Boron-Carbon Hardmask Deposition for High-Selectivity Etching
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Solution Overview
Problem
Current hardmask materials lack the desired etch selectivity for pattern transfer in integrated circuit manufacturing as critical dimensions decrease, leading to insufficient protection of underlying material layers during etching.
Innovation Solution
Deposition of boron-carbon films with controlled precursor ratios of hydrocarbon and boron-containing gases using RF plasma, resulting in high etch selectivity and mechanical strength for advanced integrated circuit fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hardmask materials are used for pattern transfer, then the manufacturing process is simple, but the etch selectivity is insufficient leading to consumption of the mask and damage to underlying layers
Solution Approach 1:
The patent changes the compositional parameters of the hardmask material by incorporating boron into the carbon matrix, creating boron-carbon films with specific atomic percentages (35-95% boron). This compositional parameter change fundamentally improves etch selectivity while maintaining process compatibility with existing manufacturing equipment and procedures.
Solution Approach 2:
The patent creates a composite material system combining boron and carbon in specific ratios to form boron-carbon films. This composite approach leverages the beneficial properties of both elements: carbon provides structural integrity and the boron enhances etch resistance, achieving superior etch selectivity that neither material could provide alone.
2Manufacturing precision
If the thickness of the energy sensitive resist is reduced to control pattern resolution, then the pattern resolution is improved, but the mask becomes insufficient to protect underlying material layers during etching
Solution Approach 1:
The boron-carbon film serves as an intermediate hardmask layer between the thin energy sensitive resist and the underlying material layers. This intermediary layer provides the necessary etch resistance and protection, allowing the use of thinner resist layers for improved pattern resolution without compromising the protection of underlying layers during etching.
Solution Approach 2:
By changing the material parameters of the hardmask to boron-carbon composition with controlled atomic percentages, the patent achieves high etch selectivity that enables thinner resist layers to be used effectively. The boron-carbon film's superior etch resistance compensates for the reduced thickness of the overlying resist layer.
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 boron-carbon films provide improved etch selectivity and mechanical robustness, enabling the fabrication of high aspect-ratio features and smaller dimension devices without requiring significant changes to existing manufacturing processes.
Implementation Method 1
generating a radio frequency (RF) plasma in the processing volume to deposit a boron-carbon film on the substrate
Implementation Method 2
generating a radio frequency (RF) plasma in the processing volume to deposit a boron-carbon film on the substrate
Implementation Method 3
exposing the substrate positioned in a processing volume of a processing chamber to a hydrocarbon-containing gas mixture, exposing the substrate to a boron-containing gas mixture, and generating a radio frequency (RF) plasma in the processing volume to deposit a boron-carbon film on the substrate
Data Source
AI summary
Embodiments of the present disclosure generally relate to a method of processing a substrate. The method includes exposing the substrate positioned in a processing volume of a processing chamber to a hydrocarbon-containing gas mixture, exposing the substrate to a boron-containing gas mixture, and generating a radio frequency (RF) plasma in the processing volume to deposit a boron-carbon film on the substrate. The hydrocarbon-containing gas mixture and the boron-containing gas mixture are flowed into the processing volume at a precursor ratio of (boron-containing gas mixture/((boron-containing gas mixture)+hydrocarbon-containing gas mixture) of about 0.38 to about 0.85. The boron-carbon hardmask film provides high modulus, etch selectivity, and stress for high aspect-ratio features (e.g., 10:1 or above) and smaller dimension devices (e.g., 7 nm node or below).