FinFET Gate Segmentation for Leakage Reduction
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Solution Overview
Problem
FinFETs face challenges in reducing leakage current and capacitance between doped regions within the fin-shaped structure, which affect the electrical characteristics of semiconductor devices.
Innovation Solution
The semiconductor device includes a fin-shaped structure with a gate structure that straddles the fin, featuring a first and second doped region separated by an intermediate region, and a gate structure with a bottom surface lower than or coplanar with the first doped region, reducing leakage current and capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If doped regions are placed close together in the fin-shaped structure to maintain compact device design, then device area is reduced, but leakage current and capacitance between doped regions increase
Solution Approach 1:
The gate structure is segmented into multiple portions (first gate portion, second gate portion, third gate portion) with different widths, allowing each segment to independently control different regions of the fin-shaped structure. This segmentation enables better spatial separation of doped regions under different gate portions, reducing leakage current and capacitance while maintaining compact overall device area.
Solution Approach 2:
Different portions of the gate structure are designed with different widths to provide localized control over different regions of the fin-shaped structure. The first gate portion has a wider width to control the first doped region, while the second and third gate portions have narrower widths for controlling subsequent doped regions, optimizing the balance between area and electrical isolation.
2Reliability
If the gate structure is made wider to improve control over the fin-shaped structure, then channel control is enhanced, but the area occupied by the gate structure increases
Solution Approach 1:
The gate structure is divided into multiple segments with varying widths, where each segment provides focused control over a specific region of the fin-shaped structure. This segmentation achieves effective channel control without requiring a uniformly wide gate structure, thereby reducing the overall gate area while maintaining control reliability.
Solution Approach 2:
The gate structure implements local quality by having different widths at different positions along the fin-shaped structure. The wider first gate portion provides enhanced control where needed, while narrower second and third gate portions reduce area consumption in regions requiring less control, optimizing the balance between control reliability and area efficiency.
3Object-generated harmful factors
If doped regions are separated by an intermediate region to reduce leakage current, then leakage current is reduced, but the vertical space and device complexity increase
Solution Approach 1:
The gate structure is segmented into multiple portions that can be independently formed and controlled, allowing the intermediate region to be precisely positioned and sized. This segmentation enables effective leakage current reduction through proper spacing of doped regions while managing the complexity through a systematic multi-portion gate design approach.
Solution Approach 2:
The solution addresses the leakage current problem by utilizing the vertical dimension and lateral positioning of doped regions relative to different gate portions. By controlling the vertical positions and lateral spacing of doped regions under different gate portions, the design reduces leakage current while managing structural complexity through three-dimensional spatial arrangement.
Data Source
AI summary
A semiconductor device includes a semiconductor substrate, a fin-shaped structure, a gate structure, a first doped region, a second doped region, and an intermediate region. The fin-shaped structure is disposed on and extends upwards from a top surface of the semiconductor substrate in a vertical direction. The gate structure is disposed straddling a part of the fin-shaped structure. At least a part of the first doped region is disposed in the fin-shaped structure. The second doped region is disposed in the fin-shaped structure and disposed above the first doped region in the vertical direction. The intermediate region is disposed in the fin-shaped structure. The second doped region is separated from the first doped region by the intermediate region, and a bottom surface of the gate structure is lower than or coplanar with a top surface of the first doped region in the vertical direction.