Dual Gate Isolation Structures for Nanosheet Transistor Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The semiconductor industry faces challenges in providing suitable isolation between transistor features due to the shrinking technology nodes, which complicates device processing and increases costs, especially for multi-gate devices like nanosheet transistors with fish-bone or forksheet structures.
Innovation Solution
A method for forming semiconductor structures with two types of gate-cut structures: one extending to a dielectric wall and another to a shallow trench isolation, allowing for disparate depths and materials, facilitating efficient gate isolation between gate segments while reducing processing complexity and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional isolation methods are used for multi-gate devices, then isolation between features can be provided, but processing complexity and manufacturing costs increase due to shrinking technology nodes
Solution Approach 1:
The gate structure is divided into multiple gate segments separated by gate isolation structures. Each gate segment can be independently formed and isolated, allowing for simplified processing of multi-gate devices. The gate isolation structures act as separators between adjacent gate segments, enabling modular fabrication approaches that reduce overall processing complexity.
Solution Approach 2:
Different gate isolation structures are used at different locations: first gate isolation structures extend to the dielectric wall while second gate isolation structures extend to the shallow trench isolation. This localized differentiation allows optimization of isolation depth and material properties for specific device regions, improving isolation effectiveness without uniformly increasing processing complexity across the entire device.
2Reliability
If traditional isolation methods are used for multi-gate devices, then isolation between features can be provided, but manufacturing costs increase
Solution Approach 1:
The gate isolation structures serve multiple functions: they provide electrical isolation between gate segments, define the boundaries of active regions, and work in conjunction with the dielectric wall and shallow trench isolation to provide comprehensive device isolation. This multi-functionality reduces the need for separate isolation structures, thereby lowering manufacturing costs.
Solution Approach 2:
The gate isolation structures are integrated with the existing dielectric wall and shallow trench isolation structures to form a unified isolation system. By merging these isolation elements, the patent reduces the total number of discrete components and processing steps required, leading to cost-effective manufacturing of multi-gate devices.
3Reliability
If gate isolation structures with varying depths and materials are used, then effective gate isolation is achieved, but device complexity increases
Solution Approach 1:
The patent employs different gate isolation structure configurations at different locations: first gate isolation structures extend to the dielectric wall while second gate isolation structures extend to the shallow trench isolation. This localized differentiation optimizes isolation depth and material properties for specific device regions, achieving effective gate isolation without uniformly increasing device complexity across the entire structure.
Data Source
AI summary
Semiconductor structures and processes are provided that include a first gate isolation structure and a second gate isolation structure. The first gate isolation structure may be formed on a dielectric wall from which nanostructure channel regions extend. The second gate isolation structure may be formed on a shallow trench isolation feature. The height of the first gate isolation structure is less than the height of the second gate isolation structure. The composition of the first gate isolation structure may be different than the composition of the second gate isolation structure. In some implementations, the first gate isolation structure is formed concurrently with gate spacers.