광화학증착법에 의한 직접패턴 PZT 박막의 제조 및 특성

박형호,박형호,김태송,Park, Hyeong-Ho,Park, Hyung-Ho,Kim, Tae-Song,Hill, Ross-H. 한국재료학회 2008 한국재료학회지 Vol.18 No.2

The ferroelectric properties of UV irradiated and non-irradiated PZT films prepared via photochemical metal-organic deposition using photosensitive precursors were characterized. Fourier transform infrared spectroscopy showed that complete removal of organic groups was possible through UV exposure of the spin-coated PZT precursor films at room temperature. The measured remnant polarization values of UV-irradiated and non-irradiated PZT films after annealing at $650^{\circ}C$ were 29 and $23\;{\mu}C/cm^2$, respectively. The UV irradiation was found to be effective for the enhancement of the <111> growth orientation and ferroelectric property of PZT film and in the direct patterning in the fabrication of micro-patterned systems without dry etching.

철제유물 부식화합물 분석의 표준데이터 확보를 위한 라만 분광법 적용성 연구

박형호,이재성,유재은,Park, Hyung Ho,Lee, Jae Sung,Yu, Jae Eun 국립문화재연구소 2011 保存科學硏究 Vol.32 No.-

철 부식화합물은 부식인자들과 함께 다양한 결정구조를 가지며 2가지 이상의 부식화합물들이 혼합되어 존재하므로 각각의 특성을 밝혀내기가 매우 어렵다. 본 연구는 표준 철 부식물을 대상으로 Raman Micro-Spectroscopy 분석을 실시하여 표준 Raman Data 확보를 목적으로 수행하였다. 표준 철 부식물에 대한 신뢰성을 향상시키기 위하여 SEM-EDS 분석과 XRD 분석을 추가로 실시하였다. SEM-EDS 분석결과 모두 표준 철 부식물의 구성성분과 일치하였으나 Goethite의 경우 철 이외의 비철금속 성분이 검출되었다. XRD 분석 결과 모두 표준 철 부식물의 구조와 일치 하였으나 Iron sulfate($FeSO_4{\cdot}6H_2O$)의 경우 Rozenite($FeSO_4{\cdot}4H_2O$)로 확인되었다. Raman Micro-Spectroscopy 분석결과 기존에 연구되었던 수산화철, 산화철의 Wavenumber에서 새로운 peak이 발견되었는데 이는 레이저 파장의 변화에 따른 것으로 사료 된다. 염화철과 황산철에서 Wavenumber가 새롭게 확인되어 표준 Raman Data 8건을 확보하였다. Raman Micro-Spectroscopy는 적은양의 시료를 이용하여 물질의 특성과 구조를 비교적 간단하게 분석 할 수 있어 미세한 부분이나 시료의 양이 한정된 문화재에 활용도가 높을 것으로 판단된다. It is quite difficult to identify its corrosion compound because they have a wide variety of crystal structures and they are mixed with two component. This study was conducted with the standard iron corrosion compounds through the analysis by Raman Micro-Spectroscopy, which aims to obtain standard Raman Data. To assess the reliability of standard iron corrosion compounds, SEM-EDS analysis and XRD analysis were conducted. Through SEM-EDS analysis, the elements of corrosion compound matched with those of standards iron corrosion compounds except Goethite. XRD analysis showed that the structures of corrosion compounds were identical to those of standard iron corrosion compounds, however, it was identified that Iron sulfate ($FeSO_4{\cdot}6H_2O$) is the Rozenite ($FeSO_4{\cdot}4H_2O$). Through Raman Micro-Spectroscopy analysis, the new peak was detected from the wavenumbers of hydroxide and iron oxide. It is considered that it is due to changes in the wavelength of the laser. As the wavenumbers of iron chloride and iron sulfate have been identified, eight kinds of Raman Data were obtained. It can be considered to contribute to cultral heritage for iron objects that Raman Micro-Spectroscopy analysis which is relatively easy to compare material properties and structures can be highly applicable to the research on cultural heritage with the limited amount of samples.

