Controlling AG ink flow with a detachable inkjet mask for AR devices

Abstract

1. A method and apparatus for forming a device, the method and apparatus comprising: depositing a mask layer on a first portion of a surface, the mask layer forming a feature on the surface; depositing a mirror layer on a second portion of the surface within the feature; and removing the mask layer from the surface.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE

[0001] Embodiments of the present disclosure generally relate to waveguides and methods for fabricating waveguides. [Background technology]

[0002] 2. Description of Related Art

[0002] In waveguide devices such as virtual reality (VR) or augmented reality (AR) devices, a waveguide combiner is often used to combine virtual images and transport light within a glass substrate by total internal reflection, combining the images when it reaches the viewer's eye position. For coupling and decoupling of light, the slanted features and trenches of the waveguide combiner are usually applied as a grating for diffracting light. The orientation of the lines (fins) controls the propagation direction of the light, and the tilt angle controls the efficiency of the desired order of diffraction. Mirrors are used to reflect light in a controlled manner.

[0003]

[0003] In many applications, mirrors with a silver layer are used in these waveguide devices. To protect the silver from long-term oxidation, an encapsulation layer is often deposited on or over the silver layer. However, when the silver layer is exposed to an oxidizing environment, such as oxygen in a plasma reactor, silver atoms often migrate to adjacent layers or substrates, damaging the waveguide device. Migration is a problem not only with glass and quartz substrates and wafers, but also with silicon oxide layers in particular.

[0004]

[0004] Therefore, there is a need for improved waveguides and methods for fabricating waveguides. Summary of the Invention

[0005]

[0005] The present disclosure generally relates to a method for forming a device. The method may include depositing a mask layer on a first portion of a surface, the mask layer forming a feature on the surface. The method may include depositing a mirror layer on a second portion of the surface within the feature. The method may include removing the mask layer from the surface.

[0006]

[0006] The present disclosure generally relates to a mask layer. The mask layer may include a composition disposed on a portion of a surface, the composition capable of forming features on the surface. In one example, the composition may include an organic polymer, a photocurable component, a solvent, and an additive.

[0007]

[0007] The present disclosure generally relates to a device that may include a mask layer deposited on a first portion of a surface to form a feature on the surface, and a mirror layer deposited on a second portion of the surface within the feature.

[0008]

[0008] So that the above-mentioned features of the present disclosure may be more fully understood, a more particular description of the present disclosure, briefly summarized above, will be had by reference to embodiments. Some embodiments are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only exemplary embodiments and therefore should not be considered to limit the scope of the present disclosure, as other equally effective embodiments may also be permitted. [Brief explanation of the drawings]

[0009] [Figure 1A]

[0009] FIG. 1 is a perspective front view of a waveguide according to one or more embodiments described and illustrated herein. [Figure 1B]

[0010] 1 is a schematic cross-sectional view of a waveguide device according to one or more embodiments described and illustrated herein; [Figure 1C]

[0011] 1 is a schematic cross-sectional view of a waveguide device according to one or more embodiments described and illustrated herein; [Figure 2]

[0012] FIG. 1 is a flow diagram of a method for forming a waveguide. [Figure 3A-3G]

[0013] 1 is a schematic cross-sectional view of a waveguide according to one or more embodiments described and illustrated herein; DETAILED DESCRIPTION OF THE INVENTION

[0010]

[0014] For ease of understanding, where possible, the same reference numerals have been used to designate identical elements that are common to multiple figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0011]

[0015] Embodiments of the present disclosure generally relate to encapsulated waveguides and methods for fabricating encapsulated waveguides, which may be used in virtual reality (VR) devices, augmented reality (AR) devices, and other devices, including optical devices, display devices, and / or microelectronic devices.

[0012]

[0016] FIG. 1A is a perspective front view of a waveguide 100. The waveguide 100 described herein is an exemplary waveguide, and it should be understood that other waveguides may be used with or modified to achieve aspects of the present disclosure. The waveguide 100 includes a plurality of structures 102. The structures 102 may be disposed above, below, or on a first surface 103 of a substrate 101, or may be disposed within the substrate 101. The structures 102 are nanostructures having a submicron critical dimension, e.g., a width less than 1 micrometer. Regions of the structures 102 correspond to one or more gratings 104. In one embodiment that can be combined with other embodiments described herein, the waveguide 100 includes at least a first grating 104a corresponding to an input coupling grating and a third grating 104c corresponding to an output coupling grating. In another embodiment that can be combined with other embodiments described herein, the waveguide 100 further includes a second grating 104b. The second grating 104b corresponds to a pupil dilation grating or a folded grating. Superimposed on the view of the waveguide 100 in Figure 1A is a cut line 106. In some embodiments, the cut line 106 may correspond to the cross-sectional views of Figures 1B and 1C.

