• Korean Journal of Metals and Materials
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• v.48 no.7
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• pp.667-673
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• 2010

Copper filling into TSV (through-silicon-via) and reduction of the filling time for the three dimensional chip stacking were investigated in this study. A Si wafer with straight vias - $30\;{\mu}m$ in diameter and $60\;{\mu}m$ in depth with $200\;{\mu}m$ pitch - where the vias were drilled by DRIE (Deep Reactive Ion Etching) process, was prepared as a substrate. $SiO_2$, Ti and Au layers were coated as functional layers on the via wall. In order to reduce the time required complete the Cu filling into the TSV, the PPR (periodic pulse reverse) wave current was applied to the cathode of a Si chip during electroplating, and the PR (pulse-reverse) wave current was also applied for a comparison. The experimental results showed 100% filling rate into the TSV in one hour was achieved by the PPR electroplating process. At the interface between the Cu filling and Ti/ Au functional layers, no defect, such as a void, was found. Meanwhile, the electroplating by the PR current showed maximum 43% filling ratio into the TSV in an hour. The applied PPR wave form was confirmed to be effective to fill the TSV in a short time.

• 보존과학연구
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• s.26
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• pp.165-188
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• 2005

From the ancient to these days, there have been used many kinds of pigment which have two types that are inorganic pigment and organic pigment. At the ancient times, natural pigment had been used but the artificially mixed pigment has been used in modern times. By the way, searching for studies has been studied recently, it would be said the ancient pigments such as Danchung, Wall painting and Mural painting are the mainthema. However, studies about the pigments used in modern pictured relics have rarely can be found. Therefore, this analysis of Ilweolokdo would be important at the point of the pigments used in pictures of royal family in modern times and the results can be briefly summarized as below; Firstly, the results of qualitative analysis of the pigments that base or all pigments of picture was detected components of Ca, Fe and As, this results meaning that picture was used filler and basic paint. Secondly, a result of the analysis on the composition elements of the pigments shows that the main components in their composition are ;White - Lead Cyanamide($2PbCO_3$.$Pb(OH)_2$) or Titanium Oxide($TiO_2$)Blue - Ultramarine($2(Na_2O$.$Al_2O_3$ .$2Si_O2$).$Na_2S_2$)Green - Emerald green($C_2H_3A_s3Cu_2O_8$)Gold - Gold(Au), Red-Red Lead($Pb_3O_4$) or Cinnabar(HgS)Black - Carbon(C)Thirdly, X-ray diffraction analysis of crystalline structure for the blue and green pigment peeling off in picture shows that the components of blue pigment is Ultramarine($2(Na_2O$.$Al_2O_3$ .$2Si_O2$).$Na_2S_2$) and green pigment is Emerald green($C_2H_3A_s3Cu_2O_8$). Especially, microcrystalline structure of the green pigment was the shape like a cross section of wood. Consequently, we knew through the analysis of qualitative and microcrystallinestructures seen on the cross section of analyzed pigments layer that the all pigments used in the Ilweoloakdo is possible to use synthetic pigments in modern.

• Korean Journal of Metals and Materials
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• v.50 no.2
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• pp.152-158
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• 2012

The effect of current waveform on Cu filling into TSV (through-silicon via) and the bottom-up ratio of Cu were investigated for three dimensional (3D) Si chip stacking. The TSV was prepared on an Si wafer by DRIE (deep reactive ion etching); and its diameter and depth were 30 and $60{\mu}m$, respectively. $SiO_2$, Ti and Au layers were coated as functional layers on the via wall. The current waveform was varied like a pulse, PPR (periodic pulse reverse) and 3-step PPR. As experimental results, the bottom-up ratio by the pulsed current decreased with increasing current density, and showed a value of 0.38 on average. The bottom-up ratio by the PPR current showed a value of 1.4 at a current density of $-5.85mA/cm^2$, and a value of 0.91 on average. The bottom-up ratio by the 3-step PPR current increased from 1.73 to 5.88 with time. The Cu filling by the 3-step PPR demonstrated a typical bottom-up filling, and gave a sound filling in a short time.

