Nanosheet Gate Isolation Layout for Dense Low-Capacitance Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nanosheet semiconductor devices face challenges in reducing the spacing between oxide-definition regions due to metal gate endcap portion size restrictions and resistance-capacitance (RC) time delay issues, which affect device performance.
Innovation Solution
A method for manufacturing semiconductor devices involving the formation of dielectric walls and isolation features, allowing for reduced metal gate endcap portions without impacting threshold voltage, and optimizing the structure to minimize capacitance and enhance power efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the spacing between oxide-definition regions is reduced to increase device density, then the device functional density is improved, but the metal gate endcap portion size becomes too small to maintain threshold voltage and RC time delay increases
Solution Approach 1:
The gate structure is segmented into metal gate portions over channel features and dielectric endcap portions over oxide-definition regions. This segmentation allows the metal gate portions to maintain adequate size for threshold voltage control while the dielectric endcaps fill the spaces between oxide-definition regions, enabling reduced spacing without compromising electrical performance.
Solution Approach 2:
A dielectric material is introduced as an intermediary substance to form endcap portions between the metal gate portions. This dielectric material acts as a mediator that allows the metal gate endcap portions to be reduced or eliminated while maintaining electrical isolation and threshold voltage stability, thereby enabling closer spacing of oxide-definition regions.
2Productivity
If the metal gate endcap portion size is reduced to increase device density, then the spacing between oxide-definition regions is improved, but capacitance increases and power efficiency deteriorates
Solution Approach 1:
The dielectric constant parameter of the endcap material is changed by selecting a dielectric material with lower capacitance characteristics. This parameter change reduces the capacitance between adjacent gate structures, thereby reducing RC time delay and improving power efficiency while allowing increased device density.
3Loss of energy
If dielectric endcap portions are formed between metal gate portions to reduce capacitance, then power efficiency is improved, but device complexity increases
Solution Approach 1:
The dielectric endcap portions serve multiple functions: they provide electrical isolation between adjacent metal gate portions, maintain threshold voltage stability, reduce capacitance between gates, and enable closer spacing of oxide-definition regions. This multi-functionality reduces the need for separate structures, thereby limiting the increase in device complexity while achieving improved power efficiency.
Data Source
AI summary
A semiconductor device includes a semiconductor substrate, a first semiconductor structure, a second semiconductor structure, a third semiconductor structure, a dielectric wall, and a first isolation feature. The first semiconductor structure, the second semiconductor structure and the third semiconductor structure are disposed on the semiconductor substrate. The first semiconductor structure is disposed between the second semiconductor structure and the third semiconductor structure. The dielectric wall is disposed on the semiconductor substrate and is connected between the first semiconductor structure and the second semiconductor structure. The first isolation feature is disposed between the first semiconductor structure and the third semiconductor structure, and extends into the semiconductor substrate.