Method for manufacturing a blazed grid

Abstract

This disclosure relates to a method 100 for manufacturing a blazed grating. The method 100 includes steps 110 of preparing a substrate and a patterned mask layer on the substrate, step 120 of performing a primary dry etch of the substrate such that primary ions are accelerated in a primary etch direction and impinge on the substrate, and step 150 of performing a secondary dry etch of the substrate such that secondary ions are accelerated in a secondary etch direction and impinge on the substrate. A primary projection of the primary etch direction and a secondary projection of the secondary etch direction on the grating cross section extend perpendicular to one and the other of the blaze facet direction and the anti-blaze facet direction, respectively, and the ions accelerated in a projection direction perpendicular to the blaze facet direction on the grating cross section are collimated to form a collimated ion beam for etching the substrate.

Description

[Technical Field]

[0001] The present disclosure relates to diffraction gratings. More specifically, the present disclosure relates to blazed gratings. [Background Art]

[0002] Conventional surface relief diffraction gratings, so-called binary gratings, comprise a plurality of protrusions and grooves, wherein the tops of the protrusions and the bottoms of the grooves extend parallel to each other. There are well-known manufacturing processes for manufacturing such binary gratings. In the case of such binary gratings, normally incident light is diffracted, resulting in equal diffraction efficiency in both negative and positive diffraction orders. This effect arises from the mirror symmetry of the cross-sectional shape of binary gratings.

[0003] In many applications, for example, in many waveguide-based display structures, preferential diffraction into one or more specific diffraction orders may be desirable, while diffraction into other diffraction orders may be considered optical loss. To preferentially direct light into a specific diffraction order, a grating having a non-mirror-symmetric cross-sectional shape must be used. One example of such an asymmetric grating is a so-called blazed grating having a triangular or sawtooth cross-sectional shape.

[0004] Blazed gratings are typically manufactured using processes based on grayscale lithography. While such processes have been improved to produce gratings with acceptable characteristics, the features of blazed gratings produced using grayscale lithography, particularly the apexes, are generally relatively rounded, due to the low contrast of typical resists for grayscale lithography. Such deviations from the ideal blazed shape can reduce the diffraction efficiency of blazed gratings produced using grayscale lithography and / or increase light scattering caused by such gratings. [Summary of Invention] [Problem to be Solved by the Invention]

[0005] Considering the above, it may be desirable to develop new solutions for blazed lattices. [Means for solving the problem]

[0006] This summary is presented to introduce the conceptual options in a simplified form, which will be further explained in the detailed description below. This summary is not intended to identify, nor to limit, the main or essential functions of the subject matter described in the claims.

[0007] This specification provides a method for manufacturing a blazed lattice having ridges having blazed facets facing the blazed facet direction and anti-blazed facets facing the anti-blazed facet direction, the blazed facet direction and the anti-blazed facet direction extending along the lattice cross section. The method includes the steps of preparing a substrate and a patterned mask layer on the substrate; performing primary dry etching of the substrate such that primary ions are accelerated in the primary etching direction and collide with the substrate; and performing secondary dry etching of the substrate such that secondary ions are accelerated in the secondary etching direction and collide with the substrate.

[0008] The primary projection in the primary etching direction onto the lattice cross-section and the secondary projection in the secondary etching direction onto the lattice cross-section extend perpendicularly to one of the blaze-facet directions and the other, respectively. The ions (primary and secondary ions) accelerated onto the lattice cross-section in a projection direction perpendicular to the blaze-facet direction are parallelized to etch the substrate, forming a parallelized ion beam.

[0009] This disclosure will be better understood by reading the following detailed description in consideration of the attached drawings. [Brief explanation of the drawing]

