• Journal of Sensor Science and Technology
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• v.28 no.5
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• pp.329-333
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• 2019

Solution-processed oxide thin-film transistors (TFTs) have garnered great attention, owing to their many advantages, such as low-cost, large area available for fabrication, mechanical flexibility, and optical transparency. Negative bias stress (NBS)-induced instability of sol-gel IGZO TFTs is one of the biggest concerns arising in practical applications. Thus, understanding the bias stress effect on the electrical properties of sol-gel IGZO TFTs and proposing an effective recovery method for negative bias stressed TFTs is required. In this study, we investigated the variation of transfer characteristics and the corresponding electrical parameters of sol-gel IGZO TFTs caused by NBS and positive bias recovery (PBR). Furthermore, we proposed an effective PBR method for the recovery of negative bias stressed sol-gel IGZO TFTs. The threshold voltage and field-effect mobility were affected by NBS and PBR, while current on/off ratio and sub-threshold swing were not significantly affected. The transfer characteristic of negative bias stressed IGZO TFTs increased in the positive direction after applying PBR with a negative drain voltage, compared to PBR with a positive drain voltage or a drain voltage of 0 V. These results are expected to contribute to the reduction of recovery time of negative bias stressed sol-gel IGZO TFTs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.461-463
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• 1999

In this paper, we have systematically investigated the variation of electrical characteristics with back-gate bias of n-channel SOI MOSFET\\`s. When positive bias is applied back-gate surface is inverted and back channel current is increased. When negative bias is applied back-gate surface is accumulated but it does not affect to the electrical characteristics.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.304-305
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• 2013

We report a positive exchange bias (HE) in thinmultilayered filmscontaining nano-oxide layer. The positive HE, obtained for our system results from an antiferromagnetic coupling between the ferromagnetic (FM) CoFe and the antiferromagnetic (AFM) CoO layers, which spontaneously form on top of the nano-oxide layer (NOL). The shift in the hysteresis loop along the direction of thecooling field and the change in the sign of exchange bias are evidence of antiferromagnetic interfacial exchange coupling between the CoO and CoFe layers. Our calculation indicates that uncompensated oxygen moments in the NOL results in antiferromagnetic interfacial exchange coupling between the CoO and CoFe layers. One of the interesting features observed with our system is that it displays the positive HE even above the bulk Neel temperature (TN) of CoO. Although the positive HEsystem has a different AFM/FM interfacial spin structure compare to that of the negative HE one, the results of the angular dependence measurements show that the magnetization reversal mechanism can be considered within the framework of the coherent rotation model.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.5
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• pp.33-44
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• 2023

Entrepreneurial self-efficacy is an important variable that explains people's attitudes and behaviors toward start-ups. In this study, we focused on individual psychological characteristics variables such as luck in belief and positive cognitive bias that affect entrepreneurial self-efficacy. Among these variables, we paid particular attention to luck in belief. The belief that business success depends on luck is widespread, but scientific verification about it has not been much. The reason for the academic indifference is that luck is a kind of superstition, related to precognition or extrasensory perception, and randomly caused by the external environment. The study of luck began in earnest as a measure to measure luck as an individual characteristic variable such as personality was developed. The purpose of this study is to examine the existing studies on luck in belief and to examine the effect of this luck in belief on positive cognitive bias and entrepreneurial self-efficacy through empirical analysis. For empirical analysis, this study conducted an on-line survey of 400 ordinary people and conducted a structural equation model analysis using AMOS 21.0 to verify the hypothesis. As a result of hypothesis testing, all hypotheses that luck in belief would have a positive effect on positive cognitive bias(self-enhancement bias, illusion of control bias, unrealism optimistic bias) were adopted. The hypothesis that positive cognitive bias(self-enhancement bias, illusion of control bias, unrealistic optimism bias) will have a positive effect on entrepreneurial self-efficacy was also adopted. Additional analysis was conducted to examine the mediating role of positive cognitive bias in the relationship between luck in belief and entrepreneurial self-efficacy, which showed that 'luck in belief→positive cognitive bias →entrepreneurial self-efficacy' were statistically significant. Through this, we confirmed the mediating effect of positive cognitive bias in the relationship between luck in belief and entrepreneurial self-efficacy. In the conclusion, the implications and limitations of the study were presented based on the results of this study.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.4
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• pp.145-153
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• 2014

