Feedthrough Via Layout Between Active Regions for Gate Isolation
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Solution Overview
Problem
The existing methods for forming feedthrough vias in semiconductor structures are inefficient in terms of space usage and risk of shorting with active metal structures, as they often require additional space and dedicated cells, which decreases functional density and increases manufacturing complexity.
Innovation Solution
The formation of feedthrough vias directly between active regions, surrounded by a cut-metal-gate structure that cuts through active metal gates and interlayer dielectric layers, allowing for seamless integration and isolation from adjacent active regions, thereby reducing spacing and minimizing the risk of shorting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feedthrough vias are formed inside a dedicated feedthrough cell isolated from adjacent active regions, then isolation from active metal structures is ensured, but additional space is taken up and functional density decreases
Solution Approach 1:
The patent merges the feedthrough via formation with the active region structure by forming vias directly between adjacent active regions rather than in isolated cells. The metal gate structure serves dual purposes: as the functional gate for the transistor and as the isolation structure for the feedthrough via, eliminating the need for separate isolation regions.
Solution Approach 2:
The metal gate structure performs multiple functions simultaneously: it acts as the control gate for the transistor device and as the isolation barrier for the feedthrough via. This multi-functionality eliminates the need for dedicated isolation structures, saving space and improving functional density.
2Area of stationary object
If feedthrough vias are formed directly between active regions, then space is saved and functional density increases, but risk of shorting to active metal structures increases
Solution Approach 1:
The metal gate structure serves as both the functional gate and the isolation barrier. By forming the feedthrough via to terminate at the metal gate rather than requiring separate isolation structures, the patent achieves both space savings and reliable isolation through the conductive metal gate itself.
Solution Approach 2:
The metal gate acts as an intermediary structure that provides electrical isolation between adjacent active regions. The via is formed to contact the metal gate, which then provides the necessary electrical isolation, eliminating the need for additional insulating structures.
3Ease of manufacture
If minimum IC feature size is reduced to improve production efficiency and lower costs, then manufacturing cost decreases, but complexity of IC manufacturing processes increases
Solution Approach 1:
The patent combines the feedthrough via formation process with the existing active region fabrication steps. By forming vias directly between active regions using the same metal gate structure, the patent eliminates additional process steps that would be required for separate isolation structures, thereby reducing manufacturing complexity despite smaller feature sizes.
Data Source
AI summary
One aspect of the present disclosure pertains to a semiconductor structure. The semiconductor structure includes first and second active regions extending lengthwise along a first direction and metal gate structures extending lengthwise along a second direction over channels of the first and second active regions. The semiconductor structure includes an insulating structure cutting through the metal gate structures. The insulating structure is disposed between the first and the second active regions along the second direction. The semiconductor structure includes source/drain (S/D) contacts over the insulating structure and over S/D features of the first and second active regions. The S/D contacts extend lengthwise along the second direction. And the semiconductor structure includes a feedthrough via contacting a bottom surface of the S/D contacts and penetrating through a portion of the insulating structure. The insulating structure surrounds the feedthrough via and isolates the feedthrough via from the metal gate structures.