FinFET Backside Contact Structure for Short-Channel Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor devices face challenges in scaling density and improving current control capability while effectively suppressing short channel effects, particularly in multi-gate transistors with three-dimensional channels.
Innovation Solution
The semiconductor device incorporates a fin-shaped pattern on a substrate with specific configurations of source/drain contacts, buried conductive patterns, and wiring lines, including varying widths and spacings to enhance element performance and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multi-gate transistor with three-dimensional channel is used, then scaling is easily performed and current control capability is improved, but short channel effect still occurs influencing channel potential
Solution Approach 1:
The patent introduces a vertical dimension by forming a buried conductive pattern that extends through the substrate thickness direction, connecting source/drain contacts at different depths. This three-dimensional contact structure allows current to flow through multiple paths (via contact, via substrate, to back wiring line), effectively reducing the impact of short channel effects while maintaining scaling capability.
Solution Approach 2:
The buried conductive pattern acts as an intermediary element between the source/drain contact and the back wiring line on the substrate rear surface. This intermediate structure provides an additional current path that bypasses the problematic channel region, reducing short channel effects while maintaining effective current control.
2Reliability
If contact connection via width increases away from substrate surface, then connection reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The contact connection via is designed with an asymmetric width profile where the via width increases as it extends away from the substrate surface. This asymmetric geometry provides larger connection area at the deeper levels where contact is made, improving reliability, while the narrower upper portion simplifies alignment and manufacturing processes.
3Productivity
If source/drain contact width decreases away from substrate surface, then current control is improved, but contact resistance increases
Solution Approach 1:
The source/drain contact is designed with a width that decreases away from the substrate surface, creating a tapered structure. This three-dimensional geometry allows the contact to maintain low resistance at the broad base level where it connects to the fin, while the narrowing upper portion provides better current control and integration with overlying structures.
Data Source
AI summary
A semiconductor device a first fin-shaped pattern provided at a first surface of a substrate and extending in a second direction, a first source/drain pattern disposed on the first fin-shaped pattern and connected thereto, a first source/drain contact disposed on the first source/drain pattern and connected thereto, a buried conductive pattern extending through the substrate and connected to the first source/drain contact, a contact connection via disposed between the first source/drain contact and the buried conductive pattern. The contact connection via is directly connected to the first source/drain contact and a back wiring line disposed on a second surface of the substrate and connected to the buried conductive pattern. A width of the contact connection via increases as the contact connection via extends away from the second surface. A width of the first source/drain contact decreases as the first source/drain contact extends away from the second surface of the substrate.