Fin Shell Covering Fin Core for Lattice Mismatch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The fabrication of semiconductor devices with fin-type channels is challenging due to tight design rules for width, spacing, and complexity, requiring a new structure that can effectively integrate lattice-mismatched layers without lattice dislocation.
Innovation Solution
A fin structure comprising a fin core and a fin shell, where the fin core protrudes from a substrate and the fin shell covers a portion of the sidewalls, with careful selection of thickness and width to manage lattice mismatch and dislocation, using materials like silicon, germanium, and III-V compounds, and employing chemical mechanical polishing and shallow trench isolation layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lattice-mismatched layers are integrated to improve device performance, then device performance is enhanced, but lattice dislocation occurs
Solution Approach 1:
The fin structure is divided into two distinct segments: a fin core and a fin shell. The fin core is formed from a first material while the fin shell is formed from a second material with different lattice constant. This segmentation allows each material to be optimized for specific functions while managing lattice mismatch through spatial separation, preventing dislocation by controlling the interface geometry and relative dimensions.
Solution Approach 2:
Different regions of the fin structure are assigned different material compositions and properties. The fin core uses one material optimized for certain electrical characteristics, while the fin shell uses another material optimized for different characteristics. This local differentiation allows each region to contribute its optimal properties to the overall device performance while the结构设计 manages the interface between different materials.
2Area of stationary object
If fin width and spacing are reduced to meet tight design rules, then device density is improved, but manufacturing precision becomes more difficult
Solution Approach 1:
The fin shell acts as an intermediary structure that can be selectively formed, removed, or retained to achieve the desired final fin dimensions. By using the shell as a temporary or permanent structural element during fabrication, the process can achieve tighter width and spacing control through selective etching or deposition steps, enabling higher device density while maintaining manufacturing precision.
3Reliability
If fin shell thickness is increased to reduce scattering, then device performance is improved, but lattice strain increases
Solution Approach 1:
The structure utilizes controlled variations in dimensional parameters - specifically the thickness of the fin shell and the width of the fin core - to optimize performance. By carefully selecting these parameters, the design achieves sufficient shell thickness to reduce scattering effects while maintaining core dimensions that limit the accumulation of lattice strain, balancing both requirements through parameter optimization.
Data Source
AI summary
According to an exemplary embodiment, a method of forming a fin structure is provided. The method includes the following operations: etching a first dielectric layer to form at least one recess and a first core portion of a fin core; form an oxide layer as a shallow trench isolation layer in the recess; etching back the oxide layer to expose a portion of the fin core; and forming a fin shell to cover a sidewall of the exposed portion of the fin core.