FinFET Doped Region Layout for Deep Fin Dopant Control
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Solution Overview
Problem
Existing FinFET manufacturing processes are inadequate for device scaling-down, particularly in achieving precise dopant distribution and control in the deeper regions of fin structures, which affects the performance and integration of semiconductor devices.
Innovation Solution
The process involves forming a fin structure with recesses, implanting dopants into these recesses, and performing an annealing process to create expanded doped regions, which allows for deeper dopant diffusion and improved control over dopant concentration, followed by the formation of source/drain structures directly over these regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional FinFET manufacturing processes are used, then basic device fabrication is achieved, but precise dopant distribution and control in deeper regions of fin structures cannot be achieved
Solution Approach 1:
The fin structure is divided into multiple regions with different doping concentrations. A first doped region is formed in the lower portion of the fin structure, and a second doped region is formed in the upper portion, allowing independent control of dopant distribution in different depth zones to achieve precise doping profiles in deeper regions
Solution Approach 2:
Different doping concentrations and types are applied to different locations within the fin structure. The first doped region has a first doping concentration while the second doped region has a second doping concentration, enabling localized optimization of electrical properties at different depths of the fin structure
2Productivity
If device scaling-down continues, then higher integration levels are achieved, but existing manufacturing processes become inadequate
Solution Approach 1:
The gate structure is formed before the doped regions are created. This preliminary formation of the gate structure enables subsequent precise doping operations in the fin structure, allowing manufacturing processes to keep pace with continued device scaling and higher integration levels
3Length of stationary object
If dopants are implanted into recesses and annealing is performed, then deeper dopant diffusion is achieved, but process complexity increases
Solution Approach 1:
Multiple doping operations are merged into a coordinated sequence where first dopants are implanted into recesses, then annealing is performed to form the first doped region, followed by formation of the gate structure, and finally second dopants are implanted to form the second doped region. This merging of operations achieves deep dopant diffusion while managing process complexity through systematic integration
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 enhances the electron efficiency of source/drain structures and reduces resistance by ensuring precise dopant distribution and control, improving the overall performance and integration of FinFET structures.
Implementation Method 1
The doped region may be expanded to form an expanded doped region by performing an annealing process
Implementation Method 2
implanting dopants from the recess to form a doped region
Data Source
AI summary
Semiconductor structures are provided. The semiconductor structure includes a fin structure protruding from a substrate and a doped region formed in the fin structure. The semiconductor structure further includes a metal gate structure formed across the fin structure and a gate spacer formed on a sidewall of the metal gate structure. The semiconductor structure further includes a source/drain structure formed over the doped region. In addition, the doped region continuously surrounds the source/drain structure and is in direct contact with the gate spacer.