Abstract: A manufacturing system performs a deposition of an etch-compatible film over a substrate. The etch-compatible film includes a first surface and a second surface opposite to the first surface. The manufacturing system performs a partial removal of the etch-compatible film to create a surface profile on the first surface with a plurality of depths relative to the substrate. The manufacturing system performs a deposition of a second material over the profile created in the etch-compatible film. The manufacturing system performs a planarization of the second material to obtain a plurality of etch heights of the second material in accordance with the plurality of depths in the profile created in the etch-compatible film. The manufacturing system performs a lithographic patterning of a photoresist deposited over the planarized second material to obtain the plurality of etch heights and one or more duty cycles in the second material.

Abstract: Disclosed herein are techniques for fabricating straight or slanted variable-etch-depth gratings. A photoresist material for fabricating a variable-etch-depth grating in a substrate is sensitive to light with a wavelength shorter than 300 nm and has an etch rate comparable to the etch rate of the substrate. A depth of an exposed portion of a photoresist material layer including the photoresist material correlates with the exposure dose. After exposure using a gray-scale mask and development, the photoresist material layer has a non-uniform thickness. The photoresist material layer with the non-uniform thickness and the underlying substrate are etched using a straight etching or slanted etching process to form the straight or slanted variable-etch-depth grating in the substrate. The variable-etch-depth grating is characterized by a non-uniform depth profile corresponding to the non-uniform thickness of the photoresist material layer before etching.

Abstract: A chemically assisted reactive ion beam etching (CAME) system for fabricating a slanted surface-relief structure in a material layer includes an reactive ion source generator configured to generate a plasma using a first reactive gas; one or more aligned collimator grids configured to extract and accelerate at least some of the reactive ions in the plasma to form a collimated reactive ion beam towards the material layer; and a gas ring configured to inject a second reactive gas onto the material layer. The plasma includes reactive ions of the first reactive gas that react with the material layer to generate volatile materials. The second reactive gas also reacts with the material layer. The collimated reactive ion beam and the second reactive gas etch the material layer both physically and chemically to form the slanted surface-relief structure in the material layer.

Abstract: A surface-relief grating includes a base surface-relief grating comprising a plurality of ridges that include a first material, and a second material on only a top surface or a single sidewall of each ridge of the plurality of ridges, where the second material is different from the first material. A method of fabricating the surface-relief grating includes etching or molding a base surface-relief grating that includes a plurality of ridges, depositing a material layer on the plurality of ridges, and selectively etching the material layer to increase a height or a slant angle of an edge of a ridge in the plurality of ridges to make the surface-relief grating that includes the base surface-relief grating.

Abstract: Techniques for fabricating a slanted structure are disclosed. In one embodiment, a method of fabricating a slanted surface-relief structure in a material layer includes forming a thin hard mask on top of an intermediate mask layer, etching the intermediate mask layer at a slant angle using the thin hard mask to form a slanted intermediate mask, and etching the material layer at the slant angle using the slanted intermediate mask to form the slanted surface-relief structure in the material layer. The intermediate mask layer is characterized by an etch rate greater than an etch rate of the material layer.

Abstract: A manufacturing system performs a deposition of an etch-compatible film over a substrate. The etch-compatible film includes a first surface and a second surface opposite to the first surface. The manufacturing system performs a partial removal of the etch-compatible film to create a surface profile on the first surface with a plurality of depths relative to the substrate. The manufacturing system performs a deposition of a second material over the profile created in the etch-compatible film. The manufacturing system performs a planarization of the second material to obtain a plurality of etch heights of the second material in accordance with the plurality of depths in the profile created in the etch-compatible film. The manufacturing system performs a lithographic patterning of a photoresist deposited over the planarized second material to obtain the plurality of etch heights and one or more duty cycles in the second material.

Abstract: A method for fabricating a diffraction grating includes generating an ionized gas, passing the ionized gas through a gating structure to selectively directed gas toward a substrate, injecting an etchant gas into the directed gas, and exposing a surface of the substrate to the directed gas and the injected etchant gas to form grating structures on the surface of the substrate.

