Silicon Oxide Film Deposition for Low-Temperature PEALD Conformality
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Solution Overview
Problem
Current methods for depositing silicon oxide films at low temperatures using Atomic Layer Deposition (ALD) processes often result in films with impurities like nitrogen, which are detrimental in semiconductor applications, and increasing the deposition temperature to above 500°C leads to reduced conformality and less control over film thickness.
Innovation Solution
A method involving the use of bis(sec-butylamino)methylsilane, bis(isobutylamino)methylsilane, or bis(cyclohexylamino)methylsilane as silicon precursors in a plasma-enhanced ALD process, combined with an oxygen-containing source such as oxygen plasma or water vapor plasma, at temperatures ranging from 25°C to 300°C, to deposit stoichiometric or non-stoichiometric silicon oxide films with improved density and conformality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If low temperature deposition (25-300°C) is used, then film conformality and control over thickness are improved, but nitrogen impurities are introduced into the film
Solution Approach 1:
The invention extracts and removes nitrogen impurities from the deposition process by selecting oxygen-containing sources (ozone, oxygen plasma, water vapor plasma) that react with the silicon precursor without introducing nitrogen, thereby eliminating the harmful nitrogen impurity while maintaining low temperature deposition benefits
Solution Approach 2:
The invention changes the chemical composition parameters of the reactants by selecting specific oxygen-containing sources (ozone, oxygen plasma, water vapor plasma) instead of traditional nitrogen-containing precursors, enabling low temperature deposition without nitrogen contamination while achieving the desired silicon oxide film
2Object-generated harmful factors
If deposition temperature is increased above 500°C, then nitrogen impurities are reduced, but film conformality deteriorates
Solution Approach 1:
The invention changes the temperature parameter from high (>500°C) to low (25-300°C) while compensating by selecting appropriate oxygen-containing sources and silicon precursors that enable complete reaction and remove nitrogen impurities at lower temperatures, thus resolving the contradiction between temperature and film quality
Solution Approach 2:
The invention introduces oxygen-containing sources (ozone, oxygen plasma, water vapor plasma) as intermediaries that facilitate the oxidation of silicon precursors at low temperatures without requiring high thermal energy, thereby achieving impurity-free deposition while maintaining conformality
3Ease of manufacture
If traditional ALD precursors are used, then deposition process is simple, but film density and quality are insufficient
Solution Approach 1:
The invention changes the chemical structure parameters of the silicon precursor by selecting compounds with specific properties (reactivity, volatility, molecular weight) that enable complete surface coverage and high-density film formation at low temperatures, thereby improving film quality while maintaining process simplicity through the use of well-established ALD techniques
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 process achieves high-quality silicon oxide films with densities of 2.1 g/cc or greater, low chemical impurities, and high conformality, while allowing for tunable carbon content and reduced etch rates, suitable for semiconductor applications.
Implementation Method 1
plasma-enhanced ALD process
Implementation Method 2
plasma-enhanced ALD process
Implementation Method 3
introducing an oxygen-containing source into the reactor
Implementation Method 4
Atomic Layer Deposition (ALD) and Plasma Enhanced Atomic Layer Deposition (PEALD) are processes used to deposit silicon oxide conformal film
Data Source
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AI summary
Described herein are compositions and methods for forming silicon oxide films. In one aspect, the film is deposited from at least one precursor having the following formula: R1nSi(NR2R3)mH4-m-n wherein R1 is independently selected from a linear C1 to C6 alkyl group, a branched C2 to C6 alkyl group, a C3 to C6 cyclic alkyl group, a C2 to C6 alkenyl group, a C3 to C6 alkynyl group, and a C4 to C10 aryl group; wherein R2 and R3 are each independently selected from hydrogen, a C1 to C6 linear alkyl group, a branched C2 to C6 alkyl group, a C3 to C6 cyclic alkyl group, a C2 to C6 alkenyl group, a C3 to C6 alkynyl group, and a C4 to C10 aryl group, wherein R2 and R3 are linked or, are not linked, to form a cyclic ring structure; n=1, 2, 3; and m=1, 2.