[0010] [Figure 1] This diagram shows a method for manufacturing a blazed grid. [Figure 2A] This diagram shows a series of subsequent steps in a method for manufacturing a blazed lattice. [Figure 2B] This diagram shows a series of subsequent steps in a method for manufacturing a blazed lattice. [Figure 2C] This diagram shows a series of subsequent steps in a method for manufacturing a blazed lattice. [Figure 2D] This diagram shows a series of subsequent steps in a method for manufacturing a blazed lattice. [Figure 2E] This diagram shows a series of subsequent steps in a method for manufacturing a blazed lattice. [Figure 3A] This diagram shows a series of subsequent steps in another method for manufacturing a blazed lattice. [Figure 3B] This diagram shows a series of subsequent steps in another method for manufacturing a blazed lattice. [Figure 3C] This diagram shows a series of subsequent steps in another method for manufacturing a blazed lattice. [Figure 3D] This diagram shows a series of subsequent steps in another method for manufacturing a blazed lattice. [Figure 3E] This diagram shows a series of subsequent steps in another method for manufacturing a blazed lattice. [Figure 3F] This diagram shows a series of subsequent steps in another method for manufacturing a blazed lattice. [Figure 3G] This diagram shows a series of subsequent steps in another method for manufacturing a blazed lattice. [Figure 3H] This diagram shows a series of subsequent steps in another method for manufacturing a blazed lattice. [Figure 4A] This figure shows a series of subsequent steps in yet another method for manufacturing a blazed lattice. [Figure 4B] This figure shows a series of subsequent steps in yet another method for manufacturing a blazed lattice. [Figure 4C] It is a diagram showing a series of successive steps of still another method for manufacturing a blazed grating. [Figure 4D] It is a diagram showing a series of successive steps of still another method for manufacturing a blazed grating. [Figure 4E] It is a diagram showing a series of successive steps of still another method for manufacturing a blazed grating. [Figure 4F] It is a diagram showing a series of successive steps of still another method for manufacturing a blazed grating. DESCRIPTION OF EMBODIMENTS

[0011] Unless specifically stated otherwise, none of the foregoing drawings may necessarily be drawn to scale, in order to emphasize specific structural aspects of the embodiments illustrated in the drawings, and accordingly, any element in the drawings may be drawn in an incorrect ratio relative to other elements in the drawings.

[0012] Corresponding elements of the embodiments shown in the drawings, for example identical or similar elements, are referenced using the same reference numerals. Corresponding elements in the foregoing drawings may be disproportionally sized relative to each other within the drawings, in order to emphasize specific structural aspects of the embodiments illustrated in the drawings.

[0013] Fig. 1 shows a method 100 for manufacturing a blazed grating, comprising a ridge having a blaze facet facing in a blaze facet direction and an anti-blaze facet facing in an anti-blaze facet direction, wherein the blaze facet direction and the anti-blaze facet direction extend along a grating cross-section. In other embodiments, the method for manufacturing a blazed grating may be the same as, similar to, or different from the method 100 of the embodiment of Fig. 1.

[0014] Method 100, in the embodiment shown in Figure 1, includes the steps of: preparing a substrate and a patterned mask layer on the substrate in step 110; performing primary dry etching of the substrate in step 120 so that primary ions are accelerated in the primary etching direction and collide with the substrate; and performing secondary dry etching of the substrate in step 150 so that secondary ions are accelerated in the secondary etching direction and collide with the substrate.

[0015] Throughout this specification, “dry etching” can refer to the removal of material by exposure to ionic shock. Typical dry etching techniques include reactive ion etching (RIE), deep reactive ion etching (DRIE), inductively coupled plasma reactive ion etching (ICP-RIE), ion milling, ion beam etching (IBE), reactive ion beam etching (RIBE), and their variations.

[0016] In this specification, performing dry etching of a substrate so that specific ions are "accelerated" in a particular direction and collide with the substrate means that the ions are given an average velocity, such as a drift velocity, in a particular direction. Such ions can typically be accelerated in a particular direction by an electric field.

[0017] In the embodiment shown in Figure 1, the primary projection in the primary etching direction onto the lattice cross section and the secondary projection in the secondary etching direction onto the lattice cross section extend perpendicularly to one of the blaze-facet direction and the other, respectively. Ions (primary and secondary ions) accelerated onto the lattice cross section in a projection direction perpendicular to the blaze-facet direction are parallelized to etch the substrate, forming a parallelized ion beam. Generally, by using such primary and secondary etching directions, and by utilizing a parallelized ion beam perpendicular to the blaze-facet direction to etch the substrate, blazed lattices with sharper or less rounded features, such as vertices and / or facets, can be easily manufactured.

[0018] In this specification, “parallelized ion beam” may refer to a beam of ions propagating from a collimator in a specific etching direction, such as a primary or secondary etching direction. Additionally or alternatively, an ion beam propagating from a collimator in a specific etching direction may be called a parallelized ion beam if, for example, the ion beam has a maximum angular error of 4°, 3°, or 2° from the primary etching direction. If the parallelized ion beam is formed to etch a substrate, such maximum angular error may be determined by the position of the substrate.

[0019] Step 120, in which primary dry etching is performed, may optionally include step 124, in which grooves extending in the substrate along the primary etching direction, as shown in Figure 1 using dashed lines; method 100 may optionally include step 130, in which a first material is deposited in the grooves to form interstitial features; and step 150, in which secondary dry etching is performed, may optionally include step 154, in which the interstitial features are used as etching stops. Generally, using interstitial features as etching stops when performing secondary dry etching makes it easy to produce blazed diffraction gratings having sharper and less rounded features, and / or smoother and / or more uniform facets. In other embodiments, the method for producing a blazed grating may or may not have one or more of these features.

