Fin Sidewall Conformal Layer Structure to Block Epitaxial Growth
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Solution Overview
Problem
The increasing complexity and scaling down of semiconductor integrated circuits (ICs) pose challenges in processing and manufacturing, requiring improved methods to prevent epitaxial features from forming on sidewalls of fin structures.
Innovation Solution
The implementation of multiple conformal layers to prevent epitaxial features from forming on the sidewalls of fin structures, combined with specific anneal processes to densify and improve the film quality of these layers, is proposed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If scaling down process is used to increase functional density, then production efficiency is improved and costs are lowered, but processing complexity increases
Solution Approach 1:
The patent segments the sidewall protection into multiple conformal layers (first conformal layer, second conformal layer, third conformal layer) with different functions. The first layer prevents epitaxial growth, the second layer provides mechanical support, and the third layer offers additional protection. This segmentation allows each layer to be optimized for its specific function, managing the overall complexity of the scaling down process.
Solution Approach 2:
The conformal layers act as intermediary structures between the fin structure and the epitaxial growth environment. These layers mediate the interaction by providing a controlled interface that prevents unwanted epitaxial features from forming on the sidewalls, thereby simplifying the processing requirements during scaling down.
2Manufacturing precision
If conformal layers are deposited to prevent epitaxial features on sidewalls, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by making each conformal layer have specific localized properties. The first conformal layer has epitaxial growth prevention properties, the second layer has enhanced mechanical stability, and the third layer has additional protection characteristics. Each layer's material composition and thickness are locally optimized for its specific function on the sidewalls.
Solution Approach 2:
The patent uses composite material structures where multiple conformal layers with different material properties are combined. The first conformal layer may use one material composition, the second layer uses another, and the third layer uses a third composition. This composite approach allows each layer to contribute its unique properties to prevent epitaxial features while managing overall structural complexity.
3Reliability
If anneal processes are used to densify conformal layers, then film quality is improved, but processing time increases
Solution Approach 1:
The patent performs preliminary densification actions during the conformal layer deposition process itself. By optimizing the deposition parameters to achieve initial densification, the need for extensive subsequent annealing is reduced. This preliminary action maintains film quality while minimizing the time lost to separate annealing processes.
Solution Approach 2:
The patent employs parameter changes in the anneal processes, such as varying temperature, time, and atmosphere conditions, to achieve optimal densification with minimal processing time. By carefully controlling these parameters, the film quality is improved without requiring excessively long annealing cycles, thus balancing reliability enhancement with time efficiency.
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 prevents epitaxial growth on sidewalls, enhances the film quality of the conformal layers, and improves the overall processing and manufacturing efficiency of semiconductor device structures.
Implementation Method 1
prevent epitaxial features from forming on sidewalls of fin structures
Implementation Method 2
specific anneal processes to densify and improve the film quality of these layers
Data Source
AI summary
Embodiments of the present disclosure provide semiconductor device structures and methods of forming the same. The method includes forming a first fin structure and a second fin structure from a substrate, depositing a first conformal layer over the first and second fin structures and between the first and second fin structures, depositing a second conformal layer on the first conformal layer, depositing a third conformal layer on the second conformal layer, depositing a fourth conformal layer on the third conformal layer, depositing a first insulating material on the fourth conformal layer between the first and second fin structures, and depositing a second insulating material on the first insulating material. The first and second fin structures are embedded by the second insulating material. The method further includes removing portions of the second insulating material and the first, second, third, and fourth conformal layers to expose the first and second fin structures.