Selective Chemical Etching of Resist Layers for Nanostructure Patterning

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Solution Overview

Problem

Existing fabrication methods for nanostructures face challenges in achieving high performance and large-scale production while integrating heterogeneous materials and device types, with limitations in device speeds, precision, and throughput due to physicochemical processes that are incommensurate with the requirements of advanced technologies like wireless smart dust and embedded computers.

Innovation Solution

A chemical etching method using bottom-up masking with resist application, where a chemical etchant selectively removes portions of a resist layer based on the properties of the underlying base layer materials, allowing for the manufacture of semiconductor nanostructures without photolithography.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If photolithography is used for patterning, then manufacturing precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improvepatterning precisionVSAvoidprocess complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the photolithography step from the fabrication process entirely. Instead of using photolithography for patterning, the invention employs direct chemical etching methods that achieve the desired patterning without this intermediate step, thereby reducing process complexity while maintaining manufacturing precision

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/optical system of photolithography with a chemical etching system. By using chemical reactions to directly pattern the structures, the process eliminates the need for photomasks, aligners, and other photolithography equipment, reducing both device complexity and cost

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If wafer-based methods are used, then manufacturing precision is improved, but productivity is reduced

Engineering Contradiction:

Improvefabrication precisionVSAvoidmanufacturing throughput

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent inverts the conventional wafer-based top-down approach by employing bottom-up chemical etching methods. This inversion allows for parallel processing of multiple structures simultaneously in solution, dramatically increasing productivity while maintaining the precision needed for nanostructure fabrication through controlled chemical reactions

Inventive Principle:

Principle #13The other way round (Inversion)

3Adaptability or versatility

If heterogeneous materials are integrated, then adaptability is improved, but manufacturing precision deteriorates

Engineering Contradiction:

Improvematerial integration capabilityVSAvoidintegration precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by using selective chemical etching that responds to local material properties. Different materials in the heterogeneous structure exhibit different etching rates or responses to the chemical etchant, allowing precise differentiation and patterning of each material type. This enables accurate integration of heterogeneous materials by exploiting their intrinsic chemical differences to achieve self-directed patterning with high precision

Inventive Principle:

Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables the seamless integration and interconnection of heterogeneous materials, simplifies the manufacturing process, and reduces costs by eliminating the need for photolithography, thereby facilitating the production of high-performance nanostructures at a large scale.

Implementation Method 1

the first chemical etchant migrates through the first portion of the resist layer to react with the first material of the first section of the base layer and removes the first portion of the resist layer

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

the first chemical etchant migrates through the first portion of the resist layer to react with the first material

Methodology Applied

Scientific EffectDiffusion: Diffusion

Data Source

PatentUS12402340B2Chemical etching methods for fabricating nanostructures

Publication Date: 2025.08.26 GEORGIA TECH RES CORP

AI summary

A method of chemically etching, comprising: providing a base layer, the base layer comprising a first section and a second section, the first section comprising a first material, the second section comprising a second material; providing a resist layer, wherein a first portion of the resist layer covers at least a portion of the first section of the base layer, and wherein a second portion of the resist layer covers at least a portion of the second section of the base layer; and exposing the first and second portions of the resist layer to a first chemical etchant, such that the first chemical etchant migrates through the first portion of the resist layer to react with the first material of the first section of the base layer and removes the first portion of the resist layer, and such that the second portion of the resist layer is not removed.