• Korean Journal of Metals and Materials
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• v.49 no.5
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• pp.388-394
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• 2011

High speed copper filling into TSV (through-silicon-via) for three dimensional stacking of Si chips was investigated. For this study, a tapered via was prepared on a Si wafer by the DRIE (deep reactive ion etching) process. The via had a diameter of 37${\mu}m$ at the via opening, and 32${\mu}m$ at the via bottom, respectively and a depth of 70${\mu}m$. $SiO_2$, Ti, and Au layers were coated as functional layers on the via wall. In order to increase the filling ratio of Cu into the via, a PPR (periodic pulse reverse) wave current was applied to the Si chip during electroplating, and a PR (pulse reverse) wave current was applied for comparison. After Cu filling, the cross sections of the vias was observed by FE-SEM (field emission scanning electron microscopy). The experimental results show that the tapered via was filled to 100% at -5.85 mA/$cm^2$ for 60 min of plating by PPR wave current. The filling ratio into the tapered via by the PPR current was 2.5 times higher than that of a straight via by PR current. The tapered via by the PPR electroplating process was confirmed to be effective to fill the TSV in a short time.

• Journal of the Korean institute of surface engineering
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• v.24 no.1
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• pp.25-30
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• 1991

The evaporation characteristics of Ag, Al, Au, Cr. Cu, In, Mg, Mn, Pb, Pd, Si, SiO, Sn, Ti and Zn with the various resistive heating sources have been studied. The employed sources are refractory metal (Mo, Ta and W) boats, W-wire, ceramic (usually Al2O3)-coated and -barriered refractory metal boats, and special boats such as baffled boats and intermetallic boats (nitride compound and graphite). We investigated the melting mode, evaporation rate at a specific power, and lifetime of the sources. A special boat holder is also discussed which is needed to cool the sources at a large heat capacity.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.371.2-371.2
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• 2016

Graphene electronics is one of the promising technologies for the next generation electronic devices due to the outstanding properties such as conductivity, high carrier mobility, mechanical, and optical properties along with extended applications using 2 dimensional heterostructures. However, large contact resistance between metal and graphene is one of the major obstacles for commercial application of graphene electronics. In order to achieve low contact resistance, numerous researches have been conducted such as gentle plasma treatment, ultraviolet ozone (UVO) treatment, annealing treatment, and one-dimensional graphene edge contact. In this report, we suggest a fabrication method of one-dimensional graphene metal edge contact without using graphene exfoliation. Graphene is grown on Cu foil by low pressure chemical vapor deposition. Then, the graphene is transferred on $SiO_2/Si$ wafer. The patterning of graphene channel and metal electrode is done by photolithography. $O_2$ plasma is applied to etch out the exposed graphene and then Ti/Au is deposited. As a result, the one-dimensional edge contact geometry is built between metal and graphene. The contact resistance of the fabricated one-dimensional metal-graphene edge contact is compared with the contact resistance of vertically stacked conventional metal-graphene contact.

• Journal of Technologic Dentistry
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• v.31 no.1
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• pp.55-61
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• 2009

Passive fitting of meso-structure and super-structures is a predominant requirement for the longevity and clinical success of osseointegrated dental implants. However, precision and passive fitting has been unpredictable with conventional methods of casting as well as for corrective techniques. Alternative to conventional techniques, electro discharge machining(EDM) is an advanced method introduced to dental technology to improve the passive fitting of implant prosthesis. In this technique material is removed by melting and vaporization in electric sparks. Regarding the efficacy of EDM, the application of this technique induces severe surface morphological and elemental alterations due to the high temperatures developed during machining, which vary between $10,000{\sim}20,000^{\circ}C$. The aim of this study was to investigate the morphological and elemental alterations induced by EDM process of casting dental gold alloy and non-precious alloy used for the production of implant-supported prosthesis. A conventional clinical dental casting alloys were used for experimental specimens patterns, which were divided in three groups, high fineness gold alloy(Au 75%, HG group), low fineness gold alloy(Au 55%, LG group) and nonprecious metal alloy(Ni-Cr, NP group). The UCLA type plastic abutment patterns were invested with conventional investment material and were cast in a centrifugal casting machine. Castings were sandblasted with $50{\mu}m\;Al_2O_3$. One casting specimen of each group was polished by conventional finishing(HGCON, LGCON, NPCON) and one specimen of each group was subjected to EDM in a system using Cu electrodes, kerosene as dielectric fluid in 10 min for gold alloy and 20 min for Ni-Cr alloy(HGEDM. LGEDM, NOEDM). The surface morphology of all specimens was studied under an energy dispersive X-ray spectrometer (EDS). The quantitative results from EDS analysis are presented on the HGEDM and LGEDM specimens a significant increase in C and Cu concentrations was found after EDM finishing. The different result was documented for C on the NPEDM with a significant uptake of O after EDM finishing, whereas Al, Si showed a significant decrease in their concentrations. EDS analysis showed a serious uptake of C and Cu after the EDM procedure in the alloys studied. The C uptake after the EDM process is a common finding and it is attributed to the decomposition of the dielectric fluid in the plasma column, probably due to the development of extremely high temperatures. The Cu uptake is readily explained from the decomposition of Cu electrodes, something which is also a common finding after the EDM procedure. However, all the aforementioned mechanisms require further research. The clinical implication of these findings is related with the biological and corrosion resistance of surfaces prepared by the EDM process.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.156-156
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• 2000

