Role of Oxygen in Amorphous In-Ga-Zn-O Thin Film Transistor for Ambient Stability
| Autor: | Po-Tsun Liu, Li Feng Teng, Simon M. Sze, Chur Shyang Fuh, Yi Teh Chou |
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| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | ECS Journal of Solid State Science and Technology. 2:Q1-Q5 |
| ISSN: | 2162-8777 2162-8769 |
| DOI: | 10.1149/2.012301jss |
| Popis: | The role of oxygen in amorphous InGaZnO thin film transistor (a-IGZO TFT) is studied for the device ambient stability. The threshold voltage (Vth) value of 350◦C annealed a-IGZO TFT decreased apparently with the staying duration, and the average value shifted from 10.2 V to 5.8 V after a 9–day staying at the atmosphere. After raising the annealing temperature to 450◦C, the electrical stability issue was improved significantly with superior electrical parameters, including low threshold voltage (Vth), low subthreshold swing, high carrier mobility and a small Vth variation of ±0.5 V. It can be attributed to the enhancement of bonding energy of oxygen in the thermally-annealed a-IGZO film with the increase of thermal annealing temperatures. Besides, the stronger oxygen bonding could also suppress the absorption/desorption and UV-induced migration at the back surface, causing better electrical reliability and immunity against UV radiation, respectively. All these results showed the ambient stability is greatly related to the oxygen in a-IGZO film, and the desired electrical characteristic can be achieved via the optimization of thermal annealing process. © 2012 The Electrochemical Society. [DOI: 10.1149/2.012301jss] All rights reserved. |
| Databáze: | OpenAIRE |
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