Antireflective Coating Composition for Lithography
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Solution Overview
Problem
In microlithography, existing antireflective coatings do not provide sufficient dry etch resistance and intermixing issues with photoresists, limiting the resolution and aspect ratio in deep and extreme ultraviolet imaging processes.
Innovation Solution
A crosslinkable polymer with a fused aromatic moiety, phenylene moiety, and hydroxybiphenyl unit, capable of self-crosslinking, is used as an antireflective coating composition to form a high carbon content layer that prevents intermixing and enhances etch resistance, allowing for high-resolution image transfer and reduced reflections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional antireflective coatings are used, then reflections are reduced, but dry etch resistance is insufficient
Solution Approach 1:
The patent employs a composite material system consisting of a silicon-containing antireflective coating layer combined with an organic mask layer containing crosslinkable polymer. This composite structure provides both the reflection reduction properties of silicon-based coatings and the enhanced dry etch resistance of carbon-rich organic materials, resolving the contradiction between reducing reflections and maintaining etch resistance.
Solution Approach 2:
The patent modifies the chemical composition parameters of the antireflective coating by incorporating crosslinkable polymer units with specific functional groups (epoxy, oxetane, orthoester) and silicon-containing moieties. By controlling the crosslinking density and carbon content through parameter adjustment, the coating achieves simultaneously low reflectivity and high dry etch resistance.
2Manufacturing precision
If photoresist sensitivity is increased for miniaturization, then imaging capability improves, but intermixing between layers occurs
Solution Approach 1:
The patent applies a preliminary protective action by forming a crosslinked organic mask layer beneath the photoresist before imaging. This pre-formed barrier layer prevents intermixing between the photoresist and underlying layers during subsequent processing steps, while still allowing high-resolution image formation through the use of advanced crosslinking chemistry.
Solution Approach 2:
The crosslinkable polymer layer acts as an intermediary between the photoresist and the silicon-containing antireflective coating. This intermediate layer with controlled carbon content and crosslinking density serves as a diffusion barrier that prevents intermixing while maintaining the imaging performance needed for miniaturization.
3Manufacturing precision
If multiple antireflective layers are used to improve performance, then lithographic performance increases, but device complexity increases
Solution Approach 1:
The patent creates a multi-functional organic mask layer that simultaneously serves as an antireflective coating, a dry etch resistance layer, and a barrier against intermixing. By combining multiple functions into a single crosslinkable polymer formulation, the patent achieves high lithographic performance without proportionally increasing structural complexity.
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 novel antireflective coating composition ensures high-resolution image transfer with high aspect ratios and reduced reflections, maintaining a high carbon content even after baking, thereby improving lithographic performance and preventing intermixing with the photoresist layer.
Implementation Method 1
a crosslinkable polymer which comprises at least one unit of formula (1), at least one unit with a phenylene group in the backbone of the polymer, at least one hydroxybiphenyl unit, and a crosslinking moiety of structure (4)
Implementation Method 2
Absorbing antireflective coatings and underlayers in photolithography are used to diminish problems that result from back reflection of light from highly reflective substrates
Data Source
AI summary
The invention relates to an antireflective coating composition comprising a crosslinkable polymer, where the crosslinkable polymer comprises at least one unit of fused aromatic moiety, at least one unit with a phenylene moiety in the backbone of the polymer, and at least one hydroxybiphenyl unit, furthermore where the polymer comprises a crosslinking moiety of structure (4),where R′3, R″3 and R′″3 are independently hydrogen or a C1-C4alkyl. The invention further relates to a process for forming an image using the composition.