[0020] In this specification, “process” can mean one or more steps that lead to a final result. A process may therefore be a single-step process or a multi-step process. A process may further be divisible into multiple sub-processes, the individual sub-processes of which may or may not share common steps.

[0021] In this specification, “step” can refer to measures taken to achieve a predefined result. For example, “atomic layer deposition step” can refer to a step in the process of forming a layer by atomic layer deposition.

[0022] Method 100 may optionally include a step 140 to expose the ridged portion of the substrate before the step 150 in which secondary dry etching is performed, as shown in Figure 1 using dashed lines. Generally, the step of exposing the ridged portion of the substrate before the step in which secondary dry etching is performed allows for the easy formation of a blazed grid without post-processing steps, thereby removing the exposed portion of the substrate during the step in which secondary dry etching is performed. In other embodiments, the method for manufacturing a blazed grid may or may not include the step of exposing the ridged portion of the substrate before the step in which secondary dry etching is performed.

[0023] Furthermore, the step 130 of depositing the first material in the groove may optionally include an atomic layer deposition step 131. Generally, by including an atomic layer deposition step in the step of depositing the first material in the groove, it is possible to easily form interlattice features in narrower grooves and / or with increased uniformity. In other embodiments, the step of depositing the first material in the groove may or may not include an atomic layer deposition step.

[0024] As shown in Figure 1 using dashed lines, the step 110 for preparing the substrate and the patterned mask layer may optionally include a step 111 for forming the mask layer by providing a plurality of elongated through-holes in the coating placed on the substrate, wherein the plurality of elongated through-holes extend perpendicular to the grid cross-section. In other embodiments, the step for preparing the substrate and the patterned mask layer may or may not include the step of forming the mask layer by providing a plurality of elongated through-holes in the coating placed on the substrate.

[0025] A method for manufacturing a blazed lattice may, in one embodiment, include a step of performing a step corresponding to the step of Method 100 in the embodiment of Figure 1. In other embodiments, a method for manufacturing a blazed lattice may include a step of performing a step corresponding to a non-optional step of Method 100 in the embodiment of Figure 1. A method for manufacturing a blazed lattice may generally include any number of additional steps or processes not disclosed herein in relation to Method 100 in the embodiment of Figure 1.

[0026] The steps of a method for manufacturing a blazed grid, which involve performing any of the steps of Method 100 in the embodiment of Figure 1, do not need to be performed in a fixed order. However, any step of Method 100, which involves performing step 110 of preparing the substrate and the patterned mask layer, may generally be performed before any step of performing any of the steps of performing either step 120 of performing primary dry etching or step 150 of performing secondary dry etching; any step of Method 100, which involves performing step 124 of forming grooves extending into the substrate, may generally be performed before any step of performing step 130 of depositing the first material in the grooves; and any step of Method 100, which involves performing step 130 of depositing the first material in the grooves, may generally be performed before any step of performing step 154 ​​of utilizing the features between the grid as etching stoppers.

[0027] Figures 2A to 2E, collectively referred to as Figure 2 throughout this specification, schematically illustrate a series of subsequent steps in a method for manufacturing a blazed lattice 200, comprising a rib 210 having blaze facets 211 facing a blaze facet direction 212 and anti-blaze facets 213 facing an anti-blaze facet direction 214, wherein, according to one embodiment, the blaze facet direction 212 and anti-blaze facet 213 extend along a lattice cross section 215. In Figure 2, the lattice cross section 215 extends perpendicularly to the plane of the drawings in Figures 2A to 2E. In other embodiments, the method for manufacturing a blazed lattice may include a series of steps similar to, or different from, the steps of the method in the embodiment of Figure 2.

[0028] The embodiment in Figure 2 may conform to any of the embodiments disclosed with reference to and / or in conjunction with Figure 1. The embodiment in Figure 2 may, additionally or alternatively, have any function of any of the embodiments disclosed with reference to and / or in conjunction with Figure 1, although not expressly described below.

[0029] Referring to Figure 2E, the blazed lattice 200 comprises a plurality of projections 210, each projection of which has a blazed facet 211 facing the blazed facet direction 212 and an anti-blazed facet 213 facing the anti-blazed facet direction 214. In other embodiments, the blazed lattice may comprise at least one such projection, or a plurality, i.e., at least two such projections.

[0030] Referring to Figures 2A and 2B, this method includes the steps of preparing a substrate 220 and a patterned mask layer 230 on the substrate 220. The steps of preparing the substrate 220 and the patterned mask layer 230 include the steps of applying a coating 232 to the substrate 220 and forming the mask layer 230 by providing a plurality of elongated through holes 231 in the coating 232. The plurality of elongated through holes 231 extend perpendicular to the grid cross-section 215.

[0031] The substrate 220 in the embodiment shown in Figure 2 may be formed of a high refractive index polymer material using any suitable coating method, such as rotary coating, spray coating, and / or inkjet printing. In other embodiments, the substrate may contain any suitable material and may be formed using any suitable process.

[0032] In the embodiment shown in Figure 2, the mask layer 230 may be formed of aluminum oxide (AlO2) deposited by electron beam deposition. In other embodiments, the mask layer may be any suitable material, for example, aluminum oxide (AlO2 / AlO2). x ), titanium dioxide (TiO2 / TiO2), silicon dioxide (SiO2 / SiO2) x ), and / or silicon nitride (Si2N3 / SiN x The inorganic material may include oxide and / or nitride materials such as ), and may be formed using any suitable process, such as sputtering, deposition, chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), inductively coupled plasma chemical vapor deposition (ICP-CVD), atomic layer deposition (ALD), and / or variations thereof.

[0033] The method of the embodiment in Figure 2 can constitute an example of a method for manufacturing a blazed grid, thereby forming a blazed grid on the surface of the waveguide for coupling light into and / or out of the waveguide. The substrate 220 can therefore be placed on the surface 271 of the waveguide 270. In other embodiments, the blazed grid may be formed on the surface of the waveguide for any suitable use in any suitable application, for example, for coupling light into and / or out of the waveguide.

[0034] When the substrate 220 is placed on the surface 271 of the waveguide 270, the blazed grid 200 in the embodiment of Figure 2 is formed on an additional material layer placed on the waveguide 270. In other embodiments, the blazed grid is formed on the surface of the waveguide to couple light into and / or out of the waveguide, and this blazed grid may or may not be placed on such additional material layer. In some such embodiments, the blazed grid may be formed directly within the waveguide.

[0035] In this disclosure, “waveguide” may refer to an optical waveguide. Additionally or alternatively, the waveguide may refer to a two-dimensional waveguide, in which light may be confined along the thickness direction of the waveguide.

[0036] Furthermore, the "surface" of a waveguide may refer to a portion of the waveguide's surface that is visible from or faces a particular line of sight. Additionally or alternatively, the surface of a waveguide may refer to a surface that is suitable for, or configured to confine light within the waveguide by total internal reflection.

[0037] This method includes the step of performing a primary dry etching of the substrate 220 such that primary ions 121, schematically shown as white dots with reference to Figure 2C, are accelerated in the primary etching direction 122 and collide with the substrate 220.

[0038] In the embodiment shown in Figure 2, the primary projection 123 in the primary etching direction 122 onto the grid section 215 extends perpendicular to the anti-blaze-facet direction 214. In other embodiments, the primary projection in the primary etching direction onto the grid section can extend perpendicular to the blaze-facet direction or the anti-blaze-facet direction.

[0039] The step of performing primary dry etching in the embodiment shown in Figure 2 includes the step of forming a groove 240 that extends into the substrate 220 along the primary etching direction 122. In other embodiments, the step of performing primary dry etching may or may not include the step of forming such a groove.

[0040] As shown in Figures 2B and 2C, the interface 222 between the substrate and the mask layer extends along the base plane 260, and the primary projection 123 extends perpendicular to the base plane 260. The base plane 260 extends perpendicular to the lattice cross section 215. Generally, primary or secondary projections extending perpendicular to the base plane can make it possible to form a blaze lattice with upright anti-blaze facets, which may improve diffraction efficiency. In other embodiments, the primary or secondary projections may or may not extend perpendicular to the base plane.

[0041] In this specification, “base plane” may refer to a virtual surface along which the interface between the substrate and the mask layer extends. The base plane may be flat, for example, in the case of a flat interface, or curved, for example, in the case of a curved interface.

[0042] In the embodiment shown in Figure 2, the primary etching direction 122 can extend parallel to the lattice cross section 215. Therefore, the primary etching direction 122 can extend perpendicular to the base plane 260. Generally, a primary or secondary etching direction extending perpendicular to the base plane can enable the use of a wider range of dry etching techniques, including reactive ion etching (RIE) and ion milling. In other embodiments, the primary or secondary etching direction may or may not extend perpendicular to the base plane. For example, in some embodiments, the first and second projections may each extend obliquely to the base plane. Generally, primary and secondary projections extending obliquely to the base plane can enable the formation of a blaze lattice with inclined anti-blaze facets, thereby allowing for easy spatial adjustment of the diffraction efficiency of the blaze lattice, for example.

