Semiconductor Gate Dielectric Fluorine Profiles for PMOS and NMOS Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing complexity of semiconductor devices due to higher integration density and smaller device sizes poses challenges in designing integrated circuits, particularly in adjusting threshold voltages and improving the quality of dielectric and interlayer layers.
Innovation Solution
The semiconductor device incorporates interlayer layers with reduced dangling bonds and adjusts the fluorine concentration of both dielectric and interlayer layers based on the impurity doping type of the active region, using a method that includes fluorine implantation and heat treatment to improve layer quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of devices per unit chip area is increased to achieve higher integration density, then productivity and device density are improved, but device size must be reduced and design complexity increases exponentially
Solution Approach 1:
The patent applies local quality by differentiating the fluorine concentration in dielectric layers based on the impurity doping type of underlying active regions. First dielectric layers over P-type regions have higher fluorine concentration than second dielectric layers over N-type regions, creating locally optimized electrical characteristics that enable higher integration density while managing the increased complexity through targeted material composition control
2Reliability
If different threshold voltages are required for PMOS and NMOS transistors, then device operation characteristics are improved, but the properties of dielectric layers must be changed and interlayer layer thickness must be adjusted
Solution Approach 1:
The patent employs parameter changes by modifying the fluorine concentration parameter in dielectric layers to achieve different threshold voltages for PMOS and NMOS transistors. The first dielectric layer has higher fluorine concentration to adjust the threshold voltage of PMOS transistors, while the second dielectric layer has lower fluorine concentration for NMOS transistors, enabling independent optimization of transistor characteristics without complex structural modifications
Solution Approach 2:
Local quality is applied by creating spatially differentiated fluorine concentration profiles in dielectric layers corresponding to different transistor types. The fluorine concentration is locally optimized in regions over P-type active regions versus N-type active regions, providing tailored electrical properties for each transistor type while maintaining a relatively simple overall device structure
3Reliability
If fluorine concentration is increased in dielectric layers to adjust threshold voltage, then transistor characteristics are improved, but dangling bonds may increase affecting electronic properties
Solution Approach 1:
The patent resolves this contradiction by applying local quality through differentiated fluorine concentration control in first and second dielectric layers. The higher fluorine concentration in the first dielectric layer is localized over P-type regions where it provides beneficial threshold voltage adjustment, while the second dielectric layer over N-type regions maintains lower fluorine concentration to minimize dangling bond formation. This spatially selective approach allows threshold voltage control while mitigating harmful effects in specific regions
Solution Approach 2:
Parameter changes are applied by optimizing the fluorine concentration parameter differently in dielectric layers corresponding to different transistor types. The fluorine concentration is tuned to achieve the desired threshold voltage characteristics while maintaining levels that prevent excessive dangling bond formation, balancing electrical performance with material quality
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 quality of dielectric and interlayer layers, stabilizes threshold voltages, and improves the operational characteristics of semiconductor devices by reducing defects and optimizing fluorine distribution.
Implementation Method 1
a method that includes fluorine implantation and heat treatment to improve layer quality
Implementation Method 2
a method that includes fluorine implantation and heat treatment to improve layer quality
Data Source
AI summary
A semiconductor device includes a semiconductor substrate formed to include a first active region and a second active region, first and second dielectric layer disposed over the first and second active regions, first and second gate electrode disposed over the first and second dielectric layers, respectively; and wherein the first and second active region have different impurity doping types from each other, and fluorine concentration of the first dielectric layer is higher than fluorine concentration of the second dielectric layer.