FUNDAMENTAL STUDIES OF RADIATION DAMAGE MECHANISMS IN WIDE-BAND-GAP SEMICONDUCTORS
Abstract
We will use first-principles methodology, in conjunction with experimental studies, to investigate mechanisms of radiation damage, particularly related to heavy-ion-induced single-event effects (SEE). The SEE cause high leakage current, and sometimes outright burnout or gate rupture, due to defect creation along the ion path. The materials of interest include GaN (bandgap 3.4 eV) and the ultrawide-bandgap semiconductors AlxGa1-xN (3.4-6.2 eV) and ?-Ga2O3 (4.8 eV). Our efforts will support ongoing research in the Center of Excellence in Radiation Effects Research. For modeling, we will conduct cutting-edge computational research in several areas- (1) Point defect formation and temporal evolution, calculating formation energies of relevant point defects and investigating motion of point defects during or right after an irradiation event; (2) Fundamental studies of defect formation mechanisms, developing formalisms to address the mechanisms that take place during excitation, particularly in the presence of large concentrations of electron-hole pairs; (3) Role of pre-existing defects, examining whether the defect states that are present at dislocations may act as nucleation sites for damage generation, and investigating hot-electron mediated release of hydrogen from hydrogenated defects; (4) Connecting to experimental characterization by calculating defect signatures that can be directly compared with experiment and will enable the identification of defects observed in irradiation experiments; (5) Effects of electric fields, assessing the impact of large fields on damage creation through investigations of impact ionization, conduction through defect sites, and phonon scattering. In addition, experimental work will address growth, characterization, and processing of GaN and ?-Ga2O3- based structures, including growth using plasma-assisted molecular beam epitaxy (PAMBE) and ammonia MBE (NH3 MBE).
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502210165
Entities
People
- Christian Van De Walle
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of California, Santa Barbara