[0043] Since the primary etching direction 122 can extend perpendicular to the base plane 260, the process of performing primary dry etching in the embodiment of Figure 2 may include a RIE step. During the RIE step, the substrate 220 can be etched using, for example, oxygen plasma. In other embodiments where the primary or secondary etching direction extends perpendicular to the base plane, the process of performing primary dry etching may include any preferred steps, such as a RIE step and / or an ion milling step.

[0044] This method includes the step of performing secondary dry etching of the substrate 220 such that secondary ions 151, schematically shown as black dots with reference to Figure 2D, are accelerated in the secondary etching direction 152 and collide with the substrate 220.

[0045] In the embodiment shown in Figure 2, the secondary projection 153 on the grid section 215 in the secondary etching direction 152 extends perpendicular to the blaze-facet direction 212. In other embodiments, the secondary projection on the grid section in the secondary etching direction can extend perpendicular to the blaze-facet direction or the anti-blaze-facet direction.

[0046] In the embodiment shown in Figure 2, secondary ions 151 are parallelized to form a parallelized secondary ion beam for etching the substrate 220. In other embodiments, primary ions and / or secondary ions can be parallelized to form a parallelized primary ion beam and / or a parallelized secondary ion beam for etching the substrate.

[0047] In the embodiment shown in Figure 2, the step of performing secondary dry etching may include a RIBE step. During such a RIBE step, the substrate 220 can be etched using, for example, oxygen ions. In other embodiments, the step of performing dry etching, in which ions are accelerated onto the lattice cross section in a projection direction perpendicular to the blaze facet direction, and these ions are parallelized to etch the substrate to form a parallelized ion beam, may include any preferred steps, such as an IBE step and / or a RIBE step.

[0048] Referring to Figure 2E, this method further includes a post-processing step, which removes the open portions of the substrate 220 during the process of performing secondary dry etching, thereby forming a plurality of ridges 210. In other embodiments, the method for producing the blazed grid may or may not include such a post-processing step.

[0049] The post-processing step in the embodiment of Figure 2 can be carried out as a wet cleaning step, such as a water immersion step. In other embodiments, the method for manufacturing a blazed grid includes a post-processing step, which removes the exposed portions of the substrate during the process of performing secondary dry etching, thereby forming one or more ridges, and the post-processing step can be carried out in any preferred manner, for example, as a wet cleaning step, such as a water immersion step.

[0050] In the embodiment shown in Figure 2, under primary etching conditions (i.e., during the process of performing primary dry etching), primary ion 121 can exhibit a first primary chemical reactivity with the mask layer 230 and a second primary chemical reactivity with the substrate 220 that is higher than the first primary chemical reactivity. Furthermore, under secondary etching conditions (i.e., during the process of performing secondary dry etching), secondary ion 151 can exhibit a first secondary chemical reactivity with the mask layer 230 and a second secondary chemical reactivity with the substrate 220 that is higher than the first secondary chemical reactivity. Generally, utilizing such reactive ions for substrate etching can increase the selectivity of the dry etching process and, furthermore, allow for the easy production of blazed lattices with sharper and less rounded shapes. Examples of dry etching techniques that utilize such reactive ions include RIE, DRIE, ICP-RIE, RIBE, and variations thereof. In other embodiments, the primary ions may or may not exhibit a first primary chemical reactivity with the mask layer and a second primary chemical reactivity with the substrate that is higher than the first primary chemical reactivity under primary etching conditions, and / or the secondary ions may or may not exhibit a first secondary chemical reactivity with the mask layer and a second secondary chemical reactivity with the substrate that is higher than the first secondary chemical reactivity under secondary etching conditions.

[0051] Figures 3A to 3H, collectively referred to as Figure 3 throughout this specification, schematically illustrate a series of subsequent steps in a method for manufacturing a blazed lattice 200, comprising a rib 210 having blaze facets 211 facing a blaze facet direction 212 and anti-blaze facets 213 facing an anti-blaze facet direction 214, wherein, according to one embodiment, the blaze facet direction 212 and anti-blaze facet 213 extend along a lattice cross section 215. In Figure 3, the lattice cross section 215 extends perpendicularly to the plane of the drawings in Figures 3A to 3H. In other embodiments, the method for manufacturing a blazed lattice may include a series of steps similar to, or different from, the steps of the method in the embodiment of Figure 3.

[0052] The embodiment in Figure 3 may conform to any embodiment disclosed with reference to and / or in conjunction with either Figure 1 or Figure 2. The embodiment in Figure 3 may, additionally or alternatively, have any preferred functions of any embodiment disclosed with reference to and / or in conjunction with either Figure 1 or Figure 2, although not expressly described below.

