High-Temperature ALD Silicon Oxide Films Without CVD Self-Reaction
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Solution Overview
Problem
Existing thermal oxidation processes for depositing silicon oxide films in semiconductor applications have low deposition rates and introduce impurities like hydrogen, carbon, and nitrogen, while conventional ALD processes at higher temperatures lead to self-reacting precursors and reduced conformality.
Innovation Solution
A high-temperature atomic layer deposition process using halidocarbosilane precursors and oxygen-containing sources, such as ozone, at temperatures above 600°C, to form silicon oxide films with low impurities and high conformality, employing a cyclical process to deposit silicon oxide films with specific precursors and purge gases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If thermal oxidation process is used to deposit silicon oxide films, then high purity and highly conformal films are achieved, but deposition rate is very low (less than 0.0007 Å/s at 700°C)
Solution Approach 1:
The invention changes the deposition temperature parameter to above 600°C and uses specific halidocarbosilane precursors with controlled reactivity to achieve both high deposition rates and film quality. The temperature parameter is optimized to enable ALD mode operation while maintaining conformality and purity.
Solution Approach 2:
The invention introduces halidocarbosilane precursors as intermediary compounds that react controllably at high temperatures to form silicon oxide films. These precursors serve as mediators between the deposition process and the final film structure, enabling both high rate and high quality.
2Manufacturing precision
If deposition temperature is increased to above 500°C to reduce impurities in ALD-deposited silicon dioxide, then film purity improves, but precursors self-react and deposit in CVD mode reducing conformality
Solution Approach 1:
The invention optimizes multiple parameters including temperature (above 600°C), precursor selection (halidocarbosilanes), and process timing to maintain ALD mode operation at high temperatures. These parameter changes enable high purity deposition while preserving the sequential reaction mechanism of ALD.
Solution Approach 2:
The invention replaces conventional silicon precursors with halidocarbosilane precursors that have different chemical reactivity characteristics. This substitution allows the process to operate in ALD mode at temperatures above 600°C, preventing self-reaction and maintaining conformal deposition.
3Productivity
If conventional precursors are used in ALD process at high temperatures, then deposition rate increases, but precursors self-react and thermally decompose leading to CVD mode deposition with reduced conformality
Solution Approach 1:
The invention substitutes conventional silicon precursors with halidocarbosilane precursors that exhibit enhanced thermal stability. These new precursors resist self-reaction and thermal decomposition at temperatures above 600°C, maintaining ALD mode operation while achieving high deposition rates.
Solution Approach 2:
The invention uses halidocarbosilane compounds that combine silicon, halogen, and carbosilane groups in specific configurations. This composite molecular structure provides both the reactivity needed for high deposition rates and the stability required to prevent premature decomposition at elevated temperatures.
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 above 2.1 g/cm³, low carbon content, and improved conformality, suitable for advanced semiconductor structures like V-NAND memory technology.
Implementation Method 1
at these higher temperatures, conventional precursors employed by semi-conductor industries tend to self-react, thermally decompose, and deposit in chemical vapor deposition (CVD) mode
Implementation Method 2
the CVD mode deposition process imparts less control of film or material thickness than does the ALD mode deposition
Implementation Method 3
supplying a source gas to the substrate wherein the source gas contains the predetermined element, chlorine and oxygen with a chemical bond of the predetermined element and oxygen
Data Source
AI summary
A method and composition for depositing a silicon oxide film in an atomic layer deposition process at one or more temperatures of 600° C. or greater are provided. In one aspect, there is provided a method to deposit a silicon oxide film or material on a substrate in a reactor at one or more temperatures ranging from about 600° C. to 1000° C.; comprising the steps of: introducing into the reactor at least one halidocarbosilane precursor selected from the group of compounds having Formulae I and II described herein; purging the reactor with a purge gas; introducing an oxygen-containing source into the reactor; and purging the reactor with a purge gas; and wherein the steps are repeated until a desired thickness of silicon oxide is deposited.