[0013]

[0017] FIG. 1B is a cross-sectional view of one embodiment of a waveguide 100. The cross-sectional view may correspond to cut line 106 in FIG. 1A. Cut line 106 corresponds to a grating 104, such as first grating 104a. The embodiments described herein may apply to the first grating 104a as an input coupler grating, the second grating 104b as a pupil dilation grating, the third grating 104c as an output coupler grating, or a combination thereof. The waveguide 100 of FIG. 1B includes a structure 102 on a substrate 101. In some embodiments, the structure 102 may be disposed above, below, or on a first surface 103 of the substrate 101, or may be disposed within the substrate 101. As shown in FIG. 2, the structure 102 is disposed on the first surface 103. The waveguide 100 of FIG. 1B includes a mirror layer 108 disposed on a second surface 114 of the substrate 101 opposite the first surface 103. The mirror layer 108 may be disposed across the substrate 101 from the light engine 112. In some embodiments, the material of the mirror layer 108 may include silver (Ag). The mirror layer 108 is on a proximal region 111 of the second surface 114 adjacent to the structure 102 of the grating 104. The proximal region 111 and a region 113 of the surface surrounding the grating 104 do not include the mirror layer 108. That is, the mirror layer is present only in the proximal region 111 and the opposing area 115 of the grating 104. In some cases, the waveguide 100 of FIG. 1B optionally includes an encapsulation layer 110. The encapsulation layer 110 may be disposed on the mirror layer 108 such that the encapsulation layer 110 is disposed on a bottom surface 116 and each side surface 118 of the mirror layer 108. The encapsulation layer 110 may extend from the mirror layer 108 and be disposed on a portion of the bottom surface 114 of the substrate 101.

[0014]

[0018] FIG. 1C is a cross-sectional view of one embodiment of a waveguide 100. The cross-sectional view may correspond to cut line 106 in FIG. 1A. Cut line 106 corresponds to a grating 104, such as first grating 104a. The embodiments described herein may apply to the first grating 104a of an input coupler grating, the second grating 104b of a pupil dilation grating, the third grating 104c of an output coupler grating, or a combination thereof. The waveguide 100 of FIG. 1C includes a structure 102 disposed on a first surface 103 of a substrate 101. A mirror layer 108 is located on a proximal region 111 of a second surface 114 adjacent to the structure 102 of the grating 104. The proximal region 111 and a region 113 of the surface surrounding the grating 104 do not include the mirror layer 108. That is, the mirror layer 108 is present only in the proximal region 111 and the opposing area 115 of the grating 104. 1C includes a mirror layer 108 disposed over a substrate 101, on a first surface 103 of the substrate 101. The mirror layer may be disposed across the substrate 101 from the light engine 112. In some cases, the waveguide 100 of FIG. 1C optionally includes an encapsulation layer 110. The encapsulation layer 110 may be disposed over the mirror layer 108 such that the encapsulation layer 110 is disposed on a top surface 120 and each side surface 118 of the mirror layer 108. The encapsulation layer 110 may extend from the mirror layer 108 and be disposed over a portion of the first surface 103 of the substrate 101.

[0015]

[0019] FIG. 2 illustrates a flow diagram of a method 200 for forming a waveguide (e.g., waveguide 100, waveguide 300) according to one or more embodiments of the present disclosure. FIGS. 3A-3G illustrate cross-sectional schematic views of waveguide 300 during method 200 according to one or more embodiments of the present disclosure. It should be understood that FIGS. 3A-3G illustrate only a partial schematic view of waveguide 300, and that the waveguide may include any number of features and additional materials having the aspects shown in the figures. It should also be noted that while method 200 illustrated in FIG. 2 is described sequentially, other process sequences including one or more steps omitted and / or added and / or rearranged in another desired order are within the scope of the disclosed embodiments provided herein. In some embodiments, waveguide 300 in FIGS. 3A-3G may be understood with reference to waveguide 100. In other embodiments, waveguide 300 may be understood independently of waveguide 100.

