Silylene Precursors for Low-Temperature Semiconductor Film Deposition
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Solution Overview
Problem
Current semiconductor fabrication processes face challenges in depositing high-purity silicon-based thin films at low temperatures, particularly below 400°C, due to the need for stable and reactive silicon precursors that can decompose cleanly and form homogeneous, conformal films, while maintaining thermal stability during handling and transport.
Innovation Solution
The use of silylene compounds, such as bis(N-t-amyl)ethylenediamine silylene and bis(N-i-propyl)-t-butyl-amidinate bis(trimethylsilyl)amido silylene, as silicon precursors in vapor deposition processes like CVD and ALD, which are volatile, chemically reactive, and thermally stable, allowing for low-temperature film growth and deposition of SiO2, Si3N4, and other silicon-containing films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional precursors like TEOS are used for vapor deposition, then high-purity SiO2 films can be deposited, but deposition temperatures must be maintained above 400°C
Solution Approach 1:
The patent changes the chemical parameters of the precursor molecule by introducing silylene compounds with specific functional groups (amido, alkoxo, halogen) that modify the decomposition temperature and reaction kinetics, enabling low-temperature deposition while maintaining film quality
Solution Approach 2:
The invention uses composite precursor molecules combining silicon centers with multiple ligand types (amido, alkoxo, halogen groups) that work synergistically to provide both thermal stability for handling and low-temperature reactivity for deposition
2Temperature
If the deposition temperature is reduced below 400°C, then low-temperature film formation is achieved, but precursor stability during handling and transport deteriorates
Solution Approach 1:
The patent adjusts the thermal stability parameter of the precursor by selecting ligands with appropriate bond strengths to silicon, creating a stability window that allows room-temperature handling while enabling low-temperature decomposition for deposition
Solution Approach 2:
The precursor is designed with pre-positioned labile groups (halogen, alkoxo) that are stable during handling but readily react at the deposition surface, separating the stability function from the reactivity function in different spatial and temporal contexts
3Ease of operation
If stable liquid precursors like TEOS are used, then ease of handling and transport is improved, but clean decomposition at low temperatures becomes difficult
Solution Approach 1:
The patent employs composite molecular structures where the silicon center is coordinated with multiple functional ligands that collectively provide liquid-state stability while enabling clean solid-film formation through controlled decomposition
Solution Approach 2:
The invention extracts the reactive functionality from the bulk precursor molecule by positioning labile groups (halogen, alkoxo) at the periphery, allowing these groups to decompose first and cleanly while the core structure maintains stability during handling
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 silylene precursors enable the formation of high-purity, conformal silicon-containing films at temperatures between 50°C and 200°C, ensuring process stability and achieving the desired film properties for microelectronic devices, including microprocessors and memory devices, while maintaining the amorphous character of hafnium or zirconium oxide materials during elevated temperature processing.
Implementation Method 1
chemical precursors are required that decompose cleanly to yield the desired films
Implementation Method 2
volatilizing a silicon precursor composition to produce corresponding precursor vapor, and contacting the precursor vapor with the substrate under vapor deposition conditions to form the silicon-containing film
Implementation Method 3
These compounds exhibit high volatility and chemical reactivity, but are stable with respect to thermal degradation at temperatures involved in volatilization of the precursor
Data Source
AI summary
A silicon precursor composition is described, including a silylene compound selected from among: silylene compounds of the formula: wherein each of R and R1 is independently selected from organo substituents; amidinate silylenes; and bis(amidinate) silylenes. The silylene compounds are usefully employed to form high purity, conformal silicon-containing films of SiO2, Si3N4, SiC and doped silicates in the manufacture of microelectronic device products, by vapor deposition processes such as CVD, pulsed CVD, ALD and pulsed plasma processes. In one implementation, such silicon precursors can be utilized in the presence of oxidant, to seal porosity in a substrate comprising porous silicon oxide by depositing silicon oxide in the porosity at low temperature, e.g., temperature in a range of from 50° C. to 200° C.