Stacked FinFET With Insulator Segments For Strain Management
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Solution Overview
Problem
The miniaturization of metal oxide semiconductor field effect transistors (MOSFETs) has led to the need for advanced non-planar semiconductor devices like FinFETs, which require efficient strain management and epitaxial growth techniques to optimize device performance and density.
Innovation Solution
A semiconductor structure featuring a fin stack with a first semiconductor material fin portion, an insulator fin portion, and a second semiconductor material fin portion, where epitaxial semiconductor material structures are grown using maskless epitaxial growth processes to enhance device performance and density, with the option of different semiconductor materials for each fin portion to accommodate n-FET and p-FET devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If stacked semiconductor fins are formed to increase device density, then device density is improved, but strain management becomes more difficult
Solution Approach 1:
The fin stack is divided into multiple discrete fin portions (first semiconductor material fin portion, second semiconductor material fin portion, third semiconductor material fin portion) separated by insulator fin portions. This segmentation allows each fin portion to be independently strained and processed, enabling high device density while managing strain complexity through modular design.
Solution Approach 2:
Different semiconductor materials with different strain characteristics are placed in different fin portions within the same fin stack. The first, second, and third semiconductor material fin portions can have different tensile or compressive strain configurations, allowing local optimization of device performance while maintaining overall high density.
2Reliability
If multiple semiconductor materials are used in different fin portions to optimize n-FET and p-FET performance, then device performance is improved, but manufacturing process complexity increases
Solution Approach 1:
The first, second, and third semiconductor material layers are formed in a predetermined stacked configuration before fin patterning. This preliminary stratification of different semiconductor materials allows subsequent processing steps to treat the entire fin stack uniformly, reducing manufacturing complexity despite the presence of multiple materials.
Solution Approach 2:
The fin stack structure serves multiple functions simultaneously: it provides mechanical support, electrical isolation (through insulator fin portions), and hosts multiple device types (n-FETs and p-FETs) with different strain requirements. This multi-functionality is achieved through a unified stacked structure that simplifies manufacturing while accommodating diverse device performance requirements.
3Length of moving object
If fin dimensions are reduced to achieve miniaturization, then device scaling is improved, but drive current decreases
Solution Approach 1:
The fin stack employs composite semiconductor materials including silicon, silicon-germanium alloys, and other semiconductor materials with different strain characteristics. These composite materials enable enhanced carrier mobility and drive current in miniaturized fins through engineered tensile and compressive strain, allowing continued scaling while maintaining or improving power performance.
Solution Approach 2:
The invention changes the physical and chemical parameters of the semiconductor materials by introducing different compositions (e.g., silicon-germanium with varying germanium content) and strain states (tensile vs. compressive). These parameter changes enable optimization of carrier mobility and drive current even as fin dimensions are reduced for miniaturization.
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 enables higher drive currents and increased density in FinFETs by effectively utilizing strained semiconductor materials and epitaxial growth to optimize the performance of n-FET and p-FET devices within a single fin stack structure.
Implementation Method 1
epitaxial semiconductor material structures are grown using maskless epitaxial growth processes
Data Source
AI summary
A semiconductor structure is provided that includes a fin stack structure of, from bottom to top, a first semiconductor material fin portion, an insulator fin portion and a second semiconductor material fin portion. The first semiconductor material fin portion can be used as a first device region in which a first conductivity-type device (e.g., n-FET or p-FET) can be formed, while the second semiconductor material fin portion can be used as a second device region in which a second conductivity-type device (e.g., n-FET or p-FET), which is opposite the first conductivity-type device, can be formed.