[0016]

[0020] FIG. 3A illustrates a waveguide 300 at step 202. In step 202, as shown in FIG. 3A, a mask layer 202 is deposited on a substrate 101. In some embodiments, the mask layer 302 is deposited on only a portion 320 of the substrate. In some embodiments, the mask layer 302 may be deposited at step 202 by an inkjet deposition process. The inkjet deposition process may have a viscosity of about 1 cP or more to about 100 cP or less and a surface tension of about 20 mN / m or more to about 60 mN / m or less. In some embodiments, the mask layer 302 may be deposited at step 202 by a screen printing deposition process. The inkjet deposition process may have a viscosity of about 10 cP or more to about 100,000 cP or less and a surface tension of about 20 mN / m or more to about 60 mN / m or less.

[0017]

[0021] In some embodiments, the mask layer 302 can be a water-soluble mask. The water-soluble mask can include a polymer component, a photocurable component, a solvent, and an additive. The polymer component of the water-soluble solution can include, but is not limited to, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone-co-polyvinyl alcohol, polypropylene glycol, partially hydrolyzed polyvinyl acetate, or a combination thereof.

[0018]

[0022] Photocurable components include, but are not limited to, monomers, crosslinkers, oligomers, photoinitiators, or combinations thereof. Monomers include, but are not limited to, water-soluble (meth)acrylates, epoxies, or combinations thereof. Crosslinkers include, but are not limited to, water-soluble multifunctional (meth)acrylates or epoxies, or combinations thereof. Oligomers include, but are not limited to, water-soluble (meth)acrylates, epoxy-functionalized oligomers, or combinations thereof. Photoinitiators include, but are not limited to, photoinitiators capable of generating radicals and / or protons when exposed to ultraviolet and / or visible light.

[0019]

[0023] A water-soluble mask solvent that may be evaporated after dilution during baking. The solvent may include, but is not limited to, ester-, ether-, and alcohol-based organic solvents with a boiling point of about 250°C to about 350°C, e.g., less than about 300°C, and a pressure of 0.5 atm to about 1.5 atm, e.g., 1 atm. The solvent may include, but is not limited to, a mixture of an organic solvent and HO, e.g., a mixture with an HO content ranging from about 0% to about 80%. Such organic solvents include DPGME (34590-94-8), DPGBE (29911-28-2), TPGME (25498-49-1), DPGPE (29911-27-1), DPGDME (111109-77-4), TPGBE (55934-93-5), PGBE (5131-66-8), DEGME (111-77-3), DEGEE (111-90-0), TEGME (112-35-6), PGME (107-98-2), PGPE (1569-1-3), PGMEA (108-65-6), DPGMEA (88917-22-0), ethanol ( 64-17-5), methanol (67-56-1), isopropanol (67-63-0), 1-butanol (71-36-3), 2-butanol (78-92-2), 1-pentanol (71-41-0), 2-pentanol (6032-29-7), 3-pentanol (584-2-1), 1-hexanol (111-27-3), 2-hexanol (626-93-7), 3-hexanol (623-37-0), butyl acetate (123-86-4), butyl lactate (138-22-7), or combinations thereof.

[0020]

[0024] The additives include surfactants, polymers, or a combination thereof. The surfactants can adjust the surface tension. The polymers can adjust the viscosity of the formulation.

[0021]

[0025] In some embodiments, mask layer 302 can be an ashing mask, including but not limited to, epoxy, polystyrene, PMMA, novolac resin, PVP, or combinations thereof.

[0022]

[0026] Photocurable components include, but are not limited to, monomers, crosslinkers, oligomers, photoinitiators, or combinations thereof. Monomers include, but are not limited to, water-soluble (meth)acrylates, epoxies, or combinations thereof. Crosslinkers include, but are not limited to, water-soluble multifunctional (meth)acrylates or epoxies, or combinations thereof. Oligomers include, but are not limited to, water-soluble (meth)acrylates, epoxy-functionalized oligomers, or combinations thereof. Photoinitiators include, but are not limited to, photoinitiators capable of generating radicals and / or protons when exposed to ultraviolet and / or visible light.

