Dual Work Function Gate Bridge for Hot Carrier Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated circuit devices experience breakdown due to hot carrier injection across device dielectric layers under high voltage conditions, leading to reduced performance and lifespan.
Innovation Solution
A structure with a conductive bridge over an insulator within a substrate, coupled to active regions, and featuring gate dielectric layers and work function metals, which reduces parasitic capacitance and hot carrier injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If higher voltages are applied across IC devices to increase power demand, then device performance is improved, but hot carrier injection across device dielectric layers causes device breakdown and reduces lifespan
Solution Approach 1:
The gate electrode is segmented into multiple portions (first gate electrode portion and second gate electrode portion) with different work function metals. This segmentation allows each portion to be optimized for specific functions: one portion minimizes hot carrier injection while the other controls threshold voltage, thereby maintaining device performance and reliability under high voltage conditions without requiring a single compromised design
2Ease of manufacture
If conventional single work function metal gate structures are used, then manufacturing is simpler, but hot carrier injection reliability deteriorates under high voltage
Solution Approach 1:
Different work function metals are applied to different portions of the gate electrode structure. The first work function metal (e.g., tungsten) is used in the first gate electrode portion to minimize hot carrier injection, while the second work function metal (e.g., titanium nitride) is used in the second gate electrode portion for threshold voltage control. This local differentiation of material properties enables simultaneous optimization of reliability and manufacturability
3Reliability
If stress relief measures are implemented to improve hot carrier injection reliability, then device lifespan is extended, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into a single gate electrode structure. The segmented gate electrode with different work function metals simultaneously achieves hot carrier injection mitigation, threshold voltage control, and stress management. By combining these functions in one integrated structure rather than adding separate components, the patent improves reliability without proportionally increasing device complexity
Data Source
AI summary
A structure, including an insulator within a substrate. The substrate includes a first active region adjacent a first sidewall of the insulator and a second active region adjacent a second sidewall of the insulator opposite the first sidewall. The structure further includes a conductive bridge over the insulator and coupling the first active region of the substrate to the second active region of the substrate. The structure includes a gate dielectric layer over the conductive bridge, a first work function metal over the first active region, and a second work function metal over the second active region.