C54구조의 $TiSi_2$와 As 이온 주입된 다결정 Si계에서 고온 열처리에 의한 표면상태 거칠어짐과 TiAs 침전물 형성에 관한 연구

박형호,조경익,이희태,성명모,이상환,권오준,남기수,Park, Hyung-Ho,Cho, Kyoung-Ik,Lee, Hee-Tae,Sung, Myung-Mo,Lee, Sang-Hwan,Kwon, Oh-Joon,Nam, Kee-Soo 대한전자공학회 1990 전자공학회논문지 Vol. No.

비로소 높게 이온주입된 다결정 실리콘에 대한 C54 구조를 갖는 $TiSi_{2}$의 열적 안정성과 $TiSi_{2}{\times}As{\longrightarrow}TiAs{\times}2Si$의 TiAs 석출물 형성반응이 다결정 실리콘 박막의 표면 상태 거칠어짐에 미치는 영향을 살펴보았다. Thermal stability of $TiSi_{2}$ with C54 structure and morphology degradation of poly silicon layer resulted from the formation of TiAs precipitate through the reaction between T>$TiSi_{2}$</TEXT> and arsenic ion implanted in poly silicon have been studied.

단극하전을 이용한 나노입자 응집성장 제어

박형호,김상수,장혁상,Park, Hyung-Ho,Kim, Sang-Soo,Chang, Hyunk-Sang 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.1

Effects of electric force on the morphology and growth of aggregates were studied experimentally. Nano-sized NaCl particles were supplied to a flame to perform the unipolar charging state. This electric precursor did not modify a temperature profile of the flame. The morphology of aggregates was measured by TEM image processing technique and the light scattering technique. In the unipolar charged state, the fractal dimension of aggregates was smaller than that of' the electrically neutral state. This result was in good agreement with our previous numerical simulations.

단극하전 나노입자의 응집성장 과정에서 입자의 전기전도도의 효과에 대한 연구

박형호,김상수,장혁상,Park, Hyung-Ho,Kim, Sang-Soo,Chang, Hyuk-Sang 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.2

Effects of the electric conductivity of particles were studied for the aggregation process of charged particles with a Brownian dynamic simulation in the free molecular regime. A periodic boundary condition was used for the calculation of the aggregation process in each cell with 500 primary particles of 16 nm in diameter. We considered two extreme cases, a perfect conductor and a perfect nonconductor. The electrostatic force on a particle in the simulation cell was considered as a sum of electrostatic forces from other particles in the original cell and its replicate cells. We assumed that aggregates were only charged with pre-charged primary particles. The morphological shape of aggregates was described in terms of the fractal dimension. The fractal dimension for the uncharged aggregate was D$_{f}$= 1.761. However, the fractal dimension decreased from 1.694 to 1.360 for the case of the perfect conductor, and from 1.610 to 1.476 for the case of the perfect nonconductor, with the increase of the average number of charges on the primary particle from 0.2 to 0.3. These values were smaller than that of the centered charge case.e.

철제유물 부식인자에 대한 부식양상 및 부식화합물 실험 연구

박형호,이재성,유재은,Park, Hyung Ho,Lee, Jae Sung,Yu, Jae Eun 국립문화재연구소 2012 保存科學硏究 Vol.33 No.-

