Method for manufacturing an optical device structure

Abstract

Embodiments described herein provide methods of forming an optical device structure. The method utilizes rotation of a substrate to form an optical device structure on the substrate, and utilizes tunability of an etch rate of one of a patterned resist disposed over the substrate and a device layer or the substrate, without the need for multiple lithographic patterning steps and angled etch steps.

Description

[0001] This application is a divisional application of the invention patent application filed on July 28, 2021, with application number 202180063159.6 and invention title "Method for Manufacturing Optical Device Structure". Technical Field

[0002] Embodiments of the present invention generally relate to optical devices for augmented reality, virtual reality, and mixed reality. More specifically, embodiments described herein provide structures for forming blazed optical devices. Background Technology

[0003] Virtual reality is generally considered to be a computer-generated simulated environment in which the user has a tangible physical presence. Virtual reality experiences can be generated in 3D and viewed using a head-mounted display (HMD), such as glasses or other wearable display devices with display panels that act as lenses close to the eyes, to display a virtual reality environment that replaces the real environment.

[0004] However, augmented reality enables experiences where users can still see their surroundings through glasses or other HMD device display lenses, and also see images of virtual objects generated to be displayed and appear as part of the environment. Augmented reality can include any type of input, such as audio and haptic input, as well as virtual images, graphics, and videos of the environment that enhance or augment the user experience. As an emerging technology, augmented reality faces many challenges and design constraints.

[0005] One such challenge is displaying virtual images superimposed on the surrounding environment. Optics, including waveguide combiners (such as augmented reality waveguide combiners) and planar optics (such as metasurfaces), are used to aid in image superposition. The generated light is propagated through the optics until it exits and superimposes onto the surrounding environment. The optics may require a structure with a blazed angle relative to the surface of the optics substrate. It is known that fabricating blazed optical structures using one or more angled etching tools requires multiple photolithographic patterning steps and angled etching steps. These multiple photolithographic patterning and angled etching steps increase fabrication time and cost.

[0006] Therefore, what is needed in the art is an improved method for forming optical devices including blazed optical structures using angled etching tools. Summary of the Invention

[0007] In one embodiment, a method is provided. The method includes positioning a substrate in a beam path at a first rotation angle φ1. The beam is configured to project onto the substrate surface at a beam angle ϑ relative to the normal to the substrate surface. A patterned resist is formed on the substrate, wherein the patterned resist includes two or more resist structures and one or more gaps. Each of the resist structures has a width, and each of the gaps is defined by an adjacent resist structure and has a linewidth defined by the adjacent resist structure. The method includes beam etching of the substrate positioned at the first rotation angle φ1, rotating the substrate to a second rotation angle φ2, and etching sidewalls of the resist structures oriented toward the beam, such that the width of the resist structures decreases and the linewidth of the gaps increases. The method further includes rotating the substrate to the first rotation angle φ1, beam etching of the substrate located at the first rotation angle φ1, and forming two or more optical device structures in the substrate. Forming an optical device structure includes repeatedly rotating the substrate to a second rotation angle φ2 and etching the sidewalls of the resist structure with a beam, and rotating the substrate to a first rotation angle φ2 and etching the substrate with a beam until the resist structure is removed or the linewidth of the gap has a predetermined linewidth.

[0008] In another embodiment, a method is provided. The method includes positioning a substrate in a beam path at a first rotation angle φ1. The beam is configured to project onto the substrate surface at a beam angle ϑ relative to the normal to the substrate surface. A device layer is formed over the substrate, and a patterned resist is formed on the device layer. The patterned resist includes two or more resist structures and one or more gaps. Each of the resist structures has a width, and each of the gaps is defined by an adjacent resist structure and has a linewidth defined by the adjacent resist structure. The method includes etching the device layer of the substrate positioned at the first rotation angle φ1 with the beam, rotating the substrate to a second rotation angle φ2, and etching sidewalls of the resist structures oriented towards the beam, such that the width of the resist structures decreases and the linewidth of the gaps increases. The method further includes rotating the substrate to the first rotation angle φ1 and etching the device layer located at the first rotation angle φ1 with the beam, and forming two or more optical device structures in the device layer. Forming an optical device structure includes repeatedly rotating the substrate to a second rotation angle φ2 and etching the sidewalls of the resist structure with a beam, and rotating the substrate to a first rotation angle φ2 and etching the device layer with a beam until the resist structure is removed or the linewidth of the gap has a predetermined linewidth.

