Chemical Amplification Resist for Ultrafine Pattern Formation

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Solution Overview

Problem

Conventional chemical amplification resist compositions for electron beam lithography face challenges in forming ultrafine patterns with low line width roughness (LWR) and high sensitivity, particularly in nanoimprint processes, due to the proximity effect and limitations in pattern transfer accuracy.

Innovation Solution

A chemical amplification resist composition is developed, incorporating a resin with acid-decomposable groups and an acid generator, which increases solubility in alkali developers upon irradiation, allowing for improved pattern formation and etching treatment as a mask for nanoimprint processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional chemical amplification resist composition is used for electron beam lithography, then the process is simple and well-established, but the line width roughness is high and sensitivity is insufficient for ultrafine patterns

Engineering Contradiction:

Improveline width roughnessVSAvoidsensitivity

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent modifies the chemical parameters of the resist composition by incorporating specific resin components with acid-decomposable groups and optimizing the acid generator concentration. This changes the chemical amplification mechanism to achieve lower line width roughness while maintaining high sensitivity for ultrafine pattern formation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite resist composition by combining multiple resin components (including those with acid-decomposable groups) and acid generators in specific ratios. This composite approach synergistically improves both the line width roughness and sensitivity, enabling successful ultrafine pattern formation that neither component could achieve alone

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If electron beam scanning is performed in the r-θ direction on a discotic substrate to prepare mold structural body, then the mold can be formed for information recording medium, but the proximity effect causes formation of latent image in unirradiated portions

Engineering Contradiction:

Improvemold preparation capabilityVSAvoidpattern accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent converts the proximity effect, which normally causes unwanted latent images, into a beneficial by enhancing the chemical amplification mechanism. The acid-decomposable groups and optimized acid generator create a more localized and controlled chemical reaction that actually reduces the harmful scattering effects, allowing accurate pattern transfer even in r-θ scanning mode

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the chemical parameters of the resist to be more responsive to localized acid generation, which counteracts the electron scattering effects. By optimizing the resin structure and acid generator concentration, the resist becomes less susceptible to proximity effect while maintaining high sensitivity for the desired pattern formation

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If mask pattern with approximately double size is prepared for lithography application, then the process allows reduction exposure and is practical, but the nanoimprint process requires pattern transfer at same magnification with 20 nm line width

Engineering Contradiction:

Improvelithography application flexibilityVSAvoidpattern size accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent optimizes the resist composition parameters specifically for high-resolution direct pattern transfer at 1:1 magnification. By adjusting the resin molecular weight, acid-decomposable group density, and acid generator concentration, the resist achieves the sensitivity and resolution required for 20 nm line width patterns without requiring reduction exposure

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent enhances the local chemical response of the resist by incorporating acid-decomposable groups that create highly localized solubility changes upon acid generation. This local quality enhancement allows precise pattern definition at the intended size, enabling direct 1:1 pattern transfer for nanoimprint while maintaining the flexibility to adapt to different pattern requirements

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

The composition achieves enhanced sensitivity and resolution, reducing line width roughness and improving pattern transfer accuracy, enabling the formation of precise semiconductor microcircuits and information recording media.

Implementation Method 1

a compound (B) capable of generating an acid upon irradiation with an actinic ray or radiation

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

a resin (A) capable of decomposing by an action of an acid to increase a solubility of the resin (A) in an alkali developer

Methodology Applied

Scientific EffectChemical decomposition: Decomposition (biological)

Data Source

PatentUS9090722B2Chemical amplification resist composition, and mold preparation method and resist film using the same

Publication Date: 2015.07.28 FUJIFILM CORP

AI summary

A chemical amplification resist composition that is used for preparation of a mold, and a mold preparation method and a resist film each using the composition are provided.