Silicon-Metal Hardmask Composition for Thin High-Selectivity Patterning
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Solution Overview
Problem
Conventional hardmask materials face limitations in selectivity and transparency as device sizes shrink, requiring thicker films for vertical structures, which can affect patterning uniformity and etching processes in semiconductor fabrication.
Innovation Solution
The development of silicon-and-metal-containing hardmask materials, formed using deposition precursors like silicon tetrafluoride and metal-containing precursors such as tungsten hexafluoride, with controlled flow rates and plasma power to achieve a metal concentration of greater than 20 at.%, allowing for improved etching selectivity and structural formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional hardmask materials are used, then etching selectivity is limited, but reducing film thickness improves patterning uniformity
Solution Approach 1:
The patent applies composite materials by combining silicon and metal (e.g., tungsten, molybdenum, cobalt, tantalum, ruthenium, titanium, rhenium, hafnium, or zirconium) to form a silicon-and-metal-containing hardmask material. This composite structure provides both the thickness reduction needed for patterning uniformity and the enhanced etching selectivity required for reliable fabrication, resolving the contradiction between these two parameters.
2Reliability
If thicker hardmask films are used to improve etching selectivity, then vertical structure formation is improved, but patterning uniformity deteriorates
Solution Approach 1:
The silicon-and-metal composite material enables the hardmask to maintain high etching selectivity while being used at reduced thicknesses. The metal component enhances the material's interaction with etching chemistry, allowing selective removal of the hardmask after it has served its protective function, thereby resolving the contradiction between selectivity and patterning uniformity.
Solution Approach 2:
The patent changes the chemical composition parameters of the hardmask material by incorporating metals at concentrations greater than or about 20 at.%. This parameter change fundamentally alters the material's etching behavior and physical properties, enabling it to achieve both high selectivity and good patterning uniformity at optimized thicknesses.
3Illumination intensity
If hardmask transparency is improved for better structure development, then etching selectivity decreases
Solution Approach 1:
The silicon-and-metal composite material provides a new degree of freedom in balancing optical and chemical properties. The metal component enhances etching selectivity through improved chemical interaction, while the silicon base maintains appropriate optical transparency, allowing the hardmask to fulfill both optical and chemical functions simultaneously without compromise.
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
These materials provide enhanced etching selectivity and structural formation capabilities, enabling reduced thickness hardmasks with improved transparency and hardness, facilitating the fabrication of complex semiconductor structures like taller capacitor structures in DRAM nodes.
Implementation Method 1
generating plasma effluents of the deposition precursors
Implementation Method 2
generating plasma effluents of the deposition precursors. The methods may include forming a layer of silicon-and-metal-containing material on the substrate
Data Source
AI summary
Exemplary methods of semiconductor processing may include providing deposition precursors to a processing region of a semiconductor processing chamber. The deposition precursors may include a silicon-and-halogen-containing precursor and a metal-containing precursor. A substrate may be housed within the processing region. The methods may include generating plasma effluents of the deposition precursors. The methods may include forming a layer of silicon-and-metal-containing material on the substrate.