[0009] In another embodiment, a method is provided. The method includes positioning a substrate in a beam path at a first rotation angle φ1. The beam is configured to project onto the substrate surface at a beam angle ϑ relative to the normal to the substrate surface. A patterned resist is formed on the substrate, wherein the patterned resist comprises two or more resist structures and one or more gaps. Each of the resist structures has a width, and each of the gaps is defined by an adjacent resist structure and has a linewidth defined by the adjacent resist structure. The substrate is etched with a beam generated by a substrate etching chemical, and the resist structures are etched with a beam generated by a resist etching chemical different from the substrate etching chemical. The method further includes etching the substrate positioned at the first rotation angle φ1 with a beam generated by the substrate etching chemical, rotating the substrate to a second rotation angle φ2, and etching the sidewalls of the resist structures with the beam at a beam angle ϑ. The beam generated by the resist etching chemical etches the sidewalls of the resist structures oriented towards the beam, such that the width of the resist structures decreases and the linewidth of the gaps increases. The method further includes rotating the substrate to a first rotation angle φ1 and etching the substrate located at the first rotation angle φ1 using a beam generated by substrate etching chemicals, and forming two or more optical device structures in the substrate. Forming the optical device structures includes repeatedly rotating the substrate to a second rotation angle φ2 and etching the sidewalls of the resist structure using a beam generated by resist etching chemicals, and rotating the substrate to the first rotation angle φ1 and etching the substrate using a beam generated by substrate etching chemicals until the resist structure is removed or the linewidth of the gap has a predetermined linewidth. Attached Figure Description

[0010] To gain a more detailed understanding of the features described above in this disclosure, reference can be made to the embodiments for a more detailed description of the disclosure briefly outlined above, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only exemplary embodiments and should not be construed as limiting the scope of this disclosure, and may allow for other equally effective embodiments.

[0011] Figure 1A This is a perspective front view of an optical device according to the embodiments described herein.

[0012] Figure 1B and Figure 1C These are schematic cross-sectional views of various device structures according to the embodiments described herein.

[0013] Figure 2 This is a schematic side view of an angled etching system according to the embodiments described herein.

[0014] Figure 3 This is a schematic cross-sectional view of an angled etching system according to the embodiments described herein.

[0015] Figure 4 This is a flowchart of a method for forming multiple blazing device structures according to the embodiments described herein.

[0016] Figures 5A to 5E This is a schematic cross-sectional view of a portion of a substrate during a method for forming a plurality of blazing device structures according to the embodiments described herein.

[0017] Figures 5F to 5J This is a schematic top view of a portion of a substrate during a method for forming a plurality of blazing device structures according to the embodiments described herein.

[0018] To facilitate understanding, the same reference numerals are used to denote common elements in the figures where possible. Elements and features of one embodiment are contemplated to be advantageously incorporated into other embodiments without further description. Detailed Implementation

[0019] Embodiments of the present invention generally relate to optical devices for augmented reality, virtual reality, and mixed reality. More specifically, embodiments described herein provide a method for forming an optical device structure. This method utilizes rotation of a substrate to form the optical device structure on the substrate, and utilizes the tunability of the etching rate of a patterned resist disposed above the substrate and one of the device layers or the substrate to form the optical device structure without requiring multiple photolithographic patterning steps and angled etching steps.

[0020] In one embodiment, the method includes positioning a substrate in a beam path at a first rotation angle φ1, the beam being configured to project onto the substrate surface at a beam angle ϑ relative to the normal to the substrate surface. A patterned resist is formed on the substrate. The patterned resist includes two or more resist structures. Each of the resist structures has a width and one or more gaps. Each of the gaps is defined by an adjacent resist structure and has a linewidth defined by the adjacent resist structure. The substrate positioned at the first rotation angle φ1 is etched with the beam. The substrate is rotated to a second rotation angle φ2, and the sidewalls of the resist structures are etched with the beam at a beam angle ϑ, such that the width of the resist structures decreases and the linewidth of the gaps increases. The substrate is rotated to the first rotation angle φ1, and the substrate located at the first rotation angle φ1 is etched with the beam. Two or more optical device structures are formed in the substrate. Forming an optical device structure includes repeatedly rotating the substrate to a second rotation angle φ2 and etching the sidewalls of the resist structure with a beam, and rotating the substrate to a first rotation angle φ1 and etching the substrate with a beam until the resist structure is removed or the linewidth of the gap has a predetermined linewidth.

