2D Metalloid Vacuum Transistor With Gate-Controlled Electron Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional field-effect transistors (FETs) with solid-state channels are limited by the velocity of charge carriers, leading to reduced output power and operating frequency due to scattering effects, and existing vacuum channel transistors face challenges with electron emission methods and gate electrode placement.
Innovation Solution
A transistor device using a metalloid material with a two-dimensional structure as an emitter, enabling electron emission through quantum tunneling by applying a gate voltage to modulate the Fermi level and work function, with a gate electrode positioned to control electron emission without being between the emitter and drain electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a solid semiconductor channel is used in conventional FETs, then the device structure is simple and manufacturable, but the charge carrier velocity is limited by scattering effects, reducing output power and operating frequency
Solution Approach 1:
The patent changes the fundamental parameter of the channel medium from solid semiconductor to vacuum, eliminating scattering effects that limit charge carrier velocity. This parameter change enables electrons to achieve velocities up to 10^9 cm/s, directly resolving the contradiction between speed and power by removing the scattering mechanism that caused the trade-off.
Solution Approach 2:
The patent replaces the solid-state mechanical channel with a vacuum channel, substituting the physical medium that causes scattering with an empty space where electrons can travel ballistically. This substitution eliminates the scattering mechanism while maintaining the transistor's functional structure, enabling both high velocity and high power output.
2Speed
If the channel length is reduced to increase operating frequency in solid-state FETs, then higher frequency operation is achieved, but capacitance increases and output impedance degrades, reducing overall performance
Solution Approach 1:
The patent changes the channel medium parameter from solid to vacuum, which fundamentally alters the relationship between channel length and performance. In vacuum, electrons experience no scattering, allowing the channel length to be reduced for high-frequency operation without the parasitic capacitance and impedance degradation that occur in solid-state devices.
3Productivity
If field emission is induced using a sharp tip emitter, then electron emission efficiency is improved, but the geometric structure becomes complex and difficult to manufacture
Solution Approach 1:
The patent applies local quality by creating field enhancement specifically at the edge of the 2D material emitter rather than requiring a sharp tip throughout. The high conductivity and edge geometry of the 2D material provide localized field enhancement that achieves sharp-tip emission efficiency while maintaining a planar, easily manufacturable structure through top-down lithography.
Solution Approach 2:
The patent replaces the mechanical sharp-tip geometry with a 2D material edge structure that achieves similar field enhancement through its intrinsic high conductivity and geometry. This substitution maintains electron emission efficiency while dramatically simplifying the manufacturing process.
4Ease of operation
If the gate electrode is positioned between the emitter and drain electrode in vacuum devices, then electron emission control is achieved, but the interval increases requiring higher operating voltage and reducing electron mobility
Solution Approach 1:
The patent repositions the gate electrode from the traditional between-emitter-and-drain location to a position adjacent to the emitter edge. This dimensional repositioning allows the gate to control electron emission through capacitive coupling without increasing the electron travel path, maintaining both emission control and high electron mobility.
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 operates efficiently at high frequencies up to terahertz bands with improved output power and frequency, overcoming limitations of solid-state channels by utilizing a vacuum channel and quantum tunneling.
Implementation Method 1
modulation of the amount of current passing through and traversing the vacuum channel is enabled by applying a gate voltage to change a Fermi level and a work function of the emitter
Implementation Method 2
applying a gate voltage to change a Fermi level and a work function of the emitter
Implementation Method 3
a method of emitting electrons through a quantum mechanical tunneling effect of microparticles by applying an electric field
Implementation Method 4
an electron emission device using an electric field effect based on tunneling
Implementation Method 5
when the tip of the emitter has a sharp and pointed geometric structure, a charge distribution inside the tip of the emitter is rearranged to compensate for an external electric field, thereby resulting in a locally increased charge density and a local field enhancement effect
Implementation Method 6
In a vacuum, because all scattering components excluding electron-electron scattering are reduced, electrons passing through a vacuum channel may move at a much higher velocity than when passing through a solid-state channel
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A transistor device may include: an emitter located on a substrate including a dielectric material, the emitter being formed of a metalloid material with a two-dimensional (2D) structure and configured to selectively emit electrons; a source electrode electrically contacting a portion of the emitter; a drain electrode located on the substrate, spaced apart from the emitter, and electrically separated from the source electrode; and a gate structure located on the emitter and configured to apply a gate voltage for controlling electron emission by the emitter to the emitter by modulating a work function of the emitter. The transistor device may include a vacuum region as a path through which emitted electrons move, and may be a three-terminal or four-terminal field-effect transistor configured to adjust emission current by applying a gate voltage to change a Fermi level of the emitter tip of the 2D metalloid material.