scholarly journals Effects of Active Layer Thickness on the Electrical Characteristics and Stability of High-Mobility Amorphous Indium–Gallium–Tin Oxide Thin-Film Transistors

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1295
Author(s):  
Dae-Hwan Kim ◽  
Hyun-Seok Cha ◽  
Hwan-Seok Jeong ◽  
Seong-Hyun Hwang ◽  
Hyuck-In Kwon

Herein, we investigated the effects of active layer thickness (tS) on the electrical characteristics and stability of high-mobility indium–gallium–tin oxide (IGTO) thin-film transistors (TFTs). IGTO TFTs, with tS values of 7 nm, 15 nm, 25 nm, 35 nm, and 50 nm, were prepared for this analysis. The drain current was only slightly modulated by the gate-to-source voltage, in the case of the IGTO TFT with tS = 50 nm. Under positive bias stress (PBS), the electrical stability of the IGTO TFTs with a tS less than 35 nm improved as the tS increased. However, the negative bias illumination stress (NBIS) stability of these IGTO TFTs deteriorated as the tS increased. To explain these phenomena, we compared the O1s spectra of IGTO thin films with different tS values, acquired using X-ray photoelectron spectroscopy. The characterization results revealed that the better PBS stability, and the low NBIS stability, of the IGTO TFTs with thicker active layers were mainly due to a decrease in the number of hydroxyl groups and an increase in the number of oxygen vacancies in the IGTO thin films with an increase in tS, respectively. Among the IGTO TFTs with different tS, the IGTO TFT with a 15-nm thick active layer exhibited the best electrical characteristics with a field-effect mobility (µFE) of 26.5 cm2/V·s, a subthreshold swing (SS) of 0.16 V/dec, and a threshold voltage (VTH) of 0.3 V. Moreover, the device exhibited robust stability under PBS (ΔVTH = 0.9 V) and NBIS (ΔVTH = −1.87 V).

2012 ◽  
Vol 100 (17) ◽  
pp. 173501 ◽  
Author(s):  
Hyun-Sik Choi ◽  
Sanghun Jeon ◽  
Hojung Kim ◽  
Jaikwang Shin ◽  
Changjung Kim ◽  
...  

2010 ◽  
Vol 11 (12) ◽  
pp. 1920-1927 ◽  
Author(s):  
L. Reséndiz ◽  
M. Estrada ◽  
A. Cerdeira ◽  
B. Iñiguez ◽  
M.J. Deen

2011 ◽  
Vol 58 (5(1)) ◽  
pp. 1307-1311 ◽  
Author(s):  
Kwang-Seok Jeong ◽  
Yu-Mi Kim ◽  
Jeong-Gyu Park ◽  
Seung-Dong Yang ◽  
Ho-Jin Yun ◽  
...  

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1875
Author(s):  
Hwan-Seok Jeong ◽  
Hyun Seok Cha ◽  
Seong Hyun Hwang ◽  
Hyuck-In Kwon

In this study, we examined the effects of the annealing atmosphere on the electrical performance and stability of high-mobility indium-gallium-tin oxide (IGTO) thin-film transistors (TFTs). The annealing process was performed at a temperature of 180 °C under N2, O2, or air atmosphere after the deposition of IGTO thin films by direct current magnetron sputtering. The field-effect mobility (μFE) of the N2- and O2-annealed IGTO TFTs was 26.6 cm2/V·s and 25.0 cm2/V·s, respectively; these values were higher than that of the air-annealed IGTO TFT (μFE = 23.5 cm2/V·s). Furthermore, the stability of the N2- and O2-annealed IGTO TFTs under the application of a positive bias stress (PBS) was greater than that of the air-annealed device. However, the N2-annealed IGTO TFT exhibited a larger threshold voltage shift under negative bias illumination stress (NBIS) compared with the O2- and air-annealed IGTO TFTs. The obtained results indicate that O2 gas is the most suitable environment for the heat treatment of IGTO TFTs to maximize their electrical properties and stability. The low electrical stability of the air-annealed IGTO TFT under PBS and the N2-annealed IGTO TFT under NBIS are primarily attributed to the high density of hydroxyl groups and oxygen vacancies in the channel layers, respectively.


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