학술논문

Flexible IGZO TFTs and Their Suitability for Space Applications
Document Type
Periodical
Source
IEEE Journal of the Electron Devices Society IEEE J. Electron Devices Soc. Electron Devices Society, IEEE Journal of the. 7:1182-1190 2019
Subject
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Flexible electronics
Radiation effects
Thin film transistors
Wearable electronics
Magnetic noise
Magnetic shielding
Amorphous materials
space applications
amorphous oxides
wearables
thin film transistors
Language
ISSN
2168-6734
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 $10^{12}\,\,{\mathrm{ e}}^{-}$ /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 $-(0.6\pm 0.5)\,\,{\mathrm{ cm}}^{2}{\mathrm{ V}}^{-1}{\mathrm{ s}}^{-1}$ . Subsequent low temperature exposure resulted in additional shifts of +0.38 V and $-5.95\,\,{\mathrm{ cm}}^{2}{\mathrm{ V}}^{-1}{\mathrm{ s}}^{-1}$ 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.