Effects of fluorine plasma and ammonia annealing on pentacene thin -film transistor with ZrLaOx as gate dielectric

Pentacene organic thin-film transistor (OTFT) based on ZrLaOx gate dielectric is proposed and has been fabricated. The effects of fluorine plasma and ammonia annealing on the properties of the OTFT have been studied. It reveals that the plasma treatment can greatly improve carrier mobility and shift the threshold voltage in the positive direction. With a threshold voltage less than 0.5 V, the OTFT can work at very low supply voltage. On the other hand, the ensuing ammonia annealing counteracts the plasma treatment and shifts the threshold voltage in the opposite direction. © 2012 IEEE.published_or_final_versio

A Microcantilever-based Gas Flow Sensor for Flow Rate and Direction Detection

The purpose of this paper is to apply characteristics of residual stress that causes cantilever beams to bend for manufacturing a micro-structured gas flow sensor. This study uses a silicon wafer deposited silicon nitride layers, reassembled the gas flow sensor with four cantilever beams that perpendicular to each other and manufactured piezoresistive structure on each micro-cantilever by MEMS technologies, respectively. When the cantilever beams are formed after etching the silicon wafer, it bends up a little due to the released residual stress induced in the previous fabrication process. As air flows through the sensor upstream and downstream beam deformation was made, thus the airflow direction can be determined through comparing the resistance variation between different cantilever beams. The flow rate can also be measured by calculating the total resistance variations on the four cantilevers.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

High-Performance Pentacene Thin-Film Transistor With High-κ HfLaON as Gate Dielectric

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High-performance pentacene thin-film transistor with ZrLaO gate dielectric passivated by fluorine incorporation

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A low-frequency noise model with carrier generation-recombination process for pentacene organic thin-film transistor

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High-mobility pentacene OTFT with TaLaO gate dielectric passivated by fluorine plasma

Pentacene thin-film transistor with high-κ TaLaO as gate dielectric has been fabricated and shows a carrier mobility of 0.73 cm2/V s, much higher than that based on pure La2O3 (0.43 cm2/V s) due to the smoother surface of the TaLaO film and thus larger pentacene islands grown on it in the initial stage. Moreover, among various times for fluorine-plasma treatment on the TaLaO gate dielectric, 100 seconds result in the highest carrier mobility of 1.12 cm2/V s due to (1) smoothest oxide surface achieved by fluorine passivation of oxide traps, as measured by AFM and supported by smallest sub-threshold swing and lowest low-frequency noise; (2) the largest pentacene grains grown on the smoothest oxide surface, as demonstrated by AFM. Pentacene islands on on TaLaO or La2O3 gate dielectric with different plasma treatment times.postprin

High-mobility pentacene thin-film transistor by using LaxTa(1-x)Oy as gate dielectric

Pentacene organic thin-film transistors (OTFTs) using LaxTa(1−x)Oy as gate dielectric with different La contents (x = 0.227, 0.562, 0.764, 0.883) have been fabricated and compared with those using Ta oxide or La oxide. The OTFT with La0.764Ta0.236Oy can achieve a carrier mobility of 1.21 cm2 V−1s−1s, which is about 40 times and two times higher than those of the devices using Ta oxide and La oxide, respectively. As supported by XPS, AFM and noise measurement, the reasons lie in that La incorporation can suppress the formation of oxygen vacancies in Ta oxide, and Ta content can alleviate the hygroscopicity of La oxide, resulting in more passivated and smoother dielectric surface and thus larger pentacene grains, which lead to higher carrier mobility.postprin