Cyclical Oxide Film Deposition for Plasma-Free High-Aspect Features
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Solution Overview
Problem
Conventional methods for depositing silicon oxide films in semiconductor device fabrication face challenges such as high temperature requirements, anisotropic film properties, and plasma excitation, which are not suitable for next-generation devices with reduced thermal budgets and high aspect ratio features.
Innovation Solution
A cyclical deposition process involving a first sub-cycle for depositing a metal oxide film and a second sub-cycle for depositing a silicon oxide film directly on the metal oxide film, using alternating pulses of precursors in a plasma-free environment to achieve conformal and isotropic film deposition at reduced temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional CVD or PEALD methods are used to deposit silicon oxide films, then high-quality oxide films can be obtained, but high deposition temperatures or plasma excitation are required which are not suitable for next-generation devices with reduced thermal budgets
Solution Approach 1:
The deposition process is divided into two distinct sub-cycles: a first sub-cycle for depositing metal oxide film and a second sub-cycle for depositing silicon oxide film. This segmentation allows each sub-cycle to be optimized independently, enabling low-temperature deposition while maintaining film quality.
Solution Approach 2:
The invention changes the deposition parameters by using a cyclical process with alternating precursor pulses instead of continuous deposition. This parameter change enables deposition at reduced temperatures below 450°C while achieving conformal and isotropic film properties that were previously only attainable at high temperatures.
2Manufacturing precision
If conventional deposition methods are used, then oxide films can be deposited, but anisotropic film properties result which are not suitable for high aspect ratio features
Solution Approach 1:
The invention employs periodic action through cyclical deposition with alternating precursor pulses. The first sub-cycle deposits metal oxide and the second sub-cycle deposits silicon oxide, repeating this sequence to build up the film. This periodic deposition ensures conformal coverage and isotropic properties throughout the film structure, even over high aspect ratio features.
Solution Approach 2:
The invention creates a composite oxide film structure by depositing metal oxide and silicon oxide in alternating layers. This composite structure combines the benefits of both materials, achieving superior conformality and isotropy that neither material could achieve alone in conventional deposition processes.
3Temperature
If plasma-enhanced methods are used to deposit oxide films at reduced temperatures, then deposition temperature can be lowered, but plasma excitation causes defects and thermal damage
Solution Approach 1:
The invention extracts the harmful plasma excitation step from the deposition process. By using a cyclical chemical vapor deposition approach without plasma, the method achieves reduced deposition temperatures without introducing plasma-induced defects, removing the harmful factor while preserving the beneficial low-temperature deposition capability.
Solution Approach 2:
The invention uses simple, non-plasma chemical reactions with short-lived precursor pulses to achieve deposition. Instead of relying on expensive and potentially damaging plasma excitation, the process uses transient chemical species that react and deposit without the harmful effects of plasma, effectively replacing a complex harmful system with a simpler benign alternative.
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
This approach allows for the deposition of high-quality oxide films with superior conformality and isotropic properties over high aspect ratio features, avoiding thermal damage and plasma-induced defects, while maintaining excellent film quality and etch resistance.
Implementation Method 1
depositing a metal oxide film over a substrate utilizing at least one deposition cycle of a first sub-cycle of the cyclical deposition process; and depositing a silicon oxide film directly on the metal oxide film utilizing at least one deposition cycle of a second sub-cycle of the cyclical deposition process
Data Source
AI summary
A method for depositing an oxide film on a substrate by a cyclical deposition is disclosed. The method may include: depositing a metal oxide film over the substrate utilizing at least one deposition cycle of a first sub-cycle of the cyclical deposition process; and depositing a silicon oxide film directly on the metal oxide film utilizing at least one deposition cycle of a second sub-cycle of the cyclical deposition process. Semiconductor device structures including an oxide film deposited by the methods of the disclosure are also disclosed.