Gallium Nitride Semiconductor Resonant Tunneling Transistor

Area of Science:

• Semiconductor Physics
• Materials Science
• Nanoelectronics

Background:

• Quantum tunneling devices, like resonant tunneling diodes (RTDs), are crucial for multi-valued logic and memory.
• Gallium Nitride (GaN) based RTDs offer superior properties due to their wide bandgap nature.
• Conventional GaN RTDs lack current gain, hindering functional modulation and performance.

Purpose of the Study:

• To demonstrate a three-terminal GaN resonant tunneling transistor (RTT) overcoming the limitations of two-terminal RTDs.
• To achieve gate-tunable negative differential resistance (NDR) in GaN-based devices.
• To explore enhanced functionalities for nitride-based electronics beyond Moore's Law.

Main Methods:

• Epitaxial integration of an AlN/GaN double-barrier RTD with a GaN high-electron-mobility transistor (HEMT).
• Utilizing the HEMT channel's carrier concentration to tune the NDR characteristics of the integrated RTD.
• Configuring RTTs in series and parallel to analyze voltage span and current amplification.

Main Results:

• Demonstrated gate-tunable NDR behavior in three-terminal GaN RTTs.
• Achieved a significantly enhanced NDR voltage span (4.1 V) in series-connected RTTs compared to conventional RTDs (0.41 V).
• Observed a 10-fold amplification of peak current in parallel-configured RTTs via gate voltage regulation.

Conclusions:

• The developed GaN RTT offers a feasible method for tuning NDR performance.
• This work presents a novel approach for engineering nitride-based electronics with enhanced functionality.
• The RTTs pave the way for beyond binary logic systems and address challenges posed by Moore's Law saturation.