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Description
With their high breakdown voltage and ability to withstand high temperatures, wide bandgap-based devices are ideally suited for high-power and high-frequency applications in satellite communications, RADAR, and defense power switching. However, these devices, based on wide bandgap (WBG) semiconductor materials, are known to be prone to single-event effects (SEE). The susceptibility to single event transients (SETs) in the harsh particle radiation environment of space can disrupt the device’s normal operation, potentially leading to failure events and posing a significant reliability issue.
The US Naval Research Laboratory (NRL) developed a laser beam line (Fig. 1) to study SEEs in WBG semiconductors. Single-photon and two-photon absorption processes are used for a pulsed-laser SEE (PL SEE) study on GaN-, Ga2O3-, and SiC-based devices. It is determined that the shape of laser-induced SETs depends strongly on laser pulse energy, deposited charge distribution profile, bias, and the presence of growth-related or radiation-induced defects. SET mapping of WBG GaN (Fig. 2), Ga2O3, and SiC material-based devices reveals regions of enhanced charge collection – “hot spots,” identifying areas most likely susceptible to radiation-induced failure. PL SEE has emerged as a new tool for locating and characterizing defects, with laser wavelength tunability allowing for probing specific electron transitions and tailoring charge deposition profiles to specific experimental needs.
