• 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).

• Phonetics and Speech Sciences
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• v.7 no.3
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• pp.55-64
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• 2015

Previous research on syntactic processing shows that the interpretation of a syntactically ambiguous sentence is frequently strongly biased towards one meaning over another. The current study investigated the effect of bias strength on the production of disambiguating prosody for English ambiguous sentences. In Experiment 1, 40 speakers gave default readings of 18 syntactically ambiguous sentences. Questioning was used to prove intended meanings behind default readings. Intended meanings were treated as interpretation biases when a majority of speakers read a sentence with the same intended meaning. The size of the majority was used to establish bias strength. In Experiment 2, 10 speakers were instructed to use prosody to disambiguate given alternate meanings of the sentences from Experiment 1. The results indicated an effect of bias strength on disambiguating prosody: speakers used temporal juncture cues to reliably disambiguate alternate meanings for sentences with a weak interpretation bias, but not for those with a strong bias. Overall, the results indicated that interpretation biases strongly affect the production of prosody.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.303-306
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• 1999

On the effect of substrate bias at first stage of diamond synthesis at lower substrate temperature(approximately 673K) using microwave plasma CVD and effect of reaction gas system for the bias enhanced nucleation were studied. The reaction gas was mixture of methane and hydrogen or carbon monoxide and hydrogen. The nucleation density of applied bias -150V using $CH_4-H_2$ reaction gas system, significantly higher than that of $C-H_2$ reaction gas system. When the $CH_4-H_2$ reaction was used, nucleation density was increased because of existence of SiC as a interface for diamond nucleation. By use of this negative bias effect for fabrication of CVD diamond film using two-step diamond growth without pre-treatment, fabrication of the diamond film consist of diamond grains $0.2\mu\textrm{m}$ in diameter was demonstrated

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.492-492
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• 2012

RF biased inductively coupled plasma (ICP) has been widely used in various semiconductor etching processes and laboratory plasma researches. However, almost researches for the RF bias have been focused on the controls of dc self-bias voltages, even though the RF bias can change plasma parameters, such as electron temperature, plasma density, electron energy distribution (EED), and their spatial distributions. In this study, we report on the effect of the RF bias on the plasma parameters and the EEDs with various external parameters, such the RF bias power, the ICP power, the gas pressure, the gas mixture, and the frequency of RF bias. Our study shows the correlation between the RF bias and the plasma parameters and gives a crucial key for the understanding of collisionless electron heating mechanism in the RF biased ICP.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.178-180
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• 1993

The back bias effect on the breakdown voltage of SOI $p^+$-n diode is investigated. The breakdown voltage of the SOI $p^+$-n diode increases with the applied back bias. When the cathode electrode is used as a back bias, it is necessary to put the dielectric material between the Si-substrate and the bottom cathode electrode.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.130-131
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• 2009

AIP(arc ion plating)방법과 마그네슘 스퍼터링(DC reactive magnetron sputtering) 방법을 결합시킨 하이브리드 코팅 시스템으로 Cr-Si-N 코팅막을 합성하였다. 고분해능 TEM 및 SEM 분석들로부터 negative bias voltage에 따른 미세구조의 영향을 나타내었다. negative bias voltage의 증가에 따라 columnar microstructure가 amorphous microstructure로 변화하였다. bias voltage effect에 의해 Cr-Si-N 코팅막내 입자의 크기가 미세해지고 나노 복합체를 잘 형성하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.159-160
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• 2009

AIP(arc ion plating)방법으로 CrN 코팅막을 합성하였다. 고분해능 SEM과 AFM 분석들로부터 negative bias voltage에 따른 미세구조의 영향을 나타내었다. negative bias voltage의 증가에 따라 columnar microstructure가 amorphous microstructure로 변화하였다. bias voltage effect에 의해 CrN 코팅막내 입자의 크기가 미세해지고 나노 복합체를 잘 형성하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.445-448
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• 2006

Bias stress effect in pentacene organic thin-flim transistors with cross-linked PVA gate dielectric is analyzed. For negative gate bias stress, positive threshold voltage shift is observed. The injected charges from the gate electrode to the defect states of gate dielectric are regarded as the main origin of $V_T$ shift. The reduced bias stress effect using $SiO_2$ blocking layer confirms the assumed mechanism. It is also demonstrated that the inverter with $SiO_2$ blocking layer shows the negligible hysteresis owing to the reduced bias stress effect.

• Journal of the Korean institute of surface engineering
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• v.29 no.2
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• pp.93-99
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• 1996

In this work BN thin films were deposited on Si substrate by R. F. sputtering method at $200^{\circ}C$ and in Ar + $N_2$ mixed gas atmosphere. In order to investigate the effect of ion bombardment on substrate for c-BN bonding, substrate bias voltage was applied. The optimum substrate bias voltage for c-BN bonding was determined by FTIR analysis on specimens which were deposited with various bias voltages. Then BN thin film was deposited with this optimum condition and its phase, morphology, chemical composition, and refractive index were compared with those of BN film which was deposited without bias voltage. FTIR results showed that BN films deposited with substrate bias voltage were composed of mixed phases of c-BN and h-BN, while those deposited without bias voltage were h-BN only. When pure Ar gas was used for sputtering gas, BN films were delaminated easily from substrate in air, while when 10% $N_2$ gas was added to the sputtering gas, although c-BN specific infrared peak was reduced, delamination did not occur. GXRD and TEM results showed that BN films were amorphous phases regardless of substrate bias voltage, and AES results showed that the chemical compositions of B/N were about 1.7~1.8. The refractive index of BN film deposited with bias voltage was higher than that without bias voltage. The reason is believed to be the existence of c-BN bonding in BN film and the higher density of film that deposited with the substrate bias voltage.

• 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.