Ballistic Bloch FET Gate Profile for Submicron Scaling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional MOSFET transistors face limitations in scaling due to parasitic junctions, thin dielectric layers, and the classical principle of operation, which restricts further miniaturization and performance enhancement.
Innovation Solution
The ballistic Bloch field-effect transistor (BBFET) operates on a new principle using a two-dimensional conducting layer with a lateral gate configuration, creating periodic energy band gaps to control electron flow, allowing for multiple DC states and oscillatory behavior without the need for a dielectric layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If MOSFET dimensions are reduced to submicron scale, then transistor miniaturization is achieved, but parasitic junction transistors are activated and effectiveness is dramatically reduced
Solution Approach 1:
The invention extracts and eliminates the p-n junctions from the transistor structure by using a fully n-type semiconductor channel. This removes the parasitic junction transistor effect that occurs in conventional MOSFETs when dimensions are reduced, allowing submicron scaling without the harmful parasitic effects.
Solution Approach 2:
Instead of using the conventional p-n junction structure, the invention inverts the approach by using a fully n-type channel with selective gating. This fundamental structural inversion eliminates the parasitic junction problem while maintaining transistor functionality through a different physical mechanism.
2Length of moving object
If oxide layer thickness is reduced to enable further miniaturization, then transistor size is reduced, but electrons tunnel through the oxide and transistor function fails
Solution Approach 1:
The invention extracts and removes the thin oxide layer from the gate structure. By eliminating this problematic dielectric layer, the invention avoids the electron tunneling issue that occurs when oxide thickness reaches a fraction of a nanometer, enabling continued miniaturization without functional failure.
Solution Approach 2:
The invention introduces a novel gate structure that acts as an intermediary between the control electrode and the channel, using a different physical mechanism (image force potential modulation) that does not require a thin dielectric barrier, thus avoiding tunneling while maintaining gate control.
3Ease of operation
If conventional MOSFET operation principle is used, then transistor switching is achieved, but further advancement is fundamentally prevented
Solution Approach 1:
The invention changes the fundamental operating parameter from charge carrier concentration modulation to image force potential modulation. By controlling the gate voltage to modulate the image force potential in a fully n-type channel, the invention achieves switching while maintaining constant electron concentration, enabling new functionality and continued advancement.
Solution Approach 2:
The invention substitutes the conventional charge-based switching mechanism with a potential-based mechanism using image force effects. This replacement of the operating mechanism enables new modes of operation including multiple DC states and oscillatory behavior, greatly enhancing adaptability and versatility.
4Length of moving object
If thin dielectric layer is used in MOSFET, then transistor size is reduced, but manufacturing complexity increases and reliability decreases
Solution Approach 1:
The invention extracts and eliminates the thin dielectric layer from the gate structure, simplifying the manufacturing process. By removing this complex fabrication step and the associated reliability issues, the invention enables continued miniaturization with reduced manufacturing complexity and improved reliability.
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
BBFET achieves improved performance and scalability by maintaining constant electron concentration during switching, enabling faster operation and reduced power dissipation, potentially extending transistor capabilities beyond the limits of traditional MOSFETs.
Implementation Method 1
The channel has a length L less than or equal to an electron mean free path of the material from which the channel is made so as to have a ballistic electron transport. The first gate has a periodic profile along an inner boundary of the first arm. The periodic profile of the first gate creates a periodic potential in the channel that generates energy band gaps.
Implementation Method 2
The periodic profile of the first gate creates a periodic potential in the channel that generates energy band gaps. When an energy gap generated by the periodic profile crosses the Fermi level, the BBFET is in an OFF state.
Implementation Method 3
The channel has a length L less than or equal to an electron mean free path of the material from which the channel is made so as to have a ballistic electron transport.
Data Source
AI summary
A semiconductor device includes a source, a drain, and a channel electrically connected to the source and the drain. The channel has a channel length from the drain to the source which is less than or equal to an electron mean free path of the channel material. A first gate has two arms, each extending between the drain and the source (i.e., at least a portion of the distance between the source and the drain). Each arm of the first gate is disposed proximate to a corresponding first and second edge of the channel. Each arm of the first gate has a periodic profile along an inner boundary, wherein the periodic profiles of each arm are offset from each other such that a distance between the arms is constant. A Bloch voltage applied to the first gate will reduce the effective channel with such that Bloch resonance conditions are met.