Browsing by Author "Chen, Yi-Hsien"

Now showing 1 - 5 of 5

Characterization of environment-dependent hysteresis in indium gallium zinc oxide thin film transistors
(2013-09-01)
Chen, Yu-Chun
;
Chang, Ting-Chang
;
Li, Hung-Wei
;
Chung, Wan-Fang
;
Chen, Shih-Cheng
This study investigates environmentally dependent electrical performance as a function of hysteresis phenomena for amorphous indium-gallium-zinc-oxide (a-IGZO) thin film transistors (TFTs). Because ambient gas has a great influence on the electrical characteristics of zinc oxide-based TFTs during electrical measurements, the hysteresis for current-voltage and capacitance-voltage measurements are employed in different ambient gases (ambient air, vacuum, oxygen ambient and moisture ambient) to study this issue. Although the hysteresis phenomenon has been explained by the charge trapping and de-trapping model, in order to obtain stable electrical characteristics it is necessary to clarify the original principal mechanism leading to threshold voltage instability under gate bias operations in different environments. Also, the relationship between de-trapping rate and electrical hysteresis is investigated by prolonging the integration time of the semiconductor parameter analyzer. This study may be of importance in explaining the dynamic relationship between the TFT electrical characteristics and ambient gas, as well as providing a better understanding of the environment-dependent hysteresis phenomenon of the IGZO TFTs. (C) 2012 Elsevier B.V. All rights reserved.
Dependence of Light-Accelerated Instability on Bias and Environment in Amorphous Indium-Gallium-Zinc-Oxide Thin Film Transistors
(2013)
Chen, Yu-Chun
;
Chang, Ting-Chang
;
Li, Hung-Wei
;
Chung, Wan-Fang
;
Hsieh, Tien-Yu
This study examines the dependence of light-accelerated instability on bias and environment in amorphous indium-gallium-zinc-oxide thin film transistors. When device is in vacuum ambient, the threshold voltage of device after negative gate bias illumination stress (NBIS) showed bias-dependent electrical degradation behavior. However, experimental results show the degradation of electrical characteristic in a-IGZO devices does not only rely on the charge trapping mechanism for NBIS. During NBIS in oxygen, moisture-simulated and atmosphere ambient, the negative shift in electrical characteristic is suppressed when compared to that in vacuum. This implies that the adsorbent gas species in the surrounding environment dominates the electrical characteristic degradation of devices during NBIS, which leading the change of dominant mechanism from photon-created carrier trapping to adsorbed/desorbed gas phenomenon. (C) 2013 The Electrochemical Society. All rights reserved.
Design and Implement Binary Fuzzing based on libFuzzer
(2018-01-01)
Chao, Wei-Chieh
;
Lin, Si-Chen
;
Chen, Yi-Hsien
;
Tien, Chin-Wei
;
Huang, Chun-Ying
We design and implement libFuzzer-bin, a coverage-guided binary fuzzer based on libFuzzer. We discuss how libFuzzer-bin is implemented, measure the overheads of our implementation, and compare its performance against the American Fuzzy Lop (AFL) fuzzer. This is a work-in-progress. Our evaluation results show that, compared with the vanilla AFL, the current implementation brings only limited overheads and is able to identify possible vulnerabilities in a shorter time.
High-stability oxygen sensor based on amorphous zinc tin oxide thin film transistor
(2012-06-25)
Chen, Yu-Chun
;
Chang, Ting-Chang
;
Li, Hung-Wei
;
Chung, Wan-Fang
;
Wu, Chang-Pei
This research presents a sol-gel derived zinc tin oxide thin film transistor (TFT) as a high-stability oxygen sensor. Due to its high sensitivity, oxygen has been traditionally regarded as having a negative influence on the electrical characteristics of zinc-based TFTs; however, TFTs can also act as an oxygen sensor. After illumination with visible light in oxygen-rich ambient, a significant increase in drain current of nearly 10 4 times occurs with fixed gate and drain voltages. It is expected that an optimized method of illumination can help to reset the electrical characteristics or distinguish the on/off state of this reliable oxygen sensor. (C) 2012 American Institute of Physics. [ http://dx.doi.org/10.1063/1.4731773]
Surface states related the bias stability of amorphous In-Ga-Zn-O thin film transistors under different ambient gasses
(2011-12-30)
Chen, Yu-Chun
;
Chang, Ting-Chang
;
Li, Hung-Wei
;
Chen, Shih-Cheng
;
Chung, Wan-Fang
This paper investigates the origin of the bias stability under ambient gas (oxygen, moisture and vacuum) of In-Ga-Zn-O thin film transistors with different annealing temperatures. In Zn-based TFTs, the electrical characteristic of device is a strongly function with the ambient gas, the simultaneous gas ambient and bias stresses are applied on devices annealed in atmosphere ambient to study this issue. The result shows the device which is annealed at temperature up to 330 degrees C has worst reliability. We suppose that the sensitivity of gas ambient depend the defect state, which is associated to the annealing temperature, of surface in a-IGZO. (C) 2011 Elsevier B.V. All rights reserved.