Annealing of electronic devices is performed at elevated temperatures since conventional wisdom suggests that only thermal energy can mobilize and annihilate the defects that are grown in the semiconductor or induced by device processing steps. To demonstrate that elevated temperature is not a prerequisite for annealing, commercially available 1700 V silicon carbide MOSFETs were first intentionally degraded using Co-60 gamma irradiation to a total dose of 1 Mrad(Si). A direct current was then applied to induce an electron wind force—a mechanical stimulus arising from the transfer of electron momentum to lattice defects. Throughout the treatment, the device junction temperature was maintained at ∼20 °C by actively cooling the chamber to −35 °C using nitrogen gas flow. Post-irradiation transfer, output, capacitance–voltage, and drain-lag responses revealed dose-dependent negative threshold voltage shifts and enhanced drain current due to positive oxide charge buildup. Remarkably, the applied electron flux provided sufficient momentum to liberate trapped carriers and reconfigure metastable defects, enabling ∼98–100% recovery of threshold voltage, drain current, and capacitance across all irradiation doses. These findings indicate that high temperature may not be the only driving force for defect mitigation in conducting and semiconducting materials, thereby impacting the resilience of power electronics in aerospace and nuclear applications.
Chavda et al. (Fri,) studied this question.