본 연구는 부식인자에 따른 부식현상을 관찰하고 구성성분과 결정구조 분석을 통하여 철제유물에 영향을 미치는 부식위험인자를 확인하고자 하였다. 부식인자가 녹아있는 HCl, $HNO_3$, $H_2SO_4$, $H_2O$ 용액에 순수한 Fe powder(99%)를 침적시켜 부식화합물을 채취하였다. 채취된 부식화합물의 색상과 형태를 파악하기 위하여 실체 현미경 관찰을 실시하였으며 부식인자와 성장성을 확인하기 위하여 SEM-EDS분석을 실시하였다. 생성된 부식화합물의 결정구조와 조성을 알아보기 위하여 XRD, Raman 분석을 실시하였다. 실험결과 산성환경에서의 부식 속도가 빠르며 HCl, $H_2SO_4$의 부식이 $HNO_3$보다 크게 나타났다. HCl의 부식화합물은 $Cl^-$이온의 영향을 받아 침상형, 밤송이형태로 성장하였으며 X-선 회절분석과 Raman 분석결과 Goethite와 Lepidocrocite가 검출되었다. $H_2SO_4$의 부식화합물은 S이온의 영향을 받아 가느다란 침상형, 원기둥형태로 성장하였으며 X-선 회절분석과 Raman 분석결과 Goethite와 Lepidocrocite가 검출되었다. $HNO_3$의 부식화합물은 O이온의 영향을 받아 구상형, 판상형태로 성장하였으며 X-선 회절분석과 Raman 분석결과 Magnetite와 Lepidocrocite가 검출되었다. $H_2O$의 부식화합물은 O이온의 영향을 받아 구상형, 판상형태로 성장하였지만 대부분 구상형으로 관찰되며 X-선 회절분석과 Raman 분석결과 부식화합물이 검출되지 않았다. 부식인자에 따른 부식양상과 부식화합물이 다양하게 나타난다는 사실을 알게 되었다. The corrosion phenomena of the iron artifacts was studied by morphology observation and instrumental analysis(EDS, XRD, Raman) with various corrosion factors in oder to verify to confirm the danger of corrosion factors. Corrosion compounds were collected by depositing pure Fe powder(99%) into a HCl, $HNO_3$, $H_2SO_4$, and $H_2O$ solution which contained the corrosion factors. Stereoscopic-microscope observations were then conducted determine the colors and shapes of the collected corrosion compounds, and SEM-EDS analysis was conducted to confirm the corrosion factors and the growth of these compounds. X-ray diffraction (XRD), Raman analyses were conducted to examine the crystal structure and compositions of the created corrosion compounds. The results of the experiment revealed that corrosion speed was faster in an acidic environment and corrosion of HCl and $H_2SO_4$ was greater than that of $HNO_3$. The corrosion compounds of HCl grew into a needle or chestnut-like shape after being affected by Cl- ion, and XRD and Raman analyses detected goethite and lepidocrocite. The corrosion compounds of $H_2SO_4$ was affected by S ion and grew into a slender-needle-like or cylindrical shape, and the XRD and Raman analyses detected goethite and lepidocrocite. The corrosion compounds of $HNO_3$ grew into a spherical or plate-like shape after being affected by O ion and the XRD and Raman analyses detected magnetite and lepidocrocite. Although the corrosion compounds of $H_2O$ grew into a spherical or plate-like shape after being affected by O ion, most of them were observed to have had spherical shapes, and the XRD and Raman analyses failed to detect corrosion compounds in them. It was found in the study that corrosion characteristics and compounds are diversely displayed according to the corrosion factor.

$CHF_3/C_2F_6$ 반응성이온 건식식각에 의해 변형된 실리콘 표면의 열적 거동에 관한 연구

박형호,권광호,곽병화,이중환,이수민,권오준,김보우,성영권,Park, Hyung-Ho,Kwon, Kwang-Ho,Koak, Byong-Hwa,Lee, Joong-Whan,Lee, Soo-Min,Kwon, Oh-Joon,Kim, Bo-Woo,Seong, Yeong-Gwon 한국재료학회 1992 한국재료학회지 Vol.2 No.1

