Contact Plug Barrier Structure for Diffusion-Ion Protection
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Solution Overview
Problem
Conventional semiconductor devices face poor electrical performance due to weak control over channel current and leakage currents caused by poor quality metal plugs, which are prone to damage from diffusion ions.
Innovation Solution
A semiconductor device structure and fabrication method involving a substrate with a dielectric layer, a metal silicide layer, a barrier layer, and a plug layer, where the barrier layer isolates the metal silicide layer from the plug layer, preventing damage from diffusion ions, and an adhesion layer is used to enhance the plug's quality and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal plug is formed directly in the contact hole to achieve electrical connection, then the device structure is simple, but the formation quality of the metal plug is poor and it is damaged by diffusion ions
Solution Approach 1:
The patent divides the metal plug formation into multiple sequential layers: metal silicide layer, barrier layer, and adhesion layer. Each layer serves a specific function - the metal silicide layer provides low resistance contact, the barrier layer prevents diffusion ion damage, and the adhesion layer ensures strong bonding. This segmentation resolves the contradiction by improving plug quality through functional division while maintaining overall structural coherence.
Solution Approach 2:
The patent introduces intermediate layers (barrier layer and adhesion layer) between the substrate and the final metal plug. The barrier layer acts as a mediator to protect the metal silicide layer from diffusion ions, while the adhesion layer mediates the bonding between different materials. These intermediaries resolve the contradiction by protecting critical layers without significantly increasing overall device complexity.
2Reliability
If the contact hole is fully filled with plug layer to ensure good electrical connection, then the electrical performance is improved, but the formation process becomes complex and quality control is difficult
Solution Approach 1:
The patent performs preliminary actions by forming the metal silicide layer and barrier layer on the substrate surface before filling the contact hole with the plug layer. This ensures that the underlying layers are properly prepared and protected before the final plug formation, improving manufacturing precision. The preliminary formation of these layers establishes a stable foundation that simplifies subsequent plug filling and ensures consistent electrical performance.
Solution Approach 2:
The patent applies different materials and properties to different regions and layers: the metal silicide layer provides high conductivity at the contact interface, the barrier layer provides diffusion protection where needed, and the adhesion layer provides bonding strength at interfaces. This local quality differentiation resolves the contradiction by optimizing each region for its specific function, ensuring good electrical connection while maintaining manufacturability through clear functional zones.
3Reliability
If a conventional planar transistor structure is used to simplify device fabrication, then the manufacturing process is simple, but the control ability on channel current is weak causing short channel effect and leakage current
Solution Approach 1:
The patent changes the physical and chemical parameters of the transistor structure by introducing metal silicide layers and barrier layers with specific material properties. These parameter changes - including material composition, layer thickness, and electrical properties - enable better channel current control and reduced leakage without fundamentally altering the planar transistor architecture. The parameter modifications allow the device to achieve improved performance while maintaining relatively simple fabrication processes.
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
The solution improves the quality and electrical performance of semiconductor devices by preventing damage to the plug layer from diffusion ions, resulting in enhanced reliability and functionality.
Implementation Method 1
forming a reaction layer on the metal layer, and after forming the plug layer over the reaction layer, performing an annealing treatment to form the metal silicide layer
Implementation Method 2
performing an annealing treatment to form the metal silicide layer on the surface of the substrate
Implementation Method 3
the barrier layer isolates the metal silicide layer from the plug layer, preventing damage from diffusion ions
Data Source
AI summary
A semiconductor device and a fabrication method of the semiconductor device are provided. The semiconductor device includes a substrate, and a dielectric layer disposed over the substrate. The dielectric layer contains a contact hole, and a bottom of the contact hole exposes a surface of the substrate. The semiconductor device also includes a metal silicide layer disposed on the surface of the substrate exposed by the bottom of the contact hole. Further, the semiconductor device includes a barrier layer disposed on a surface of the metal silicide layer, and a plug layer disposed over the barrier layer and fully filling the contact hole.