Void-Free Silicon Oxide Gap Fill via Amorphous Silicon Compensation
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Solution Overview
Problem
The challenge in semiconductor processing is to achieve void-free gap fill in high aspect ratio trenches, as existing techniques either result in low film density due to residual carbon and hydroxyl species or cause volumetric shrinkage during high-temperature annealing, leading to inferior device performance and electrical issues.
Innovation Solution
A method involving the deposition of a silicon oxide layer with residual water and carbon species, followed by exposure to silicon-containing species and subsequent annealing in an oxidative environment to oxidize amorphous silicon components and remove residual hydroxyl and carbon species, resulting in a dense, void-free silicon oxide film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-temperature annealing is used to remove residual carbon and hydroxyl species, then film purity is improved, but volumetric shrinkage occurs leading to void formation
Solution Approach 1:
The patent introduces silicon-containing species into the dielectric film before annealing to compensate for the volumetric shrinkage that will occur during the annealing process. This preliminary addition of silicon ensures that after shrinkage, the film still maintains complete trench filling without voids.
Solution Approach 2:
The patent modifies the composition of the dielectric film by adding silicon-containing species, changing the physical and chemical parameters of the material. This composition adjustment allows the film to undergo shrinkage during annealing while maintaining adequate fill volume and avoiding void formation.
2Manufacturing precision
If deposition rate is slowed to improve conformality, then gap fill quality is improved, but processing time increases reducing productivity
Solution Approach 1:
The patent applies partial annealing treatment rather than complete high-temperature annealing, or uses a modified annealing process that achieves sufficient film quality improvement without requiring excessively long processing times, thus balancing quality and productivity.
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 ensures high-quality, dense silicon oxide films that effectively fill narrow trenches without voids or seams, enhancing mechanical strength and maintaining flow-like characteristics necessary for high aspect ratio gap-fill processes.
Implementation Method 1
annealing the first silicon oxide layer partially intermixed with the plurality of amorphous silicon components in an oxidative environment to form a second silicon oxide layer on the substrate. At least a portion of amorphous silicon components are oxidized to become part of the second silicon oxide layer
Implementation Method 2
exposing the first silicon oxide layer to a plurality of silicon-containing species during which at least a portion of the plurality of silicon-containing species either react with at least a portion of the residual water and hydroxyl groups, or are thermally decomposed
Data Source
AI summary
A method of forming a silicon oxide layer on a substrate. The method includes providing a substrate and forming a first silicon oxide layer overlying at least a portion of the substrate, the first silicon oxide layer including residual water, hydroxyl groups, and carbon species. The method further includes exposing the first silicon oxide layer to a plurality of silicon-containing species to form a plurality of amorphous silicon components being partially intermixed with the first silicon oxide layer. Additionally, the method includes annealing the first silicon oxide layer partially intermixed with the plurality of amorphous silicon components in an oxidative environment to form a second silicon oxide layer on the substrate. At least a portion of amorphous silicon components are oxidized to become part of the second silicon oxide layer and unreacted residual hydroxyl groups and carbon species in the second silicon oxide layer are substantially removed.