Si/SiGe Flash Memory Heterostructure for Low-Voltage Endurance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current flash memory devices face challenges in achieving efficient operation and high endurance due to issues with oxide interface quality and carrier mobility, leading to limitations in voltage thresholds and memory window degradation.
Innovation Solution
A flash memory device utilizing a Si/SiGe heterostructure with a semiconductor quantum well layer, spacer, and channel layer, where the semiconductor spacer has a higher germanium atomic percentage than the quantum well and channel layers, enhancing carrier tunneling and reducing oxide breakdown, allowing for efficient programming and erasing with lower voltage requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional flash memory devices are used, then they can store information, but they suffer from oxide interface quality issues and low carrier mobility leading to voltage threshold limitations and memory window degradation
Solution Approach 1:
The patent employs a Si/SiGe heterostructure with a quantum well layer, spacer layer, and channel layer. The semiconductor spacer has a higher germanium atomic percentage than the quantum well and channel layers, creating a composite material system that enhances carrier tunneling efficiency and reduces oxide breakdown, thereby improving reliability without compromising interface quality
Solution Approach 2:
The patent introduces a semiconductor spacer layer with distinct local properties (higher germanium content) positioned between the quantum well and channel layers. This localized modification optimizes carrier transport in the critical tunneling region while maintaining overall device functionality, addressing oxide interface quality issues at the specific location where carrier tunneling occurs
2Duration of action of moving object
If conventional flash memory devices are used, then they can operate, but they require high voltage and suffer from memory window degradation after multiple cycles
Solution Approach 1:
The patent modifies the germanium atomic percentage parameter across different layers to optimize device performance. The semiconductor spacer has a higher germanium content than the quantum well and channel layers, which changes the band structure and enhances carrier tunneling efficiency, enabling operation at lower voltages and extending the number of viable operation cycles
Solution Approach 2:
The heterostructure combines multiple semiconductor materials with different germanium compositions to create a system that enables efficient carrier tunneling at lower voltage thresholds, thereby extending operational lifetime without requiring high voltage operation
3Reliability
If conventional flash memory devices are used, then they can store data, but they exhibit limited carrier mobility and susceptibility to short channel effects
Solution Approach 1:
The patent uses a composite Si/SiGe heterostructure with a quantum well layer, spacer layer, and channel layer where each layer has a specific germanium composition. This composite structure enhances carrier mobility through improved band alignment and reduced scattering, while the split gate configuration provides excellent short channel effect control
Solution Approach 2:
The channel region is segmented into distinct layers (quantum well, spacer, channel) with different material compositions. This segmentation allows independent optimization of each layer's properties to maximize carrier mobility while maintaining overall device control and minimizing short channel effects
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 device exhibits improved carrier mobility, high endurance with over 10,000 operation cycles without memory window degradation, and maintains performance from 4K to 120K, integrating well with logic and quantum devices on a single platform.
Implementation Method 1
a semiconductor quantum well layer, a semiconductor spacer, and a semiconductor channel layer
Implementation Method 2
enhancing carrier tunneling and reducing oxide breakdown
Data Source
AI summary
A flash memory device includes a substrate, a semiconductor quantum well layer, a semiconductor spacer, a semiconductor channel layer, a gate structure, and source/drain regions. The semiconductor quantum well layer is formed of a first semiconductor material and is disposed over the substrate. The semiconductor spacer is formed of a second semiconductor material and is disposed over the first semiconductor channel layer. The semiconductor channel layer is formed of the first semiconductor material and is disposed over the semiconductor spacer. Thea gate structure is over the second semiconductor channel layer. The source/drain regions are over the substrate and are on opposite sides of the gate structure.