2D Material Hard Mask for High Aspect Ratio Etching
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Solution Overview
Problem
Current semiconductor manufacturing techniques face challenges in achieving precise vertical profiles and pattern formation due to the reduced size of semiconductor devices, leading to issues like pattern defects and difficulties with amorphous carbon layers as hard masks.
Innovation Solution
A two-dimensional material hard mask with a layered crystalline structure, composed of hydrogen, oxygen, and a 2D material layer, such as graphene, is developed, offering high etch resistance and selectivity, which is manufactured using chemical vapor deposition and doped with impurities to enhance its properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If amorphous carbon layer (ACL) is used as hard mask, then etch resistance is provided, but pattern precision and vertical profile formation deteriorate due to large aspect ratio
Solution Approach 1:
The patent changes the structural parameters of the carbon layer by creating a nanocrystalline structure with specific grain sizes (5-50 nm) and controlled hydrogen content (20-80 atomic %), transforming it from amorphous to nanocrystalline form. This parameter change improves etch resistance while maintaining pattern precision and enabling vertical profile formation, resolving the contradiction between etch resistance and pattern precision
Solution Approach 2:
The patent creates a composite structure by combining nanocrystalline carbon domains within the carbon layer, forming a composite material with specific grain boundaries and phases. This composite nanocrystalline structure provides enhanced etch resistance compared to amorphous carbon while maintaining the precision needed for vertical profile formation, thus resolving the technical contradiction
2Length of moving object
If photoresist film thickness is reduced to match reduced semiconductor device size, then exposure wavelength is reduced, but vertical profile formation becomes difficult
Solution Approach 1:
The patent introduces a nanocrystalline carbon hard mask layer as an intermediary between the photoresist and the underlying material layer. This intermediate layer with its specific nanocrystalline structure and controlled thickness provides the necessary etch resistance and profile control, enabling vertical profile formation even when the photoresist film thickness is reduced to match smaller device sizes
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 2D material hard mask enables the correct transfer of desired patterns to structures with large aspect ratios, improving etch resistance and selectivity, thus overcoming the limitations of traditional hard masks like amorphous carbon layers.
Implementation Method 1
depositing a hard mask material on the substrate by supplying a source gas into the material layer deposition apparatus
Data Source
AI summary
A 2D material hard mask includes hydrogen, oxygen, and a 2D material layer having a layered crystalline structure. The 2D material layer may be a material layer including one of a carbon structure (for example, a graphene sheet) and a non-carbon structure.