Abstract: Gray-tone lithography techniques for controlling the thickness profile of an overcoat layer on a surface-relief grating that has a non-uniform grating parameter (e.g., depth, duty cycle, or period), compensating for the non-uniform etch rate in a large area, defining etch/block regions, and/or controlling the thickness of the grating layer.

Abstract: A waveguide display includes a waveguide, an input coupler configured to couple display light into the waveguide, and a surface-relief grating on the waveguide and configured to couple the display light out of the waveguide towards an eyebox of the waveguide display on a first side of the waveguide. The surface-relief grating is formed in a plurality of grating layers having uniform or non-uniform thickness profiles. The plurality of grating layers is characterized by a refractive index modulation that increases and then decreases as the distance of the grating layer from the waveguide increases.

Abstract: Disclosed herein are techniques for fabricating a straight or slanted surface-relief grating with a uniform or non-uniform grating depth. According to certain embodiments, a gray-tone photoresist includes a novolac resin, a diazonaphthoquinone (DNQ) dissolution inhibitor, and one or more crosslinking agents for crosslinking the novolac resin at an elevated temperature to increase a glass transition temperature of the gray-tone photoresist and/or lower an etch rate of the gray-tone photoresist. After gray-tone photo exposure and development, the gray-tone photoresist is baked at the elevated temperature to crosslink. The crosslinked gray-tone photoresist has a higher density and a higher glass transition temperature, and thus would not become flowable to cause ripples or other surface roughness during the etching.

Abstract: A multilayer architecture includes an amorphous optical layer, a crystalline optical layer overlying the amorphous optical layer, and a barrier layer located between the amorphous optical layer and the crystalline optical layer. The barrier layer may be configured to mediate the structure of the later-formed amorphous optical layer. For instance, a low absorption barrier layer may be formed over the crystalline optical layer within the multilayer architecture and accordingly inhibit crystallization within a subsequently formed optical layer, thus providing phase separation between the neighboring optical layers and a desired refractive index gradient within the multilayer architecture without adversely affecting the optical path length therethrough. Such a multilayer structure may be configured as a light retention layer, antireflective coating, bandpass filter, etc.

Abstract: Gray-tone lithography techniques for controlling the thickness profile of an overcoat layer on a surface-relief grating that has a non-uniform grating parameter (e.g., depth, duty cycle, or period), compensating for the non-uniform etch rate in a large area, defining etch/block regions, and/or controlling the thickness of the grating layer.

Abstract: A method of fabricating gratings with variable grating depths including depositing a first grating material layer with a uniform thickness profile on a substrate, forming an etch mask layer having a variable thickness profile on the first grating material layer, etching the etch mask layer and the first grating material layer to change the uniform thickness profile of the first grating material layer to a non-uniform thickness profile, forming a patterned hard mask on the first grating material layer, and etching, using the patterned hard mask, the first grating material layer to form a grating with a variable depth in the first grating material layer.

Abstract: A waveguide display includes a waveguide, an input coupler configured to couple display light into the waveguide, and a surface-relief grating on the waveguide and configured to couple the display light out of the waveguide towards an eyebox of the waveguide display on a first side of the waveguide. The surface-relief grating is formed in a plurality of grating layers having uniform or non-uniform thickness profiles. The plurality of grating layers is characterized by a refractive index modulation that increases and then decreases as the distance of the grating layer from the waveguide increases.

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: 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: Embodiments of methods and systems for patterning of low aspect ratio stacks are described. In one embodiment, a method may include receiving a substrate comprising a patterned organic planarizing layer (OPL) mask wherein a surface of the OPL mask is exposed, the OPL mask landing on a dielectric layer. The method may also include performing a partial etch of the dielectric layer in a region exposed by the OPL mask. Additionally, the method may include depositing a capping material on a surface of the OPL mask. The method may also include performing a cyclical process of the partial etch of the dielectric layer and deposition of the capping material on a surface of the OPL mask until the dielectric layer is removed to a target depth. In such embodiments, the cyclical process generates an output patterned substrate with a target line edge roughness (LER).

Abstract: Embodiments of methods and systems for patterning of low aspect ratio stacks are described. In one embodiment, a method may include receiving a substrate comprising a patterned organic planarizing layer (OPL) mask wherein a surface of the OPL mask is exposed, the OPL mask landing on a dielectric layer. The method may also include performing a partial etch of the dielectric layer in a region exposed by the OPL mask. Additionally, the method may include depositing a capping material on a surface of the OPL mask. The method may also include performing a cyclical process of the partial etch of the dielectric layer and deposition of the capping material on a surface of the OPL mask until the dielectric layer is removed to a target depth. In such embodiments, the cyclical process generates an output patterned substrate with a target line edge roughness (LER).

