Conductive Liners Over Silicide Contacts for Lower Resistance
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Solution Overview
Problem
The increasing resistance in semiconductor devices poses a challenge for achieving faster and more energy-efficient performance as semiconductor technology advances.
Innovation Solution
The implementation of conductive liners over silicide structures, formed through specific deposition and annealing processes, to reduce resistance and protect silicide structures from oxidation, combined with the use of oxygen-free conductive liner layers to further minimize resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional materials and processes are used in semiconductor manufacturing, then manufacturing simplicity is maintained, but device resistance increases
Solution Approach 1:
The patent segments the contact structure into multiple functional layers: silicide structure, conductive liner layer, and fill metal layer. This segmentation allows each layer to perform its specific function optimally - the silicide provides low resistance contact to the semiconductor region, the conductive liner prevents oxidation and ensures adhesion, and the fill metal provides the final low resistance path. This multi-layer approach reduces overall device resistance while maintaining manufacturing feasibility through standardized deposition and etching processes.
Solution Approach 2:
The conductive liner layer acts as an intermediary between the silicide structure and the fill metal. It prevents direct oxidation of the silicide during subsequent manufacturing steps while maintaining electrical continuity. The liner layer mediates the interface between different materials, ensuring adhesion and preventing harmful interactions, thereby reducing contact resistance without requiring complex protective measures.
2Reliability
If silicide structures are exposed to oxygen during manufacturing, then manufacturing process simplicity is maintained, but oxidation increases resistance
Solution Approach 1:
The conductive liner layer is deposited over the silicide structure before any oxygen-exposed manufacturing steps. This preliminary protective action prevents oxidation of the silicide during subsequent etching and filling operations. By establishing this protective barrier in advance, the patent eliminates the need for complex in-situ protection methods while ensuring low contact resistance is maintained throughout the manufacturing process.
3Productivity
If geometry size decreases in semiconductor devices, then device integration is improved, but resistance increases
Solution Approach 1:
The patent employs a composite contact structure combining multiple materials with complementary properties. The silicide layer (e.g., cobalt silicide or nickel silicide) provides low resistance contact to the semiconductor region, while the conductive liner (e.g., tungsten or cobalt) offers both protection and conductivity. This composite approach allows the contact structure to maintain low resistance even as overall device dimensions shrink, enabling continued device integration without sacrificing electrical performance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces the overall resistance of semiconductor devices, maintaining performance by minimizing contact resistance and oxidation, thereby enhancing device efficiency.
Implementation Method 1
protect silicide structures from oxidation
Implementation Method 2
formed through specific deposition and annealing processes
Implementation Method 3
formed through specific deposition and annealing processes
Data Source
AI summary
A semiconductor device includes a semiconductor substrate, an epitaxial structure, a silicide structure, a conductive structure, and a protection segment. The epitaxial structure is disposed in the semiconductor substrate. The silicide structure is disposed in the epitaxial structure. The conductive structure is disposed over the silicide structure and is electrically connected to the silicide structure. The protection segment is made of metal nitride, is disposed over the silicide structure, and is disposed between the silicide structure and the conductive structure.