This study examined the linkage between positive cognitive bias and entrepreneurial intention. Self-enhancement, unrealistic optimism, and illusion of control have been collectively referred as positive cognitive bias. We examined the effects of positive cognitive bias on attitudes toward success and failure. And we also examined the effect of attitudes toward success and failure on entrepreneurial intension. This study investigated these relationships using 240 high school students. The result of analysis indicated that the self-enhancement bias and unrealistic optimism bias had positive effects on attitude toward failure, but it had not any effect on attitude toward success. The illusion of control bias has positive effects on attitude toward success, but it had not any effect on attitude toward failure. The attitudes toward success and failure had positive effect on entrepreneurial intension. Then results of this study suggests that the cognitive biases showed a role of antecedents of attitudes toward success and failure. Finally, this study concluded with a discussion of the implications of the research findings and directions for future research.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1258-1261
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• 2005

The ramp type bias voltage applied to the common electrode during a reset-period is newly proposed to lower the background luminance and to improve the address discharge characteristics in AC-PDP. The positive ramp bias voltage is applied during the ramp-up period, whereas the negative ramp bias voltage is applied during the ramp-down period. The effects of the voltage slopes in both the positive and negative ramp bias voltages on the background luminance and address voltage characteristics are examined intensively. It is observed that the optimized positive and negative ramp bias voltages applied to the common electrode during the ramp-period can lower the background luminance and also enhance the address discharge characteristics of the AC-PDP.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.3
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• pp.326-333
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• 2015

This paper reports an adaptive positive feedback bias control technique for operational transconductance amplifiers to adjust the bias current based on the output current monitored by a current replica circuit. This technique enables operational transconductance amplifiers to quickly adapt their power consumption to various analog workloads when they are configured with negative feedback. To prove the concept, a test voltage follower is fabricated in $0.5-{\mu}m$ CMOS technology. Measurement result shows that the power consumption of the test voltage follower is approximately linearly proportional to the load capacitance, the signal frequency, and the signal amplitude for sinusoidal inputs as well as square pulses.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.11
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• pp.869-873
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• 2001

The effects of alternate bias stress on p-channel poly-Si TFT\`s has been systematically investigated. We alternately applied positive and negative bias stress on p-channel poly-Si TFT\`s, device Performance(V$\_$th/, g$\_$m/, leakage current, S-slope) are alternately appeared to be increasing and decreasing. It has been shown that device performance degrade under the negative bias stress while improve under the positive bias stress. This effects have been related to the hot carrier injection into the gate oxide rather than the generation of defect states within the poly-Si/SiO$_2$ interface under alternate bias stress.

• Journal of the Korean Vacuum Society
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• v.7 no.2
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• pp.94-103
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• 1998

We investigated a bias effect for diamond films deposited by a HFCVD(Hot Filament Chemical Vapor Deposition) method using a methane-hydrogen gas mixture. During deposition total chamber pressure, methane concentration, filament temperature and substrate temperature was 20 torr, 1.0%, $2100^{\circ}C$ and $980^{\circ}C$ respectively. Also DC bias was applied during both the nucleation stage and the growth stage systematically. We found that negative bias enhanced the nucleation density at the nucleation stage, but it made a bad influence on the morpholohy of films at the growth stage. Positive bias enhanced the growth rate and resulted in a good morpholohy of films. Therefore we concluded that it was effective to apply the negative bias during the nucleation stage and then to switch into the positive bias during the growth stage in the fabrication of diamond films.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1440-1441
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• 2006

In this study, we synthesized CNTs(carbon nanotubes) on the glass substrate by microwave plasma enhanced chemical vapor deposition (MPECVD), Effect of bias voltage on the grown behavior and morphology of CNTs were investigated. Recently, it has been proposed that aligned CNTs can also be achieved by the application of electric bias to the substrate during growth, the first time reported the bias effect such that the nanotube alignment occurred only when a positive bias was applied to the substrate whereas no aligned growth occurred under a negative bias and no tube growth was observed without bias. On the country, several researchers reported some different observations that aligned nanotubes could also be grown under negative substrate biases. This discrepancy as for the effect of positive and negative bias may indicate that the bias effect is not fully understood yet. The glass and Si wafers were first deposited with TiN buffer layer by r.f sputtering method, and then Ni catalyst same method, The thickness of TiN and Ni layer were 200 nm and 60 nm, respectively. The main process parameters include the substrate bias (0 to - 300 V), and deposition pressure (8 to 20 torr).