실릴콘 산화막을 $CHF_3/C_2F_6$ 혼합가스를 사용하여 반응성이온 건식식각을 행할 때 실리콘 표면에 형성되는 잔류막과 손상충의 열적 거동을 X-선 광전자 분광기(XPS)와 이차이온 질량 분석기 (SIMS)를 사용, 연구하였다. 저항가열을 통한 in-situ 분석에 의해 폴리머 잔류막은 $200^{\circ}C$부터 분해가 시작되고 $400^{\circ}C$ 이상의 가열에서는 graphite 형태의 탄소 결합체를 형성하며 분해됨을 알았다. 질소 분위기하의 급속 열처리를 통해 잔류막의 열분해는 $800^{\circ}C$ 이상에서 완료되고 손상층을 형성하는 침투 불순원소의 기판 외부로의 확산이 관찰되었다. Thermal behavior of residue and damaged layer formed by reactive ion etching (RIE) in $CHF_3/C_2F_6$ were investigated using X-ray photoelectron spectroscopy(XPS) and secondary ion mass spec-trometry(SIMS) techniques. Decomposition of polymer residue film begins at $200^{\circ}C$ and above $400^{\circ}C$ carbon compound as graphite mainly forms by in-situ resistive heating. It reveals that thermal decomposition of residue can be completed by rapid thermal anneal treatment above $800^{\circ}C$ under nitrogen atmosphere and out-diffusion of carbon and fluorine of damaged layer is observed.

전기장이 형성된 관성 충돌기에서 대전 입자의 거동과 부착 특성에 대한 연구

박형호,김상수,Park, Hyung-Ho,Kim, Sang-Soo 대한기계학회 1999 大韓機械學會論文集B Vol.23 No.3

Effect of electrostatic and inertial forces on the pre-charged particle deposition was theoretically and experimentally studied by introducing the inertia impactor subjected to an electric field. To derive the analytic solution, we assumed that a flow was an ideal stagnation flow, a particle had saturation charges, and the electric field within the test section was uniform. On the other hand, $Al_2O_3$ particle groups were used as the test particles, which mean sizes were $1{\mu}m$, $3{\mu}m$, and $5{\mu}m$. To measure the deposition efficiency, the light scattering method was used. The results showed that the deposition efficiency was minimized at a certain nozzle velocity as increasing the nozzle velocity, only if the electric force was applied. As the electric field strength increased, $Stk_{50}{^{1/2}}$ was decreased, and its decreasing rate was reduced with increasing the flow velocity. Moreover the existence of electric field was against the cut-off performance of the inertia impactor.

정보통신과 지역발전 ; 기업경영과 정보통신 - 전남기업을 중심으로 -

박형호(Hyung Ho Park) 전남대학교 지역개발연구소 1986 지역개발연구 Vol.18 No.1

N/A N/A

Photo-induced hybrid nanopatterning of metal oxide via direct imprint lithography

박형호(Hyeong-Ho Park),최대근(Dae-Geun Choi),Xin Zhang,김기돈(Ki-don Kim),최준혁(Jun-Hyuk Choi),이지혜(Jihye Lee),박형호(Hyung-Ho Park),Ross Henry Hill,이응숙(Eung-Sug Lee),정준호(Jun-Ho Jeong) 한국생산제조학회 2011 한국생산제조시스템학회 학술발표대회 논문집 Vol.2011 No.4

A novel ultraviolet (UV)-assisted imprinting procedure that employs photosensitive zirconyl 2-ethylhexanoate is presented for the fabrication of both amorphous and crystalline zirconium dioxide (ZrO₂) nanostructures. Upon annealing at 400 C for 1 h, the lateral shrinkage and thickness shrinkage of ZrO₂ nanostructures were 69.8 and 66.7%, respectively, indicating an isotropic volume loss. During UV irradiation and annealing treatment, the refractive index of UV-irradiated ZrO₂ film is gradually increased by improvement in the packing density and crystallinity of the film. With increasing UV exposure time and annealing temperature, the optical band gap (Eg) of the UV-irradiated ZrO₂ film is red-shifted from 5.745 to 5.265 eV, due to the removal of organic groups and the resultant densification of the film during the photochemical reaction and the heat-induced increase in the crystallinity of the film. These results suggest that the refractive index and optical Eg of ZrO₂ nanostructures could be controlled by tuning the conditions of UV exposure time and annealing treatment. Nanopatterns of ZrO₂, fabricated by direct UV-assisted nanoimprint lithography, are potential candidates for protective coatings for optical mirrors and filters, e.g. high-reflectivity mirrors and broadband interference filters, as well as active electro-optical devices where ordered surface nanostructures are necessary.