Amorphous Solid Water Condensate for Electron Beam Lithography

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Solution Overview

Problem

Conventional electron beam lithography processes often damage or contaminate fragile nanoscale structures like carbon nanotubes and graphene due to the use of organic photoresists, which are incompatible with these materials and can obscure their intrinsic electrical properties.

Innovation Solution

A method using a vapor-deposited amorphous solid water condensate layer as a protective coating and resist for electron beam imaging and lithography, allowing non-destructive imaging and patterning of substrates while preventing contamination and residue formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional organic photoresist is used in electron beam lithography, then lithographic patterning can be achieved, but the fragile nanoscale structures are damaged or contaminated and their intrinsic electrical properties are obscured

Engineering Contradiction:

Improvelithographic patterningVSAvoidcontamination and damage to nanoscale structures

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary substance - a layer of amorphous solid water (ice) - that is deposited on the nanoscale structures before electron beam lithography. This ice layer acts as a protective mediator that prevents direct interaction between the electron beam/organic photoresist and the fragile structures, thereby eliminating contamination and damage while allowing lithographic patterning to proceed

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates an inert environment by coating the nanoscale structures with amorphous solid water, which is chemically inert and non-reactive with organic photoresists. This inert coating layer provides a protective atmosphere that isolates the sensitive structures from harmful interactions during the lithographic process

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

2Measurement precision

If electron beam mapping is performed on surface topology prior to patterning, then reference points for patterning are provided, but the features and topology on the surface are damaged or destroyed

Engineering Contradiction:

Improvesurface topology mappingVSAvoiddamage to features and topology

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by depositing the amorphous solid water layer on the nanoscale structures before any electron beam mapping or patterning operations. This pre-deposited protective layer remains in place during mapping, allowing high-resolution surface topology imaging to be performed without damaging the underlying features, and the same layer continues to protect during subsequent patterning

Inventive Principle:

Principle #10Preliminary action

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 high-resolution, contamination-free imaging and patterning of nanoscale structures, maintaining their native characteristics and facilitating the production of devices with improved electrical properties.

Implementation Method 1

a vapor is condensed to an amorphous solid water condensate layer on a surface of a solid state substrate

Methodology Applied

Scientific EffectCondensation: Condensation

Implementation Method 2

an image of at least a portion of the substrate surface is produced by scanning an electron beam along the substrate surface through the water condensate layer

Methodology Applied

Scientific EffectElectron beam imaging: Electron Beam

Data Source

PatentUS8790863B2Electron beam processing with condensed ice

Publication Date: 2014.07.29 PRESIDENT & FELLOWS OF HARVARD COLLEGE

AI summary

In a method for imaging a solid state substrate, a vapor is condensed to an amorphous solid water condensate layer on a surface of a solid state substrate. Then an image of at least a portion of the substrate surface is produced by scanning an electron beam along the substrate surface through the water condensate layer. The water condensate layer integrity is maintained during electron beam scanning to prevent electron-beam contamination from reaching the substrate during electron beam scanning. Then one or more regions of the layer can be locally removed by directing an electron beam at the regions. A material layer can be deposited on top of the water condensate layer and any substrate surface exposed at the one or more regions, and the water condensate layer and regions of the material layer on top of the layer can be removed, leaving a patterned material layer on the substrate.