Silicon Oxide Deposition Cycle for Voidless Gap Fill
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The miniaturization of integrated circuit elements has led to high aspect ratio gaps and trenches, making it difficult to fill them with dielectric materials like silicon oxide without creating voids or seams, which results in unpredictable and inferior device performance due to electrical crosstalk and charge leakage.
Innovation Solution
A multicycle deposition process using a combination of organo-silicon and atomic oxygen precursors, where each silicon oxide layer is deposited and etched to reduce carbon content, followed by annealing, to form a seamless, high-quality silicon oxide film that can efficiently fill gaps and trenches from the bottom up.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the deposition rate of the dielectric material is slowed to achieve more conformal deposition, then void and seam formation is reduced, but deposition time increases and processing efficiency decreases
Solution Approach 1:
The deposition process is divided into multiple cycles, with each cycle depositing a thin layer followed by an etch step to remove carbon-containing impurities. This segmentation allows the use of higher deposition rates while maintaining film quality through intermediate purification steps.
Solution Approach 2:
The process employs periodic alternation between deposition and etching steps. During deposition, higher rates can be used to maintain productivity, while periodic etching cycles remove impurities that would otherwise accumulate and cause defects, enabling sustained high-rate deposition without sacrificing quality.
2Reliability
If water vapor or peroxide is added to increase the flowability of the deposited dielectric material, then void filling is improved, but film density decreases and wet etch rate ratio increases
Solution Approach 1:
Instead of adding substances to improve flowability, the process extracts carbon-containing impurities through etching steps. This removal approach improves film quality and density without introducing the adverse effects of adding water vapor or peroxide.
Solution Approach 2:
The process converts the potentially harmful effect of carbon-containing impurities into a benefit by using controlled etching to selectively remove these impurities. The impurities that would normally degrade film quality are systematically eliminated, improving both flowability and density without adverse side effects.
3Manufacturing precision
If multiple thin silicon oxide layers are deposited and etched to reduce carbon content, then film quality and dielectric properties are improved, but process complexity increases
Solution Approach 1:
Multiple deposition and etching cycles are merged into an integrated process sequence that systematically builds up the dielectric film while continuously removing impurities. The repetitive structure is streamlined into a cohesive process that achieves high film quality without proportionally increasing overall process complexity.
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 process ensures voidless and seamless dielectric films with high deposition rates and flowability, maintaining the quality of the finished fill without adverse effects on the dielectric properties, resulting in improved device performance and reduced electrical noise.
Implementation Method 1
a remote plasma generating system coupled to the deposition chamber, where the plasma generating system is used to generate an atomic oxygen precursor
Implementation Method 2
reacting the precursors to form a first silicon oxide layer in the gap on the substrate
Implementation Method 3
etching the first silicon oxide layer to reduce the carbon content in the layer
Implementation Method 4
The silicon oxide layers may be annealed after the gap is filled
Data Source
AI summary
Methods of filling a gap on a substrate with silicon oxide are described. The methods may include the steps of introducing an organo-silicon precursor and an oxygen precursor to a deposition chamber, reacting the precursors to form a first silicon oxide layer in the gap on the substrate, and etching the first silicon oxide layer to reduce the carbon content in the layer. The methods may also include forming a second silicon oxide layer on the first layer, and etching the second layer to reduce the carbon content in the second layer. The silicon oxide layers are annealed after the gap is filled.