 110a of the first optical device structure 109a is aligned with a first top surface 112a of the first matrix stack structure 123a. Each of the plurality of second optical device structures 109b includes a bottom surface in contact with the optical device substrate 102 and a side surface in contact with an adjacent second matrix stack structure 123b. A second top surface 110b of the second optical device structure 109b is aligned with a second top surface 112b of the second matrix stack structure 123b. The depth 113a is about 100 nm to about 750 nm, corresponding to the thickness of the second matrix layer 104b. In embodiments including the etch stop layer 106, the depth 113b is about 200 nm to about 1550 nm, corresponding to the total thickness of the first matrix layer 104a, the optional etch stop layer 106, and the second matrix layer 104b. In embodiments without the etch stop layer 106, the depth 113b is about 200 nm to about 1500 nm, corresponding to the total thickness of the first matrix layer 104a and the second matrix layer 104b. The thickness of the first matrix layer 104a is about 100 nm to about 750 nm. The thickness of the optional etch stop layer 106 is less than 50 nm.

[0018] The matrix stack structure 123 has a matrix stack refractive index corresponding to the average of the refractive indexes of the materials of the first matrix layer 104a, the optional etch stop layer 106, and the second matrix layer 104b. The matrix stack refractive index is less than 2.0, for example less than about 1.5. The contrast ratio between the device refractive index and the matrix stack refractive index is about 1.7:1.45 to about 3.7:1.45. The optional etch stop layer 106 may comprise the same material or a different material as the optical device substrate 102. The optional etch stop layer 106 comprises the same material or a different material as the first matrix layer 104a. The optional etch stop layer 106 comprises the same material or a different material as the first matrix layer 104a and the second matrix layer 104b. The second matrix layer 104b comprises the same material or a different material as the first matrix layer 104a.

[0019] The first matrix layer 104a and the second matrix layer 104b include, but are not limited to, silicon dioxide (SiO2). The optional etch stop layer 106 includes, but is not limited to, one or more of the following materials: silicon (e.g., amorphous silicon), silicon carbide (SiC), silicon oxycarbide (SiOC), titanium dioxide (TiO2), silicon dioxide (SiO2), vanadium (IV) oxide (VOx), aluminum oxide (Al2O3), aluminum-doped zinc oxide (AZO), indium tin oxide (ITO), tin dioxide (SnO2), zinc oxide (ZnO), tantalum pentoxide (Ta2O5), silicon nitride (Si3N4), zirconium dioxide (ZrO2), niobium oxide (Nb2O5), cadmium stannate (Cd2SnO4), or silicon carbonitride (SiCN).

[0020] The optical device substrate 102 may be any suitable material so long as the optical device substrate 102 can adequately transmit light of a desired wavelength or range of wavelengths. The substrate selection may include substrates of any suitable material, including, but not limited to, amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, silicon oxides, polymers, and combinations thereof. In some embodiments that may be combined with other embodiments described herein, the optical device substrate 102 includes a transparent material. In one embodiment that may be combined with other embodiments described herein, the optical device substrate 102 includes, but is not limited to, one or more of silicon (Si), silicon dioxide (SiO2), silicon carbide (SiC), germanium (Ge), silicon germanium (SiGe), indium phosphide (InP), gallium arsenide (GaAs), gallium nitride (GaN), fused silica, quartz, or sapphire. In another embodiment that may be combined with other embodiments described herein, the optical device substrate 102 includes a high index transparent material, such as a high refractive index (high RI) glass.

[0021] 2 is a flow diagram of a method 200 for forming an optical device 150. FIGS. 3A-3G are schematic cross-sectional views of a portion 100 of an optical device substrate 102.

[0022] In step 202, as shown in FIG. 3A, a matrix stack 101 is disposed on an optical device substrate 102. The matrix stack 101 includes a first matrix layer 104a, an optional etch stop layer 106, and a second matrix layer 104b. The first matrix layer 104a is disposed between the optical device substrate 102 and the optional etch stop layer 106. The second matrix layer 104b is disposed on the optional etch stop layer 106. The first matrix layer 104a has a thickness that is substantially equal to or different from the second matrix layer 104b.

