FinFET Blocking Layer Prevents Ion Implantation Damage
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Solution Overview
Problem
The challenge in semiconductor manufacturing lies in forming reliable three-dimensional fin-like field effect transistors (FinFETs) as feature sizes decrease, making fabrication processes increasingly difficult due to issues like short channel effects and leakage current.
Innovation Solution
A semiconductor device structure is formed by creating a doped anti-punch-through region on a substrate, followed by a blocking layer, multiple semiconductor layers, and fin structures, with a gate stack encircling the fin channel structures to control them from multiple sides, and source/drain structures are formed adjacent to the fin channel structures to enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes continue to decrease to increase production efficiency and lower costs, then productivity improves, but manufacturing precision deteriorates due to increasingly difficult fabrication processes
Solution Approach 1:
The fabrication process is divided into multiple sequential steps: forming the blocking layer first, then creating the fin structure, and finally performing ion implantation. This segmentation allows each step to be optimized independently, enabling precise control at smaller feature sizes while maintaining overall productivity
Solution Approach 2:
The blocking layer is formed in advance before the fin structure is created. This preliminary action protects the substrate and controls dopant diffusion paths before the critical fin formation occurs, enabling higher precision fabrication at scaled dimensions
2Reliability
If ion implantation is performed to dope the substrate, then electrical properties improve, but fin structures may be damaged during the process
Solution Approach 1:
The blocking layer is formed before ion implantation to define precise dopant diffusion boundaries. This preliminary structure guides the ion implantation process, ensuring dopants are deposited only in desired regions without damaging the fin structures
Solution Approach 2:
The blocking layer acts as an intermediary between the ion implantation process and the fin structure. It mediates the dopant delivery, allowing electrical doping while protecting the fin structure from direct ion bombardment damage
3Reliability
If a gate is provided over the fin to control the channel, then device performance improves, but leakage current occurs due to short channel effects
Solution Approach 1:
The planar gate structure is transformed into a three-dimensional FinFET structure where the gate wraps around the fin channel from multiple sides. This dimensional change increases the effective gate control over the channel, suppressing short channel effects and reducing leakage current while maintaining high device 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 improves device quality and reliability by preventing damage to fin structures during ion implantation, reducing leakage current, and enhancing carrier mobility, thereby achieving better performance and reliability in FinFETs.
Implementation Method 1
a blocking layer between the fin channel structure and the doped region
Implementation Method 2
forming an anti-punch-through region over a semiconductor substrate
Data Source
AI summary
Structures and formation methods of a semiconductor device structure are provided. The semiconductor device structure includes a semiconductor substrate and a fin channel structure over the semiconductor substrate. The semiconductor device structure also includes a gate stack covering a portion of the fin channel structure. The semiconductor device structure further includes a source/drain structure adjacent to the fin channel structure and a doped region between the semiconductor substrate and the fin channel structure. In addition, the semiconductor device structure includes a blocking layer between the fin channel structure and the doped region.