Flowable TiO2 Gap Fill With Fluorine Ratio Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor manufacturing, gap fill processes using flowable insulating layers like TiO2 are prone to damage the gap structure due to fluorine exposure, and delamination issues occur between protective layers, leading to incomplete filling with voids or seams, which affect device performance.
Innovation Solution
A method involving repeated flowable gap-fill cycles is employed, where a first solid layer is formed on the gap surface, converted into a flowable layer using a fluorine source, and then back into a second solid layer, with the fluorine flow amount controlled based on the layer thickness to protect the gap structure and prevent delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a protective layer (HfO2) is formed on the gap surface before forming TiO2 layer, then the gap structure is protected from fluorine damage, but delamination occurs between TiO2 layer and HfO2 layer during annealing process due to different thermal expansion coefficients
Solution Approach 1:
The patent uses the same material (TiO2) for both the protective layer and the gap fill layer, ensuring homogeneous material composition. This eliminates delamination issues during annealing because identical materials have matching thermal expansion coefficients, while still providing fluorine protection during the gap fill process.
2Manufacturing precision
If a flowable TiO2 layer is used to fill the gap, then the gap is filled without void or seam, but the solid TiO2 layer becomes damaged by fluorine exposure during the process
Solution Approach 1:
The patent forms a protective TiO2 layer on the gap surface before introducing the fluorine source. This preliminary action creates a barrier that protects the underlying TiO2 layer from fluorine damage while allowing the fluorine to activate the surface for subsequent gap filling without causing harm.
Solution Approach 2:
The protective TiO2 layer acts as an intermediary between the fluorine source and the gap structure. It allows the fluorine to perform its useful function of activating the surface for gap filling while preventing the harmful effects of fluorine exposure to the underlying layers.
3Object-affected harmful factors
If different materials are used for protective layer and TiO2 layer, then the gap structure is protected, but delamination occurs due to different thermal expansion coefficients
Solution Approach 1:
The patent employs homogeneous material composition by using TiO2 for both the protective layer and the gap fill layer. This eliminates the stability issue caused by thermal expansion coefficient mismatches that occur with heterogeneous material combinations like HfO2 and TiO2.
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 effectively fills gaps without voids or seams, protects the gap structure from fluorine damage, and ensures seamless integration of layers, enhancing device performance and throughput.
Implementation Method 1
turning the first solid layer into a flowable layer by supplying a fluorine flow amount of a fluorine source activated by a power to the first solid layer
Implementation Method 2
Filling the gap with a flowable insulating layer is an effective void-free or seamless gap fill method as the flowability of the layer enables to fill the gap more effectively from the bottom of the gap
Implementation Method 3
converting the flowable layer into a second solid layer
Data Source
AI summary
A method of filling a gap provided to a substrate, comprises: providing the substrate in a reactor, and performing a flowable gap-fill cycle repeatedly, the flowable gap-fill cycle includes forming a first solid layer on the surface of the gap, turning the first solid layer into a flowable layer by supplying a fluorine flow amount of a fluorine source activated by a power, and converting the flowable layer into a second solid layer. The method of filling a gap comprises calculating a ratio of fluorine flow amount to thickness of the first solid layer and controlling the fluorine flow amount based on the calculated ratio.