[0023] In step 204, as shown in FIG. 3B, a first patterned hard mask 114 is formed on the matrix stack 101. The first patterned hard mask 114 includes a first hard mask structure 133a formed on the first section 130 of the optical device substrate 102. The first hard mask structure 133a forms an exposed first portion 115a of the matrix stack 101 of the first section 130 by defining a first contact hole 118a in the first patterned hard mask 114. Forming the first patterned hard mask 114 includes disposing a first hard mask material on the matrix stack 101, disposing a photoresist on the first hard mask material, patterning the photoresist to expose a portion of the first hard mask material, and removing the exposed portion of the first hard mask material to form the first hard mask structure 133a. The first hard mask material may include, but is not limited to, silicon nitride (Si3N4).

[0024] In step 206, as shown in FIG. 3C, the exposed first portion 115a of the matrix stack 101 of the first section 130 is removed. By removing the exposed first portion 115a of the matrix stack 101, a first matrix stack structure 123a is formed. The first matrix stack structure 123a defines the first via 121a such that two adjacent first matrix stack structures 123a have the first via 121a disposed therebetween. Forming the first matrix stack structure 123a includes removing the second matrix layer 104b to expose the optional etch stop layer 106. In an optional step, at least one of the first via 121a, the second via 121b, the first contact hole 118a, or the second contact hole 118b is reduced.

[0025] In step 208, as shown in FIG. 3D, a second patterned hard mask 120 is formed on the matrix stack 101. The second patterned hard mask 120 includes a second hard mask structure 133b formed on the second section 140 of the optical device substrate 102. The second hard mask structure 133b forms an exposed second portion 115b of the matrix stack 101 of the second section 140 by defining a second contact hole 118b in the second patterned hard mask 120. Forming the second patterned hard mask 120 includes disposing a second hard mask material on the matrix stack 101, disposing a photoresist on the second hard mask material, patterning the photoresist to expose portions of the second hard mask material, and removing the exposed portions of the second hard mask material to form the second hard mask structure 133b. The second hard mask material may include, but is not limited to, silicon nitride (Si3N4).

[0026] In step 210, the exposed second portion 115b of the matrix stack 101 of the second section 140 is removed, as shown in FIG. 3E. By removing the exposed second portion 115b, a second matrix stack structure 123b is formed. The second matrix stack structure 123b defines a second via 121b such that two adjacent second matrix stack structures 123b have a second via 121b disposed therebetween. Forming the second matrix stack structure 123b includes removing the second matrix layer 104b, the optional etch stop layer 106, and the first matrix layer 104a to expose the optical device substrate 102.

[0027] In step 212, the first patterned hardmask 114 and the second patterned hardmask 120 are removed, as shown in Figure 3F. Any remaining photoresist material is also removed.

[0028] In step 214, the device material 108 is disposed in the first via 121a and the second via 121b, as shown in FIG. 3G. In one example, the device material 108 is disposed by atomic layer deposition (ALD). The device material may include one or more of the following materials: silicon oxycarbide (SiOC), titanium dioxide (TiO2), silicon dioxide (SiO2), vanadium (IV) oxide (VOx), aluminum oxide (Al2O3), aluminum-doped zinc oxide (AZO), indium tin oxide (ITO), tin dioxide (SnO2), zinc oxide (ZnO), tantalum pentoxide (Ta2O5), silicon nitride (Si3N4), zirconium dioxide (ZrO2), niobium oxide (Nb2O5), cadmium stannate (Cd2SnO4), or silicon carbonitride (SiCN).

[0029] In step 216, the device material 108 is planarized, as shown in Figure 1. The device material 108 is planarized to form a first optical device structure 109a and a second optical device structure 109b such that a first top surface 110a of the first optical device structure 109a is aligned with a first top surface 112a of the first matrix stack structure 123a and a second top surface 110b of the second optical device structure 109b is aligned with a second top surface 112b of the second matrix stack structure 123b. In one example, the excess portion 108a of the device material 108 may be removed using chemical mechanical planarization (CMP).

