Superlattice Quantum Dot Structure for Higher Carrier Mobility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor devices face limitations in achieving enhanced performance due to constraints in charge carrier mobility and material properties, despite advancements in strained material layers and superlattice structures.
Innovation Solution
The development of a semiconductor device with a superlattice structure that includes stacked groups of semiconductor and non-semiconductor monolayers, where the non-semiconductor monolayers are constrained within the crystal lattice of adjacent semiconductor portions, enhancing charge carrier mobility and providing a lower conductivity effective mass, and incorporating quantum dots of a different semiconductor material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If strained material layers and superlattice structures are used to enhance charge carrier mobility, then device performance is improved, but manufacturing complexity increases
Solution Approach 1:
The superlattice structure is segmented into alternating thin layers of different semiconductor materials (e.g., SiGe and Si), each layer being only a few nanometers thick. This segmentation creates multiple interfaces that generate piezoelectric fields to enhance carrier mobility while keeping each individual layer simple to manufacture
Solution Approach 2:
The patent employs composite superlattice structures combining different semiconductor materials with complementary properties. The SiGe/Si superlattice combines the high piezoelectric effect of SiGe with the mechanical stability of Si, achieving enhanced mobility while maintaining manufacturability through established semiconductor fabrication processes
2Adaptability or versatility
If quantum dots are incorporated to enhance device functionality, then device performance is improved, but manufacturing precision requirements increase
Solution Approach 1:
Quantum dots are formed in-situ during the epitaxial growth process, before subsequent device fabrication steps. This preliminary formation ensures precise positioning and uniform size distribution of quantum dots, as they self-organize during the controlled deposition of alternating SiGe and Si layers, eliminating the need for post-growth manipulation
Solution Approach 2:
The quantum dots self-organize and self-limit in size and position during the epitaxial growth process. The alternating SiGe/Si layers create a self-organizing system where quantum dots naturally form at specific interfaces with controlled sizes (5-50 nm), reducing the need for external precision control mechanisms
3Speed
If non-semiconductor monolayers are constrained within the crystal lattice to reduce scattering, then charge carrier mobility is improved, but manufacturing complexity increases
Solution Approach 1:
Non-semiconductor monolayers (such as oxide or nitride layers) are inserted locally at specific interfaces within the superlattice structure, rather than throughout the entire structure. These localized monolayers provide scattering reduction and interface passivation exactly where needed, while keeping the overall structure manufacturable through standard epitaxial processes
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 results in improved charge carrier mobility, reduced scattering effects, and enhanced device performance, including piezoelectric, pyroelectric, and ferroelectric properties, while also acting as a barrier to dopant diffusion and reducing unwanted scattering, thus benefiting various semiconductor devices.
Implementation Method 1
enhanced device performance, including piezoelectric, pyroelectric, and ferroelectric properties
Implementation Method 2
enhanced device performance, including piezoelectric, pyroelectric, and ferroelectric properties
Implementation Method 3
enhanced device performance, including piezoelectric, pyroelectric, and ferroelectric properties
Implementation Method 4
reduced scattering effects
Data Source
AI summary
A method for making a semiconductor device may include forming at least one semiconductor layer including a superlattice therein. The superlattice may include a plurality of stacked groups of layers, with each group of layers including stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The method may further include forming quantum dots spaced apart in the at least one semiconductor layer above the superlattice and including a different semiconductor material than the semiconductor layer.