[0021] Figure 1AA perspective front view of the optical device 100 is shown. It should be understood that the optical device 100 described below is an exemplary optical device. In one embodiment, which may be combined with other embodiments described herein, the optical device 100 is a waveguide combiner, such as an augmented reality waveguide combiner. In another embodiment, which may be combined with other embodiments described herein, the optical device 100 is a planar optical device, such as a metasurface. The optical device 100 includes components disposed in a substrate 101 (e.g., Figure 1B (as shown) or disposed on the substrate (e.g.) Figure 1C Multiple device structures 102 (as shown). For example... Figure 1C As shown, device structure 102 is formed in device layer 114, which is formed on substrate 101. Device structure 102 can be a nanostructure with submicron dimensions, such as nanometer-sized dimensions, like a critical size less than 1 μm. In one embodiment that can be combined with other embodiments described herein, a region of device structure 102 corresponds to one or more gratings 104, such as a first grating 104a, a second grating 104b, and a third grating 104c. In one embodiment that can be combined with other embodiments described herein, optical device 100 is a waveguide combiner that includes at least a first grating 104a corresponding to an input coupling grating and a third grating 104c corresponding to an output coupling grating. The waveguide combiner according to an embodiment that can be combined with other embodiments described herein may include a second grating 104b corresponding to an intermediate grating.

[0022] Figure 1B and Figure 1CThis is a schematic cross-sectional view of multiple device structures 102. In one embodiment, which can be combined with other embodiments described herein, device structure 102 is a blazed device structure 106 of a planar optical device, such as a metasurface. The method 400 described herein forms the blazed device structure 106. In another embodiment, which can be combined with other embodiments described herein, device structure 102 is a blazed device structure 106 of a waveguide combiner (such as an augmented reality waveguide combiner). The waveguide combiner according to an embodiment that can be combined with other embodiments described herein may include the blazed device structure 106 in at least one grating in grating 104. Each of the blazed device structures 106 includes a blazed surface 108, sidewalls 112, depth h, and linewidth d. The blazed surface 108 has a plurality of steps 110. In one embodiment, which can be combined with other embodiments described herein, the blazed surface 108 includes at least 16 steps 110, for example, more than 32 steps 110, for example, 64 steps 110. The blazed surface 108 has a blaze angle γ. The blazing angle γ is the angle between the surface parallelism p of the blazing surface 108 and the substrate 101, and the angle between the surface normal of the substrate 101 and the facet normal f of the blazing surface 108. The depth h corresponds to the height of the sidewall 112, and the linewidth d corresponds to the distance between the sidewalls 112 of adjacent blazing device structures 106.

[0023] In one embodiment that can be combined with other embodiments described herein, the blaze angle γ of two or more blaze device structures 106 is different. In another embodiment that can be combined with other embodiments described herein, the blaze angle γ of two or more blaze device structures 106 is the same. In one embodiment that can be combined with other embodiments described herein, the depth h of two or more blaze device structures 106 is different. In another embodiment that can be combined with other embodiments described herein, the depth h of two or more blaze device structures 106 is the same. In one embodiment that can be combined with other embodiments described herein, the linewidth d of two or more blaze device structures 106 is different. In another embodiment that can be combined with other embodiments described herein, the linewidth d of one or more blaze device structures 106 is the same.

[0024] The substrate 101 may also be selected to transmit a suitable amount of light of a desired wavelength or wavelength range (such as one or more wavelengths from about 100 nanometers to about 3000 nanometers). Without limitation, in some embodiments, the substrate 101 is configured such that the IR to UV region of the transmission spectrum of the substrate 101 is greater than or equal to about 50% to about 100%. The substrate 101 can be formed of any suitable material, provided that the substrate 101 can sufficiently transmit light of the desired wavelength or wavelength range and can adequately support the blazed device structure 106 described herein (when the blazed device structure 106 is formed in the device layer 114). The choice of substrate may include substrates of any suitable material, including but not limited to amorphous dielectrics, non-amorphous dielectrics, crystalline dielectrics, silicon oxide, polymers, and combinations thereof. In some embodiments that may be combined with other embodiments described herein, the substrate 101 comprises a transparent material. Suitable examples may include oxides, sulfides, phosphides, tellurides, or combinations thereof. In one example, substrate 101 includes silicon (Si), silicon dioxide (SiO2), germanium (Ge), silicon-germanium (SiGe), sapphire, and high-refractive-index transparent materials, such as high-refractive-index glass.

[0025] In some embodiments that can be combined with other embodiments described herein, device layer 114 includes, but is not limited to, materials containing silicon oxycarbide (SiOC), materials containing titanium dioxide (TiO2), materials containing silicon dioxide (SiO2), and materials containing vanadium oxide (IV) (VO2). x The material may be one or more of the following: 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). In some embodiments that may be combined with other embodiments described herein, the material of device layer 114 may have a refractive index between about 1.5 and about 2.65. In other embodiments that may be combined with other embodiments described herein, the material of device layer 114 may have a refractive index between about 3.5 and about 4.0.

[0026] Figure 2This is a schematic side view of the angled etching system 200. It should be understood that the angled etching system 200 described below is an exemplary angled etching system, and other angled etching systems may also be used with, or modified to manufacture, the optical device 100 having the blazing device structure 106, according to embodiments of this disclosure.

