Title :
Performance Comparison of Single- and Dual-Gate Carbon-Nanotube Thin-Film Field-Effect Transistors
Author :
Narasimhamurthy, K.C. ; Paily, Roy
Author_Institution :
Dept. of Electron. & Electr. Eng., Indian Inst. of Technol. Guwahati, Guwahati, India
fDate :
7/1/2011 12:00:00 AM
Abstract :
In this paper, we present the performance comparison of a planar dual-gate semiconducting-nanotube thin-film transistor (SNTFT) with single-gate SNTFTs. A thin film of 95% enriched semiconducting single-walled carbon nanotubes (SWCNTs) is deposited on the amino-silane-modified hafnium oxide (HfOx) surface. HfOx deposited by radio-frequency sputtering is used as the dielectric material for the back gate of the SNTFT, and SiO2 is used as the dielectric material for the top gate. The performance of SNTFTs with the gate structures located at the top, bottom, or both the top and the bottom (dual gate) of the SWCNT thin-film channel is compared. All SNTFTs have exhibited a p-type output characteristic behavior with distinct saturation and a linear region of operation. The electrical characterization of these devices shows that the dual-gate SNTFT out performs the single-gate devices in terms of subthreshold slopes, threshold voltage, and on-off current ratios. The dual-gate SNTFT exhibits a subthreshold slope of 280 mV/dec, a threshold voltage of -0.65 V, and a maximum on-off drain current ratio of 1.2 × 103. A maximum transconductance value of 5.89 μS and a charge carrier mobility value of 2.26 cm2/V · s obtained for the dual-gate SNTFT are greater compared with the corresponding values of single-gate SNTFTs having identical dimensions.
Keywords :
carbon nanotubes; field effect transistors; silicon compounds; sputter deposition; thin film transistors; C; HfOx; SWCNT thin-film channel; SiO2; amino-silane-modified hafnium oxide surface; charge carrier mobility; dielectric material; dual-gate SNTFT; dual-gate carbon-nanotube thin-film field-effect transistors; planar dual-gate semiconducting-nanotube thin-film transistor; radiofrequency sputtering; semiconducting single-walled carbon nanotubes; single-gate SNTFT; single-gate devices; voltage 0.65 V; Geographic Information Systems; Logic gates; Performance evaluation; Radio frequency; Surface treatment; Threshold voltage; Transistors; Dual gate; hafnium oxide $(hbox{HfO}_{X})$ ; single-walled carbon nanotube (SWCNT); subthreshold slope; thin-film transistor (TFT); transconductance;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2011.2145379