[0030] FIG. 4A is a perspective front view of the optical device 150 in a first configuration. FIG. 4B is a schematic top view of the optical device 150 in a first configuration. It should be understood that the described optical device 150 in the first and second configurations are exemplary optical devices. In one embodiment that can be combined with other embodiments described herein, the optical device 150 in the first configuration is a waveguide combiner, such as an augmented reality waveguide combiner. In another embodiment that can be combined with other embodiments described herein, the optical device 150 in the second configuration is a planar optical device, such as a metasurface. The optical device 150 includes a plurality of optical device structures 109 disposed on the optical device substrate 102. The plurality of optical device structures 109 includes a plurality of first optical device structures 109a and a plurality of second optical device structures 109b. In one embodiment that can be combined with other embodiments described herein, the regions of the optical device structure 109 correspond to one or more gratings 404, such as a first grating 404a, a second grating 404b, and a third grating 404c. In one embodiment that can be combined with other embodiments described herein, the optical device 150 is a waveguide combiner that includes at least a first grating 404a corresponding to an input coupling grating and a third grating 404c corresponding to an output coupling grating. The waveguide combiner according to this embodiment, which can be combined with other embodiments described herein, includes a second grating 404b corresponding to an intermediate grating. Although FIG. 4B illustrates the optical device structure 109 as having a square or rectangular cross section, the cross section of the optical device structure 109 can have other shapes, including, but not limited to, a circular, triangular, elliptical, regular polygonal, irregular polygonal, and / or irregularly shaped cross section. In some embodiments that can be combined with other embodiments described herein, the cross sections of the optical device structures 109 on a single optical device 150 are different.

[0031] In summary, optical devices and methods for forming optical devices are provided having a multi-depth optical device structure with a refractive index of 2.0 or greater. The optical devices and methods include forming a first matrix stack structure and a second matrix stack structure. The adjacent first matrix stack structure forms a first via having a first depth and the adjacent second matrix stack structure forms a second via having a second depth. The first depth of the first via differs from the second depth of the second via resulting from the formation of a sub-micron multi-depth optical device structure when the vias are backfilled with device material.

[0032] While the forgoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof, which scope is determined by the following claims.

Claims

1. disposing a matrix stack on a substrate, the substrate having at least a first section and a second section; forming a first patterned hardmask on the matrix stack, the first patterned hardmask having a first hardmask structure on the first section; removing an exposed first portion of the matrix stack of the first section to form a first matrix stack structure, the first matrix stack structure defining a first via; forming a second patterned hardmask on the matrix stack, the second patterned hardmask having a second hardmask structure on the second section; removing an exposed second portion of the matrix stack of the second section to form a second matrix stack structure, the second matrix stack structure defining a second via; and removing the first patterned hardmask and the second patterned hardmask; forming a first optical device structure on the first section and a second optical device structure on the second section, wherein forming the first optical device structure and the second optical device structure includes disposing a device material in the first via and the second via; A method comprising:

2. The method of claim 1 , wherein the device material has a device refractive index of 2.0 or greater.

3. The method of claim 2 , wherein the first matrix stack structure and the second matrix stack structure have a matrix stack refractive index less than 2.

0.

4. 4. The method of claim 3, wherein the contrast ratio between the device refractive index and the matrix stack refractive index is from about 1.7:1.45 to about 3.7:1.

45.

5. The method of claim 1 , wherein the matrix stack comprises a first matrix layer, an etch stop layer, and a second matrix layer.

6. removing the exposed first portion of the matrix stack in the first section includes removing the second matrix layer to expose the etch stop layer; 6. The method of claim 5, wherein the removing the exposed second portion of the matrix stack in the second section comprises removing the first matrix layer, the etch stop layer, and the second matrix layer to expose the substrate.

7. the first optical device structure has a first depth from the etch stop layer to a first top surface of the first optical device structure; The method of claim 6 , wherein the second optical device structure has a second depth from the substrate to a second top surface of the second optical device structure.

8. an adjacent first hard mask structure defining a first contact hole; The method of claim 1 , wherein the adjacent second hard mask structure defines a second contact hole.

