TY - JOUR
T1 - Al-doped ZnO thin films deposited by confocal sputtering as electrodes in ZnO-based thin-film transistors
AU - Hernandez-Como, N.
AU - Morales-Acevedo, A.
AU - Aleman, M.
AU - Mejia, I.
AU - Quevedo-Lopez, M. A.
N1 - Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2016/1/25
Y1 - 2016/1/25
N2 - Aluminum doped zinc oxide (AZO) films were deposited by confocal RF magnetron sputtering at different substrate temperatures. AZO films with a transparency up to 90% in the visible spectrum were obtained. Polycrystalline AZO films, with planes in the (002) and (103) orientations of the zincblende (hexagonal) structure, were obtained at substrate temperatures higher than 60 °C. The best AZO films, obtained at 75 °C, showed an electrical resistivity of 8.8 × 10-4 Ω-cm, with a carrier concentration of 4 × 1020 cm-3 and mobility of 20 cm2/V-s. These are appropriate values for solar cell applications. In addition, ZnO-based thin-film transistors (TFTs) were fabricated for evaluating the behavior of the AZO films as source and drain contacts on the transistors. The field effect mobility and the threshold voltage of the fabricated devices were 20 cm2/V-s and 7 V, respectively. The TFTs showed an Ion/Ioff ratio of up to 9 orders of magnitude. A specific contact resistance of approximately 0.06 Ω-cm2 was determined for the AZO/ZnO interface. This result corresponds to the first report of the ZnO/AZO specific contact resistance obtained with a maximum processing temperature of 100 °C. Therefore, this TFT technology is fully compatible with flexible substrates and can be used for transparent and large area electronics.
AB - Aluminum doped zinc oxide (AZO) films were deposited by confocal RF magnetron sputtering at different substrate temperatures. AZO films with a transparency up to 90% in the visible spectrum were obtained. Polycrystalline AZO films, with planes in the (002) and (103) orientations of the zincblende (hexagonal) structure, were obtained at substrate temperatures higher than 60 °C. The best AZO films, obtained at 75 °C, showed an electrical resistivity of 8.8 × 10-4 Ω-cm, with a carrier concentration of 4 × 1020 cm-3 and mobility of 20 cm2/V-s. These are appropriate values for solar cell applications. In addition, ZnO-based thin-film transistors (TFTs) were fabricated for evaluating the behavior of the AZO films as source and drain contacts on the transistors. The field effect mobility and the threshold voltage of the fabricated devices were 20 cm2/V-s and 7 V, respectively. The TFTs showed an Ion/Ioff ratio of up to 9 orders of magnitude. A specific contact resistance of approximately 0.06 Ω-cm2 was determined for the AZO/ZnO interface. This result corresponds to the first report of the ZnO/AZO specific contact resistance obtained with a maximum processing temperature of 100 °C. Therefore, this TFT technology is fully compatible with flexible substrates and can be used for transparent and large area electronics.
KW - Al-doped zinc oxide
KW - RF sputtering
KW - Specific contact resistance
KW - Thin film transistors
UR - http://www.scopus.com/inward/record.url?scp=84946761478&partnerID=8YFLogxK
U2 - 10.1016/j.mee.2015.10.017
DO - 10.1016/j.mee.2015.10.017
M3 - Artículo
SN - 0167-9317
VL - 150
SP - 26
EP - 31
JO - Microelectronic Engineering
JF - Microelectronic Engineering
ER -