[0027] The angled etching system 200 includes an ion beam chamber 202. A power source 204, a first gas source 206, and a second gas source are coupled to the ion beam chamber 202. In one embodiment, which may be combined with other embodiments described herein, the power source 204 is a radio frequency (RF) power source. The first gas source 206 is in fluid communication with the internal volume 205 of the ion beam chamber 202. The first gas source 206 is an inert gas source that supplies an inert gas, such as argon, hydrogen, or helium, to the ion beam chamber 202. The second gas source 208 is in fluid communication with the internal volume 205 of the ion beam chamber 202. The second gas source 208 is a process gas source that supplies a process gas to the ion beam chamber 202. The process gas includes, but is not limited to, one or more of chlorine-containing gases, fluorine-containing gases, bromine-containing gases, oxygen-containing gases, silicon-containing gases, nitrogen-containing gases, and hydrogen-containing gases. In embodiments of the method 400 described herein, which may be combined with other embodiments described herein, two or more process gases may be used.

[0028] The first processing gas may have a substrate etching chemical that is selective for resist materials. The etching selectivity of the first processing gas having the substrate etching chemical provides a selectivity of approximately 5:1 or greater for the substrate material relative to the resist material (described below). The etching selectivity of the first processing gas having the device material etching chemical provides a selectivity of approximately 5:1 or greater for the device material relative to the resist material. In one embodiment, which may be combined with other embodiments described herein, the substrate etching chemical includes a chlorine-containing gas, a fluorine-containing gas, or a combination thereof. In another embodiment, which may be combined with other embodiments described herein, the device material etching chemical includes a chlorine-containing gas, a fluorine-containing gas, or a combination thereof.

[0029] The second processing gas may have a resist etching chemical that is selective for substrate or device materials. The etching selectivity of the second processing gas having the resist etching chemical provides a selectivity of approximately 10:1 or greater for the resist material relative to the substrate material, or a selectivity of approximately 10:1 or greater for the resist material relative to the device material. In one embodiment that can be combined with other embodiments described herein, the resist etching chemical includes oxygen (O2) and carbon tetrafluoride (CF4). In another embodiment that can be combined with other embodiments described herein, the resist etching chemical includes argon (Ar), nitrogen (N2), and hydrogen (H2). In yet another embodiment that can be combined with other embodiments described herein, the resist etching chemical includes nitrogen (N2) and hydrogen (H2).

[0030] In operation, plasma is generated in the ion beam chamber 202 by applying RF power to the inert gas and process gas supplied to the internal volume 205 of the ion beam chamber 202 via power supply 204 to generate plasma. Ions of the plasma from the inert gas and process gas are extracted via apertures 210 of extraction plate 212 to generate an ion beam 216. Apertures 210 of the ion beam chamber 202 are operable to guide the ion beam 216 at an angle α relative to a reference plane 218 (i.e., surface normal s) oriented perpendicular to the substrate 101. The ion beam 216 includes, but is not limited to, a spot beam, a strip beam, or a full-substrate-size beam. Depending on the process gas used, the generated ion beam 216 contains one of substrate etching chemicals, device material etching chemicals, or resist etching chemicals.

[0031] The substrate 101 is held on a pressure plate 214 coupled to a first actuator 219. The first actuator 219 may be a linear actuator, a rotary actuator, a stepper motor, etc., configured to move the pressure plate 214 in a scanning motion along the y-direction and / or z-direction. In one embodiment, which may be combined with other embodiments described herein, the first actuator 219 is further configured to tilt the pressure plate 214 such that the substrate 101 is positioned at a tilt angle β relative to the x-axis of the ion beam chamber 202. Angle α and tilt angle β result in a beam angle ϑ relative to a reference plane 218 perpendicular to the substrate 101. A second actuator 220 may also be coupled to the pressure plate 214 to rotate the substrate 101 about the x-axis of the pressure plate 214.

[0032] Figure 3This is a schematic cross-sectional view of the angled etching system 300. It should be understood that the angled etching system 300 described below is an exemplary angled etching system, and other angled etching systems may be used with or modified to manufacture the optical device 100 having the blazing device structure 106, according to embodiments of this disclosure.

