Study on Single Event Effects of Enhanced GaN HEMT Devices under Various Conditions

Area of Science:

• Materials Science
• Semiconductor Physics
• Reliability Engineering

Background:

• Gallium Nitride (GaN) High Electron Mobility Transistors (HEMTs) are crucial for space equipment.
• These devices exhibit sensitivity to single event effects (SEE) from heavy ion radiation, impacting operational safety.

Purpose of the Study:

• To investigate the impact of pre-applied electrical stress, varying linear energy transfer (LET) values, and gate voltages on SEE in Cascode GaN power devices.
• To elucidate the underlying damage mechanisms responsible for observed SEE.

Main Methods:

• Irradiation of Cascode GaN power devices using Germanium (Ge) ions (LET = 37 MeV·cm²/mg) and Bismuth (Bi) ions (LET = 98 MeV·cm²/mg).
• Analysis of SEE under conditions of pre-applied electrical stress, different LET values, and varying gate voltages.

Main Results:

• Pre-applied electrical stress induces electron de-trapping and defect generation, enhancing charge collection and increasing drain leakage current.
• Higher LET values lead to increased ionization, greater charge collection, and a higher burn-out voltage.
• Negative gate voltages in the off-state exacerbate the back-channel effect, particularly at higher drain voltages.

Conclusions:

• The study establishes a theoretical foundation for understanding GaN power device reliability in radiation-intensive environments.
• Findings highlight the critical role of electrical stress and radiation LET in determining device susceptibility to SEE.