US-12625423-B2 - Structured film and method of using same to form a pattern on a substrate

Abstract

A structured film for forming a pattern on a substrate includes a polymeric support layer, an adhesive layer, an etch resist layer disposed between the polymeric support layer and the adhesive layer, a structured resin layer disposed between the polymeric support layer and the etch resist layer, and one or more unstructured layers disposed between the etch resist layer and the adhesive layer. The structured resin layer has a structured major surface including a plurality of engineered structures. The etch resist layer at least partially fills spaces between adjacent engineered structures to substantially planarize the structured major surface. Methods of using the structured film to form a pattern on a substrate are described.

Inventors

• Martin B. Wolk
• Karl K. Stensvad
• Steven D. Theiss
• Robert L. Brott
• Kevin W. Gotrik
• Christopher S. Lyons
• Caleb T. Nelson
• Vadim Savvateev
• James M. Nelson
• Craig R. Schardt
• Jeffrey L. Solomon

Assignees

• 3M INNOVATIVE PROPERTIES COMPANY

Dates

Publication Date

20260512

Application Date

20211215

Claims (8)

1. 1 . A structured film for forming a pattern on a substrate, the structured film comprising: a polymeric support layer; an adhesive layer; an etch resist layer disposed between the polymeric support layer and the adhesive layer; a structured resin layer disposed between the polymeric support layer and the etch resist layer, the structured resin layer comprising a structured major surface comprising a plurality of engineered structures, the etch resist layer at least partially filling spaces between adjacent engineered structures to substantially planarize the structured major surface; and a dynamic separating layer disposed between the structured resin layer and the polymeric support layer; and one or more unstructured layers having a total thickness of less than 10 microns and disposed between the etch resist layer and the adhesive layer.
2. 2 . The structured film of claim 1 , wherein the structured resin layer is permanently attached the etch resist layer.
3. 3 . The structured film of claim 1 , wherein the dynamic separating layer comprises a light-to-heat conversion layer.
4. 4 . The structured film of claim 1 , wherein the etch resist layer comprises a residual layer between a substantially unstructured major surface of the etch resist layer and the plurality of engineered structures, a ratio of an average thickness of the residual layer to an average height of plurality of engineered structures being less than 1.
5. 5 . The structured film of claim 1 , wherein the plurality of engineered structures comprises at least two different heights.
6. 6 . The structured film of claim 1 , wherein the plurality of engineered structures comprises a plurality of nanostructures.
7. 7 . The structured film of claim 1 , wherein the one or more unstructured layers comprises at least two unstructured layers.
8. 8 . The structured film of claim 1 further comprising an additional polymeric layer disposed between the dynamic separating layer and the structured resin layer, wherein the dynamic separating layer is adapted to be releasably attached to the additional polymeric layer upon activation.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a national stage filing under 35 U.S.C. 371 of PCT/IB2021/061796, filed Dec. 15, 2021, which claims the benefit of U.S. Application No. 63/127,678, filed Dec. 18, 2020, the disclosures of which are incorporated by reference in their entirety herein. BACKGROUND Structured articles, such as nanostructured articles, are useful for a variety of applications, including optical applications such as optical metasurface applications. SUMMARY The present description relates generally to structured films that can be used for forming a pattern on a substrate, to methods of forming a pattern on a substrate using a structured film, and to articles including a structured film disposed on a substrate. In some aspects of the present description, a structured film for forming a pattern on a substrate is provided. The structured film includes a polymeric support layer, an adhesive layer, an etch resist layer disposed between the polymeric support layer and the adhesive layer, a structured resin layer disposed between the polymeric support layer and the etch resist layer, and one or more unstructured layers having a total thickness of less than 10 microns and disposed between the etch resist layer and the adhesive layer. The structured resin layer has a structured major surface including a plurality of engineered structures. The etch resist layer at least partially fills spaces between adjacent engineered structures to substantially planarize the structured major surface. In some aspects of the present description, a method of forming a pattern on a substrate is provided. The method can utilize a structured film including a polymeric support layer, one or more unstructured layers, an etch resist layer disposed between the polymeric support layer and the one or more unstructured layers, and a structured resin layer disposed between the polymeric support layer and the etch resist layer. The structured resin layer has a structured major surface including a plurality of engineered structures. The etch resist layer at least partially fills spaces between adjacent engineered structures to substantially planarize the structured major surface and to define an etch resist pattern. The method includes, in sequence, providing the structured film, bonding the structured film to the substrate with the polymeric support layer facing away from the substrate, removing at least the polymeric support layer leaving at least the etch resist layer and the one or more unstructured layers disposed on the substrate, and etching into the one or more unstructured layers to transfer the etch resist pattern to the one or more unstructured layers thereby forming the pattern on the substrate. In some aspects of the present description, an optical article is provided. The optical article includes a substrate, an optically transparent etch stop layer disposed on the substrate, and a structured film disposed on the etch stop layer. The structured film includes one or more patterned layers and an adhesive layer bonding the one or more patterned layers to the etch stop layer. The structured film includes a plurality of structures defining a plurality of gaps separating adjacent structures. At least some of the gaps extend through the structured film to the etch stop layer. In some aspects of the present description, an optical article including a waveguide and a structured film disposed on the waveguide is provided. The structured film includes an optical bonding layer bonding the structured film to the waveguide, one or more patterned layers disposed on the optical bonding layer, and an etch stop layer disposed between the one or more patterned layers and the optical bonding layer. The one or more patterned layers are formed by patterning one or more unstructured layers where the one or more unstructured layers have an optical transmittance for substantially normally incident light of at least 50% for at least a first wavelength W1 in a range of 400 nm to 2500 nm. The etch stop layer has an optical transmittance for substantially normally incident light of at least 50% for at least the first wavelength W1. The optical bonding layer has a refractive index having an imaginary part less than 0.01 for at least the first wavelength W1 and has an average thickness greater than 5 nm and less than ¼ W1. These and other aspects will be apparent from the following detailed description. In no event, however, should this brief summary be construed to limit the claimable subject matter. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A-1B are schematic cross-sectional views of structured films, according to some embodiments. FIG. 1C is a schematic illustration of a method of making the structured film of FIG. 1A. FIGS. 2A-2B schematically illustrate methods of forming a pattern on a substrate. FIGS. 3A-3C are schematic cross-sectional views of articles that can be formed using a structured film, according to some embodi