FinFET Ion Implantation Support Layer for Fin Integrity
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Solution Overview
Problem
Conventional semiconductor structures with fins, such as FinFETs, suffer from poor electrical performance due to fin bending and amorphousness during the ion implantation process, which degrades device reliability and limits further size reduction.
Innovation Solution
A support layer is formed on the sidewalls of the fins before ion implantation to prevent bending and improve fin quality, using a material like silicon nitride with a thickness of approximately 10 Å to 200 Å, which supports the fins during high-temperature processing and reduces amorphousness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ion implantation is performed on fins without support layer, then doping can be achieved, but fin bending occurs and electrical performance deteriorates
Solution Approach 1:
A support layer is formed on the fins before ion implantation to prevent fin bending during the doping process. The support layer provides mechanical strength to the fins, maintaining their shape integrity when exposed to high-energy ion beams, and is subsequently removed after doping is complete.
Solution Approach 2:
The support layer acts as an intermediary protective structure between the fin and the ion implantation process. It provides the necessary mechanical support during the harmful ion implantation process, allowing doping to proceed while preventing fin deformation, then is removed to restore the original fin structure.
2Productivity
If high temperature is applied during ion implantation, then doping process can be completed, but fin amorphousness increases and quality decreases
Solution Approach 1:
The support layer is formed before ion implantation to provide thermal protection during the high-temperature doping process. It helps maintain the crystalline structure of the fin by providing thermal stability and preventing excessive heat damage that would cause amorphousness.
Solution Approach 2:
The support layer modifies the thermal parameters during ion implantation by providing thermal isolation and controlling heat distribution. This allows the ion implantation process to be completed while maintaining better thermal management and reducing the extent of fin amorphousness.
3Manufacturing precision
If support layer is added before ion implantation, then fin integrity is improved, but process complexity increases
Solution Approach 1:
The support layer is a temporary structure that is discarded after serving its protective function. It is formed before ion implantation to protect the fin, performs its protective duty during doping, and is then completely removed. This temporary addition allows for better fin integrity while minimizing long-term process complexity.
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 support layer effectively reduces fin bending and improves electrical performance by maintaining fin integrity and quality, enhancing the yield and performance of semiconductor structures.
Implementation Method 1
A support layer is formed on the sidewalls of the fins before ion implantation to prevent bending and improve fin quality
Implementation Method 2
ion implanting the fins through the support layer to form an ion doped region by an ion implantation process
Data Source
AI summary
A semiconductor structure and a fabrication method are provided. The fabrication method includes providing a base substrate including a substrate and a plurality of discrete fins on the substrate; forming a support layer at least partially on sidewalls of the fins; ion implanting the fins through the support layer to form an ion doped region by an ion implantation process; removing the support layer to expose sidewalls of the fins.