Cyclic Oxide Growth for Conformal High-Aspect-Ratio Memory Holes
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Solution Overview
Problem
Existing oxidation processes for substrates, such as semiconducting substrates, result in non-uniform oxidation leading to reduced conformality and increased processing time, particularly in thicker films, complicating the production of oxide layers in memory holes with high aspect ratios.
Innovation Solution
A cyclic growth oxidation process is implemented using a remote plasma source to form a plasma gas, producing oxidation radicals, followed by alternating oxidation and bake processes to enhance conformality and thickness of oxide layers in memory holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If slow oxidation processes are used to produce an oxide film, then conformality is improved, but processing time increases
Solution Approach 1:
The patent implements a cyclic oxidation process that alternates between oxidation steps and bake steps. During oxidation steps, oxidizing conditions are applied to grow the oxide film. During bake steps, heating without oxidizing conditions removes surface roughness and contaminants. This periodic alternation enables conformal growth on high aspect ratio structures while reducing total processing time compared to continuous slow oxidation.
2Length of moving object
If oxidation processing time is increased to produce thicker films, then film thickness is improved, but conformality deteriorates
Solution Approach 1:
The cyclic process alternates between oxidation steps that grow the oxide film and bake steps that restore surface smoothness. This periodic action allows the film to grow thicker while periodically removing surface roughness that would otherwise deteriorate conformality, enabling thick films with maintained conformality on high aspect ratio memory holes.
Solution Approach 2:
The process dynamically changes processing parameters by alternating between oxidizing conditions (for film growth) and heating conditions without oxidizing gases (for surface restoration). This parameter switching enables control over both film thickness and conformality, allowing thick films to be produced while maintaining uniform coverage on vertical sidewalls.
3Productivity
If continuous oxidation is performed, then oxide layer growth is efficient, but surface roughness and contaminant concentration increase
Solution Approach 1:
The patent implements periodic alternation between oxidation steps (which efficiently grow the oxide layer) and bake steps (which heat the substrate to remove surface roughness and contaminants). This cyclic approach maintains high productivity during oxidation phases while periodically restoring surface uniformity during bake phases, solving the contradiction between growth efficiency and surface quality.
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 cyclic process improves conformality and reduces processing time by reducing surface roughness and contaminant concentration, allowing for uniform oxide layer growth on substrates with high aspect ratio memory holes.
Implementation Method 1
forming a plasma of a plasma gas using a remote plasma source
Implementation Method 2
An oxidation radical is produced
Implementation Method 3
perform a bake process for a second period of time by introducing a bake gas to the processing chamber using the first nozzle and increasing a temperature of the processing chamber
Data Source
AI summary
The disclosure provides a system and methods of performing a cyclic growth oxidation process. The method includes forming a plasma of a plasma gas using a remote plasma source fluidly coupled to a conduit coupled to a first nozzle of a processing chamber. An oxidation radical is produced. A first oxidation process is performed by introducing the oxidation radical for a first period of time to the processing chamber using the first nozzle. A bake process is performed for a second period of time. A second oxidation process is performed by introducing the oxidation radical for a third period of time.