Direct Probing of Trap Dynamics in β-Ga₂O₃ Schottky Barrier Diodes Using Single-Voltage-Pulse Characterization

Area of Science:

• Materials Science
• Semiconductor Physics
• Electrical Engineering

Background:

• Gallium oxide (β-Ga₂O₃) is a key ultrawide-bandgap semiconductor for advanced power electronics.
• Performance limitations in β-Ga₂O₃ devices are primarily caused by trap states that capture charge carriers.

Purpose of the Study:

• To introduce and validate a single-pulse characterization method for directly analyzing trap dynamics in β-Ga₂O₃ Schottky barrier diodes (SBDs).
• To quantify trap density, carrier capture times, and activation energy under realistic operating conditions.

Main Methods:

• Systematic investigation of transient current responses in β-Ga₂O₃ SBDs under varying pulse parameters (width, rise/fall times, amplitude) and temperatures.
• Analysis of current decay during constant-voltage phases to determine trap participation.
• Exponential fitting and temperature-dependent measurements to extract time constants and activation energy.

Main Results:

• Identified progressive electron capture by traps in the neutral region, leading to current decay.
• Observed asymmetry in transients due to delayed trap response.
• Quantified a total trap density of approximately 5×10¹⁴ cm^-2 near the Schottky junction.
• Determined a carrier capture time constant of ~30 µs at 2V forward bias and a trap activation energy of ~0.16 eV.

Conclusions:

• The single-pulse method provides a direct and effective means to evaluate trap states in β-Ga₂O₃ devices.
• Understanding trap dynamics is critical for mitigating performance degradation in Gallium oxide power electronics.
• The characterized trap parameters offer valuable insights for optimizing β-Ga₂O₃ device design and reliability.