Recently, the surface electronic states have attracted much attention since their standing wave patterns created around steps, defects, and adsorbates on noble metal surfaces such as Au(111), Ag(110), and Cu(111) were observed by scanning tunneling microscopy (STM). As a typical example, a striking circular pattern of "Quantum corral" observed by Crommie, Lutz, and Eigler, covers a number of text books of quantum mechanics, demonstrating a wavy nature of electrons. After the discoveries, similar standing waves patterns have been observed on other metal and demiconductor surfaces and even on a side polane of nano-tubes. With an expectation that the surface states could be utilized as one of ideal cases for studying two dimensionakl (sD) electronic system, various properties, such as mean free path / life time of the electronic states, have been characterized based on an analysis of standing wave patterns, . for the 2D electron system, electron density is one of the most importnat parameters which determines the properties on it. One advantage of conventional 2D electron system, such as the ones realized at AlGaAs/GaAs and SiO2/Si interfaces, is their controllability of the electrondensity. It can be changed and controlled by a factor of orders through an application of voltage on the gate electrode. On the other hand, changing the leectron density of the surface-state 2D electron system is not simple. On ewqy to change the electron density of the surface-state 2D electron system is not simple. One way to change the electron density is to deposit other elements on the system. it has been known that Pd(111) surface has unoccupied surface states whose energy level is just above Fermi level. Recently, we found that by depositing Pd on Cu(111) surface, occupied surface states of Cu(111) is lifted up, crossing at Fermi level around 2ML, and approaches to the intrinsic Pd surface states with a increase in thickness. Electron density occupied in the states is thus gradually reduced by Pd deposition. Park et al. also observed a change in Fermi wave number of the surface states of Cu(111) by deposition of Xe layer on it, which suggests another possible way of changing electron density. In this talk, after a brief review of recent progress in a study of standing weaves by STM, I will discuss about how the electron density can be changed and controlled and feasibility of using the surface states for a study of 2D electron system. One of the most important advantage of the surface-state 2D electron system is that one can directly and easily access to the system with a high spatial resolution by STM/AFM.y STM/AFM.

• Economic and Environmental Geology
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• v.42 no.3
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• pp.177-193
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• 2009

The Samgwang deposit consists of eight massive mesothermal quartz veins that filled NE and NW-striking fractures along fault zones in Precambrian granitic gneiss of the Gyeonggi massif. The mineralogy and paragenesis of the veins allow two separate discrete mineralization episodes(stage I=quartz and calcite stage, stage II-calcite stage) to be recognized, temporally separated by a major faulting event. The ore minerals are contained within quartz and calcite associated with fracturing and healing of veins that occurred during both mineralization episodes. The hydrothermal alteration of stage I is sericitization, chloritization, carbonitization, pyritization, silicification and argillization. Sericitic zone occurs near and at quartz vein and include mainly sericite, quartz, and minor illite, carbonates and chlorite. Chloritic zone occurs far from quartz vein and is composed of mainly chlorite, quartz and minor sericite, carbonates and epidote. Fe/(Fe+Mg) ratios of sericite and chlorite range 0.45 to 0.50(0.48$\pm$0.02) and 0.74 to 0.81(0.77$\pm$0.03), and belong to muscovite-petzite series and brunsvigite, respectiveIy. Calculated $Al_{IV}$-FE/(FE+Mg) diagrams of sericite and chlorite suggest that this can be a reliable indicator of alteration temperature in Au-Ag deposits. Calculated activities of chlorite end member are $a3(Fe_5Al_2Si_3O_{10}(OH)_6$=0.0275${\sim}$0.0413, $a2(Mg_5Al_2Si_3O_{10}(OH)_6$=1.18E-10${\sim}$7.79E-7, $a1(Mg_6Si_4O_{10}(OH)_6$=4.92E-10${\sim}$9.29E-7. It suggest that chlorite from the Samgwang deposit is iron-rich chlorite formed due to decreasing temperature from high temperature(T>450$^{\circ}C$). Calculated ${\alpha}Na^+$, ${\alpha}K^+$, ${\alpha}Ca^{2+}$, ${\alpha}Mg^{2+}$ and pH values during wallrock alteration are 0.0476($400^{\circ}C$), 0.0863($350^{\circ}C$), 0.0154($400^{\circ}C$), 0.0231($350^{\circ}C$), 2.42E-11($400^{\circ}C$), 7.07E-10($350^{\circ}C$), 1.59E-12($400^{\circ}C$), 1.77E-11($350^{\circ}C$), 5.4${\sim}$6.4($400^{\circ}C$), 5.3${\sim}$5.7($350^{\circ}C$)respectively. Gain elements(enrichment elements) during wallrock alteration are $TiO_2$, $Fe_2O_3(T)$,CaO, MnO, MgO, As, Ag, Cu, Zn, Ni, Co, W, V, Br, Cs, Rb, Sc, Bi, Nb, Sb, Se, Sn and Lu. Elements(Ag, As, Zn, Sc, Sb, Rb, S, $CO_2$) represents a potential tools for exploration in mesothermal and epithermal gold-silver deposits.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.24-24
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• 1998