[0033] The angled etching system 300 includes an electron beam chamber 302. A power supply 304, a first gas source 306, and a second gas source 308 are coupled to the electron beam chamber 302. The first gas source 306 and the second gas source 308 are in fluid communication with the internal volume 305 of the electron beam chamber 302. For example, the first gas source 306 and the second gas source 308 may extend through an electrode 322, or the electrode 322 may include multiple orifices to serve as gas delivery nozzles. The first gas source 306 is an inert gas source that supplies an inert gas (as described above) to the electron beam chamber 302. The second gas source 308 is a process gas source (as described above) that supplies a process gas to the ion beam chamber 202. In embodiments of the method 400 described herein, which may be combined with other embodiments described herein, two or more process gases may be used. The two or more process gases include the substrate etching chemicals, device material etching chemicals, and resist etching chemicals described herein.

[0034] The substrate 101 is held on a pressure plate 314 coupled to a first actuator 321. The first actuator 321 may be a linear actuator, rotary actuator, stepper motor, etc., configured to raise and lower the pressure plate 314 within the electron beam chamber 302. A second actuator 320 may also be coupled to the pressure plate 314 to rotate the substrate 101 about a vertical axis of the pressure plate 314. The pressure plate 314 includes an electrode 324 disposed therein. In one embodiment, the electrode 324 is a clamping device, such as an electrostatic chuck, for securing the substrate 101 to the electrode during substrate 101 processing. Power from the power supply 304 may be used to bias the electrode 324 to clamp the substrate 101 to the electrode 324 or to influence electron bombardment on the substrate 101.

[0035] In operation, plasma is generated in the electron beam chamber 302 through various bulk processes and surface treatments (e.g., via inductive coupling). It is believed that ions generated by the inductively coupled plasma are influenced by an electric field that causes the plasma-generated ions from the inert gas and process gas to bombard the electrode 322. According to the embodiments described herein, other plasma generation processes can be utilized, such as capacitively coupled arrangements, hollow cathode arrangements, DC electrode bias, or electron beam plasma generation processes.

[0036] The ion bombardment of electrode 322 is thought to cause electrode 322 to emit secondary electrons. High-energy secondary electrons with a negative charge are emitted from electrode 322. Thus, electron beam 316 is accelerated from electrode 322 at a beam angle ϑ relative to a reference plane 318 (i.e., surface normal s) oriented perpendicular to substrate 101. Electron beam 316 includes, but is not limited to, spot beam, strip beam, or full-substrate-size beam. Depending on the processing gas used, the resulting electron beam 316 contains one of substrate etching chemicals, device material etching chemicals, or resist etching chemicals.

[0037] As described herein, the ion beam 216 generated from the angled etching system 200 (e.g., an ion beam etching system) and the electron beam 316 generated from the angled etching system 300 (e.g., an electron beam etching system) are collectively referred to as beam 516 (e.g., ...). Figures 5A to 5J As shown), beam 516 is either an ion beam or an electron beam. In embodiments of method 400 that can be combined with other embodiments described herein, in operation of method 400 herein, beam 516 has one of a substrate etching chemical, a device material etching chemical, or a resist etching chemical. In some embodiments that can be combined with other embodiments described herein, at least the substrate etching chemical and the resist etching chemical are different. In other embodiments that can be combined with other embodiments described herein, at least the device material etching chemical and the resist etching chemical are different. As described herein, the tunability of the etching rate of one of the resist material 506 and device layer 114 or substrate 101, and the rotation of substrate 101, form a blazed optical device structure without multiple photolithographic patterning steps and angled etching steps.

[0038] Figure 4 It is used to form such as Figures 5A to 5E and Figures 5F to 5J A flowchart of a method 400 for a plurality of blazing device structures 106 of the optical device structure 100 shown. Figures 5A to 5E This is a schematic cross-sectional view of portion 501 of substrate 101 during method 400. Figures 5F to 5J This is a schematic top view of portion 501 of substrate 101 during method 400.

[0039] To facilitate explanation, reference will be made. Figure 2 Angled etching system 200 and Figure 3Method 400 is described using an angled etching system 300. However, it should be noted that angled etching systems other than angled etching systems 200 and 300 can also be used in combination with method 400. In one embodiment that can be combined with other embodiments described herein, portion 501 may correspond to a portion or the entire surface of a substrate 101 of a planar optics to form a plurality of blazed device structures 106 thereon. In another embodiment that can be combined with other embodiments described herein, portion 501 may correspond to a portion or the entire surface of a substrate 101 of a waveguide combiner to form a plurality of blazed device structures 106 thereon. Portion 501 may correspond to one or more gratings 104. Although Figures 5A to 5E and Figures 5F to 5J An etched substrate 101 is depicted such that a blazing device structure 106 is disposed in the substrate, but a device layer 114 (as described above) may be disposed on the surface 103 such that the blazing device structure 106 is disposed in the device layer 114.