[0053] Referring to Figures 3A to 3C, this method includes the steps of preparing a substrate 220 and a patterned mask layer 230 on the substrate 220, the preparation steps of applying a coating 232 to the substrate 220 and forming a mask layer 230 by providing a plurality of elongated through holes 231 in the coating 232, and the method also includes the step of performing primary dry etching of the substrate 220 such that primary ions 121, schematically shown as white dots, are accelerated in the primary etching direction 122 and collide with the substrate 220.

[0054] In the embodiment shown in Figure 3, the primary projection 123 in the primary etching direction 122 onto the grid cross section 215 extends perpendicular to the anti-blaze facet direction 214. Furthermore, the process of performing the primary dry etching in the embodiment shown in Figure 3 includes the step of forming grooves 240 that extend into the substrate 220 along the primary etching direction 122.

[0055] The steps of preparing the substrate and the patterned mask layer, and performing the primary dry etching of the embodiment in Figure 3, can be carried out according to those disclosed above with reference to Figure 2; therefore, further details of these steps are omitted here for brevity and simplicity.

[0056] Referring to Figures 3D and 3E, this method includes the steps of depositing a first material 250 into grooves 240 to form inter-grille features 251, and removing a patterned mask layer 230 before the step of depositing the first material 250 into grooves 240. In other embodiments, the method for manufacturing a blazed grid may include or omit the step of depositing the first material into grooves to form inter-grille features. In embodiments, if the method for manufacturing a blazed grid includes the step of depositing the first material into grooves to form inter-grille features, the method may or may not include the step of removing a patterned mask layer before the step of depositing the first material into grooves.

[0057] The first material 250 in the embodiment shown in Figure 3 is aluminum oxide (AlO2 or AlO2) deposited by plasma chemical vapor deposition (PECVD). x ) may also be formed using any suitable material, for example, aluminum oxide (AlO2 / AlO2), which may be formed using any suitable process in other embodiments. x ), titanium dioxide (TiO2 / TiO2), silicon dioxide (SiO2 / SiO2) x ) or silicon nitride (Si2N3 / SiN x The first material may include oxide or nitride materials, such as ), or mixtures thereof. The first material can generally be deposited using any suitable deposition method, such as sputtering, vapor deposition, chemical vapor deposition (CVD), PECVD, inductively coupled plasma chemical vapor deposition (ICP-CVD), atomic layer deposition (ALD), and / or variations thereof.

[0058] Referring to Figure 3F, this method includes a step of exposing the ridged portion 221 of the substrate 220 before performing the secondary dry etching step. In other embodiments, the method for manufacturing the blazed grid may or may not include the step of exposing the ridged portion of the substrate before performing the secondary dry etching step.

[0059] In the embodiment shown in Figure 3, the step of exposing the ridged portion 221 of the substrate 220 may include an additional dry etching step. In other words, at least a portion of the first material 250 covering the ridged portion 221 can be etched using a dry etching method. In other embodiments, the method for manufacturing the blazed lattice includes the step of exposing the ridged portion of the substrate, and this step of exposing the ridged portion can be carried out in any preferred manner.

[0060] This method includes the step of performing secondary dry etching of the substrate 220 such that secondary ions 151, schematically shown as black dots with reference to Figure 3G, are accelerated in the secondary etching direction 152 and collide with the substrate 220. The secondary ions 151 are parallelized to form a parallelized secondary ion beam for etching the substrate 220.

[0061] In the embodiment shown in Figure 3, the step of performing secondary dry etching includes using the inter-grille features 251 as etching stoppages. In other embodiments, the step of performing secondary dry etching may or may not include the step of using the inter-grille features as etching stoppages.

[0062] In the embodiment shown in Figure 3, the inter-grille feature 251 is positioned from the ribbed portion 221 in the anti-blaze-facet direction 214. In other embodiments, the inter-grille feature may be positioned from the ribbed portion in the blaze-facet direction or in the anti-blaze-facet direction. In other embodiments, a secondary projection in the secondary etching direction onto the grille cross section extends perpendicular to one of the blaze-facet direction and the anti-blaze-facet direction, and the inter-grille feature may be positioned from the ribbed portion in the other of the blaze-facet direction and the anti-blaze-facet direction.

[0063] Referring to Figure 3H, this method further includes a post-processing step, which removes the features 251 between the grids. Such a step can be carried out, for example, as a wet etching step. In other embodiments, the method for producing the blazed grid may or may not include such a post-processing step.

