Tuning the Electrical Parameters of p-NiOx-Based Thin Film Transistors (TFTs) by Pulsed Laser Irradiation

We utilized laser irradiation as a potential technique in tuning the electrical performance of NiOx/SiO2 thin film transistors (TFTs). By optimizing the laser fluence and the number of laser pulses, the TFT performance was evaluated in terms of mobility, threshold voltage, on/off current ratio and subthreshold swing, all of which were derived from the transfer and output characteristics. The 500 laser pulses-irradiated NiOx/SiO2 TFT exhibited an enhanced mobility of 3 cm2/V-s from a value of 1.25 cm2/V-s for as-deposited NiOx/SiO2 TFT, subthreshold swing of 0.65 V/decade, on/off current ratio of 6.5 × 104 and threshold voltage of −12.2 V. The concentration of defect gap states as a result of light absorption processes explains the enhanced performance of laser-irradiated NiOx. Additionally, laser irradiation results in complex thermal and photo thermal changes, thus resulting in an enhanced electrical performance of the p-type NiOx/SiO2 TFT structure.

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Thin Film Transistors on Plastic Substrates Using Silicon Deposited by Microwave ECR-CVD

MRS Proceedings ◽

10.1557/proc-769-h2.4 ◽

2003 ◽

Vol 769 ◽

Author(s):

Lihong Teng ◽

Wayne A. Anderson

Keyword(s):

Thin Film ◽

Threshold Voltage ◽

Thin Film Transistors ◽

Field Effect ◽

Silicon Films ◽

Subthreshold Swing ◽

Field Effect Mobility ◽

Current Ratio ◽

Saturation Field ◽

Plastic Substrates

AbstractThe properties of thin film transistors (TFT's) on plastic substrates with active silicon films deposited by microwave ECR-CVD were studied. Two types of plastic were used, PEEK and polyimide. The a-Si:H TFT deposited at 200°C on polyimide substrates showed a saturation field effect mobility of 4.5 cm2/V-s, a threshold voltage of 3.7 V, a subthreshold swing of 0.69 V/dec and an ON/OFF current ratio of 7.9×106, while the TFT fabricated on PEEK at 200°C showed a saturation field effect mobility of 3.9 cm2/V-s, a threshold voltage of 4.1 V, a subthreshold swing of 0.73 V/dec and an ON/OFF current ratio of 4×106. Comparison is made to TFT's with the Si deposited at 400°C on glass.

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Improving Performance of Tin-Doped-Zinc-Oxide Thin-Film Transistors by Optimizing Channel Structure

Scientific Reports ◽

10.1038/s41598-019-53766-2 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Zhuofa Chen ◽

Dedong Han ◽

Xing Zhang ◽

Yi Wang

Keyword(s):

Thin Film ◽

Threshold Voltage ◽

Thin Film Transistors ◽

Channel Structure ◽

Oxide Thin Film ◽

Electrical Performance ◽

Processing Temperature ◽

Active Layers ◽

Low Threshold ◽

Channel Configuration

AbstractIn this paper, we investigated the performance of thin-film transistors (TFTs) with different channel configurations including single-active-layer (SAL) Sn-Zn-O (TZO), dual-active-layers (DAL) In-Sn-O (ITO)/TZO, and triple-active-layers (TAL) TZO/ITO/TZO. The TAL TFTs were found to combine the advantages of SAL TFTs (a low off-state current) and DAL TFTs (a high mobility and a low threshold voltage). The proposed TAL TFTs exhibit superior electrical performance, e.g. a high on-off state current ratio of 2 × 108, a low threshold voltage of 0.63 V, a high field effect mobility of 128.6 cm2/Vs, and a low off-state current of 3.3 pA. The surface morphology and characteristics of the ITO and TZO films were investigated and the TZO film was found to be C-axis-aligned crystalline (CAAC). A simplified resistance model was deduced to explain the channel resistance of the proposed TFTs. At last, TAL TFTs with different channel lengths were also discussed to show the stability and the uniformity of our fabrication process. Owing to its low-processing temperature, superior electrical performance, and low cost, TFTs with the proposed TAL channel configuration are highly promising for flexible displays where the polymeric substrates are heat-sensitive and a low processing temperature is desirable.

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Numerical Design of Carrier Transporting Layer in Top-Gate InGaZnO Thin-Film Transistors for Controlling Potential Energy

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2021.19248 ◽

2021 ◽

Vol 21 (7) ◽

pp. 3847-3852

Author(s):

Do-Kyung Kim ◽

Jihwan Park ◽

Premkumar Vincent ◽

Jun-Ik Park ◽

Jaewon Jang ◽

...

Keyword(s):

Thin Film ◽

Potential Energy ◽

Threshold Voltage ◽

Structural Design ◽

Thin Film Transistors ◽

High Mobility ◽

Electrical Performance ◽

Indium Gallium Zinc Oxide ◽

Semiconductor Interfaces ◽

Efficient Charge

Top-gate amorphous indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) are designed with numerical analysis to control their electron potential energy. Design simulations show the effects of structural design on the electrical characteristics of these TFTs. In particular, the thicknesses of the channel (tch) and conducting (tc) layers, which play vital roles in TFT electrical performance, are varied from 1 to 50 nm to investigate the effect of thicknesses on the electron potential energies of the channel region and the electrode-semiconductor interfaces. The potential energies are precisely optimized for efficient charge transport, injection, and extraction, thus enhancing the electrical performance of these devices. It is also demonstrated that tch mainly affects mobility and threshold voltage, while tc mainly affects on-current. An acceptable threshold voltage of 0.55 V and high mobility of 14.7 cm2V−1s−1 are obtained with a tch of 30 nm and tc of 10 nm. Controllability of the electron potential energies and electrical performance of IGZO TFTs by means of structural design will contribute to realization of next-generation displays that have large areas and high resolutions.

