scholarly journals Channel Defect Profiling and Passivation for ZnO Thin-Film Transistors

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1186
Author(s):  
Soo Cheol Kang ◽  
So Young Kim ◽  
Sang Kyung Lee ◽  
Kiyung Kim ◽  
Billal Allouche ◽  
...  

The electrical characteristics of Zinc oxide (ZnO) thin-film transistors are analyzed to apprehend the effects of oxygen vacancies after vacuum treatment. The energy level of the oxygen vacancies was found to be located near the conduction band of ZnO, which contributed to the increase in drain current (ID) via trap-assisted tunneling when the gate voltage (VG) is lower than the specific voltage associated with the trap level. The oxygen vacancies were successfully passivated after the annealing of ZnO in oxygen ambient. We determined that the trap-induced Schottky barrier lowering reduced a drain barrier when the drain was subjected to negative bias stress. Consequentially, the field effect mobility increased from 8.5 m2 V−1·s−1 to 8.9 m2 V−1·s−1 and on-current increased by ~13%.

2016 ◽  
Vol 56 ◽  
pp. 29-33 ◽  
Author(s):  
M. Estrada ◽  
M. Rivas ◽  
I. Garduño ◽  
F. Avila-Herrera ◽  
A. Cerdeira ◽  
...  

2011 ◽  
Vol 21 (35) ◽  
pp. 13524 ◽  
Author(s):  
Taehwan Jun ◽  
Keunkyu Song ◽  
Yangho Jung ◽  
Sunho Jeong ◽  
Jooho Moon

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2300
Author(s):  
He Zhang ◽  
Yaogong Wang ◽  
Ruozheng Wang ◽  
Xiaoning Zhang ◽  
Chunliang Liu

To improve the performance of amorphous InGaZnOx (a-IGZO) thin film transistors (TFTs), in this thesis, Cs+ ions adsorbed IGZO (Cs-IGZO) films were prepared through a solution immersion method at low temperature. Under the modification of surface structure and oxygen vacancies concentrations of a-IGZO film, with the effective introduction of Cs+ ions into the surface of a-IGZO films, the transfer properties and stability of a-IGZO TFTs are greatly improved. Different parameters of Cs+ ion concentrations were investigated in our work. When the Cs+ ions concentration reached 2% mol/L, the optimized performance Cs-IGZO TFT was obtained, showing the carrier mobility of 18.7 cm2 V−1 s−1, the OFF current of 0.8 × 10−10 A, and the threshold voltage of 0.2 V, accompanied by the threshold voltage shifts of 1.3 V under positive bias stress for 5000 s.


Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1652
Author(s):  
Do-Kyung Kim ◽  
Jihwan Park ◽  
Xue Zhang ◽  
Jaehoon Park ◽  
Jin-Hyuk Bae

We demonstrate the effect of the sub-gap density of states (DOS) on electrical characteristics in amorphous indium-gallium-zinc (IGZO) thin-film transistors (TFTs). Numerical analysis based on a two-dimensional device simulator Atlas controlled the sub-gap DOS parameters such as tail acceptor-like states, tail donor-like states, Gauss acceptor-like states, and Gauss donor-like states in amorphous IGZO TFTs. We confirm accuracy by exploiting physical factors, such as oxygen vacancy, peroxide, hydrogen complex, band-to-band tunneling, and trap-assisted tunneling. Consequently, the principal electrical parameters, such as the threshold voltage, saturation mobility, sub-threshold swing, and on-off current ratio, are effectively tuned by controlling sub-gap DOS distribution in a-IGZO TFTs.


Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1146
Author(s):  
Yih-Shing Lee ◽  
Yu-Hsin Wang ◽  
Tsung-Cheng Tien ◽  
Tsung-Eong Hsieh ◽  
Chun-Hung Lai

In this work, two stacked gate dielectrics of Al2O3/tetraethyl-orthosilicate (TEOS) oxide were deposited by using the equivalent capacitance with 100-nm thick TEOS oxide on the patterned InGaZnO layers to evaluate the electrical characteristics and stability improvement of amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) devices, including positive bias stress (PBS) and negative bias stress (NBS) tests. Three different kinds of gate dielectrics (Al2O3, TEOS, Al2O3/TEOS) were used to fabricate four types of devices, differing by the gate dielectric, as well as its thickness. As the Al2O3 thickness of Al2O3/TEOS oxide dielectric stacks increased, both the on-current and off-current decreased, and the transfer curves shifted to larger voltages. The lowest ∆Vth of 0.68 V and ∆S.S. of −0.03 V/decade from hysteresis characteristics indicate that the increase of interface traps and charge trapping between the IGZO channel and gate dielectrics is effectively inhibited by using two stacked dielectrics with 10-nm thick Al2O3 and 96-nm thick TEOS oxide. The lowest ∆Vth and ∆S.S. values of a-IGZO TFTs with 10-nm thick Al2O3 and 96-nm thick TEOS oxide gate dielectrics according to the PBS and NBS tests were shown to have the best electrical stability in comparison to those with the Al2O3 or TEOS oxide single-layer dielectrics.


2011 ◽  
Vol 109 (1) ◽  
pp. 014503 ◽  
Author(s):  
Ibrahim Abdel-Motaleb ◽  
Neeraj Shetty ◽  
Kevin Leedy ◽  
Rebecca Cortez

Sign in / Sign up

Export Citation Format

Share Document