[0064] Figures 4A to 4F, collectively referred to as Figure 4 throughout this specification, schematically illustrate a series of subsequent steps in a method for manufacturing a blazed lattice 200, comprising a rib 210 having blaze facets 211 facing the blaze facet direction 212 and anti-blaze facets 213 facing the anti-blaze facet direction 214, wherein, according to one embodiment, the blaze facet direction 212 and anti-blaze facet 213 extend along the lattice cross section 215. In Figure 4, the lattice cross section 215 extends perpendicularly to the plane of the drawings in Figures 4A to 4F. In other embodiments, the method for manufacturing a blazed lattice may include a series of steps similar to, or different from, the steps of the method in the embodiment of Figure 4.

[0065] The embodiment in Figure 4 may conform to any embodiment disclosed with reference to any of Figures 1 to 3 and / or in conjunction with either Figure 1 or Figure 2. The embodiment in Figure 4 may, additionally or alternatively, have any function of any embodiment disclosed with reference to any of Figures 1 to 3 and / or in conjunction with any of Figures 1 to 3, although this is not explicitly stated below.

[0066] Referring to Figure 4A, this method includes the step of preparing a substrate 220 and a patterned mask layer 230 on the substrate 220. The method of the embodiment in Figure 2 can constitute an example of a method for manufacturing a blazed lattice, thereby forming a blazed lattice on the contact surface of a nanoimprint stamp. Therefore, the substrate 220 in the embodiment in Figure 2 may be a nanoimprint stamp 280 having a contact surface 281.

[0067] In the embodiment shown in Figure 4, the nanoimprint stamp 280 may be formed from single-crystal silicon. In other embodiments, the nanoimprint stamp may be formed from any suitable material or may contain any suitable material. In some embodiments, the nanoimprint stamp may comprise a plurality of laminates formed from different materials.

[0068] As shown in Figure 4A, the interface 222 between the substrate 220 and the mask layer 230 extends along the base plane 260, which extends perpendicular to the lattice cross-section 215.

[0069] This method performs primary dry etching of the substrate 220 such that primary ions 121, schematically shown as white dots in Figure 4B, are accelerated in the primary etching direction 122 and collide with the substrate 220. In the embodiment of Figure 4, the primary ions 121 are parallelized to form a parallelized primary ion beam for etching the substrate 220. In other embodiments, the primary ions may or may not be parallelized to form a parallelized primary ion beam for etching the substrate.

[0070] In the embodiment shown in Figure 4, the primary projection 123 on the grid section 215 in the primary etching direction 122 extends perpendicular to the blaze facet direction 212. Furthermore, the process of performing the primary dry etching in the embodiment shown in Figure 4 includes the step of forming grooves 240 that extend into the substrate 220 along the primary etching direction 122.

[0071] Referring to Figure 4C, this method includes the step of depositing a first material 250 in a groove 240 to form inter-grout features 251. In other embodiments, the method for manufacturing a blazed lattice may include or not include the step of depositing a first material in a groove to form inter-grout features.

[0072] In the embodiment shown in Figure 4, the step of depositing the first material 250 into the groove 240 includes an atomic layer deposition step. In other words, at least a portion of the first material 250 deposited in the groove 240 is deposited using atomic layer deposition. In the embodiment shown in Figure 3, the first material 250 is aluminum oxide (AlO2 or AlO2). x ) may also be the first material. In other embodiments, the step of depositing the first material in the groove includes an atomic layer deposition step, and any suitable type of first material can be used.

[0073] Referring to Figure 4D, this method includes a step of exposing the ridged portion 221 of the substrate 220 before performing the step of secondary dry etching. In the embodiment of Figure 4, the step of exposing the ridged portion 221 of the substrate 220 may include, for example, a lift-off step of removing the mask layer 230 and the first material 250 that cover the ridged portion 221.

[0074] This method includes the step of performing secondary dry etching of the substrate 220 such that secondary ions 151, schematically shown as black dots with reference to Figure 4E, are accelerated in the secondary etching direction 152 and collide with the substrate 220. The step of performing secondary dry etching includes the step of utilizing interstitial features 251 as etching stops. The interstitial features 251 are located in the blaze-facet direction 212 from the ribbed portion 221.

[0075] In the embodiment of Figure 4, the secondary etching direction 152 can extend parallel to the grid cross-section 215. The secondary etching direction 152 can therefore extend perpendicular to the base plane 260. Since the secondary etching direction 152 can extend perpendicular to the base plane 260, the process of performing primary dry etching in the embodiment of Figure 4 can include a RIE step.

[0076] Finally, referring to Figure 3F, this method further includes a post-processing step, in which the inter-grid features 251 are removed, for example, by wet etching.

[0077] It should be understood that the embodiments described above can be used in combination with each other. Further embodiments can be formed by combining some of the embodiments.

[0078] Those skilled in the art will see that, with technological advancements, the fundamental concept of the present invention can be realized by various methods. Therefore, the present invention and its embodiments are not limited to the examples described above, but can be modified within the scope of the claims.

