Flexible IGZO TFTs and Their Suitability for Space Applications

Abstract

In this paper, low earth orbit radiation (LEO), temperature, and magnetic field conditions are mimicked to investigate the suitability of flexible InGaZnO transistors for lightweight space wearables. More specifically, the impacts of high energetic electron irradiation with fluences up to 10 12 e − /cm 2 , low operating temperatures down to 78 K and magnetic fields up to 11 mT are investigated. This simulates 278 h in LEO. The threshold voltage and mobility of transistors that were exposed to e − irradiation are found to shift by +(0.09 ± 0.05) V and −(0.6 ± 0.5) cm 2 V −1 s −1 . Subsequent low temperature exposure resulted in additional shifts of +0.38 V and −5.95 cm 2 V −1 s −1 for the same parameters. These values are larger than the ones obtained from non-irradiated reference samples. Conversely, the performance of the devices was observed not to be significantly affected by the magnetic fields. Finally, a Cascode amplifier presenting a voltage gain of 10.3 dB and a cutoff frequency of 1.2 kHz is demonstrated after the sample had been irradiated, cooled down, and exposed to the magnetic fields. If these notions are considered during the systems design, these devices can be used to unobtrusively integrate sensor systems into space suits.INDEX TERMS Flexible electronics, space applications, amorphous oxides, wearables, thin film transistors.

Analog and Mixed Signal Circuit Design Techniques in Flexible Unipolar a-IGZO TFT Technology: Challenges and Recent Trends

“…Apart from temperature sensing and physiological monitoring applications, a-IGZO TFT based circuits have been used in other applications such as radiation sensing [82], magnetosensory applications [92], space applications [93], gamma ray detection [94], NO 2 gas sensing [95] etc. Moreover, IGZO TFTs have also been utilized as sensing devices in an aqueous medium for applications such as biosensing [96], virus detection [97], and artificial DNA detection [98] etc.…”

In Situ Radiation Hardness Study of Amorphous Zn–In–Sn–O Thin-Film Transistors with Structural Plasticity and Defect Tolerance

“…Utilization of electronic devices not only involve everyday usage, such as smartphones or computers, but also application in certain environments and purposes. As human society has started to expand its field of interest in space exploration and alternative energy production, the use of electronic devices in harsh radiation environments has increased over the past decades and is expected to grow even more dramatically. − For example, increased space activity and the development of civilian space programs, such as SpaceX, have boosted the popularity of the space industry and given rise to the development of radiation-resistant large-area devices for future space equipment. , Radiation-resistant electronic devices are also needed in nuclear power plants where radioactive waste is discharged . Ionizing radiation is not only problematic for electronic devices that are intended for such missions or safety-critical applications but also for general semiconductor devices, in which daily radiation exposure has become a serious problem. , Presently, as the dimensions of electronic circuits are becoming ever smaller, with certain components becoming nano-scaled, faulty products may result from cosmic radiation during the air transportation with high altitudes .…”

“…1−4 For example, increased space activity and the development of civilian space programs, such as SpaceX, 5 have boosted the popularity of the space industry and given rise to the development of radiation-resistant large-area devices for future space equipment. 6,7 Radiation-resistant electronic devices are also needed in nuclear power plants where radioactive waste is discharged. 8 Ionizing radiation is not only problematic for electronic devices that are intended for such missions or safety-critical applications but also for general semiconductor devices, in which daily radiation exposure has become a serious problem.…”

The Influence of Climate Conditions and On-Skin Positioning on InGaZnO Thin-Film Transistor Performance

“…The performances of a-IGZO TFTs fabrication on flexible substrate during tensile and compressive strain are extensively reported Park et al (2009), Munzenrieder et al (2011), Hasan et al (2017), Billah et al (2017), Münzenrieder et al (2013). In addition to the mechanical stability, the electrical stability at any environmental condition (light exposure, moisture, temperature (T), relative humidity (RH)) is a key aspect for the employment of a-IGZO TFTs on a large scale Costa et al (2019). Although different studies concerning the effects of the RH on the IGZO TFT operation have proved a reliable variation for the threshold voltage Knobelspies et al (2018), Lee and Jeong (2018), Kim et al (2017), no common trend in the variations of the other parameters was observed.…”