Mitigating Heavy Ion Irradiation-Induced Degradation in p-type SnO Thin-Film Transistors at Room Temperature

Abstract

The study investigates the mitigation of radiation damage on p-type SnO thin-film transistors (TFTs) with a fast, room-temperature annealing process. Atomic layer deposition is utilized to fabricate bottom-gate TFTs of high-quality p-type SnO layers. After 2.8 MeV Au4+ irradiation at a fluence level of 5.2 x 1012 ions cm-2, the output drain current and on/off current ratio (Ion/Ioff) decrease by more than one order of magnitude, field-effect mobility (& mu;FE) reduces more than four times, and subthreshold swing (SS) increases more than four times along with a negative shift in threshold voltage. The observed degradation is attributed to increased surface roughness and defect density, as confirmed by scanning electron microscopy (SEM), high-resolution micro-Raman, and transmission electron microscopy (TEM) with geometric phase analysis (GPA). A technique is demonstrated to recover the device performance at room temperature and in less than a minute, using the electron wind force (EWF) obtained from low-duty-cycle high-density pulsed current. At a pulsed current density of 4.0 x 105 A cm-2, approximately four times increase in Ion/Ioff is observed, 41% increase in & mu;FE, and 20% decrease in the SS of the irradiated TFTs, suggesting effectiveness of the new annealing technique. A room-temperature annealing process is demonstrated on p-type SnO thin-film transistors, intentionally degraded with heavy ion irradiation. The proposed electron wind force technique takes less than a minute to recover on-off ratio by 4 times, field-effect mobility by 40%, and subthreshold swing by 20%.image & COPY; 2023 WILEY-VCH GmbH