Rapid Improvement in Thin Film Transistors With Atomic-Layer-Deposited InOx Channels via O2 Plasma Treatment

• Published in: IEEE electron device letters Vol. 39; no. 11; pp. 1672 - 1675
• Main Authors: Ma, Qian, Shao, Yan, Wang, Y.-P., Zheng, H.-M., Zhu, B., Liu, W.-J., Ding, Shi-Jin, Zhang, D. W.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aluminum oxide; Annealing; Atomic-layer-deposition (ALD); indium oxide; O₂ plasma treatment; Performance evaluation; Plasma; Plasma temperature; Semiconductor devices; Surface roughness; Surface treatment; Thin film transistors; Threshold voltage; Transistors
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2018.2869019

To improve the electrical performance of thin-film transistors with an atomic-layer-deposited Al 2 O 3 dielectric/InO x channel, O 2 plasma surface treatments of the InO x back channel are explored in comparison with thermal annealing. It is demonstrated that the O 2 plasma treatment can enhance the device performance much more efficiently than thermal annealing, exhibiting an extremely low-thermal budget. Furthermore, it is revealed that the plasma treatment at a higher temperature can improve the device performance much faster than that at a lower temperature. For a 4 min O 2 plasma treatment at 200 °C, superior electrical characteristics are achieved, such as a field-effect mobility of 11 cm 2 V −1 s −1 , a threshold voltage of 0.9 V, a subthreshold swing of 0.38 V/dec, and good gate bias stress stabilities. This is ascribed to faster passivation of oxygen vacancies, removal of more C residues, and weaker surface damage and smaller surface roughness of the InO x back channel in comparison with long plasma treatments at lower temperatures.