SiO/TiN 박막의 증착두께에 따른 유전율 특성

김창석,이우선,정천옥,김병인 조선대학교 에너지.자원신기술연구소 2001 에너지·자원신기술연구소 논문지 Vol.23 No.2

In these days, the thinner film of dielectric materials is required while it's capacitance is required to be still large at the VLSI process. Most of such VLSI have MOS structures. For the research on this requirement, MOS capacitors were fabricated on the silicon wafer in four different thickness groups by RF sputtering method. SiO of the SiO/TiN film is used as the insulating layer and TIN is chosen as the barrier against the diffusion of Al which is the terminal connected by ohmic contact because TIN has the advantageous properties such as good thermal stability and very low diffusion rate in spite of it's relatively low specific resistance. In this study their electrical and optical characteristics are investigated to find refractive index, absorption coefficient and Permittivity.

PbTiO₃ 강유전체 박막의 유전율 특성

김창석,정천옥,김병인 조선대학교 에너지.자원신기술연구소 2001 에너지·자원신기술연구소 논문지 Vol.23 No.2

This paper evaporates PbTiO₃layer thickness differently with RF sputtering method on Si Wafer(n-100). This study is performed to examine the characteristics of electric constant, photon energy and dielectric loss according to the thickness of PbTiO₃and increase the reliability and reproduction of PbTiO₃thin film. It is confirmed that the variation of electric constant by frequency resulted from the formation of particles within thin film, the particle size and the polarization on grain boundary. In conclusion dielectric loss depends on the value of imaginary number (ε2), polarizability falls zero(o) by resonance absorption and is close to 0 of tan8 value and Q value of dielectric loss.

PbTiO₃강유전체 박막의 유전율 특성

김창석,정천옥,김병인 조선대학교 에너지.자원신기술연구소 1999 에너지·자원신기술연구소 논문지 Vol.21 No.2

This paper evaporates PbTiO_(3) layer thickness differently with RF sputtering method on Si Wafer(n-100). This study is performed to examine the characteristics of electric constant, photon energy and dielectric loss according to the thickness of PbTiO_(3) and increase the reliability and reproduction of PbTiO_(3) thin film. It is confirmed that the variation of electric constant by frequency resulted from the formation of particles within thin film, the particle size and the polarization on grain boundary. In conclusion dielectric loss depends on the value of imaginary number (ε_(2)), polarizability falls zero(0) by resonance absorption and is close to 0 of tanδ value and Q value of dielectric loss.

SrTiO₃ 박막의 C-V특성에 미치는 Ti층의 영향

김병인,정천옥,이상일 조선대학교 에너지.자원신기술연구소 1997 에너지·자원신기술연구소 논문지 Vol.19 No.2

This study makes SrTiO₃with nonpolarity among ferroelectrics by RF sputtering as dielectric layer, produces thin film of Si/SrTiO₃/Al and Si/Ti/SrTiO₃/Al of MOS structure using Ti as buffer layer, measures and examines the electrical features with C-V as a result, ferroelectrics oscillation occurrs by the interaction within a crystal by light temperature and the absorption of thin film with Ti as buffer layer is increased. It is found that the peak of permittivity value of Ti/SrTiO₃thin film has low values and is appeared late and as dipole which is found in dielectric is shown, the experiment satisfies the theory. The thicker thin film is, the lower capacitance value can be and saturation is delayed, so the experimental results satisfy the general capacitance.

단근치와 다근치의 치은연하치석제거 및 치근면활택술 시행에 따른 치주낭 깊이 변화에 관한 연구

김형석,심형순,김병옥 조선대학교 구강생물학연구소 2003 Oral Biology Research (Oral Biol Res) Vol.27 No.1

The Primary factor of periodontal diseases is bacterial plaque. En the treatment of periodontitis, removal of subgingival calculus is an essential factor in the successful treatment. The purpose of this study was to evaluate the clinical effects over 3 weeks, 6 weeks and 9 weeks following sealing and root planning. This study was carried out on 14 individuals with periodontitis. For this study, 91 teeth were selected. The subjects were separated into three group on the basis of initial probing depth(PD). These were consisted of group I(PD(3㎜). group Ⅱ(3mm(PD(6mm) ,group Ⅲ(PD)6mm). Probing depth were recorded on baseline, 3weeks, 6weeks and 9weeks after scaling and root planning. All data analyzed statically. The results were as follows 1. For single rooted teeth of group Ⅱ and Ⅲ, there was statistically significant decrease in probing depth according to time course, tooth position than baseline(p<0.05). 2. For multirooted teeth of group Ⅱ and Ⅲ, there was statistically significant decrease in probing depth according to time course. tooth position than baseline(p<0.05). 3. For single and multirooted teeth of group Ⅰ, there was not statically signiftcant decrease in probing depth(p>0.05). 4. Between single and multirooted teeth. there was not statistically significant decrease in probing depth(p>0.05).

