The radiation resistance of Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) is of great significance when applied in aerospace. However, it is still challenging to obtain MOSFETs with excellent radiation resistance. In this work, the radiation hardened MOSFETs were realized by GdF 3 -Al 2 O 3 @Bi-Ti 3 C 2 T x /epoxy (MBAG/EP) polymer-based composite coating with function of trapped interfacial electrons. The radiation resistance of resultant packed MOSFET is significantly improved, showing the lower threshold voltage negative drift value (0.41 V) than the bare MOSFET (7.89 V). This is mainly attributed to the introduction of ultra-thin Al 2 O 3 intermediate layer between Bi and GdF 3 , which effectively tailor electron dense and distribution for an effective electron attenuation, and thus improve the radiation resistance of the MOSFET. Theoretical calculations further reveal that the packed MOSFETs present the less shifted voltage and trapped charges compared with the pristine one. This work provides an interface engineering strategy for developing radiation hardened MOSFETs.
Yuxiao Fang,Chun Zhao,Ivona Z. Mitrovic,Cezhou Zhao
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 InOx/ZrLaO thin-film transistors (TFTs) were systemically investigated. The Zr0.9La0.1Oy 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 Zr0.9La0.1Oy gate dielectrics exhibited an ultralow flat band-voltage (VFB) 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, InOx/Zr0.9La0.1Oy thin-film transistors (TFTs) exhibited a large Ion/Ioff of 2 × 106, a small subthreshold swing (SS) of 0.11 V/dec, a small interface trap density (Dit) of 1 × 1012 cm–2, and a 0.16 V threshold shift (ΔVTH) under 3600 s positive bias-stress (PBS). InOx/Zr0.9La0.1Oy TFT-based resistor-loaded inverters demonstrated complete swing behavior, a static output gain of 13.3 under 4 V VDD, 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 (Vo) 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.
Developing lightweight packaging materials with high radiation protection efficiency for MOSFET radiation hardening is highly significant for enhancing the radiation resistance of MOSFETs in space radiation environments. This work presented lightweight Bi-GdF 3 /Ti 3 C 2 T x aerogel (BGTA) with high electron radiation protection efficiency (RPE) through self-assembly and directional freezing. Subsequently, a radiation hardened MOSFET was obtained by packaging with BGTA. The resulting BGTA packaging material demonstrates excellent electron protection efficiency (92.23 %) compared to conventional Al packaging materials (23.80 %) at the same areal density. Meanwhile, the BGTA-packed MOSFET shows outstanding radiation resistance, exhibiting a much smaller negative threshold voltage drift value of 0.10 V compared to the Al-packed MOSFET (1.17 V). The electron shielding mechanism of BGTA was analyzed and elucidated by FASTRAD simulation on a micro scale. Due to the synergistic effect of the honeycomb aerogel structure and Bi/GdF 3 functional filler in BGTA aerogel, the incident electrons are effectively attenuated, thereby reducing radiation damage to the SiO 2 layer of the MOSFET and improving the radiation resistance of the MOSFET. Theoretical calculation results substantiate that the BGTA-packed MOSFET exhibits lower threshold voltage shifts and trapped charges. This work presents a lightweight and highly efficient MXene aerogel packaging material for MOSFET radiation hardening.