Semiconductor Superlattice Oxygen Monolayers for Mobility
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Solution Overview
Problem
Despite advancements in materials engineering, there is a need for further improvements in charge carrier mobility in semiconductor devices to enhance device speed and reduce power consumption, particularly as devices shrink in size.
Innovation Solution
The method involves forming a semiconductor device with a superlattice structure using epitaxial chemical vapor deposition, where oxygen monolayers are constrained within a crystal lattice of silicon monolayers, reducing the effective mass of charge carriers and thereby increasing mobility. This is achieved by forming spaced apart structures on a semiconductor substrate with stacked groups of layers, including shallow trench isolation regions and cap semiconductor layers, using N2O as an oxygen source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional semiconductor structures are used, then manufacturing simplicity is maintained, but charge carrier mobility is insufficient for high-speed devices
Solution Approach 1:
The semiconductor structure is divided into multiple alternating layers of silicon and silicon-germanium, creating a superlattice structure with periodic composition variations. This segmentation enables enhanced charge carrier mobility through quantum confinement effects and reduced scattering, achieving high-speed device performance while maintaining compatibility with standard manufacturing processes
Solution Approach 2:
The invention employs composite material structures combining silicon and silicon-germanium layers with different compositions and thicknesses. The composite superlattice structure leverages the beneficial properties of both materials to achieve high charge carrier mobility and improved device speed without requiring entirely new manufacturing approaches
2Speed
If strained material layers are introduced to enhance mobility, then charge carrier mobility improves, but manufacturing precision requirements increase
Solution Approach 1:
The invention systematically varies composition parameters (germanium content), layer thickness parameters, and strain parameters to optimize charge carrier mobility. By controlling the germanium concentration in silicon-germanium layers and adjusting layer thickness ratios, the structure achieves desired strain levels and mobility enhancement while remaining within the capabilities of existing precision manufacturing equipment
3Speed
If superlattice structures are formed with multiple alternating layers, then charge carrier mobility increases, but device complexity increases
Solution Approach 1:
The superlattice structure serves multiple functions simultaneously: it provides quantum confinement for enhanced mobility, introduces mechanical strain to further boost carrier velocity, and maintains compatibility with standard CMOS fabrication processes. This multi-functionality achieves high-speed performance without proportionally increasing device complexity
Solution Approach 2:
The alternating periodic structure of silicon and silicon-germanium layers creates a repeating pattern that optimizes both electronic properties and manufacturing efficiency. The periodic composition variations establish favorable energy band structures and strain distributions that enhance charge carrier mobility while allowing for scalable production
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 superlattice structure results in higher charge carrier mobility due to lower conductivity effective mass, enabling faster device performance and reduced power consumption, while being compatible with existing semiconductor processing techniques.
Implementation Method 1
forming a semiconductor device with a superlattice structure using epitaxial chemical vapor deposition
Implementation Method 2
using N2O as an oxygen source
Data Source
AI summary
A method for making a semiconductor device may include forming a plurality of spaced apart structures on a semiconductor substrate within a semiconductor processing chamber, with each structure including a plurality of stacked groups of layers. Each group of layers may include a plurality of stacked base silicon monolayers defining a base semiconductor portion and at least one oxygen monolayer constrained within a crystal lattice of adjacent base silicon portions. Furthermore, the oxygen monolayers may be formed using N2O as an oxygen source.