Effects of the Substrate Pretreatments on the Leakage Current in the Low-Temperature Poly-Si TFTs

1996 ◽  
Vol 448 ◽  
Author(s):  
Tae-Kyung Kim ◽  
Byung-Il Lee ◽  
Tae-Hyung Ihn ◽  
Seung-Ki Joo

AbstractPoly-Si TFT’s were fabricated on the glass substrate by the Metal Induced Lateral Crystallization(MILC). Before deposition of the active a-Si thin films(1000 Å), the glass substrate was pretreated in three different ways such as oxidation of a-Si(100 Å), oxide buffer layer deposition(1000 Å), and ion mass doping of the glass substrates. The leakage current at reverse bias could be reduced by one order of magnitude by the substrate pretreatment. Field effect mobility of n-channel TFT’s was 108cm2/Vsec, subthreshold slope and on/off current ratio were 0.7 V/dec. and about 106, respectively.

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Sheng-Po Chang ◽  
San-Syong Shih

We reported on the performance and electrical properties of co-sputtering-processed amorphous hafnium-indium-zinc oxide (α-HfIZO) thin film transistors (TFTs). Co-sputtering-processedα-HfIZO thin films have shown an amorphous phase in nature. We could modulate the In, Hf, and Zn components by changing the co-sputtering power. Additionally, the chemical composition ofα-HfIZO had a significant effect on reliability, hysteresis, field-effect mobility (μFE), carrier concentration, and subthreshold swing (S) of the device. Our results indicated that we could successfully and easily fabricateα-HfIZO TFTs with excellent performance by the co-sputtering process. Co-sputtering-processedα-HfIZO TFTs were fabricated with an on/off current ratio of~106, higher mobility, and a subthreshold slope as steep as 0.55 V/dec.


2007 ◽  
Vol 124-126 ◽  
pp. 407-410
Author(s):  
Sang Chul Lim ◽  
Seong Hyun Kim ◽  
Gi Heon Kim ◽  
Jae Bon Koo ◽  
Jung Hun Lee ◽  
...  

We report the effects of instability with gate dielectrics of pentacene thin film transistors (OTFTs) inverter circuits. We used to the UV sensitive curable resin and poly-4-vinylphenol(PVP) by gate dielectrics. The inverter supply bias is VDD= -40 V. For a given dielectric thickness and applied voltage, pentacene OTFTs with inverter circuits measurements field effect mobility, on-off current ratio, Vth. The field effect mobility 0.03~0.07 cm2/Vs, and the threshold voltage is -3.3 V ~ -8.8 V. The on- and off-state currents ratio is about 103~106. From the OTFT device and inverter circuit measurement, we observed hysteresis behavior was caused by interface states of between the gate insulator and the pentacene semiconductor layer.


2003 ◽  
Vol 769 ◽  
Author(s):  
Lihong Teng ◽  
Wayne A. Anderson

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.


2013 ◽  
Vol 740-742 ◽  
pp. 703-706
Author(s):  
Michael Grieb ◽  
Stefan Noll ◽  
Dick Scholten ◽  
Martin Rambach

In the present work, we studied the influence of the post-implantation annealing temperature on the performance and oxide reliability of lateral 4H-SiC MOSFETs. The maximum field effect mobility of the MOSFETs at 25°C decreases from 22.4cm2/Vs to 17.2cm2/Vs by increasing annealing temperature from 1600°C to 1800°C. Respectively, the measured meantime to failure is about one order of magnitude higher for the 1700°C annealed sample at an applied field of 8.5MV/cm compared to the 1600°C and 1800°C annealed samples.


1987 ◽  
Vol 106 ◽  
Author(s):  
W. Schmolla ◽  
J. Diefenbach ◽  
G. Blang ◽  
W. Senske

ABSTRACTPoly-Si films were e-gun evaporated onto glass substrates. The Hall-mobility for holes was found to be about 2 cm2/Vs in undoped poly-Si films deposited at 400°C and 9 cm2/Vs at 500°C. TFTs were fabricated on the base of poly-Si evaporation technique on borosilicate glass at a highest process temperature of 550°C without ion implantation. The electrical TFT characteristics yield electron field-effect mobilities higher than 10 cm2/Vs as well as threshold voltages less than IV and an on/off current ratio in excess of 104.