Abstract: A formed back-end-of-line (BEOL) metal line layer may include a plurality of metal lines with dielectric oxide caps that are disposed in between each metal lines. To overlay an interconnecting layer of metal lines on a selected metal line of the BEOL metal line layer, a block copolymer (BCP) may be formed on a patterning layer. Thereafter, a selective etching of the formed BCP creates a recess above the selected metal line. The created recess facilitates the overlaying of the interconnecting layer of metal lines.

Abstract: Techniques herein include methods of processing photoresist patterns and photoresist materials for successful use in multi-patterning operations. Techniques include combinations of targeted deposition, curing, and trimming to provide a post-processed resist that effectively enables multi-patterning using photoresist materials to function as mandrels. Photoresist patterns and mandrels are hardened, strengthened, and/or dimensionally adjusted to provide desired dimensions and/or mandrels enabling straight sidewall spacers. Polymer is deposited with tapered profile to compensate for compressive stresses of various conformal or subsequent films to result in a vertical profile despite any compression.

Abstract: A formed back-end-of-line (BEOL) metal line layer may include a plurality of metal lines with dielectric oxide caps that are disposed in between each metal lines. To overlay an interconnecting layer of metal lines on a selected metal line of the BEOL metal line layer, a block copolymer (BCP) may be formed on a patterning layer. Thereafter, a selective etching of the formed BCP creates a recess above the selected metal line. The created recess facilitates the overlaying of the interconnecting layer of metal lines.

Abstract: A method for the dry removal of a material on a microelectronic workpiece is described. The method includes receiving a workpiece having a surface exposing a target layer composed of silicon selected from the group consisting of amorphous silicon (a-Si), polycrystalline silicon (poly-Si), and doped silicon that fills a trench or via within a retention layer, and selectively removing at least a portion of the target layer from the retention layer. The selective removal includes exposing the surface of the workpiece to a chemical environment containing N, H, and F at a first setpoint temperature to chemically alter a surface region of the target layer, and then, elevating the temperature of the workpiece to a second setpoint temperature to remove the chemically treated surface region of the target layer.

Abstract: Provided is a method of creating structure profiles on a substrate using faceting and passivation layers. A first plasma etch process performed generating a faceted sidewall and a desired inflection point; a second plasma etch process is performed using an oxygen, nitrogen, or combined oxygen and nitrogen plasma, generating a passivation layer; and a third plasma etch process using operating variables of an etch chemistry on the faceted sidewall and the passivation layer to induce differential etch rates to achieve a breakthrough on near-horizontal surfaces of the structure, wherein the third plasma etch used is configured to produce a target sidewall profile on the substrate down to the underlying stop layer. Selected two or more plasma etch variables are controlled in the performance of the first plasma etch process, the second plasma etch process, and/or the third plasma etch process in order to achieve target sidewall profile objectives.

Abstract: Techniques herein include methods of processing photoresist patterns and photoresist materials for successful use in multi-patterning operations. Techniques include combinations of targeted deposition, curing, and trimming to provide a post-processed resist that effectively enables multi-patterning using photoresist materials to function as mandrels. Photoresist patterns and mandrels are hardened, strengthened, and/or dimensionally adjusted to provide desired dimensions and/or mandrels enabling straight sidewall spacers. Polymer is deposited with tapered profile to compensate for compressive stresses of various conformal or subsequent films to result in a vertical profile despite any compression.

Abstract: Provided is a method of creating structure profiles on a substrate using faceting and passivation layers. A first plasma etch process performed generating a faceted sidewall and a desired inflection point; a second plasma etch process is performed using an oxygen, nitrogen, or combined oxygen and nitrogen plasma, generating a passivation layer; and a third plasma etch process using operating variables of an etch chemistry on the faceted sidewall and the passivation layer to induce differential etch rates to achieve a breakthrough on near-horizontal surfaces of the structure, wherein the third plasma etch used is configured to produce a target sidewall profile on the substrate down to the underlying stop layer. Selected two or more plasma etch variables are controlled in the performance of the first plasma etch process, the second plasma etch process, and/or the third plasma etch process in order to achieve target sidewall profile objectives.