• Journal of the Korean Vacuum Society
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• v.8 no.3A
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• pp.249-255
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• 1999

Deposition characteristics of Cu thin films using Ar carrier gas and $H_2$ processing gas at various working pressures and substrate temperatures were investigated. Also, effects of $H_2$ pretreatment using plasma at $200^{\circ}C$ of substrate temperature and 0.6 Torr of chamber pressure were stdied. Cu thin films were deposited on TiN/Si substrate at working pressure of 0.5~1.5 Torr, substrate temperatures of 140~$240^{\circ}C$ with (hface)Cu(tmvs). Substrates were pretreated by $H_2$ plasma, and Cu films deposited in situ using twofold shower head. The purity, electrical resistivity, thickness, surface morphology, optical properties of the deposited Cu films were measured b the AES, four point probe, stylus profiler, SEM,. and the uv-visible spectrophotometer. This study suggests that $H_2$ plasma is an effective method for enhancing deposition rate and for producing high quality copper thin films.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.855-858
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• 2003

Carbon nanotubes (CNTs) were grown on Ni-coated TiN/Si substrate by microwave plasma chemical vapor deposition using mixture gas of $H_2/CH_4$ at low temperature of 500 $^{\circ}C$. Average diameter of CNTs could be easily controlled by $H_2$ plasma pretreatment time before CNTs growth. The turn-on voltages of CNT emitters were varied from 3.5 $V/{\mu}m$ to 9 $V/{\mu}m$ according to the hydrogen pretreatment conditions. The close relationship between electron emission characteristics and pretreatment time indicates that pretreatment condition can be a key process parameter in CNTs growth for field emission displays..

• Journal of the Korean Vacuum Society
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• v.22 no.6
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• pp.277-284
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• 2013

Carbon coils could be synthesized using $C_2H_2/H_2$ as source gases and $SF_6$ as an incorporated additive gas under thermal chemical vapor deposition system. The Ni layer on the $SiO_2$ substrate was used as a catalyst for the formation of the carbon coils. The characteristics (formation densities, morphologies, and geometries) of the as-grown carbon coils on the substrate with or without the $H_2$ plasma pretreatment process were investigated. By the relatively short time (1 minute) $H_2$ plasma pretreatment on the Ni catalyst layered-substrate prior to the carbon coils synthesis reaction, the dominant formation of the carbon microcoils on the substrate could be achieved. After the relatively long time (30 minutes) $H_2$ plasma pretreatment process, on the other hand, we could obtain the noble-shaped geometrical nanostructures, namely the formation of the numerous carbon nanocoils along the growth of the carbon microcoils. This noble-shaped geometrical nanostructure seemed to play a promising role as the good catalyst support for holding the very tiny Ni catalyst grains.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.397-400
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• 1994

The effect of xylazine administration on plasma cortisol, prolactin, glucose and packed cell volume (PCV) responses to immobilization and heat stress was investigated. Immobilization of rats for 2 hours by ligation of the fore and hind legs strongly caused approximately two-fold increase in plasma cortisol and prolactin levels. Plasma glucose and PCV were not significantly changed. Pretreatment of immobilized rats with xylazine (20 mg/kg body weight i.m.) resulted in approximately 20% reduction in both plasma cortisol and prolactin concentrations. A marked hyperglycemia and increase in the PCV value was observed. On the other hand, rats exposed to acute heat stress ($40^{\circ}C$, and 60% relative humidity) for 2 hours, also developed two fold increase in both plasma cortisol and prolactin concentrations and the pretreatment with xylazine caused a 20% reduction in the levels of both hormones. Plasma glucose level was not significantly changed in heat stressed rats but it was markedly increased after pretreatment with xylazine. PCV was significantly incrcased under heat stress and pretreatment with xylazine induced a pronounced elevation in this value. It was suggested that stimulation of cortisol and prolactin secretion in response to immobilization or heat stress can be partially reduced by an alpha 2-adrenergic agonist.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.120-120
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• 2003

MOCVD법으로 TiN 표면에 Ru을 증착함에 있어서 Ru의 핵생성을 고양시키기 위한 ECR plasma 전처리 세정이 필요하다. 본 연구에서는 Ru 증착시 ECR $H_2O$$_2$, AE Plasma 전처리 세정 효과를 SEM, AES, XRD로 분석하였다. Ru의 핵생성은 ECR H$_2$, Ar Plasma의 노출시간이 증가할수록 향상된 반면, ECR $O_2$ plasma의 경우 노출시간이 증가할수록 핵생성 효과는 감소하였다. H$_2$ plasma 내의 H$_2$ion은 Ti와 NH$_3$를 형성하기 위해서 TiN과 반응하여 TiN을 Ti로 개질 시켰으며, Ar plasma 전처리 세정하는 동안 Ar plasma 내의 Ar ion은 TiN 또는 TiON 표면의 질소와 산소원자를 제거하는 효과를 나타내었다. 그 결과 TiN 표면상에서도 Ru의 핵생성이 쉽게 이루어졌으며 H$_2$, Ar ECR Plasma 전처리 세정에서 RU 핵생성이 향상되는 결과를 얻었다. 세 종류의 plasma중에서 Ar ECR plasma로 전처리 세정한 경우에 가장 높은 Ru 핵생성 밀도를 얻을 수 있었다.

