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US 12,498,643 B2Granted
Fabrication of microscale structures
AssigneeAuthentix, Inc.
InventorsMilad Khoshnegar Shahrestani, Ripon Dey
Life of this patent
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Abstract
A method for patterning a substrate involves depositing a layer of resist material on a surface of the substrate, lithographically patterning (electron beam exposing and then developing) the layer of the resist material to form a patterned resist layer having a pattern multi-faceted microscale structures with a depth profile that varies over an area of the layer of resist material, and using the patterned resist layer in an etching step to transfer the pattern of multi-faceted microscale structures from the patterned resist layer to the substrate.
Claims20
A method for patterning a substrate, comprising:
- depositing a layer of resist material on a surface of the substrate, the substrate comprising a substrate material;
- lithographically patterning the layer of the resist material to provide a patterned resist layer having a pattern with a depth profile that varies over an area of the layer of resist material, the lithographic patterning comprising:
- exposing the layer of the resist material to an electron beam while varying an energy of the electron beam over the area in a pattern that corresponds to the depth profile to provide an exposed resist layer;
- and
- developing the exposed resist layer to selectively remove resist material from the exposed resist layer to form the patterned resist layer;
- etching the patterned resist layer and the substrate by exposing the patterned resist layer and the substrate to a plasma under conditions sufficient to transfer the pattern of the patterned resist layer to the substrate by removing substrate material from the substrate to form a patterned substrate having a depth profile corresponding to the depth profile of the patterned resist layer, thereby providing a patterned substrate;
- and
- between lithographically patterning and etching, exposing the patterned resist to a thermal reflow process comprising elevating a temperature of the substrate and the patterned resist material above a glass transition temperature of the patterned resist material and below a glass transition temperature of the substrate.
5 more elements
A method for patterning a substrate, comprising:
- depositing a layer of resist material on a surface of the substrate, the substrate comprising a substrate material;
- lithographically patterning the layer of the resist material to form a patterned resist layer, wherein the patterned resist layer has a pattern with a depth profile that varies over an area of the layer of resist material, the lithographic patterning comprising:
- exposing the layer of the resist material to an electron beam while varying an energy of the electron beam over the area in a pattern that corresponds to the depth profile to form an exposed resist layer;
- and
- selectively removing the exposed resist layer to form the patterned resist layer, wherein the patterned resist layer comprises a plurality of resist microstructures, wherein each resist microstructure comprises a plurality of resist facets, wherein each resist facet has a slope, and wherein the energy of the electron beam is varied in the exposing step so that the resist facets have predetermined different slopes, and
- using the patterned resist layer in an etching step to transfer the pattern of the patterned resist layer to the substrate, wherein the etching step involves exposing the patterned resist layer and the substrate to a plasma to form a pattern in the substrate, wherein the pattern in the substrate has a depth profile corresponding to the depth profile of the patterned resist layer, wherein the pattern in the substrate comprises a plurality of substrate microstructures, wherein each substrate microstructure has a plurality of substrate facets, wherein there is a one-to-one relationship between resist microstructures of the patterned resist layer and substrate microstructures of the substrate, wherein at least one of the substrate microstructures is less than 250 square microns in area and comprises at least 50 substrate facets.
3 more elements
A method for patterning a substrate, comprising:
- depositing a layer of resist material on a surface of the substrate, the substrate comprising a substrate material;
- lithographically patterning the layer of the resist material to provide a patterned resist layer having a pattern with a depth profile that varies over an area of the layer of resist material, the lithographic patterning comprising:
- exposing the layer of the resist material to an electron beam while varying an energy of the electron beam over the area in a pattern that corresponds to the depth profile to provide an exposed resist layer;
- and
- selectively removing the exposed resist layer to form the patterned resist layer, wherein the patterned resist layer comprises a plurality of resist microstructures, wherein each resist microstructure comprises a plurality of resist facets, wherein each resist facet has a slope, and wherein the energy of the electron beam is varied in the exposing step so that the resist facets have predetermined slopes;
- and
- using the patterned resist layer in an etching step to transfer the pattern of the patterned resist layer to the substrate, wherein the etching step involves exposing the patterned resist layer and the substrate to a plasma to form a pattern in the substrate, wherein the pattern in the substrate has a depth profile corresponding to the depth profile of the patterned resist layer, wherein the pattern in the substrate comprises a plurality of substrate microstructures, wherein each substrate microstructure has a plurality of substrate facets, wherein there is a one-to-one relationship between resist microstructures of the patterned resist layer and substrate microstructures of the substrate.
4 more elements
Dependencies are inferred from the claim text.