Abstract: Techniques for overcoating slanted structures and devices obtained using the techniques are disclosed. In some embodiments, a method of forming an overcoat layer on a surface-relief structure on a substrate includes receiving the substrate with the surface-relief structure. The surface-relief structure includes a plurality of ridges slanted with respect to the substrate, and a plurality of grooves each between two adjacent ridges. The method further includes depositing, in each cycle of a plurality of cycles, a uniform layer of an overcoat material on surfaces of the plurality of ridges and bottoms of the plurality of grooves. The deposited layers of the overcoat material and the plurality of ridges collectively form a light-coupling structure on the substrate. A surface of the overcoat layer is planar.

Abstract: Techniques for producing an overcoat layer on slanted surface-relief structures and devices obtained using the techniques are disclosed. In some embodiments, a method of planarizing an overcoat layer over a surface-relief structure includes removing a portion of the overcoat layer using an ion beam at a glancing angle. The overcoat layer includes planar surface portions and non-planar surface portions. Each of the non-planar surface portions includes a first sloped side and a second sloped side facing the first sloped side. The glancing angle is selected such that the first sloped side of each non-planar surface portion is shadowed from the ion beam by an adjacent planar surface portion such that the ion beam does not reach at least the first sloped side of each non-planar surface portion but reaches the second sloped side of each non-planar surface portion.

Abstract: Techniques for fabricating a slanted structure are disclosed. In one embodiment, a method of fabricating a slanted structure in a material layer includes injecting a first reactive gas into an reactive ion source generator, generating a plasma that includes reactive ions in the reactive ion source generator, extracting at least some of the reactive ions from the plasma to form a collimated reactive ion beam towards the material layer, and injecting a second reactive gas onto the material layer. The collimated reactive ion beam and the second reactive gas etch the material layer both physically and chemically to form the slanted surface-relief structure.

Abstract: A manufacturing system performs a deposition of an etch-compatible film over a substrate. The etch-compatible film includes a first surface and a second surface opposite to the first surface. The manufacturing system performs a partial removal of the etch-compatible film to create a surface profile on the first surface with a plurality of etch heights relative to the substrate. The manufacturing system performs a lithographic patterning of a photoresist deposited over the created profile in the etch-compatible film to obtain the plurality of etch heights and one or more duty cycles corresponding to the etch-compatible film deposited over the substrate.

Abstract: Techniques for fabricating slanted surface-relief structures are disclosed. In some embodiments, a method for of fabricating a target slanted surface-relief structure, such as a nanoimprint lithography (NIL) mold or a slanted surface-relief grating, includes manufacturing a preliminary surface-relief structure that includes a plurality of ridges and modifying a parameter of the preliminary surface-relief structure to make the target slanted surface-relief structure. The parameter includes a width of each of the plurality of ridges, a height of each of the plurality of ridges, a surface energy of the preliminary surface-relief structure, or a slant angle of an edge of the plurality of ridges. Modifying the parameter includes depositing a material layer on the preliminary surface-relief structure and etching or surface-treating the material layer.

Abstract: Techniques for fabricating a slanted structure are disclosed. In one embodiment, a method for fabricating a slanted structure on a material layer includes forming a mask layer on the material layer, and implanting ions into a plurality of regions of the material layer at a slant angle greater than zero using an ion beam and the mask layer. The slant angle is measured with respect to a surface normal of the material layer. Implanting the ions into the plurality of regions of the material layer changes a refractive index or an etch rate of the plurality of regions of the material layer. In some embodiments, the method further includes wet-etching the material layer using an etchant to remove materials in the plurality of regions of the material layer. In some embodiments, the method includes either simultaneous or post-implantation etching of modified material through a dry etching process using reactive etchants in feed gas.

Abstract: Techniques for fabricating slanted surface-relief structures are disclosed. In some embodiments, a method for of fabricating a target slanted surface-relief structure, such as a nanoimprint lithography (NIL) mold or a slanted surface-relief grating, includes manufacturing a preliminary surface-relief structure that includes a plurality of ridges and modifying a parameter of the preliminary surface-relief structure to make the target slanted surface-relief structure. The parameter includes a width of each of the plurality of ridges, a height of each of the plurality of ridges, a surface energy of the preliminary surface-relief structure, or a slant angle of an edge of the plurality of ridges. Modifying the parameter includes depositing a material layer on the preliminary surface-relief structure and etching or surface-treating the material layer.

