PEALD Oxidative Conversion Using H2/N2O/O2 Plasma
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Solution Overview
Problem
Current plasma-enhanced atomic layer deposition (PEALD) processes for silicon-containing films face challenges such as limited operating windows, electrical arcing, and reduced efficacy of oxidation, particularly with Ar/O2 plasmas, while N2O/O2 plasmas offer a broader power range but compromised impurity removal, and alternative chemistries are costly or difficult to implement.
Innovation Solution
Introducing dihydrogen (H2) into the plasma gas composition, specifically in a 1:1:1 mixture with N2O and O2, enhances film quality and reduces impurities by converting surface hydridosilane groups to hydrosiloxane terminated surfaces, lowering operating temperatures and reducing oxidation on metals, thereby improving electrical properties and cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Ar/O2 plasma is used in PEALD processes, then deposition can be achieved, but electrical arcing occurs and operating window is limited
Solution Approach 1:
The patent changes the plasma gas composition parameters by replacing Ar with N2O and adding H2, transforming the plasma chemistry from Ar/O2 to N2O/O2/H2. This parameter change eliminates electrical arcing while maintaining deposition reliability and expands the operating power window.
Solution Approach 2:
The patent introduces H2 as a temporary additive to the plasma gas mixture that serves its function of reducing impurities and enhancing film quality, then is consumed in the process. This disposable approach allows significant improvement in film properties without requiring permanent system modifications.
2Adaptability or versatility
If N2O/O2 plasma is used to broaden power range, then operating window increases, but impurity removal efficacy is compromised
Solution Approach 1:
The patent modifies the plasma gas composition by adding H2 to the N2O/O2 mixture, changing the chemical reduction potential of the plasma. This parameter change enables effective impurity removal while maintaining the broad power range advantage of N2O/O2 plasma.
Solution Approach 2:
The patent creates a composite plasma gas mixture of N2O, O2, and H2 that combines the advantages of each component: N2O provides broad power range adaptability, O2 enables oxidation reactions, and H2 provides impurity removal capability through hydrogenation reactions.
3Productivity
If conventional PEALD processes are used, then deposition is achieved, but film density and quality are reduced
Solution Approach 1:
The patent changes the plasma gas composition from conventional Ar/O2 or N2O/O2 to N2O/O2/H2, which fundamentally alters the surface chemistry during deposition. This leads to higher film density and improved quality while maintaining productive deposition rates.
Solution Approach 2:
The H2 in the plasma acts as an intermediary that facilitates better film formation by reducing surface impurities and enhancing the quality of deposited silicon-containing films, resulting in higher density and improved electrical properties.
4Manufacturing precision
If oxidation is enhanced to improve film quality, then impurity removal improves, but oxidation on metals increases
Solution Approach 1:
The patent changes the plasma chemistry by adding H2, which creates a reducing environment that counteracts excessive oxidation on metal surfaces while maintaining sufficient oxidation capability for impurity removal and film quality enhancement.
Solution Approach 2:
The patent converts the potentially harmful effect of strong oxidation into a benefit by using H2 to selectively reduce metal oxidation while maintaining oxidation capability for removing organic impurities from the film, thus turning a double-edged sword into a controlled process.
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 addition of H2 to N2O/O2 plasmas results in higher density and quality films at lower temperatures, significantly reducing impurities and improving breakdown fields and leakage currents, while maintaining inhibition of residual chemistry.
Implementation Method 1
oxidative conversion in atomic layer deposition processes
Implementation Method 2
converting surface hydridosilane groups to hydrosiloxane terminated surfaces
Implementation Method 3
plasma-enhanced atomic layer deposition (PEALD) processes
Implementation Method 4
significantly reducing impurities and improving breakdown fields and leakage currents
Data Source
AI summary
A method for processing a substrate is described. A first reactant in vapor phase is introduced into a reaction chamber having the substrate therein. The first reactant is allowed to be adsorb onto the substrate surface. The non-reactive portion of the first reactant is purged from the reaction chamber after a flow of the first reactant has ceased. The second reactant is introduced in vapor phase into the reaction chamber while the first reactant is adsorbed onto the substrate surface. The second reactant comprises a 1:1:1 ratio of dihydrogen (H2), a nitro-gen-containing reactant, and an oxygen-containing reactant. A plasma is ignited based on the second reactant. The substrate surface is exposed to the plasma. The plasma is extinguished. Gas from the reaction chamber is purged.