Resist Underlayer Composition for Etching Masking

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Solution Overview

Problem

The challenge in semiconductor manufacturing is to achieve higher integration with smaller line widths while preventing pattern collapse, which requires a thinner photoresist, but this can result in the photoresist being consumed during etching, failing to etch the substrate to the desired depth due to its thin lower layer of silicon acting as an inadequate mask.

Innovation Solution

A resist underlayer composition incorporating an organosilane condensation polymerization product derived from specific hydrolyzed compounds, including a solvent and additives, is used to form a dense underlayer with improved anti-reflection characteristics and etching selectivity, allowing for effective pattern transfer even with a thin photoresist.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the photoresist thickness is reduced to achieve smaller line widths and prevent pattern collapse, then the line width and pattern stability are improved, but the photoresist is entirely consumed during etching and the substrate cannot be etched to the desired depth

Engineering Contradiction:
Improveline width controlVSAvoidphotoresist thickness
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent divides the protective function into two separate layers: a thin photoresist layer for pattern definition and a thicker underlayer for etching protection. This segmentation allows the photoresist to be thin enough for precise patterning while the underlayer provides sufficient thickness to prevent complete consumption during etching, resolving the contradiction between line width control and photoresist durability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The underlayer acts as an intermediary between the thin photoresist and the substrate. It receives the pattern from the photoresist through partial etching and then protects the substrate during subsequent etching processes. The underlayer mediates the conflict by providing the necessary protective function without requiring the photoresist to be thick, thus maintaining both precise line width control and adequate etching protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If a thicker photoresist is used to prevent complete consumption during etching, then the substrate can be etched to desired depth, but the line width increases and pattern collapse risk increases

Engineering Contradiction:
Improvephotoresist thicknessVSAvoidline width control
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The protective function is segmented between the photoresist and underlayer. The photoresist maintains thin thickness for precise line width control, while the underlayer provides the additional thickness needed for etching protection. This eliminates the need to increase photoresist thickness while maintaining both precision and protection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The underlayer serves as an intermediary that provides the missing protective thickness without requiring the photoresist to be thicker. It enables the substrate to be etched to the desired depth while the thin photoresist maintains precise line width control, resolving the contradiction between thickness and precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the photoresist layer is made thin for higher integration, then the integration density is improved, but the lower layer of silicon acts as an inadequate mask and the etching process cannot achieve desired depth

Engineering Contradiction:
Improveintegration densityVSAvoidetching mask effectiveness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The masking function is segmented into two components: the thin photoresist for pattern definition and the underlayer for etching protection. This allows the photoresist to remain thin for high integration density while the underlayer provides sufficient masking effectiveness for complete substrate etching.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The underlayer acts as an intermediary masking layer that compensates for the insufficient thickness of the thin photoresist. It enables the etching process to achieve the desired depth by providing adequate protection to the substrate, while the thin photoresist maintains high integration density through precise patterning.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution enables the formation of a dense underlayer with enhanced etching resistance against oxygen plasma and improved storage stability, allowing for successful pattern transfer and etching of the substrate without consuming the photoresist, thus addressing the issue of pattern collapse and achieving desired integration.

Implementation Method 1

an organosilane condensation polymerization product of hydrolyzed products produced from a compound represented by Chemical Formula 1, a compound represented by Chemical Formula 2, and a compound represented by Chemical Formula 3

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

an organosilane condensation polymerization product of hydrolyzed products

Methodology Applied
Scientific EffectCondensation polymerization:

Data Source

PatentUS8841218B2Resist underlayer composition and process of producing integrated circuit devices using same
Publication Date: 2014.09.23 CHEIL INDUSTRIES INC

AI summary

A resist underlayer composition, including a solvent, and an organosilane condensation polymerization product of hydrolyzed products produced from a compound represented by Chemical Formula 1, a compound represented by Chemical Formula 2, and a compound represented by Chemical Formula 3.