Abstract: Techniques for fabricating a slanted structure are disclosed. In one embodiment, a method of fabricating a slanted structure in a material layer includes injecting a first reactive gas into an reactive ion source generator, generating a plasma that includes reactive ions in the reactive ion source generator, extracting at least some of the reactive ions from the plasma to form a collimated reactive ion beam towards the material layer, and injecting a second reactive gas onto the material layer. The collimated reactive ion beam and the second reactive gas etch the material layer both physically and chemically to form the slanted surface-relief structure. In some embodiments, the first reactive gas includes a low-molecular-weight gas (e.g., H2 or He). In some embodiments, a surface layer of the internal cavity of the reactive ion source generator includes a layer of an oxide material (e.g., aluminum oxide or Y2O3).

Abstract: A method is described for utilizing NIL materials with switchable mechanical properties. The method comprises applying an imprint mask to a nano-imprint lithography (NIL) material layer. The NIL material layer is comprised of a NIL material with a modulus level below a flexibility threshold. The NIL material layer has an internal property, that when changed, causes a change in the modulus level of the NIL material. The method further comprises detaching the imprinted NIL material layer from the imprint mask, with the low modulus level of the NIL material causing a shape of the imprinted NIL material layer to remain unchanged after detachment. A modulus level of the NIL material is increased by changing an internal property of the NIL material, with the modulus level increased beyond a strength threshold to create a first imprint layer that has a structure that remains unaffected by a subsequent process.

Abstract: A method is described for creating a modified mask with low surface energies for a nano-imprint lithography (NIL) imprinting process. The method includes applying a master mold to an imprint mask material to create an imprint mask. The method further includes modifying the imprint mask by applying a treatment to the imprint mask to cause a surface energy level of the imprint mask to fall below a sticking threshold. The modified imprint mask is applied to a nano-imprint lithography (NIL) material to create an imprinted NIL material layer. The surface energy level of the imprint mask causes a shape of the imprinted NIL material layer to be remain unchanged when the imprinted NIL material layer is detached from the modified imprint mask.

Abstract: A method is described for modifying the mechanical properties of NIL materials. The method includes applying an imprint mask to a nano-imprint lithography (NIL) material layer to create an imprinted NIL material layer, with the NIL material layer comprised of a NIL material. The method further includes detaching the imprinted NIL material layer from the imprint mask, with the modulus level of the NIL material below a flexibility threshold to cause a shape of the imprinted NIL material layer to remain unchanged after detachment. The modulus level of the NIL material of the imprinted NIL material layer is increased beyond a strength threshold to create a first imprint layer, with the imprint layer having a structure that remains unaffected by a subsequent process to form a second imprint layer matching a master mold pattern.

Abstract: A manufacturing system for fabricating self-aligned grating elements with a variable refractive index includes a patterning system, a deposition system, and an etching system. The manufacturing system performs a lithographic patterning of one or more photoresists to create a stack over a substrate. The manufacturing system performs a conformal deposition of a protective coating on the stack. The manufacturing system performs a deposition of a first photoresist of a first refractive index on the protective coating. The manufacturing system performs a removal of the first photoresist to achieve a threshold value of first thickness. The manufacturing system performs a deposition of a second photoresist of a second refractive index on the first photoresist. The second refractive index is greater than the first refractive index. The manufacturing system performs a removal of the second photoresist to achieve a threshold value of second thickness to form a portion of an optical grating.

Abstract: A manufacturing system performs a deposition of an etch-compatible film over a substrate. The etch-compatible film includes a first surface and a second surface opposite to the first surface. The manufacturing system performs a partial removal of the etch-compatible film to create a surface profile on the first surface with a plurality of depths relative to the substrate. The manufacturing system performs a deposition of a second material over the profile created in the etch-compatible film. The manufacturing system performs a planarization of the second material to obtain a plurality of etch heights of the second material in accordance with the plurality of depths in the profile created in the etch-compatible film. The manufacturing system performs a lithographic patterning of a photoresist deposited over the planarized second material to obtain the plurality of etch heights and one or more duty cycles in the second material.