Electron-Enhanced Silicon Deposition at Positive Substrate Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing film deposition methods in the semiconductor industry face challenges such as high thermal budgets, substrate damage, equipment complexity, contamination, and selectivity issues, particularly in plasma-assisted processes, which hinder efficient and high-quality film growth.
Innovation Solution
Electron-enhanced chemical vapor deposition (EE-CVD) using electrons to activate gas-phase species near the substrate surface, enabling film deposition at lower temperatures without plasma or corrosive gases, utilizing hydride precursors like Si2H6 and reactive background gases like H2, with a positive substrate voltage to enhance deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If thermal processes are used for film deposition, then conformal film growth is achieved, but elevated deposition temperatures are required which are unsuitable for applications with stringent thermal constraints
Solution Approach 1:
The patent replaces thermal energy (mechanical/thermal system) with electron beam energy (electromagnetic system) to drive the deposition process. Electrons with specific energies (5-50 eV) activate precursor molecules through electron-stimulated desorption and dissociation, enabling film growth at room temperature or below while maintaining conformal coverage through controlled electron-precursor interactions across the substrate surface
Solution Approach 2:
The patent fundamentally changes the energy activation parameter from thermal energy (temperature) to electron beam energy (electron flux and energy distribution). By controlling electron energy, flux density, and precursor partial pressure, the process achieves deposition at temperatures where thermal processes fail, while the electron-stimulated reactions maintain the conformal growth characteristic through uniform surface activation
2Temperature
If plasma-assisted processes are used for film deposition, then high-quality films are deposited at lower substrate temperatures, but substrate damage, equipment complexity, contamination, and selectivity issues occur
Solution Approach 1:
The patent extracts and eliminates the plasma component from the deposition system, retaining only the electron beam as the activation source. By using a conventional electron gun instead of a plasma source, the process achieves low-temperature deposition without generating the ion bombardment, radical chemistry, and equipment complexity associated with plasma, thereby preventing substrate damage while maintaining low operating temperatures
Solution Approach 2:
The patent introduces electrons as an intermediary species that mediates the energy transfer from the electron beam to the precursor molecules. Electrons with 5-50 eV energies act as intermediaries that stimulate desorption and dissociation of precursors without requiring plasma, enabling controlled chemical reactions at low temperatures while avoiding the harmful effects of ionized plasma environments on the substrate
3Temperature
If plasma-assisted processes are used for film deposition, then high-quality films are deposited at lower substrate temperatures, but equipment complexity increases
Solution Approach 1:
The patent extracts the plasma generation system from the deposition equipment, replacing it with a conventional electron gun that is already standard in many semiconductor fabrication tools. This eliminates the need for radio frequency generators, matching networks, and plasma source components, significantly reducing equipment complexity while maintaining the ability to deposit at low temperatures through electron beam activation
4Manufacturing precision
If electron-enhanced deposition processes are used, then high-quality impurity-free films are deposited at low temperatures, but deposition rates are insufficient
Solution Approach 1:
The patent introduces dynamic control of multiple parameters including electron beam energy, flux density, precursor partial pressure, and substrate temperature. By dynamically optimizing these parameters during deposition, the process achieves both high film quality through controlled electron-stimulated reactions and improved deposition rates through enhanced precursor activation and surface reaction kinetics, overcoming the static limitations of conventional electron-enhanced processes
Solution Approach 2:
The patent optimizes the electron energy parameter to 5-50 eV, which is higher than conventional electron-enhanced processes, to increase the probability of precursor activation and dissociation. Additionally, the patent controls precursor partial pressure and electron flux density to maximize deposition rate while maintaining film quality, using parameter changes to simultaneously improve both productivity and manufacturing precision
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
EE-CVD allows for high-quality, impurity-free film deposition at room temperature, eliminating nucleation delays and providing precise control over deposition rates, suitable for advanced semiconductor applications like Logic 3DSFET, 3D DRAM, and embedded memory.
Implementation Method 1
electrons are new reactants, activating gas-phase species near the surface, enabling reactions that do not otherwise occur unless at high temperature or in plasma
Implementation Method 2
with a positive substrate voltage to enhance deposition
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for depositing a film includes conducting electron-enhanced chemical vapor deposition with at least one hydride precursor, at least one reactive background gas, and electrons to deposit a film on a substrate with a positive substrate voltage. In an embodiment, the method is a method for depositing a silicon film, including conducting electron-enhanced chemical vapor deposition with at least one Si precursor, at least one reactive background gas, and electrons to deposit a silicon film on a substrate with a positive substrate voltage. In the embodiment, the at least one Si precursor can include Si2H6 and the at least one reactive background gas can include H2.