Multiple Silicide Regions Through Phase-Change Diffusion Control
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Solution Overview
Problem
As the minimum feature sizes in semiconductor devices are reduced, challenges arise in efficiently manufacturing semiconductor devices with multiple silicide regions, requiring innovative processes to form segregated silicide regions effectively.
Innovation Solution
The method involves depositing a first dual material silicide precursor layer on source/drain regions, forming a first silicide phase, and then changing this phase to a second phase, allowing the second silicide precursor to diffuse and form a third silicide phase, which may include a segregated silicide region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional single-material silicide formation is used, then the manufacturing process is simple, but contact resistance is high and device performance is limited
Solution Approach 1:
The silicide formation process is segmented into multiple stages with different materials: a first silicide material (e.g., cobalt) is deposited and annealed to form an initial silicide layer, then a second silicide material (e.g., nickel) is deposited and annealed to form a final silicide layer. This segmentation allows optimization of contact resistance through material selection while managing process complexity through systematic process design.
Solution Approach 2:
The patent employs composite silicide structures where multiple silicide materials are combined in layered configurations. The first silicide layer and second silicide layer form a composite structure that leverages the advantageous properties of each material - such as the low contact resistance of cobalt silicide and the stability of nickel silicide - to achieve superior overall device performance.
2Productivity
If minimum feature sizes are reduced to increase integration density, then more components can be integrated, but manufacturing challenges and process control difficulties increase
Solution Approach 1:
The patent performs preliminary silicide formation before final device completion. The first silicide layer is formed and annealed in advance, creating a stable foundation that simplifies subsequent processing. This preliminary action allows for better control of critical dimensions and reduces variability in final device characteristics, enabling higher integration density with maintained manufacturing precision.
Solution Approach 2:
The patent utilizes parameter changes in the form of controlled annealing temperatures and deposition conditions to precisely control silicide layer formation. By adjusting annealing temperature profiles and deposition parameters, the process achieves precise control over silicide layer thickness, composition, and electrical properties, enabling manufacturing of smaller features with high precision.
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 enables the formation of segregated silicide regions with optimized silicide materials for N-type and P-type devices, reducing contact resistances and improving dopant concentrations, thereby enhancing the performance of semiconductor devices.
Implementation Method 1
changing the first phase of the first silicide to a second phase of the first silicide
Implementation Method 2
the second silicide precursor being soluble within the second phase of the first silicide and forming a third phase of the first silicide with the second silicide precursor
Data Source
AI summary
A semiconductor device with multiple silicide regions is provided. In embodiments a first silicide precursor and a second silicide precursor are deposited on a source/drain region. A first silicide with a first phase is formed, and the second silicide precursor is insoluble within the first phase of the first silicide. The first phase of the first silicide is modified to a second phase of the first silicide, and the second silicide precursor being soluble within the second phase of the first silicide. A second silicide is formed with the second silicide precursor and the second phase of the first silicide.