FinFET Epitaxial Region Radical Treatment for Strain Control
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Solution Overview
Problem
The semiconductor industry faces challenges in integrating high-performance transistors with reduced feature sizes, as existing fabrication methods struggle to optimize the formation of fins and source/drain regions in FinFETs, leading to inefficiencies in device performance and integration density.
Innovation Solution
A method involving epitaxial growth of semiconductor materials, such as silicon and silicon germanium, is employed to form fins and source/drain regions, utilizing precise patterning and doping techniques to enhance strain and alignment with the crystalline structure, along with the use of a processing system to control epitaxial growth conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional fabrication methods are used to form fins and source/drain regions, then manufacturing simplicity is maintained, but integration density and device performance are insufficient
Solution Approach 1:
The method performs preliminary patterning of mandrels and spacers before fin formation, establishing precise geometric templates that guide subsequent epitaxial growth. This preliminary structuring enables high integration density while maintaining process control through pre-defined patterns rather than attempting to achieve precision during the growth phase itself.
Solution Approach 2:
The invention utilizes epitaxial growth parameters (temperature, pressure, gas flow rates, composition ratios) to precisely control fin height, width, and material composition. By adjusting these parameters during the growth process, the method achieves high integration density with optimized device characteristics without requiring fundamentally new fabrication equipment or processes.
2Productivity
If feature size is reduced to increase integration density, then more components can be integrated, but manufacturing precision and alignment become more difficult to achieve
Solution Approach 1:
The method employs nested structures where spacers are formed around mandrels, and fins subsequently grow around the spacers. This nested approach provides self-aligned fabrication where each structure serves as a template for the next, automatically ensuring precise alignment and spacing even at reduced feature sizes without requiring additional alignment steps.
Solution Approach 2:
The epitaxial growth process is self-regulating through the spacer structures that automatically define fin dimensions and spacing. The spacers physically constrain the growth boundaries, making the alignment precision inherent to the structure formation rather than dependent on external alignment procedures. This self-service mechanism maintains manufacturing precision as feature sizes scale down.
3Reliability
If epitaxial growth is used to form fins and source/drain regions, then strain and electrical properties are improved, but process complexity and manufacturing difficulty increase
Solution Approach 1:
The method employs composite material structures with different semiconductor compositions (e.g., SiGe source/drain regions with silicon fins) to induce strain in the channel region. This composite approach improves carrier mobility and electrical performance by leveraging the beneficial properties of different materials while maintaining compatibility with standard epitaxial growth processes, thus not significantly increasing manufacturing difficulty.
Solution Approach 2:
The invention applies different material compositions and doping levels to specific regions (mandrels, spacers, fins, source/drain areas) to optimize local electrical properties. By tailoring material quality locally rather than uniformly throughout the structure, the method achieves high device performance with controlled strain regions while using the same fundamental epitaxial growth process, minimizing the increase in manufacturing 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
This approach improves the integration density and performance of FinFETs by enhancing strain in channel regions, allowing for more efficient integration of transistors with improved electrical properties.
Implementation Method 1
converting a second precursor into first radicals and first ions; converting a fourth precursor into second radicals and second ions
Implementation Method 2
separating the first radicals from the first ions
Data Source
AI summary
A method includes flowing first precursors over a semiconductor substrate to form an epitaxial region, the epitaxial region includes a first element and a second element; converting a second precursor into first radicals and first ions; separating the first radicals from the first ions; and flowing the first radicals over the epitaxial region to remove at least some of the second element from the epitaxial region.