[0040] At operation 401, such as Figure 5A and Figure 5F As shown, the substrate 101 is positioned at a first rotation angle φ1 defined by the reference line 502, as follows. Figure 5F As shown. In one embodiment that can be combined with other embodiments described herein, the first rotation angle φ1 is 0° defined by reference line 502. Substrate 101 or device layer 114 (not shown) includes a patterned resist 504 disposed thereon. The patterned resist 504 comprises a resist material 506, which is patterned into a plurality of resist structures 508 disposed on the surface 103 of substrate 101. The resist material 506 of the patterned resist 504 is selected based on substrate etching chemistry (in embodiments where substrate 101 is etched to form scintillation device structure 106) or device material etching chemistry (in embodiments where device layer 114 is etched to form scintillation device structure 106). In one embodiment, the resist material 506 is a photosensitive material, such that the patterned resist 504 can be patterned by photolithography (e.g., photolithography or digital photolithography) or by laser ablation to form a plurality of resist structures 508. In one embodiment, the resist material 506 is an imprintable material, and the patterned resist 504 can be patterned via nanoimprint processing to form a plurality of resist structures 508. In another embodiment, which can be combined with other embodiments described herein, the resist material 506 is a hard mask material, and the patterned resist 504 is patterned via one or more etching processes to form a plurality of resist structures 508. In yet another embodiment, which can be combined with other embodiments described herein, the patterned resist 504 is an optical planarization layer.

[0041] Each resist structure 508 includes a bottom surface 509, a first sidewall 510, a second sidewall 512, and a top surface 514. Each resist structure 508 has a height 515 from the bottom surface 509 to the top surface 514. Each resist structure 508 has a width 522 from the first sidewall 510 to the second sidewall 512. A plurality of gaps 518 are defined by adjacent resist structures 508. Each gap 518 has a linewidth 520 between the first sidewall 510 and the second sidewall 512 of the adjacent resist structure 508. The height 515, linewidth 520, and width 522 are selected to tune the number of steps 110 of the scintillation surface 108 and the linewidth d of the plurality of scintillation device structures 106. For example, increasing the height 515 increases the number of repeating intervals of the etched substrate 101 (or device layer 114) and the resist structures 508, thereby increasing the number of steps 110.

[0042] At operation 402, substrate 101 is exposed to beam 516 at a beam angle ϑ relative to the surface normal of substrate 101. In one embodiment, which may be combined with other embodiments described herein, the beam angle ϑ is from about 10 degrees to about 80 degrees relative to the surface normal of substrate 101. Beam 516 has a substrate etching chemical or device etching chemical that is selective to the resist material 506, i.e., the exposed portions 517 of substrate 101 or the exposed portions (not shown) of device layer 114 are removed at a higher rate than the resist material 506. After the exposed portions of substrate 101 are etched away by beam 516, at operation 402 (as described herein)... Figure 5B As shown), a depth h is formed corresponding to the exposed portion 517 of the blazing device structure 106.

[0043] At operation 403, the substrate 101 is rotated to a second rotation angle φ2 defined by the reference line 502, as follows. Figure 5HAs shown. In one embodiment that can be combined with other embodiments described herein, the pressure plates 214, 314 holding the substrate 101 are rotated to a second rotation angle φ2. In another embodiment that can be combined with other embodiments described herein, the second rotation angle φ2 corresponds to 90° relative to the reference line 502. The rotation of the substrate 101 is not limited to a rotation angle φ corresponding to 90°, but can correspond to any predetermined angle φ. Due to the masking effect, the rotation allows the beam 516 to contact the resist structure 508. In one embodiment that can be combined with other embodiments described herein, throughout method 400, the beam 516 will maintain a beam angle ϑ relative to the reference planes 218, 318 (i.e., the surface normal s) oriented perpendicular to the substrate 101. A constant beam angle allows for increased production output because the beam angle ϑ will not need to be reconfigured. In one embodiment that can be combined with other embodiments described herein, the method 400 described herein uses only one angled etching system 200, 300 and requires the resist material 506 to be patterned only once to provide high-volume production capability.

[0044] At operation 404, the resist structure is exposed to beam 516 at beam angle ϑ. Beam 516 etches one of the first sidewall 510 or the second sidewall 512, corresponding to which sidewall 510, 512 is exposed to beam 516. In embodiments that can be combined with other embodiments described herein, the first sidewall 510 is exposed to beam 516. Beam 516 has a chemical substance corresponding to the resist etching chemical substance, such that ions or electrons will substantially etch only the resist structure 508 during the resist etching process. The resist etching chemical substance is selective for the substrate 101 or device layer 114, i.e., the resist structure 508 is removed at a higher rate than the device layer 114 or substrate 101. After beam 516 etches away the resist structure 508, the width 522 of the resist structure 508 relative to... Figure 5A and Figure 5B The width shown is reduced. The line width of 520 between the first and second sidewalls is relative to... Figure 5A and Figure 5B The line width shown has increased.