• Journal of Pharmaceutical Investigation
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• v.17 no.4
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• pp.189-195
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• 1987

The effects of cimetidine or ranitidine pretreatment on the intestinal absorption, plasma and urine level of caffeine, gastric acidity of mouse, and sleeping time by hexobarbital sodium were investigated pharmacokinetically. Cimetidine and ranitidine pretreatments were found to increase both the rate and extent of absorption of caffeine in rats. Cimetidine pretreatment increased blood level of caffeine and decreased urine level, while ranitidine pretreatment had no effect on urine level of caffeine. Ranitidine pretreatment inhibited gastric secretion due to caffeine more than cimetidine pretreatment. Cimetidine pretreatment increased the action of caffeine and showed shorter sleeping time by hexobarbital sodium, comparing with ranitidine pretreatment.

• Korean Journal of Materials Research
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• v.11 no.9
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• pp.802-809
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• 2001

Electroplating is an attractive alternative deposition method for copper with the need for a conformal and conductive seed layer In addition, the Cu seed layer should be highly pure so as not to compromise the effective resistivity of the filled copper interconnect structure. This seed layer requires low electrical resistivity, low levels of impurities, smooth interface, good adhesion to the barrier metal and low thickness concurrent with coherence for ensuring void-free fill. The electrical conductivity of the surface plays an important role in formation of initial Cu nuclei, Cu nucleation is much easier on the substrate with higher electrical conductivities. It is also known that the nucleation processes of Cu are very sensitive to surface condition. In this study, copper seed layers deposited by magnetron sputtering onto a tantalum nitride barrier layer were used for electroplating copper in the forward pulsed mode. Prior to electroplating a copper film, the Cu seed layer was cleaned by plasma H$_2$ and $N_2$. In the plasma treatment exposure tome was varied from 1 to 20 min and plasma power from 20 to 140W. Effects of plasma pretreatment to Cu seed/Tantalum nitride (TaN)/borophosphosilicate glass (BPSG) samples on electroplating of copper (Cu) films were investigated.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.163-163
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• 2003

TiN barrier막 위에 metal organic chemical deposition(MOCVD)법으로 RuO$_2$ 를 증착시 TiN막 표면을 세정처리하지 않을 경우 RuO$_2$의 핵생성이 어렵고, 그로 인해 RuO$_2$ 연속막이 형성되기 힘들다. 그러므로 RuO$_2$의 핵생성을 향상시키기 위해 TiN막에 대한 전처리 세정이 필수적이다. TiN막의 전처리 세정방법으로 ECR plasma 세정법을 사용하였으며, $O_2$ plasma와 H$_2$ plasma 그리고 Ai plasma를 이용해 각각의 exposure time을 변화시키며 전처리 세정을 실시하였다. H$_2$ plasma와Ar plasma의 exposure time이 증가됨에 따라 RuO$_2$의 핵생성이 향상되었다. 본 연구에서는 scanning electron microscopy(SEM), Auger electron emission spectrometry(AES), Atomic Force Microscope(AFM), X-ray diffraction (XRD) 등의 분석을 통해 TiN막 표면에 대한 ECR plasma 전처리 세정 이 RuO$_2$의 핵생성과 연속막 성장에 미치는 효과에 대해 조사하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1254-1257
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• 2004

Comparative study on the effects of $H_2$ vs. $O_2$ plasma pretreatment of gate oxide on the degradation phenomenon of p-channel low-temperature polysilicon (LTPS) thin-film transistors (TFTs) were performed. After high drain current stress (HDCS) with $V_{gs}$ = $V_{ds}$, the p-channel TFTs pretreated by $O_2$ plasma showed increased immunity to the degradation of device characteristics such as threshold voltage and maximum field effect mobility because of the higher binding energy of Si-O bond than that of Si-H bond. The investigation of degradation phenomenon of these parameters with the applied power suggests that self-heating can be the major cause of degradation of polysilicon TFTs.

• Journal of Pharmaceutical Investigation
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• v.34 no.4
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• pp.283-288
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• 2004

The pharmacokinetics of nifedipine was studied after oral coadministration of nifedipine (5 mg/kg) with quercetin (1.5, 7.5, 15 and 30 mg/kg, respectively) and 0.5 h or 3days pretreatment with quercetin (1.5 and 7.5mg/kg) in rabbits. Pretreatment of quercetin significantly (p<0.05, at 0.5 h; p<0.01, at 3 days) increased the plasma concentration of nifedipine, but not significant in coadministraiton. The area under the plasma concentration-time curve (AUC) and the peak concentration $(C_{max})$ of nifedipine pretreated with quercetin were increased significantly (p<0.05, at 0.5 h; p<0.01, at 3 days) compared to the control. By coadministration of quercetin, only 7.5 mg/kg of quercetin increased plasma AUC and $C_{max}$ of nifedipine significantly (p<0.05) compared to the control. Plasma AUC of intravenous nifedipine (1 mg/kg) is $4235\;{\pm}\;1192\;ng/ml{\cdot}hr$. Pretreatment of quercetin significantly (p<0.05, at 0.5 h; p<0.01, at 3 days) increased the absolute bioavailability (AB%) of nifedipine to 23.9-29.2% compared to the control (17.8%). Coadministration of quercetin showed no significant effect on the AB% of nifedipine except for 7.5 mg/kg. It is suggested that quercetin alters disposition of nifedipine by inhibition of P-glycoprotein efflux pump and its first-pass metabolism. The dosage of nifedipine should be adjusted when it is administered chronically with quercetin in a clinical situation.