Amorphous Boron Nitride Hard Mask for High-Aspect-Ratio Patterning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge of accurately forming ultra-fine patterns with high aspect ratios in semiconductor devices using conventional lithography methods is addressed by employing a hard mask with higher etch selectivity than photoresist.
Innovation Solution
A hard mask comprising an amorphous boron nitride film is used, which has a specific composition and structural properties such as an sp3 hybrid bond ratio less than 20%, a density of 1.8 g/cm3 or more, and a dielectric constant of 2.5 or less, enabling precise patterning through dry etching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional lithography method using photoresist is used, then the process is simple and easy to manufacture, but it is difficult to accurately form ultra-fine patterns of high aspect ratio
Solution Approach 1:
The patent employs a composite material system consisting of amorphous boron nitride film combined with photoresist layer. The amorphous boron nitride provides high etch selectivity and mechanical stability for precise ultra-fine patterning, while the photoresist layer enables conventional lithography processes. This composite approach allows achieving high patterning precision for high aspect ratio structures while maintaining compatibility with existing manufacturing processes.
Solution Approach 2:
The patent utilizes dry etching processes with carefully controlled parameters including gas composition, pressure, and power settings to achieve selective removal of amorphous boron nitride film. By optimizing etching parameters such as using CF4 or SF6 based gases with specific pressure ranges (1-100 mTorr) and power levels, the process achieves high aspect ratio patterning precision while maintaining ease of manufacture through standardized process control.
2Strength
If amorphous boron nitride film with high sp3 hybrid bond ratio is used, then the film has higher hardness and strength, but the etch selectivity decreases
Solution Approach 1:
The patent precisely controls the sp3 hybrid bond ratio parameter of amorphous boron nitride film to be within 10-20%, optimizing the balance between film strength and etch selectivity. This parameter optimization ensures the film has sufficient mechanical strength to maintain pattern integrity during high aspect ratio formation, while maintaining high etch selectivity for precise patterning. The controlled sp3 ratio also enables good adhesion to underlying layers.
Solution Approach 2:
The patent creates different structural properties within the amorphous boron nitride film by controlling local bonding characteristics. The film exhibits regions with varying sp3/sp2 hybrid bond ratios, where the overall sp3 content is maintained at 10-20% for optimal etch selectivity, while local structural variations provide necessary mechanical strength and adhesion properties for the specific patterning application.
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 amorphous boron nitride film provides excellent etch selectivity and mechanical characteristics, allowing for the uniform and precise implementation of high aspect ratio patterns without deformation, while maintaining transparency and adhesion to other layers.
Implementation Method 1
a hard mask having a higher etch selectivity than photoresist may be used
Implementation Method 2
the amorphous boron nitride film may be formed on the substrate by a deposition process or a coating process
Data Source
AI summary
Provided are a hard mask including an amorphous boron nitride film and a method of fabricating the hard mask, and a patterning method using the hard mask. The hard mask is provided on a substrate and used for a process of patterning the substrate, and the hard mask includes an amorphous boron nitride film.