[0079] It should be understood that the benefits and advantages described above may relate to one embodiment or to several embodiments. The embodiments are not limited to those that solve some or all of the problems described, or that have some or all of the benefits and advantages described.

[0080] In this specification, the term “comprising” is used to mean including subsequent functions or functions without prejudice to the existence of one or more additional functions or functions. It will be further understood that a reference to “one” item refers to one or more such items. [Explanation of symbols]

[0081] 100 ways 110 Steps to prepare the substrate and the patterned mask layer. 111 Step of creating multiple elongated through holes in the coating. 120 Steps to perform primary dry etching 121 Primary Ions 122 Primary etching direction 123 Primary projection 124 Step of forming grooves extending in the substrate 130 Step of depositing the first material in the groove 131 Atomic layer deposition 140 Step to expose the protruding portion 150 Steps to perform secondary dry etching 151 Secondary ions 152 Secondary etching direction 153 Secondary projection 154 Step of using the shapes between the grid as etching fixation 200 Blazed Grid 210 protrusion 211 Blaise Facet 212 Blaze Facet Direction 213 Anti-Blaise Facet 214 Anti-blaze facet direction 215 Grid cross section 220 circuit boards 221 Projection part 222 Interface 230 mask layers 231 Through hole 232 Coating 240 Groove 250 First material 251 Forms between lattices 260 base plane 270 Waveguides 271 sides 280 Nanoimprint Stamps 281 Contact surface

Claims

1. A method (100) for manufacturing a blazed lattice comprising ridges having blaze facets and anti-blaze facets, wherein the blaze facet direction, which is perpendicular to the blaze facets, and the anti-blaze facet direction, which is perpendicular to the anti-blaze facets, extend along the lattice cross section, and the method - A step (110) of preparing a substrate and a mask layer with a pattern formed on the substrate, - A step (120) of performing primary dry etching of the substrate such that primary ions are accelerated in the primary etching direction and collide with the substrate, - A step (150) of performing secondary dry etching of the substrate such that secondary ions are accelerated in the secondary etching direction and collide with the substrate. The primary projection onto the lattice cross section in the primary etching direction is perpendicular to the anti-blaze facet direction, the secondary projection onto the lattice cross section in the secondary etching direction is perpendicular to the blaze facet direction, and the ions accelerated to the lattice cross section in a projection direction perpendicular to the blaze facet direction are parallelized to etch the substrate, forming a parallelized ion beam. Method (100) is characterized in that, prior to step (150) of performing secondary dry etching, a portion of the substrate that is to be etched by secondary dry etching and which covers the protruding portion of the substrate is removed to expose the protruding portion of the substrate, and the mask layer comprises an inorganic material.

2. The method (100) according to claim 1, wherein the step (120) of performing primary dry etching includes a step (124) of forming grooves extending in the substrate along the primary etching direction, the method (100) includes a step (130) of depositing a first material in the grooves to form interlattice features, and the step (150) of performing secondary dry etching includes a step (154) of using the interlattice features as etching stoppers.

3. The method according to claim 2 (100), wherein the step (130) of depositing the first material in the groove includes an atomic layer deposition (131) step.

4. The method according to any one of claims 1 to 3 (100), wherein the interface between the substrate and the mask layer extends along the base plane, and the primary projection or the secondary projection is perpendicular to the base plane.

5. The method according to claim 4 (100), wherein the primary etching direction or the secondary etching direction is perpendicular to the base plane.

6. The method according to any one of claims 1 to 3 (100), wherein the interface between the substrate and the mask layer extends along the base plane, and the primary projection and the secondary projection are oblique to the base plane.

7. The method according to any one of claims 1 to 3 (100), wherein the step (110) of preparing a substrate and a patterned mask layer includes a step (111) of forming a mask layer by providing a plurality of elongated through holes in a coating disposed on the substrate, wherein the plurality of elongated through holes extend perpendicular to the grid cross section.

8. The method according to any one of claims 1 to 3 (100), wherein the primary ions exhibit a first primary chemical reactivity with the mask layer and a second primary chemical reactivity with the substrate that is higher than the first primary chemical reactivity under primary etching conditions, and / or the secondary ions exhibit a first secondary chemical reactivity with the mask layer and a second secondary chemical reactivity with the substrate that is higher than the first secondary chemical reactivity under secondary etching conditions.

9. The method according to any one of claims 1 to 3 (100), wherein the blazed grating is formed on the surface of the waveguide for coupling light into the waveguide and / or out of the waveguide.

10. The method according to any one of claims 1 to 3 (100), wherein the blazed lattice is formed on the contact surface of a nanoimprint stamp.

Images