Abnormal Behavior of Threshold Voltage Shift in Bias-Stressed a-Si:H Thin Film Transistor under Extremely High Intensity Illumination

2015 ◽  
Vol 7 (28) ◽  
pp. 15442-15446 ◽  
Author(s):  
Sang Youn Han ◽  
Kyung Tea Park ◽  
Cheolkyu Kim ◽  
Sanghyun Jeon ◽  
Sung-Hoon Yang ◽  
...  
2011 ◽  
Vol 99 (6) ◽  
pp. 062108 ◽  
Author(s):  
Bosul Kim ◽  
Eugene Chong ◽  
Do Hyung Kim ◽  
Yong Woo Jeon ◽  
Dae Hwan Kim ◽  
...  

RSC Advances ◽  
2019 ◽  
Vol 9 (36) ◽  
pp. 20865-20870 ◽  
Author(s):  
Dong-Gyu Kim ◽  
Jong-Un Kim ◽  
Jun-Sun Lee ◽  
Kwon-Shik Park ◽  
Youn-Gyoung Chang ◽  
...  

We studied the effect of X-ray irradiation on the negative threshold voltage shift of bottom-gate a-IGZO TFT. Based on spectroscopic analyses, we found that this behavior was caused by hydrogen incorporation and oxygen vacancy ionization.


Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 327
Author(s):  
Je-Hyuk Kim ◽  
Jun Tae Jang ◽  
Jong-Ho Bae ◽  
Sung-Jin Choi ◽  
Dong Myong Kim ◽  
...  

In this study, we analyzed the threshold voltage shift characteristics of bottom-gate amorphous indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs) under a wide range of positive stress voltages. We investigated four mechanisms: electron trapping at the gate insulator layer by a vertical electric field, electron trapping at the drain-side GI layer by hot-carrier injection, hole trapping at the source-side etch-stop layer by impact ionization, and donor-like state creation in the drain-side IGZO layer by a lateral electric field. To accurately analyze each mechanism, the local threshold voltages of the source and drain sides were measured by forward and reverse read-out. By using contour maps of the threshold voltage shift, we investigated which mechanism was dominant in various gate and drain stress voltage pairs. In addition, we investigated the effect of the oxygen content of the IGZO layer on the positive stress-induced threshold voltage shift. For oxygen-rich devices and oxygen-poor devices, the threshold voltage shift as well as the change in the density of states were analyzed.


2021 ◽  
Vol 21 (3) ◽  
pp. 1754-1760
Author(s):  
Joel Ndikumana ◽  
Jyothi Chintalapalli ◽  
Jin-Hyuk Kwon ◽  
Jin-Hyuk Bae ◽  
Jaehoon Park

We investigate the effects of environmental conditions on the electrical stability of spin-coated 5,11-bis(triethylsilylethynyl)anthradithiophene (TES-ADT) thin-film transistors (TFTs) in which crosslinked poly(4-vinylphenol-co-methyl methacrylate) (PVP-co-PMMA) was utilized as a gate insulator layer. Atomic force microscopy observations show molecular terraces with domain boundaries in the spin-coated TEST-ADT semiconductor film. The TFT performance was observed to be superior in the ambient air condition. Under negative gate-bias stress, the TES-ADT TFTs showed a positive threshold voltage shift in ambient air and a negative threshold voltage shift under vacuum. These results are explained through a chemical reaction between water molecules in air and unsubstituted hydroxyl groups in the cross-linked PVP-co-PMMA as well as a charge-trapping phenomenon at the domain boundaries in the spin-coated TES-ADT semiconductor.


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