[0023]

[0027] A water-soluble mask solvent that may be evaporated after dilution during baking. The solvent may include, but is not limited to, ester-, ether-, and alcohol-based organic solvents with a boiling point of about 250°C to about 350°C, e.g., less than about 300°C, and a pressure of 0.5 atm to about 1.5 atm, e.g., 1 atm. The solvent may include, but is not limited to, a mixture of an organic solvent and HO, e.g., a mixture with an HO content ranging from about 0% to about 80%. Such organic solvents include DPGME (34590-94-8), DPGBE (29911-28-2), TPGME (25498-49-1), DPGPE (29911-27-1), DPGDME (111109-77-4), TPGBE (55934-93-5), PGBE (5131-66-8), DEGME (111-77-3), DEGEE (111-90-0), TEGME (112-35-6), PGME (107-98-2), PGPE (1569-1-3), PGMEA (108-65-6), DPGMEA (88917-22-0), ethanol ( 64-17-5), methanol (67-56-1), isopropanol (67-63-0), 1-butanol (71-36-3), 2-butanol (78-92-2), 1-pentanol (71-41-0), 2-pentanol (6032-29-7), 3-pentanol (584-2-1), 1-hexanol (111-27-3), 2-hexanol (626-93-7), 3-hexanol (623-37-0), butyl acetate (123-86-4), butyl lactate (138-22-7), or combinations thereof.

[0024]

[0028] The additives include surfactants, polymers, or a combination thereof. The surfactants can adjust the surface tension. The polymers can adjust the viscosity of the formulation.

[0025]

[0029] In some embodiments, the material of the mask layer 302 may be modifiable so that the surface tension, viscosity, and air pressure of the system may be adjusted to suit a particular application.

[0026]

[0030] 3B shows waveguide 300 at step 204. As shown in FIG. 3B, in step 204, mask layer 302 is cured to form trench feature 322 in the surface of substrate 101. In some embodiments, mask layer 302 can be cured using a thermal or ultraviolet curing process. In some embodiments, structure 102 can be formed below substrate 101, opposite mask layer 302. In other embodiments not shown, structure 102 can be formed above substrate 101, on top of mask layer 302.

[0027]

[0031] 2, step 206, as illustrated in waveguide 300 in Figures 3C and 3D. Specifically, mask layer 302 enables mirror layer 108 to be deposited within trench feature 322 along desired deposition edge limits 330. Mask layer 302 accomplishes this by preventing mirror layer 108 from extending beyond desired deposition edge limits 330 during initial deposition (as shown in Figure 3C) and optional reflow (as shown in Figure 3D). In effect, mask layer 302 may act as a wall that inhibits reflow of mirror layer 108 material.

[0028]

[0032] In some embodiments, the material of the mirror layer 108 can include silver (Ag). In some embodiments, the mirror layer 108 can be deposited in step 206 by an inkjet deposition process. The inkjet deposition process can have a viscosity of about 1 cP to about 100 cP and a surface tension of about 20 mN / m to about 60 mN / m. In some embodiments, the mirror layer 108 can be deposited in step 202 by a screen printing deposition process. The inkjet deposition process can have a viscosity of about 10 cP to about 100,000 cP and a surface tension of about 20 mN / m to about 60 mN / m. In some embodiments, the mirror layer 108 can be disposed on or opposite the first grating 104a, which corresponds to the input coupling grating, as shown in FIG. 1A. In some embodiments, the mirror layer 108 can have a width of about 1 μm. In some embodiments, the mirror layer 108 may have a height of about 20 nm to about 20 μm, for example, about 5 μm to about 10 μm. In some embodiments, the thickness of the mirror layer 108 may be substantially laterally uniform, substantially laterally non-uniform, or substantially laterally semi-uniform.

[0029]

[0033] 3E shows waveguide 300 at step 208. In some embodiments, mirror layer 108 can be cured using a thermal or UV curing process. In some embodiments, structure 102 can be formed below substrate 101, opposite mirror layer 108. In other embodiments not shown, structure 102 can be formed above substrate 101, on top of mirror layer 108.

[0030]

[0034] 3F shows the waveguide 300 at step 210. In step 210, the mask layer 302 is removed from the surface of the substrate 101. In some embodiments, the mask layer 302 can be removed using a cleanable process, where the mask layer 302 is water soluble and dissolves when the substrate 101 is exposed to an aqueous solution. In some embodiments, the mask layer 302 can be removed using an ashing process, such as a plasma ashing process, where the mask layer 302 is etched away as a result of physical exposure to radical species.