황금(黃芩)의 4-VO로 유발한 흰쥐뇌허혈에 대한 신경방어효과

李秉哲,林康鉉,金榮玉,金善礪,安德均,朴虎君,金護哲 대한본초학회 1999 大韓本草學會誌 Vol.14 No.2

Scutellariae Radix(SR), the root of Scutellaria baicalensis G_EORGI, whose property, flavour and channel tropism is bitter in flavour, cold in property(寒), acting on the lung, gallbladder, stomach and large intestine channels(歸?,?,?,大??), has the effects of clearing away heat and dampness(淸熱??), purging fire, detoxicating(?火解?), stopping bleeding(止血) and preventing miscarriage(安?). This drug is one of the popular drugs in traditional Korean medicine, which has been used to antipyretic, antibacterial, antitoxic and antihypersensitive effects. So this study was planned to check the neuroprotective effect of SR on the global ischemia induced by 4-vessel occlusion in Wister rats. and SR extract was lyophilized after extraction with 70% methanol. We induced 4-vessel occlusion for 10 minutes and reperfused again. The number of CA1 pyramidal neurons were counted after 7 days of reperfusion under the cresyl violet staining. The result obtained that in 4-VO ischemia, SR showed significantly neuroprotective effects(1,000 and 500 ㎎/㎏ of SR extracts, p<0.05) compared with control group. Each neuroprotective ratio was about 27.4 %, 23.2 % respectively. Consequently, Scutellariae Radix has neuroprotective effects on the global ischemia induced by 4-vessel occlusion in Wistar rats.

SrTiO₃ 박막의 유전특성에 미치는 Ti층의 영향

정천옥,김병인,김창석 조선대학교 에너지.자원신기술연구소 2001 에너지·자원신기술연구소 논문지 Vol.23 No.2

This study makes SrTiO₃with nonpolarity among ferroelectrics by RF sputtering as dielectric layer, produces thin film of Si+SrTiO₃and Si+Ti+SrTiO₃of MOS structure using Ti as buffer layer, measures and examines the electrical features with optical refractive index, absorption coefficient, electric permittivity, photon energy and as a result, ferroelectrics oscillation occurrs by the interaction within a film by light temperature and the absorption coefficient of thin film with Ti as buffer layer is increased. It is found that the peak of electric permittivity value of Ti+SrTiO₃thin film has low values and is appeared late and as dipole which is found in dielectric is shown, the experiment satisfies the theory. In the nature of electric permittivity by photon energy, imaginary value is higher and current variation slope of thin film of thickness SrTiO₃has lower values in reverse bias.

광자에너지에 의한 TiN-Oxide 박막의 유전율 특성

정천옥,김병인,김창석 조선대학교 생산기술연구소 1997 生産技術硏究 Vol.19 No.1

VLSI require thinner dielectric film and also larger capacitance. Most of such VLSI have MOS structures. For the research on this requirement, MOS capacitors were fabricated on the silicon wafer in four different thickness groups by RF sputtering method and investigated on their electrical and optical characteristics by photon energy variation. SiO film is used as the insulating layer and TiN film is chosen as the barrier against the diffusion of Al which is the terminal connected by ohmic contact because TiN has the advantageous properties such as good thermal stability and very low diffusion rate in spite of it's relatively low specific resistance.

광자에너지에 의한 TiN-Oxide 박막의 유전율 특성

정천옥,김병인,김창석 조선대학교 에너지.자원신기술연구소 2001 에너지·자원신기술연구소 논문지 Vol.23 No.2

VLSI require thinner dielectric film and also larger capacitance. Most of such VLS I have MOS structures. For the research on this requirement, MOS capacitors were fabricated on the silicon wafer in four different thickness groups by RF sputtering method and investigated on their electrical and optical characteristics by photon energy variation. SiO film is used as the insulating layer and TIN film is chosen as the barrier against the diffusion of Al which is the terminal connected by ohmic contact because TIN has the advantageous properties such as good thermal stability and very low diffusion rate in spite of it's relatively low specific resistance.

SrTiO_3 박막의 유전특성에 미치는 Ti층의 영향

정천옥,김병인,김창석 조선대학교 동력자원연구소 1997 動力資源硏究所誌 Vol.19 No.1

This study makes SrTiO₃ with nonpolarity among ferroelectrics by RF sputtering as dielectric layer, produces thin film of Si/SrTiO₃ and Si/Ti/SrTiO₃ of MOS structure using Ti as buffer layer, measures and examines the electrical features with optical refractive index, absorption coefficient, electric permittivity, photon energy and as a result, ferroelectrics oscillation occurrs by the interaction within a film by light temperature and the absorption coefficient of thin film with Ti as buffer layer is increased. It is found that the peak of electric permittivity value of Ti/SrTiO₃ thin film has low values and is appeared late and as dipole which is found in dielectric is shown, the experiment satisfies the theory. In the nature of electric permittivity by photon energy, imaginary value is higher and current variation slope of thin film of thickness SrTiO₃ has lower values in reverse bias.