Fast Response GaN Nanoscale Air Channel Diodes with Highly Stable 10 mA Output Current toward Wafer-Scale Fabrication

Area of Science:

• Materials Science
• Semiconductor Devices
• Nanotechnology

Background:

• Nanoscale air channel transistors (NACTs) offer high-frequency and switching speeds due to ballistic electron transport.
• Existing NACTs suffer from low currents and instability, hindering practical applications.
• Gallium Nitride (GaN) is a promising material for field emission due to its favorable electronic and physical properties.

Purpose of the Study:

• To develop a stable, high-current vertical GaN nanoscale air channel diode (NACD).
• To investigate the performance characteristics of GaN NACDs for potential NACT applications.
• To explore the feasibility of low-cost, IC-compatible fabrication for GaN NACDs.

Main Methods:

• Fabrication of a vertical GaN NACD with a 50 nm air channel using IC-compatible manufacturing on a sapphire wafer.
• Characterization of field emission current, stability under various voltage conditions (cyclic, long-term, pulsed), switching speed, and repeatability.
• Analysis of temperature-dependent performance to understand device behavior under extreme conditions.

Main Results:

• Achieved a record field emission current of 11 mA at 10 V in air.
• Demonstrated outstanding stability during cyclic, long-term, and pulsed voltage testing.
• Exhibited fast switching characteristics with a response time under 10 ns and good repeatability.

Conclusions:

• The developed GaN NACD overcomes the limitations of low current and instability in conventional NACTs.
• The device shows significant promise for realizing practical, high-current NACTs.
• Findings provide guidance for designing GaN NACTs for applications in extreme environments.