[0031]

[0035] FIG. 3G shows the waveguide 300 at optional step 212. In step 210, the encapsulation layer 110 is deposited on the mirror layer 108. The encapsulation layer 110 may be disposed on the mirror layer 108 in a manner similar to the deposition of the encapsulation layer 110 described above in FIGS. 1B and 1C. In some embodiments, the encapsulation layer 110 may be deposited in step 212 by an inkjet deposition process. The inkjet deposition process may have a viscosity of about 1 cP or more to about 100 cP or less and a surface tension of about 20 mN / m or more to about 60 mN / m or less. In some embodiments, the mask layer 302 may be deposited in step 202 by a screen printing deposition process. The inkjet deposition process may have a viscosity of about 10 cP or more to about 100,000 cP or less and a surface tension of about 20 mN / m or more to about 60 mN / m or less.

[0032]

[0036] While the above description is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, the scope of which is determined by the claims that follow.

Claims

1. 1. A method for forming a device, comprising: depositing a mask layer over a first portion of a surface, the mask layer forming a feature on the surface; depositing a mirror layer on a second portion of the surface within the feature; removing the mask layer from the surface; and A method comprising:

2. curing the mask layer using thermal or ultraviolet radiation; hardening the mirror layer using thermal or ultraviolet radiation; The method of claim 1 further comprising:

3. The method of claim 1 , further comprising reflowing the mirror layer over the second portion of the surface.

4. The method of claim 1 , wherein depositing the mask layer on the first portion of the surface comprises depositing the mask layer using an inkjet deposition process or a screen printing deposition process.

5. The method of claim 1 , wherein depositing the mirror layer on the second portion of the surface comprises depositing the mirror layer using an inkjet deposition process or a screen printing deposition process.

6. The method of claim 1 , wherein removing the mask layer comprises dissolving the mask layer in an aqueous solution or etching the mask layer with radical species.

7. The method of claim 1 , wherein the mirror layer comprises at least a silver (Ag) material.

8. The method of claim 1 , wherein the surface is located remotely from a light engine.

9. A mask layer, A composition disposed on a portion of a surface, said composition capable of forming a feature on said surface, said composition comprising: organic polymers photocurable component, a solvent, and additives A composition comprising a mask layer,

10. The mask layer of claim 9 , wherein the composition is water-soluble.

11. 11. The mask layer of claim 10, wherein the organic polymer comprises at least one of polyvinylpyrrolidone (PVP), a copolymer, block copolymer, random or alternating copolymer of PVP, polyvinylpyrrolidone-co-polyvinyl alcohol, or copovidone.

12. The mask layer of claim 9 , wherein the composition is ashing.

13. 13. The mask layer of claim 12, wherein the organic polymer comprises at least one of an epoxy, a derivative of an epoxy, polystyrene, a derivative of polystyrene, polymethyl methacrylate (PMMA), a derivative of PMMA, a novolac resin, a derivative of a novolac resin, or polyvinylpyrrolidone (PVP).

14. 10. The mask layer of claim 9, wherein the photocurable component comprises at least one of a monomer, a water soluble (meth)acrylate, an epoxy, a crosslinker, a water soluble multifunctional (meth)acrylate, an oligomer, a functionalized oligomer, or a photoinitiator.

15. The solvent may be DPGME (34590-94-8), DPGBE (29911-28-2), TPGME (25498-49-1), DPGPE (29911-27-1), DPGDME (111109-77-4), TPGBE (55934-93-5), PGBE (5131-66-8), DEGME (111-77-3), DEGEE (111-90-0), TEGME (112-35-6), PGME (107-98-2), PGPE (1569-1-3), PGMEA (108-65-6), DPGMEA (88917-22-0), ethanol 10. The mask layer of claim 9, comprising at least one of: 1-pentanol (6032-29-7), 2-pentanol (6032-29-7), 3-pentanol (584-2-1), 1-hexanol (111-27-3), 2-hexanol (626-93-7), 3-hexanol (623-37-0), butyl acetate (123-86-4), or butyl lactate (138-22-7).

16. The additive is a surfactant capable of adjusting the surface tension value of the composition, and 10. The mask layer of claim 9, further comprising at least one of a polymer capable of adjusting the viscosity value of the composition.

17. A device, a mask layer deposited on a first portion of the surface, the mask layer forming features on the surface; a mirror layer deposited on a second portion of the surface within the feature.

18. 20. The device of claim 17, wherein the mirror layer is deposited on or substantially opposite the plurality of gratings.

19. The device of claim 17 , wherein the surface is positioned substantially away from the light engine.

20. 20. The device of claim 17, wherein the mirror layer comprises at least a silver (Ag) material.

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