The total ionizing dose (TID) effect of semiconductor devices stems from radiation-induced $E^{\prime }$ defects in the $a$-${\mathrm{Si}\mathrm{O}}_2$ dielectrics, but the conventional “hole-transport-trapping” model of defect generation fails to explain recent basic experiments. Here, we propose an alternative “nonradiative carrier capture–structural relaxation” (NCCSR) mechanism that can consistently explain the puzzling temperature and electric-field dependence. To this end, we have made spin-polarized HSE06 hybrid functional and full phonon spectrum calculations alignment of defect formation energies and charge capture cross sections of large-sample oxygen vacancies in $a$-${\mathrm{Si}\mathrm{O}}_2$. It is revealed that, the long-assumed $V_{O\gamma }$ precursors with high formation energy cannot survive in high-temperature-grown $a$-${\mathrm{Si}\mathrm{O}}_2$; whereas the stable $V_{O\delta }$ can capture irradiation-induced holes via strong electron-phonon coupling, generating metastable $E_{\delta }^{\prime }$ that most relax into stable $E_{\gamma }^{\prime }$. A fractional power-law dynamic model is derived based on the mechanism and the Kohlrausch-Williams-Watts decay function. It can uniformly describe nonlinear data over a wide dose and temperature range. This work not only provides a solid cornerstone for prediction and hardening of TID effects of ${\mathrm{Si}\mathrm{O}}_2$-based semiconductor devices, but also offers a general approach for studying ionizing radiation physics in alternative dielectrics with intrinsic electronic metastability and dispersion. The calculated defect parameters aligning with EPR and carrier injection experiments can support broad $V_O$-related reliability and function research.

Close

PrevNext

View figure in article

• Electron-phonon coupling
• Irradiation effects
• Point defects
• Vacancies
• Amorphous materials
• Dielectrics
• Wide band gap systems
• Density functional calculations