TY - GEN
T1 - Low-voltage ZnO double-gate thin film transistor circuits
AU - Li, Yuanyuan V.
AU - Ramirez, J. Israel
AU - Sun, Kaige G.
AU - Jackson, Thomas N.
PY - 2012
Y1 - 2012
N2 - We report here double-gate ZnO thin film transistor (TFT) circuits with operation at low voltage. TFTs with low voltage operation have been reported previously, but often use very thin (few nm thick) gate dielectric which may limit manufacturability [1]. Oxide semiconductor-based TFTs have been extensively studied as competitive candidates for next-generation display technology and other large-area electronics. For many applications, operation at voltages compatible with low-voltage CMOS is important. Double-gate TFTs are of interest because they allow threshold voltage tuning, improved device performance, and circuit applications like mixers. [2,3] We have previously reported bottom-gate ZnO TFTs and circuits fabricated on glass and flexible polymeric substrates using plasma enhanced atomic layer deposition (PEALD) [4,5]. Here we report double-gate ZnO TFTs and circuits fabricated on glass substrates using PEALD with a maximum process temperature of 200 °C. Compared to bottom-gate ZnO TFTs, double-gate ZnO TFTs have higher mobility, and reduced substhreshold slope. In these devices, the top gate can be used to vary the bottom-gate threshold voltage by more than 4 V. This allows the logic transition point for circuits to be adjusted as desired and allows logic operation at low voltage. 15 stage double-gate ZnO TFT ring oscillators operate well with V DD = 1.2 V, I D = 32 μA, and propagation delay of 2.1 μs/stage.
AB - We report here double-gate ZnO thin film transistor (TFT) circuits with operation at low voltage. TFTs with low voltage operation have been reported previously, but often use very thin (few nm thick) gate dielectric which may limit manufacturability [1]. Oxide semiconductor-based TFTs have been extensively studied as competitive candidates for next-generation display technology and other large-area electronics. For many applications, operation at voltages compatible with low-voltage CMOS is important. Double-gate TFTs are of interest because they allow threshold voltage tuning, improved device performance, and circuit applications like mixers. [2,3] We have previously reported bottom-gate ZnO TFTs and circuits fabricated on glass and flexible polymeric substrates using plasma enhanced atomic layer deposition (PEALD) [4,5]. Here we report double-gate ZnO TFTs and circuits fabricated on glass substrates using PEALD with a maximum process temperature of 200 °C. Compared to bottom-gate ZnO TFTs, double-gate ZnO TFTs have higher mobility, and reduced substhreshold slope. In these devices, the top gate can be used to vary the bottom-gate threshold voltage by more than 4 V. This allows the logic transition point for circuits to be adjusted as desired and allows logic operation at low voltage. 15 stage double-gate ZnO TFT ring oscillators operate well with V DD = 1.2 V, I D = 32 μA, and propagation delay of 2.1 μs/stage.
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U2 - 10.1109/DRC.2012.6256969
DO - 10.1109/DRC.2012.6256969
M3 - Conference contribution
AN - SCOPUS:84866916651
SN - 9781467311618
T3 - Device Research Conference - Conference Digest, DRC
SP - 239
EP - 240
BT - 70th Device Research Conference, DRC 2012 - Conference Digest
T2 - 70th Device Research Conference, DRC 2012
Y2 - 18 June 2012 through 20 June 2012
ER -