[0045] like Figure 5C As shown, this forms the first step of a plurality of steps 110. The plurality of steps 110 form a structure as shown... Figure 1B and Figure 1CThe blazing surface 108 is shown. The blazing angle γ is the angle between the blazing surface 108 and the surface parallelism p of the substrate 101. The blazing angle γ can be achieved by increasing or decreasing the etching rate of the beam 516. The blazing angle γ can be adjusted by etching at different rates such that the depth h, linewidth 520, and width 522 are all at predetermined values ​​corresponding to different numbers of steps 110 formed on the blazing surface 108. Therefore, the blazing angle γ can be adjusted, and the blazing device structure 106 (such as the blazing device structure 104) can modulate the light propagating through the optics 100 as needed.

[0046] At operation 405, repeat operations 401-404 until a predetermined number of steps 110 are formed on the optical device 100 (e.g., ...). Figure 1B and Figure 1C (As shown). In one embodiment, which can be combined with other embodiments described herein, the substrate 101 is rotated to a first rotation angle φ1, and the substrate 101 or device layer 114 is etched with a beam 516 until the resist structure 508 is removed or the linewidth 520 of the gap 518 has a predetermined linewidth. Figure 5I As shown, the pressure plates 214 and 314, on which the substrate 101 is placed, are rotated to a first rotation angle φ1. Figure 5D As shown, the depth h corresponding to the exposed portion 517 of the blazing device structure 106 is relative to... Figures 5A to 5C The depth h shown increases. (As indicated) Figure 5J As shown, the pressure plates 214 and 314 on which the substrate 101 is placed are rotated to a second rotation angle φ2 defined by the reference line 502. After the beam 516 etches away the resist structure 508, the width 522 of the resist structure 508 relative to... Figures 5A to 5D The width shown is reduced. The line width 520 between the first sidewall 510 and the second sidewall 512 is relative to... Figures 5A to 5D The linewidth 520 shown is increased. In optional operation 406, residual resist material 506 disposed on device layer 114 or substrate 101 is removed. Although only four resist structures 508 and three gaps 518 are illustrated, the entire patterned resist 504 can be etched to form a desired number of blazed device structures 106 according to the predetermined design of optical device 100.

[0047] In summary, this paper describes a method for forming optical device structures. This method utilizes substrate rotation to form blazed optical device structures on the substrate, and leverages the tunability of the etching rate of a patterned resist disposed above the substrate and either the device layer or the substrate itself to form the blazed optical device structures without requiring multiple photolithographic patterning steps and angled etching steps. A constant beam angle allows for increased production throughput because the beam angle ϑ does not need to be reconfigured. Only one angled etching system can be used, and the resist material only needs to be patterned once to provide high-volume production capabilities.

[0048] Although the foregoing relates to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is defined by the appended claims.

Claims

1. An augmented reality waveguide combiner, comprising: An optical device substrate, the optical device substrate comprising a substrate material; as well as A first grating is disposed above the optical device substrate. The first grating contains a device material different from the substrate material. The first grating has a plurality of blazing device structures, each of the plurality of blazing device structures including a blazing surface, the blazing surface having: Multiple steps; Each of the steps is parallel to the facet normal of the main surface of the optical device substrate; and The blaze angle defined by the blazing surface and the facet normal; as well as A second grating containing the device material is disposed above the optical device substrate and adjacent to the first grating.

2. The augmented reality waveguide combiner of claim 1, wherein the blazing surface has at least 16 steps.

3. The augmented reality waveguide combiner of claim 1, wherein the blazing surface has at least 32 steps.

4. The augmented reality waveguide combiner of claim 1, wherein the blaze angles of two of the plurality of blaze device structures are different.

5. The augmented reality waveguide combiner of claim 1, wherein the blaze angles of two of the plurality of blaze device structures are the same.

6. The augmented reality waveguide combiner of claim 1, wherein two of the plurality of blazed device structures have different depths.

7. The augmented reality waveguide combiner of claim 1, wherein the device material of the first grating comprises one or more of the following: a material containing silicon oxycarbonate (SiOC), a material containing titanium dioxide (TiO2), a material containing silicon dioxide (SiO2), or a material containing vanadium oxide (IV) (VO2). x Materials containing aluminum oxide (Al2O3), materials containing aluminum-doped zinc oxide (AZO), materials containing indium tin oxide (ITO), materials containing tin dioxide (SnO2), materials containing zinc oxide (ZnO), materials containing tantalum pentoxide (Ta2O5), materials containing silicon nitride (Si3N4), materials containing zirconium dioxide (ZrO2), materials containing niobium oxide (Nb2O5), materials containing cadmium stannate (Cd2SnO4), or materials containing silicon carbonitride (SiCN).