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Threshold Voltage Shift Variation of a-Si:H TFTs With Anneal Time

MRS Proceedings ◽

10.1557/proc-1245-a19-02 ◽

2010 ◽

Vol 1245 ◽

Cited By ~ 2

Author(s):

Anil Indluru ◽

Sameer M Venugopal ◽

David R Allee ◽

Terry L Alford

Keyword(s):

Thin Film ◽

Threshold Voltage ◽

Thin Film Transistors ◽

Liquid Crystal Display ◽

Electrical Performance ◽

Threshold Voltage Shift ◽

Voltage Shift ◽

Active Matrix ◽

Improved Performance ◽

Anneal Time

AbstractHydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) are widely used in many areas and the most important application is in active matrix liquid crystal display. However, the instability of the a-Si:H TFTs constrains their usability. These TFTs have been annealed at higher temperatures in hope of improving their electrical performance. But, higher anneal temperatures become a constraint when the TFTs are grown on polymer-based flexible substrates. This study investigates the effect of anneal time on the performance of the a-Si:H TFTs on PEN. Thin-film transistors are annealed at different anneal times (4 h, 24 h, and 48 h) and were stressed under different bias conditions. Sub-threshold slope and the off-current improved with anneal time. Off-current was reduced by two orders of magnitude for 48 hours annealed TFT and sub-threshold slope became steeper with longer annealing. At positive gate-bias-stress (20 V), threshold voltage shift (∆Vt) values are positive and exhibit a power-law time dependence. High temperature measurements indicate that longer annealed TFTs show improved performance and stability compared to unannealed TFTs. This improvement is due to reduction of interface trap density and good a-Si:H/insulator interface quality with anneal time.

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Ultrathin-Body TiO2 Thin Film Transistors With Record On-Current Density, ON/OFF Current Ratio, and Subthreshold Swing via O2 Annealing

IEEE Electron Device Letters ◽

10.1109/led.2019.2927571 ◽

2019 ◽

Vol 40 (9) ◽

pp. 1463-1466 ◽

Cited By ~ 1

Author(s):

Jie Zhang ◽

Maria Gabriela Sales ◽

Guangyang Lin ◽

Peng Cui ◽

Paul Pepin ◽

...

Keyword(s):

Thin Film ◽

Current Density ◽

Thin Film Transistors ◽

Tio2 Thin Film ◽

Subthreshold Swing ◽

Current Ratio

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Effective performance improvement of organic thin film transistors with multi-layer modifications

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200138 ◽

2020 ◽

Vol 91 (3) ◽

pp. 30201

Author(s):

Hang Yu ◽

Jianlin Zhou ◽

Yuanyuan Hao ◽

Yao Ni

Keyword(s):

Thin Film ◽

Thin Film Transistors ◽

Performance Enhancement ◽

Organic Thin Film Transistors ◽

Electrical Performance ◽

Hole Injection ◽

Organic Thin Film ◽

Effective Performance ◽

Significant Performance ◽

P Type

Organic thin film transistors (OTFTs) based on dioctylbenzothienobenzothiophene (C8BTBT) and copper (Cu) electrodes were fabricated. For improving the electrical performance of the original devices, the different modifications were attempted to insert in three different positions including semiconductor/electrode interface, semiconductor bulk inside and semiconductor/insulator interface. In detail, 4,4′,4′′-tris[3-methylpheny(phenyl)amino] triphenylamine (m-MTDATA) was applied between C8BTBTand Cu electrodes as hole injection layer (HIL). Moreover, the fluorinated copper phthalo-cyanine (F16CuPc) was inserted in C8BTBT/SiO2 interface to form F16CuPc/C8BTBT heterojunction or C8BTBT bulk to form C8BTBT/F16CuPc/C8BTBT sandwich configuration. Our experiment shows that, the sandwich structured OTFTs have a significant performance enhancement when appropriate thickness modification is chosen, comparing with original C8BTBT devices. Then, even the low work function metal Cu was applied, a normal p-type operate-mode C8BTBT-OTFT with mobility as high as 2.56 cm2/Vs has been fabricated.

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Effect of Illumination on Organic Polymer Thin-Film Transistors

MRS Proceedings ◽

10.1557/proc-771-l10.17 ◽

2003 ◽

Vol 771 ◽

Cited By ~ 3

Author(s):

Michael C. Hamilton ◽

Sandrine Martin ◽

Jerzy Kanicki

Keyword(s):

Thin Film ◽

Thin Film Transistors ◽

Drain Current ◽

Charge Carriers ◽

Electrical Performance ◽

Organic Polymer ◽

Light Illumination ◽

Polymer Thin Film ◽

Channel Region ◽

White Light Illumination

AbstractWe have investigated the effects of white-light illumination on the electrical performance of organic polymer thin-film transistors (OP-TFTs). The OFF-state drain current is significantly increased, while the drain current in the strong accumulation regime is relatively unaffected. At the same time, the threshold voltage is decreased and the subthreshold slope is increased, while the field-effect mobility of the charge carriers is not affected. The observed effects are explained in terms of the photogeneration of free charge carriers in the channel region due to the absorbed photons.

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