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

Abstract

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 Zr0.9La0.1O 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 Zr0.9La0.1O 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 /Zr0.9La0.1O 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 /Zr0.9La0.1O 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 (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.

High‐Performance Full‐Solution‐Processed Oxide Thin‐Film Transistor Arrays Fabricated by Ultrafast Scanning Diode Laser

“…These values are comparable to the values of previously reported dielectric thin films, which deposited by solution processed. [30,[45][46][47][48][49][50][51][52][53] And it can be due to the fact that the solution-processed HAO thin film exhibits relatively more complete oxide lattice formation and densification, resulting in the higher k value when annealed at higher laser peak temperature. Furthermore, the C-f measurements exhibit that the device (annealed at laser peak temperature of 800 °C) is more stable in the range of measured frequencies that its average capacitance also is higher than the ones of other laser peak temperatures, that it is consistent with the C-V results.…”

Enhancement of electrical stability of metal oxide thin-film transistors against various stresses

“…77,135,136 There have been a few recent efforts to diminish/prevent the degradation of AOS TFTs under ionizing radiation stress (Table 5). 137–141…”

“…Fang et al employed radiation-hardened ZrLaO gate dielectric layers to reduce/prevent defects induced by gamma-ray radiation for indium oxide (InOx) TFTs. 141 Doping of La in ZrO 2 demonstrated better electrical performance of the resulting device with radiation hardness due to the higher La–O bond dissociation energy than that of the Zr–O bond and the suppressed V O generation in the oxide layer. The Zr 0.9 La 0.1 O y -based metal-oxide-semiconductor capacitors (MOSCAPs) exhibited a low flat band-voltage ( V FB ) sensitivity of 0.11 mV krad −1 under low dose and 0.19 mV krad −1 under high dose gamma-ray radiation exposure, respectively (Fig.…”

“…77,135,136 There have been a few recent efforts to diminish/prevent the degradation of AOS TFTs under ionizing radiation stress (Table 5). [137][138][139][140][141] To prevent the degradation of AOS TFTs by X-ray radiation exposure, radiation-hardened fully flexible TFT with a GIZO and a multilayer high-k dielectric Ta 2 O 5 /SiO 2 was introduced by Cramer et al 137 To assess radiation hardness, the TFTs were exposed to photons emitted from a Mo X-ray at a dose rate of 1.5 krad min À1 (SiO 2 ). As shown in Fig.…”

Enhancing radiation-resistance of amorphous indium–zinc-oxide thin-film transistors by group IV transition element doping

“…25 The presence of oxygen binders in AOSs can enhance the structural robustness of the metal-oxide lattice, preventing atomic displacement within the lattice. 26 A few research groups have reported that controlling the concentration of metal cations such as Hf 4+ and W 6+ in the semiconductor channel could improve the radiation-resistance of AOSs. 27,28 Such metal cations might prevent or reduce the formation of oxygen vacancies which function as shallow-donor states, owing to their high affinity with oxygen.…”