8. The augmented reality waveguide assembly of claim 1, wherein the substrate material of the optical device substrate comprises an amorphous dielectric, a crystalline dielectric, silicon oxide, a polymer, or a combination thereof.

9. The augmented reality waveguide assembly of claim 1, wherein the substrate material of the optical device substrate comprises silicon (Si), silicon dioxide (SiO2), germanium (Ge), silicon-germanium (SiGe), sapphire, or a combination thereof.

10. The augmented reality waveguide combiner of claim 1, wherein the optical substrate is configured to transmit wavelengths from 100 to 3000 nanometers.

11. The augmented reality waveguide combiner of claim 1, wherein each of the plurality of blazed device structures has a refractive index between 1.5 and 2.

65.

12. The augmented reality waveguide combiner of claim 1, wherein each of the plurality of blazed device structures has a refractive index between 3.5 and 4.

0.

13. An augmented reality waveguide combiner, comprising: An optical device substrate, the optical device substrate comprising a substrate material; as well as A first grating is disposed above the optical device substrate. The first grating contains a device material different from the substrate material. The first grating has a plurality of blazing device structures, each of the plurality of blazing device structures including a blazing surface, the blazing surface having: Multiple steps; Each of the steps is parallel to the facet normal of the main surface of the optical device substrate; and The blaze angle defined by the blazing surface and the facet normal, wherein the blaze angles of two blaze device structures of the plurality of blaze device structures are different; as well as A second grating containing the device material is disposed above the optical device substrate and adjacent to the first grating, and the second grating includes multiple device structures.

14. The augmented reality waveguide combiner of claim 13, wherein two of the plurality of blazed device structures have different depths.

15. The augmented reality waveguide combiner of claim 13, wherein the device material of the first grating comprises one or more of the following: a material containing silicon oxycarbonate (SiOC), a material containing titanium dioxide (TiO2), a material containing silicon dioxide (SiO2), or a material containing vanadium oxide (IV) (VO2). x Materials containing aluminum oxide (Al2O3), materials containing aluminum-doped zinc oxide (AZO), materials containing indium tin oxide (ITO), materials containing tin dioxide (SnO2), materials containing zinc oxide (ZnO), materials containing tantalum pentoxide (Ta2O5), materials containing silicon nitride (Si3N4), materials containing zirconium dioxide (ZrO2), materials containing niobium oxide (Nb2O5), materials containing cadmium stannate (Cd2SnO4), or materials containing silicon carbonitride (SiCN).

16. An augmented reality waveguide combiner, comprising: An optical device substrate, the optical device substrate comprising a substrate material; as well as An input coupling grating is disposed above the optical device substrate. The input coupling grating comprises a device material different from the substrate material. The input coupling grating has multiple blazed device structures, each of which includes a blazed surface. The blazed surface has: Multiple steps, wherein the uppermost surface of each blazing device structure is wider than each step; The facet normal perpendicular to the gleaming surface; as well as The blaze angle is defined by the surface perpendicular to the substrate of the optical device and the facet normal; as well as An output coupling grating containing the device material is disposed above the optical device substrate and adjacent to the input coupling grating, and the output coupling grating has multiple device structures.

17. The augmented reality waveguide combiner of claim 16, wherein the device material of the input coupling grating comprises one or more of the following: a material containing silicon oxycarbonate (SiOC), a material containing titanium dioxide (TiO2), a material containing silicon dioxide (SiO2), or a material containing vanadium oxide (IV) (VO2). x Materials containing aluminum oxide (Al2O3), materials containing aluminum-doped zinc oxide (AZO), materials containing indium tin oxide (ITO), materials containing tin dioxide (SnO2), materials containing zinc oxide (ZnO), materials containing tantalum pentoxide (Ta2O5), materials containing silicon nitride (Si3N4), materials containing zirconium dioxide (ZrO2), materials containing niobium oxide (Nb2O5), materials containing cadmium stannate (Cd2SnO4), or materials containing silicon carbonitride (SiCN).

18. The augmented reality waveguide assembly of claim 16, wherein the substrate material of the optical device substrate comprises an amorphous dielectric, a crystalline dielectric, silicon oxide, a polymer, or a combination thereof.

19. The augmented reality waveguide combiner of claim 16, wherein the substrate material of the optical device substrate comprises silicon (Si), silicon dioxide (SiO2), germanium (Ge), silicon-germanium (SiGe), sapphire, or a combination thereof.

20. The augmented reality waveguide combiner of claim 16, wherein each of the plurality of blazed device structures has a refractive index between 1.5 and 2.65.

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