FinFET Deep Contact Structure for Low Resistance and Latch-Up Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing FinFET devices and fabrication methods face challenges in achieving optimal performance due to issues such as electrical interference and crosstalk, which affect the efficiency and reliability of the devices.
Innovation Solution
The method involves forming a FinFET device structure with a fin structure etched into a substrate, surrounded by an isolation structure, and a gate structure with low-k dielectric gate spacer layers, along with source/drain structures and a deep contact structure that reduces contact resistance and prevents latch-up by directly connecting to the substrate without passing through a fin or epitaxial layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional contact structure is used in FinFET devices, then the fabrication process is simpler, but the contact resistance is higher and latch-up cannot be prevented
Solution Approach 1:
The contact structure is segmented into multiple distinct components: a shallow contact structure for standard electrical connection and a deep contact structure extending to the substrate for latch-up prevention. This segmentation allows each contact type to perform its specific function optimally without interfering with the other, resolving the contradiction between reliability improvement and device complexity.
Solution Approach 2:
The contact structure extends into the vertical dimension by creating a deep contact that penetrates through the isolation structure to reach the substrate. This dimensional extension enables the deep contact to provide a separate electrical path that prevents latch-up, while the shallow contact maintains standard connectivity, thus improving reliability without excessive complexity.
2Productivity
If FinFET devices are fabricated with higher device density and smaller dimensions, then manufacturing cost decreases, but electrical interference and crosstalk increase
Solution Approach 1:
The isolation structure serves as an intermediary element between adjacent FinFET devices. By positioning the deep contact within this isolation structure and ensuring it reaches the substrate, the design creates an electrical barrier that mediates between closely spaced devices, preventing crosstalk and electrical interference while maintaining high device density.
Solution Approach 2:
The deep contact structure provides localized electrical control at specific critical points where latch-up and crosstalk are most likely to occur. By concentrating the latch-up prevention function in the deep contact regions rather than uniformly across the entire device, the design maintains high device density while addressing electrical interference at problem areas.
Data Source
AI summary
A FinFET device structure and method for forming the same is provided. The FinFET device structure includes an isolation structure formed over a substrate, and a gate structure formed over the isolation structure. The FinFET device structure includes a first dielectric layer formed over the isolation structure and adjacent to the gate structure and a source/drain (S/D) contact structure formed in the first dielectric layer. The FinFET device structure also includes a deep contact structure formed through the first dielectric layer and adjacent to the S/D contact structure. The deep contact structure is through the isolation structure, and a bottom surface of the S/D contact structure is higher than a bottom surface of the deep contact structure.