Multi-Layer Hardmask Patterning for IC Density
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Solution Overview
Problem
The increasing complexity of forming patterns with various shapes, sizes, and densities in integrated circuit devices poses challenges due to miniaturization, leading to process difficulties and reduced margins in manufacturing.
Innovation Solution
A method involving the formation of a hardmask structure with multiple layers on a substrate, followed by a one-time exposure process to create photoresist patterns, which are then transferred onto reversible and gap-fill hardmask layers to form island and line patterns, allowing for simultaneous patterning in areas with different densities using intaglio and embossed techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple exposure processes are used to form patterns with various shapes, sizes, and densities, then pattern formation capability is improved, but process complexity increases
Solution Approach 1:
The substrate is divided into multiple areas with different pattern densities, and each area is assigned a specific hardmask layer configuration. The hardmask structure includes a first hardmask layer for high-density areas and a second hardmask layer for low-density areas, allowing simultaneous formation of various patterns through a single exposure process while maintaining process simplicity
Solution Approach 2:
The hardmask structure is designed to serve multiple functions: the first hardmask layer handles high-density pattern formation, the second hardmask layer handles low-density pattern formation, and both layers work together in a single exposure process to achieve versatile pattern formation across different areas with varying requirements
2Area of moving object
If feature sizes are miniaturized to achieve down-scaling, then integration density is improved, but manufacturing precision deteriorates
Solution Approach 1:
Different hardmask layer configurations are applied to different areas based on their specific pattern density requirements. High-density areas use the first hardmask layer with optimized thickness and material properties, while low-density areas use the second hardmask layer, ensuring each area receives the optimal hardmask structure for its specific feature size and pattern complexity
Solution Approach 2:
The hardmask layer parameters such as thickness, material composition, and structural configuration are adjusted according to the pattern density of each area. This allows optimization of etching selectivity and pattern transfer fidelity for miniaturized features in high-density areas while maintaining manufacturability
3Adaptability or versatility
If various shapes and sizes of patterns are formed simultaneously, then design freedom is improved, but process difficulty increases
Solution Approach 1:
The substrate is segmented into multiple areas, each with optimized hardmask layer configurations suitable for their specific pattern requirements. This segmentation allows simultaneous formation of various shapes and sizes through a single exposure process while keeping the manufacturing process manageable by treating different areas with area-specific hardmask structures
Solution Approach 2:
The multi-layer hardmask structure is designed to universally handle various pattern types (island patterns, line patterns, contact holes, etc.) across different areas through a single exposure process, achieving design freedom without increasing process difficulty by using the same exposure step for all pattern types
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
This approach simplifies the process, reduces defects, and increases design freedom by enabling the formation of patterns with varying shapes and sizes across different areas without increasing process complexity, even when pattern densities and levels differ.
Implementation Method 1
By exposing and developing the photoresist layer, a photoresist pattern including a first photoresist pattern in the first area and a second photoresist pattern in the second area is formed
Data Source
AI summary
A hardmask structure including a plurality of hardmask layers is formed on a target layer in a first area and a second area, a first photoresist pattern in the first area and a second photoresist pattern in the second area are formed, a reversible hardmask pattern including a plurality of openings is formed by transferring shapes of the first and second photoresist patterns to a reversible hardmask layer that is one of the plurality of hardmask layers, a gap-fill hardmask pattern is formed by filling some of the plurality of openings formed in the first area with a gap-fill hardmask pattern material, and a feature pattern is formed in the target layer by transferring a shape of the gap-fill hardmask pattern to the target layer in the first area and a shape of the reversible hardmask pattern to the target layer in the second area.