2011 ◽  
Vol 1285 ◽  
Author(s):  
Xiaoxiao Ma ◽  
Shahrukh A. Khan ◽  
Nackbong Choi ◽  
Miltiadis Hatalis ◽  
Mark Robinson

ABSTRACTWe report Fe-42%Ni as a novel high-performance substrate for a-IGZO TFT fabrication after evaluating 8 different metals for chemical compatibility, mechanical flexing and dimensional stability. Excellent flexibility and rollability indicates that Fe-42%Ni would be a good choice as flexible substrate for R2R process. Pre-annealing process for stabilizing the substrate is studied and applied to the Fe-42%Ni foil before TFT fabrication. Staggered bottom gate a-IGZO TFTs which were fabricated on this substrate have field effect mobility of 12 cm2/V.s, threshold voltage of 2V, sub-threshold swing of 0.6V/decade and on/off current ratio exceeding 107.


2019 ◽  
Vol 963 ◽  
pp. 469-472 ◽  
Author(s):  
Teruaki Kumazawa ◽  
Mitsuo Okamoto ◽  
Miwako Iijima ◽  
Yohei Iwahashi ◽  
Shinji Fujikake ◽  
...  

The SiO2/SiC interface quality has a significant effect on the performance of 4H-SiC MOS devices. The introduction of nitrogen to the SiO2/SiC interface is a well-known method for reducing the interface state density (Dit). In this study, we introduced nitrogen to the SiO2/SiC interface by forming SiNx films using atomic layer deposition (ALD) and thus improved the interface quality. O2 annealing with a SiNx interface layer of optimal thickness enhanced the field effect mobility.


1994 ◽  
Vol 345 ◽  
Author(s):  
Chul Ha Kim ◽  
Il Lee ◽  
Ki Soo Sohn ◽  
Su Chul Chun ◽  
Jin Jang

AbstractWe have studied the effect of O2 plasma exposure on the performance of polycrystalline silicon (poly-Si) thin film transistor (TFTs). The field effect mobility is increased and the drain currents at negative gate voltages are reduced by O2 plasma exposure on the surface of the TFT. These improvements in the performance of the poly-Si TFTs are larger in offset structure compared to overlap one. We obtained the on/off current ratio of ∼ 108 after O2 plasma exposure for the poly-Si TFTs with 3 or 4 μm offset length.


Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 955 ◽  
Author(s):  
Hyunjae Lee ◽  
Seunghyun Ha ◽  
Jin-Hyuk Bae ◽  
In-Man Kang ◽  
Kwangeun Kim ◽  
...  

The effect of annealing ambient on SnO2 thin-film transistors (TFTs) fabricated via an ethanol-based sol-gel route was investigated. The annealing ambient has a significant effect on the structural characteristics and chemical composition and, in turn, the device performance. Although the crystalline-grain size of the SnO2 films annealed in air was the smallest, this size yielded the highest field-effect mobility. Compared with the minimization of boundary scattering via crystalline-size increase, augmentation of the free carrier concentration played a more critical role in the realization of high-performance devices. The fabricated SnO2 TFTs delivered a field-effect mobility, subthreshold swing, and on/off current ratio of 10.87 cm2/Vs, 0.87 V/decade, and 107, respectively.


Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4140
Author(s):  
Maksym Dub ◽  
Pavlo Sai ◽  
Aleksandra Przewłoka ◽  
Aleksandra Krajewska ◽  
Maciej Sakowicz ◽  
...  

Electrical and noise properties of graphene contacts to AlGaN/GaN heterostructures were studied experimentally. It was found that graphene on AlGaN forms a high-quality Schottky barrier with the barrier height dependent on the bias. The apparent barrier heights for this kind of Schottky diode were found to be relatively high, varying within the range of φb = (1.0–1.26) eV. AlGaN/GaN fin-shaped field-effect transistors (finFETs) with a graphene gate were fabricated and studied. These devices demonstrated ~8 order of magnitude on/off ratio, subthreshold slope of ~1.3, and low subthreshold current in the sub-picoamperes range. The effective trap density responsible for the 1/f low-frequency noise was found within the range of (1–5) · 1019 eV−1 cm−3. These values are of the same order of magnitude as reported earlier and in AlGaN/GaN transistors with Ni/Au Schottky gate studied as a reference in the current study. A good quality of graphene/AlGaN Schottky barrier diodes and AlGaN/GaN transistors opens the way for transparent GaN-based electronics and GaN-based devices exploring vertical electron transport in graphene.


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