The Co-60 gamma-ray irradiation effects on the Al/HfSiO4/p-Si/Al MOS capacitors

High-Performance and Radiation-Hardened Solution-Processed ZrLaO Gate Dielectrics for Large-Area Applications

Radiation hardness is important for electronics operating in harsh radiation environments such as outer space and nuclear energy industries. In this work, radiation-hardened solution-processed ZrLaO thin films are demonstrated. The radiation effects on solution-processed ZrLaO thin films and InO_x/ZrLaO thin-film transistors (TFTs) were systemically investigated. The Zr_0.9La_0.1O_y thin films demonstrated excellent radiation hardness with negligible roughness, composition, electrical property, and bias-stress stability degradation after radiation exposure. The metal-oxide-semiconductor capacitors (MOSCAPs) based on Zr_0.9La_0.1O_y gate dielectrics exhibited an ultralow flat band-voltage (V_FB) sensitivity of 0.11 mV/krad and 0.19 mV/krad under low dose and high dose gamma irradiation conditions, respectively. The low dose condition had a 103 krad (SiO₂) total dose and a 0.12 rad/s low dose rate, whereas the high dose condition had a 580 krad total dose and a 278 rad/s high dose rate. Furthermore, InO_x/Zr_0.9La_0.1O_y thin-film transistors (TFTs) exhibited a large I_on/I_off of 2 × 10⁶, a small subthreshold swing (SS) of 0.11 V/dec, a small interface trap density (D_it) of 1 × 10¹² cm^-2, and a 0.16 V threshold shift (ΔV_TH) under 3600 s positive bias-stress (PBS). InO_x/Zr_0.9La_0.1O_y TFT-based resistor-loaded inverters demonstrated complete swing behavior, a static output gain of 13.3 under 4 V V_DD, and an ∼9% radiation-induced degradation. Through separate investigation of the radiation-induced degradation on the semiconductor layer and dielectric layer of TFTs, it was found that radiation exposure mainly generated oxygen vacancies (V_o) and increased electron concentration among gate oxide. Nevertheless, the radiation-induced TFT instability was mainly related to the semiconductor layer degradation, which could be possibly suppressed by back-channel passivation. The demonstrated results indicate that solution-processed ZrLaO is a high-potential candidate for large-area electronics and circuits applied in harsh radiation environments. In addition, the detailed investigation of radiation-induced degradation on solution-processed high-k dielectrics in this work provided clear inspiration for developing novel flexible rad-hard dielectrics.