반도체장비를 포함하는 초고진공장비의 園훌化가 급속히 그리고 절실히 요구되고 있는 것이 현실정이다. 當面해서 실현할 국산진공장비의 대상은 廣範圍하다. 즉, 각종 진공 pump ( (rotary, dry, diffusion, cryo, ion, turbo melecular pump), 진공 chamber, 진공 line, gate valve 를 위 시 한 진공 V머ve, flange, gasket, fl않d야lU, mainpulater 퉁 진공 部品이 다. 진공계 의 핵심 은 適切하고 優良한 진공재료의 선태파 사용이다. 진공장비는 사용자가 원하는 진공도를 원하 는 시간 동안 륨空度를 유지해 주어야 한다. 진공재료 선태의 기준사항은:(1) 기체의 透過성 (2) 薰했훌 (3) 혔體放出특성 - -outgassing과 degassing- (4) 機械的 량훌度 (5) 온도 의존성 (6) 化學톡성 (7) 加I성 및 鎔接 성 (8) 課電특성 (9) 磁氣특성 (10) 高速함子 및 放射線 특성 (11) 經濟성 및 調達생 둥이 다. 우량한 초고진공계재료는 풍부하게 개발되어 왔고, 또 新材料들이 개발되고 있다. 여기에서는 주로 초고진공 내지는 극고진공계의 構造材料, 機能材料, 部品材料 일반파 몇가지 신재료의 특 성에 관해서 記述한다. M Mild SteeHSAE, 1112, 1010, 1020, 1022, etc)., S Stainless SteeHAlSI, 304, 304L, 310, 316, 321, 347): 구조재료, chamber, fl하1ges A Aluminum과 Alloys (1060, 1100, 2014, 4032, 6(뻐1): 구조재료, chamber, flanges, gaskets A AI, Al 떠loy는 SS에 代替하는 역 할올 시 작하고 있다. C Copper, Copper Alloys(C11$\alpha$)0, C26800, C61400, Cl7200): 내장인자, gasket, cryopanel, tubing T Titanium, Ziriconium, Haf띠um 및 Alloys: 특히 Ti은 10n pump 용 getter material 이 외 에 U UHV,XHV용 chamber계로서 관심올 끌고 있다. N Nickel, Nickel Alloys (200, 204, 211, monel, nichrome): 부식 방지 , 전자장치 , 자기 장치 귀 금속(Ag, Au, Pt, Pd, Rh, Ir, Os, Ru): 보조부품, gasket, filament, coating, thermocouple, 접 합부위 T TiC, SiC, zrC, HfC, TaC 둥의 탄화물과, BN, TiN, AlN 동의 질화물, 붕화물이 둥장하고 었 다. 유리: Soda Lime, Borosilicate, Potash Soda Lead: View Port, Chamber envelope C Ceramics: AlZ03, BeO, MgO, zrOz, SiOz, MgOzSiOz, 3Alz032SiOz, Z$textsc{k}$hSiOz S상N4: e electrical, thermal insulators, crucibles, boats, single crystals, sepctr려 windows 저자는 최근 저자들이 발견한 Zr-Ti-Cu-Ni-Be amorphous alloys coated cham뾰r가 radiation p proof로 이용될 수 있는 사실을 점검하고 었다 .. Z.Y. Hua 들은 Cs3Sb를 새로운 photocathode 재료로 보고하고 있다.