Small-Subthreshold-Swing and Low-Voltage Flexible Organic Thin-Film Transistors Which Use HfLaO as the Gate Dielectric

High Performance Organic Thin-Film Transistors and Nonvolatile Memory Devices Using High-Dielectric Layers

“…Using high- HfLaO as the gate dielectric, the pentacene OTFTs fabricated on SiO 2 showed even comparable device performance with SPC poly-Si TFTs, with extra merit of much better sub-threshold swing for low voltage and low power application . Similar good device performance was also achieved using high- HfLaO on pentacene OTFTs, fabricated on low-cost flexible polyimide substrates and useful for portable low power electronics (Chang et al, 2009). Besides the logic TFTs, non-volatile memory function is also necessary for system-on-panel (SOP) application (Yin et al, 2008).…”

“…The V t and mobility were extracted from the linear I d 1/2 -V g plot. (Chang et al, 2009). The low operation voltage of -2.4 V is due to the low V t and small sub-threshold swing.…”

“…To lower the internal stress, a thin 100 nm SiO 2 was deposited on the polyimide substrate at room temperature by electron beam evaporation. Then the pentacene/HfLaO/TaN OTFTs were fabricated on SiO 2 /polyimide by following the similar process steps in previous section on SiO 2 /Si, with lower 200 o C PDA temperature and thicker 30 nm HfLaO gate dielectric (Chang et al, 2009). The thicker HfLaO is to compensate the degraded gate leakage current when processed at lower temperature.…”

Dry growth of n-octylphosphonic acid monolayer for low-voltage organic thin-film transistors

“…Thick high-k dielectrics resulted in still high capacitance values while reducing the gate leakage current. However, with the exceptions of [10], such OTFTs typically exhibited high inverse subthreshold slope [9,11] and low on/off current ratio [8,12].…”

Pentacene based thin film transistors with high-k dielectric Nd2O3 as a gate insulator

“…Most successful gate dielectric for pentacene based OTFTs is thermally grown silicon dioxide but the operating voltage of these silicon dioxide insulated OTFTs is large, above 20 V. For portable applications, especially for radio frequency identification devices requiring low power consumption, it is necessary to reduce the operating voltage to below 5 V. The key to low voltage operation is reduction of threshold voltage and sub threshold swing. The use of a high dielectricconstant (k) gate dielectric lowering the operation voltage of TFTs is one of the main technical trends [4,5]. Therefore researchers all over the world worked on the way to reduce operating voltage of pentacene based OTFTs using various high dielectric constant insulators Al 2 O 3 [4], H f LaO [5,6], H f SiO x [7], Pr 6 O 11 [8], La 2 O 3 [9] etc.…”