9. The method of claim 8 , further comprising shrinking at least one of the first vias.

10. The method of claim 1 , further comprising planarizing the device material.

11. The device material is silicon oxycarbide (SiOC), titanium dioxide (TiO ２ ), silicon dioxide (SiO ２ ), vanadium (IV) oxide (VOx), aluminum oxide (Al ２ O ３ ), aluminum doped zinc oxide (AZO), indium tin oxide (ITO), tin dioxide (SnO ２ ), zinc oxide (ZnO), tantalum pentoxide (Ta ２ O ５ ), silicon nitride (Si ３ N ４ ), zirconium dioxide (ZrO ２ ), niobium oxide (Nb ２ O ５ ), cadmium stannate (Cd ２ SnO ４ 10. The method of claim 1, further comprising one or more of the following materials: silicon carbide (SiCN);

12. disposing a matrix stack of a first matrix layer, an etch stop layer, and a second matrix layer on a substrate, the substrate having at least a first section and a second section; forming a first patterned hardmask on the matrix stack, the first patterned hardmask having a first hardmask structure on the first section; removing an exposed first portion of the second matrix layer in the first section to form a first matrix stack structure, the first matrix stack structure removing an exposed first portion of the second matrix layer in the first section defining a first via; forming a second patterned hardmask on the matrix stack, the second patterned hardmask having a second hardmask structure on the second section; removing an exposed second portion of the second matrix layer, the etch stop layer, and the second section of the first matrix layer to form a second matrix stack structure, the second matrix stack structure defining a second via; and forming a first optical device structure on the first section and a second optical device structure on the second section, wherein forming the first optical device structure and the second optical device structure includes disposing a device material in the first via and the second via; Including, the first optical device structure has a first depth from the etch stop layer to a first top surface of the first optical device structure; The method, wherein the second optical device structure has a second depth from the substrate to a second top surface of the second optical device structure.

13. The method of claim 12 , further comprising shrinking at least one of the first vias.

14. A first section of a first optical device structure, comprising: a first matrix stack structure defining the first optical device structure; the first matrix stack structure includes a second matrix layer disposed on a first matrix layer; the first optical device structure has a first depth from the first matrix layer to a first top surface of the first optical device structure; a first section of a first optical device structure; a second section of a second optical device structure, a second matrix stack structure defining the second optical device structure; the second matrix stack structure includes the first matrix layer and the second matrix layer disposed on the first matrix layer; the second optical device structure has a second depth from an optical device substrate to a second top surface of the second optical device structure. a second section of a second optical device structure; and An optical device comprising:

15. The optical device of claim 14 , wherein the first optical device structure and the second optical device structure have a device refractive index of 2.0 or greater.

16. The optical device of claim 15 , wherein the first matrix stack structure and the second matrix stack structure have a matrix stack refractive index less than 2.

0.

17. 17. The optical device of claim 16, wherein the contrast ratio between the device refractive index and the matrix stack refractive index is from about 1.7:1.45 to about 3.7:1.

45.

18. The optical device of claim 14 , wherein the second matrix layer is disposed on an etch stop layer, and the second matrix stack structure further comprises the etch stop layer.

19. The first optical device structure and the second optical device structure are made of silicon oxycarbide (SiOC), titanium dioxide (TiO ２ ), silicon dioxide (SiO ２ ), vanadium (IV) oxide (VOx), aluminum oxide (Al ２ O ３ ), aluminum doped zinc oxide (AZO), indium tin oxide (ITO), tin dioxide (SnO ２ ), zinc oxide (ZnO), tantalum pentoxide (Ta ２ O ５ ), silicon nitride (Si ３ N ４ ), zirconium dioxide (ZrO ２ ), niobium oxide (Nb ２ O ５ ), cadmium stannate (Cd ２ SnO ４ 20. The optical device of claim 15, comprising one or more of the following materials: silicon carbide (SiC), or silicon carbonitride (SiCN).

20. 15. The optical device of claim 14, wherein the first matrix layer has a thickness of about 100 to about 750 nanometers (nm) and the second matrix layer has a thickness of about 100 to about 750 nm.

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