FinFET Bowl-Shaped Gate Isolation for Low Leakage Breakdown
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing FinFET technologies and fabrication methods have limitations in achieving optimal performance and reliability due to challenges in design and fabrication, particularly in achieving effective gate isolation and high breakdown voltage with low leakage current.
Innovation Solution
A semiconductor device structure is formed using FinFETs with a bowl-shaped insulating gate isolation structure between fin structures, comprising a high-k dielectric material and a nitride-based insulating layer, which provides enhanced isolation and reliability by allowing wider gate-to-gate distance and resistance to etching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional gate isolation structures are used, then fabrication is simpler, but breakdown voltage is insufficient and leakage current is high
Solution Approach 1:
The gate isolation structure employs a bowl-shaped configuration with curved sidewalls instead of conventional planar or vertical structures. This curvature provides wider spacing between adjacent gate structures at the top level while maintaining compact footprint, thereby enhancing breakdown voltage and reducing leakage current through improved electrical isolation.
Solution Approach 2:
The gate isolation structure utilizes composite material layers including high-k dielectric materials and nitride-based insulating layers. This multi-material approach provides superior electrical isolation properties and resistance to etching processes, simultaneously improving breakdown voltage while managing structural complexity through functional material differentiation.
2Reliability
If gate-to-gate distance is increased, then isolation and breakdown voltage improve, but device area increases
Solution Approach 1:
The bowl-shaped configuration with curved sidewalls allows the gate isolation structure to achieve wider top-level spacing between gates while maintaining a compact overall footprint. The curved geometry efficiently utilizes vertical and lateral space, providing enhanced isolation properties without proportionally increasing the device area.
Solution Approach 2:
The invention transitions from conventional two-dimensional planar isolation to a three-dimensional bowl-shaped structure. This dimensional change enables wider gate-to-gate distance at the critical top level where electrical isolation is most needed, while the structure's vertical extent and curved profile maintain compact lateral dimensions, thereby improving isolation without significant area penalty.
3Reliability
If bowl-shaped gate isolation structure is used, then breakdown voltage and isolation improve, but fabrication complexity increases
Solution Approach 1:
The bowl-shaped structure is formed using standard semiconductor fabrication techniques including conformal deposition of insulating layers followed by anisotropic etching. The curved profile emerges from the interaction between conformal layer deposition and directional etching processes, allowing complex geometry to be achieved through conventional process steps without requiring specialized equipment or highly complex process sequences.
Solution Approach 2:
The use of composite material layers with distinct etch selectivities (high-k dielectric and nitride-based insulating layers) enables the bowl-shaped structure to be formed through standard multi-step deposition and etching processes. Each material layer serves a specific function and can be processed with appropriate etch chemistry, making the complex structure manufacturable using existing fabrication capabilities.
Data Source
AI summary
Structures and formation methods of a semiconductor device structure are provided. The semiconductor device structure includes an isolation structure formed over a semiconductor substrate. A first fin structure and a second fin structure extend from the semiconductor substrate and protrude above the isolation structure. A first gate structure is formed across the first fin structure and a second gate structure is formed across the second fin structure. A gate isolation structure is formed between the first fin structure and the second fin structure and separates the first gate structure from the second gate structure. The gate isolation structure includes a bowl-shaped insulating layer that has a first convex sidewall surface adjacent to the first gate structure and a second convex sidewall surface adjacent to the second gate structure.