FinFET Thermal Conductive Layers for Self-Heating Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The self-heating effect in FinFET semiconductor devices is severe due to poor thermal conductivity of materials like silicon germanium, leading to reduced carrier mobility and increased leakage current, which affects the performance and service life of the devices.
Innovation Solution
The method involves forming thermal conductive layers with higher thermal conductivity than the fin material in specific regions of the fins, allowing for improved heat transfer and reduced self-heating, while maintaining carrier mobility by retaining second regions under gate structures and replacing first regions with thermal conductive layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicon germanium material is used for fins to improve carrier mobility, then device performance is enhanced, but thermal conductivity decreases leading to severe self-heating effect
Solution Approach 1:
The patent applies local quality by forming thermal conductive layers with high thermal conductivity material specifically in the first regions of the fins (source/drain regions), while maintaining the original fin material in the second regions (channel regions). This localized approach allows different parts of the fin structure to have different thermal properties, solving the self-heating problem in source/drain regions without affecting carrier mobility in channel regions.
Solution Approach 2:
The patent uses composite materials by combining the original fin material (e.g., silicon germanium) with thermal conductive layers (e.g., tungsten, copper, or aluminum) in a layered structure. The thermal conductive layers are formed by filling openings with conductive material, creating a composite fin structure that leverages the high carrier mobility of the original material and the high thermal conductivity of the added layers.
2Productivity
If fin size is reduced to increase component density, then integration density improves, but heat dissipation capability deteriorates
Solution Approach 1:
The patent applies local quality by concentrating thermal management resources (thermal conductive layers) specifically in the source and drain regions where heat is generated, rather than uniformly distributing thermal management across the entire fin structure. This allows efficient heat dissipation in critical regions while maintaining small overall fin dimensions for high density.
3Temperature
If thermal conductive layers are added to fins to improve heat transfer, then self-heating effect is reduced, but device structure becomes more complex
Solution Approach 1:
The patent applies segmentation by dividing the fin structure into distinct functional regions (first regions for thermal conduction, second regions for carrier transport) and adding thermal conductive layers only in specific segments (source/drain regions). This segmented approach adds thermal management functionality without complicating the entire fin structure, maintaining simplicity in the channel region while enhancing performance in source/drain regions.
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 configuration effectively reduces the self-heating effect and enhances carrier mobility, thereby improving the performance and service life of semiconductor devices by efficiently transferring heat generated during operation.
Implementation Method 1
forming thermal conductive layers in the first openings... A material of the fins has a first thermal conductivity, a material of the thermal conductive layers have a second thermal conductivity, and the second thermal conductivity is larger than the first thermal conductivity
Data Source
AI summary
A method for fabricating a semiconductor structure includes providing a substrate and forming a plurality of fins on a surface of the substrate. Along an extending direction of the fins, the fins include first regions, second regions, and gate structures across the second regions. The first regions are located at both sides of the second regions. The method also includes forming first openings in the fins by removing the first regions of the fins at both sides of the gate structures until the substrate is exposed. Further, the method includes forming thermal conductive layers in the first openings, and forming doped layers on top surfaces of the thermal conductive layers. A material of the fins has a first thermal conductivity, a material of the thermal conductive layers have a second thermal conductivity, and the second thermal conductivity is larger than the first thermal conductivity.