Hardmask Composition for Fine Pattern Etch Resistance

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Solution Overview

Problem

Current lithographic techniques face challenges in forming fine patterns with desirable profiles, especially as pattern sizes decrease, leading to difficulties in achieving effective etch resistance and gap-fill characteristics in semiconductor manufacturing.

Innovation Solution

A hardmask composition comprising a monomer with a specific aromatic ring-containing polymer and solvent, applied using a spin-on-coating method, which forms a hardmask layer that provides improved etch resistance, gap-fill characteristics, and planarization, enabling the formation of fine patterns with reduced voids and minimal out-gas generation at high temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a photoresist layer is directly used for etching material layers, then the process is simple, but etch resistance is insufficient for fine patterns

Engineering Contradiction:

Improveetch resistanceVSAvoidlayer structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the single photoresist layer into two separate functional layers: a photoresist layer for pattern formation and a hardmask layer for etching protection. This segmentation allows each layer to be optimized for its specific function, with the hardmask layer providing enhanced etch resistance for fine patterns while the photoresist layer maintains pattern fidelity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The hardmask layer serves as an intermediary layer between the photoresist layer and the material layer. It transfers the pattern from the photoresist to the material layer while providing the necessary etch resistance, acting as a mediator that enables fine pattern etching without requiring the photoresist to directly contact the material layer.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If conventional hardmask materials are used, then etch resistance is improved, but gap-fill characteristics and planarization are degraded

Engineering Contradiction:

Improveetch resistanceVSAvoidgap-fill characteristics

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent modifies the chemical composition parameters of the hardmask layer by incorporating specific compounds (e.g., silane-based compounds, titanium-based compounds) with controlled concentrations. These parameter changes enable the hardmask layer to achieve both high etch resistance and improved gap-fill characteristics by adjusting the molecular structure and cross-linking density of the material.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The hardmask layer is formulated as a composite material containing multiple components: a base polymer matrix, cross-linking agents (silane or titanium-based compounds), and potentially fillers. This composite structure combines the advantages of different materials to achieve simultaneous improvement in etch resistance, gap-fill characteristics, and planarization.

Inventive Principle:

Principle #40Composite materials

3Manufacturing precision

If high aspect ratio patterns are formed, then fine pattern resolution is achieved, but void formation increases

Engineering Contradiction:

Improvepattern resolutionVSAvoidvoid formation

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent adjusts the viscosity and molecular weight parameters of the hardmask composition to optimize flow characteristics during deposition. Lower viscosity formulations enable better penetration into high aspect ratio structures, filling gaps and reducing void formation while maintaining fine pattern resolution. The cross-linking density is also tuned to balance structural integrity with void prevention.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The hardmask layer is applied and cured before the etching process, creating a pre-formed protective structure that prevents void formation during subsequent processing. The preliminary cross-linking and structural stabilization of the hardmask layer ensure that high aspect ratio patterns maintain their integrity throughout the etching process without developing voids.

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

The hardmask composition effectively transfers fine photoresist patterns to material layers, offering enhanced chemical resistance, heat resistance, and etch resistance, while maintaining planarization and gap-fill capabilities, suitable for advanced semiconductor processes like dual damascene techniques.

Implementation Method 1

applied using a spin-on-coating method, which forms a hardmask layer

Methodology Applied

Scientific EffectSpin coating: Spin Coating

Implementation Method 2

selectively removing the hardmask layer using the resist pattern to expose a part of the material layer, and etching an exposed part of the material layer

Methodology Applied

Scientific EffectEtch resistance: