• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.347-350
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• 1998

차세대 CMOS 구조에서 래치업 최소화를 위하여 고에너지 이온주입을 이용한 retrograde well 과 매몰층의 최적 공정 설계 변수 값들을 설정하였다. 본 논문에서는 두 가지의 모듸 모델 구조를 제안하고 silvaco 틀에 의한 시뮬레이션 결과를 비교 분석하엿다. 첫 번째 모델은 매몰층과 retrograde well을 조합한 구조이며, p+ injection trigger current가 600.mu.A/.mu.m 이상의 결과를 얻었고, 두번째 모델은 twin retrograde well을 이용하여 p+ injection 유지전류가 2500.mu.A/.mu.m이상의 결과를 얻었다. 시뮬레이션 결과, 두 모델 모두 도즈량이 많을수록 래치업 면역 특성이 좋아짐을 보았다. 시뮬레이션 조건에서 두 모델 모두 n+/p+ 간격은 2..mu.m 로 고정하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.4
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• pp.289-300
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• 2002

In this study, the experiments are carried out by boron ion implantation at energies ranging from 700keV to 2MeV in silicon. The distribution of boron profiles are measured by SIMS(Cameca 6f). Boron dopants profiles after high temp]erasure annealing are also explained by comparisons of experimental and simulated data. A new electronic stopping model for Monte Carlo simulation of high energy implantation is presented. Also the comparisons of profiles by profiles boron ion implantations are demonstrated and interpreted with theoretical models. Finally range moments of SIMS and SRP profiles are calculated and compared with simulation results.

• Korean Journal of Materials Research
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• v.13 no.6
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• pp.398-403
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• 2003

Shallow $p^{＋}$ n junction was formed using a ULE(ultra low energy) implanter. Deactivation phenomena were investigated for the shallow source/drain junction based on measurements of post-annealing time and temperature following the rapid thermal annealing(RTA) treatments. We found that deactivation kinetics has two regimes such that the amount of deactivation increases exponentially with annealing temperature up to $850^{\circ}C$ and that it decreases linearly with the annealing temperature beyond that temperature. We believe that the first regime is kinetically limited while the second one is thermodynamically limited. We also observed "transient enhanced deactivation", an anomalous increase in sheet resistance during the early stage of annealing at temperatures higher than X$/^{\circ}C$. Activation energy for transient enhanced deactivation was measured to be 1.75-1.87 eV range, while that for normal deactivation was found to be between 3.49-3.69 eV.

• Journal of Biomedical Engineering Research
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• v.25 no.2
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• pp.157-163
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• 2004

Nitrogen ion implantation and ion plating techniques were applied for improvement of the wear resistance of metallic implant materials. In this work, the wear dissolution behaviour of a nitrogen ion implanted super stainless steel (S.S.S, 22Cr-20Ni-6Mo-0.25N) was compared with those of S.S.S, 316L SS and TiN coated 316L SS. The amounts of Cr and Ni ions worn-out from the specimens were Investigated using an electrothermal atomic absorption spectrometry. Furthermore, the Ti(Grade 2) disks were coated with TiN, ZrN and TiCN by use of low temperature arc vapor deposition and the wear resistance of the coating layers was compared with that of titanium. The chemical compositions of the nitrogen ion implanted and nitride coated layers were examined with a scanting auger electron spectroscopy. It wat observed that the metal ions released from the nitrogen ion implanted S.S.S surface were significantly reduced. From the results obtained, it was shown that the nitrogen ion implanted zone obtained with 100 KeV ion energy was easily removed within 200,000 revolutions from a wear dissolution testing under a similar load condition when applied to artificial hip joint. The remarkable improvement in wear resistance weir confirmed by the nitrides coated Ti materials and the wear properties differ greatly according to the chemical composition of the coating layers. for specimens with the same coating thickness of about 3$\mu\textrm{m}$, TiCN coated Ti showed the highest wear resistance. However, after removing the coating layers, the wear rates of all nitrides coated Ti reverted to their normal rates of below 10,000 revolutions from Ti-disk-on-disk wear testing under the same load condition. From the results obtained, it is suggested that the insufficient depth of the 100 Kel N$\^$＋/ ion implanted zone and of the nitrides coated layers of 3$\mu\textrm{m}$ are subject to restriction when used as frictional parts of load bearing implants.

• Journal of the Korean Vacuum Society
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• v.12 no.4
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• pp.275-280
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• 2003

Epitaxial Gd$_2O_3:Eu^{3+}$luminescent thin films have been grout on Si(III) substrates using ionized Cluster Beam Deposition (ICBD). After the film growing, they were implanted and post annealed to change the crystal structure. The initial growth stage was monitored by using in-situ Reflection High Energy Electron Diffraction (RHEED). The formed crystal structure was identified with X-ray diffraction (XRD) technique and Fourier transform infrared (FT-R) spectroscopy. The electronic states variations were investigated by Near Edge X-ray Absorption Fine Structure (NEXAFS). Photoluminescence (PL), Cathodoluminescence (CL). and Vacuum ultraviolet (VUV) spectrum were used for examining the optical properties. We report the optical property changes depending on crystal structure and the electronic states.

• Journal of IKEEE
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• v.22 no.4
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• pp.1226-1229
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• 2018

We investigated the improvement of surface roughness and states after high temperature annealing using reduced-graphene oxide (r-GO) capping layer on ion-implanted 4H-SiC epitaxial layer. The specification of the 4H-SiC wafer grown on n-type $4^{\circ}$ off-axis 4H-SiC was $10{\mu}m$-thick and n-type epitaxial layer with a dose of $1.73{\times}10^{15}cm^{-2}$. The $n^+$ region were formed by multiple nitrogen ion-implantations and r-GO capping layer was produced by spray coating method. AFM measurements revealed that RMS value of the sample capped with r-GO was tenfold decrease compared to the sample without r-GO capping. The improvement of surface states was also verified by the improvement of leakage current level.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.2
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• pp.106-113
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• 2000

This study describes how a properly calibrated simulation method could be used to investigate the latchup immunity characteristics among the various high energy ion implanted CMOS twin well (retro-grade/BILLI/BL) structures. To obtain the accurate quantitative simulation analysis of retrograde well, a global tuning procedure and a set of grid specifications for simulation accuracy and computational efficiency are carried out. The latchup characteristics of BILLI and BL structures are well predicted by applying a calibrated simulation method for retrograde well. By exploring the potential contour, current flow lines, and electron/hole current densities at the holding condition, we have observed that the holding voltage of BL structure is more sensitive to the well design rule (p+to well edge space /n +to well edge space) than to the retrograde well itself.

• Journal of the Korean Ceramic Society
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• v.32 no.12
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• pp.1377-1382
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• 1995

A high-resolution transmission electron microscopy study on the lattice defects formed in the high energy P ion implanted silicon was carried out on an atomic level. Results show that Lomer dislocations, 60$^{\circ}$perfect dislocations, 60$^{\circ}$ dislocation dipole and extrinsic stacking fault formed in the near Rp of as-implanted specimen. In the annelaed specimens, interstitial Frank loops, 60$^{\circ}$perfect disolations, 60$^{\circ}$dislocation dipoles, stacking faults, precipitates, perfect dislocation loops and <112> rodlike defects existed exclusively near in the Rp with various annealing temperature and time. From these results, it is concluded that extended secondary defects as well as the point defect clusters could be formed without annealing. Even at low temperature annealing such as 55$0^{\circ}C$, small interstitial Frank loops could be formed and precipitates were also formed by $700^{\circ}C$ annealing. The defect band annealed at 100$0^{\circ}C$ for 1 hr could be divided into two regions depending on the distribution of the secondary defects.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.11
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• pp.1156-1166
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• 2004

Antimony profiles by MeV implantation are measured by secondary ion mass spectrometry (SIMS) and spreading resistance (SR). The moments of SIMS and simulated profiles are calculated and compared for the exact range in MeV energy. SRIM, DUPEX, ICECREM, and TSUPREM4 simulation programs are used for the calculation of range 1D, 2D. SRIM is a Monte Carlo simulation program and different inter-atomic potentials can be used for the calculation of nuclear stopping power cross-section (Sn) and range moments. Nevertheless, the range parameters were not influenced from nuclear stopping power in MeV. Through the modification of electronic stopping power cross-section (Se), the results of simulation are remarkably improved and matched very well with SIMS data. The values of electronic stopping power are optimized for Sb high energy implantation. For the electrical activation, Sb implanted samples are annealed under $N_2$ and $O_2$ ambient. Finally, Oxidation retard diffusion(ORD) effect of Sb implanted sample are demonstrated by SR measurements and ICECREM simulation.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.456-456
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• 2010

CMOS 소자가 서브마이크론($0.1\;{\mu}m$) 이하로 스케일다운 되면서 단채널 효과(short channel effect), 게이트 산화막(gate oxide)의 누설전류(leakage current)의 증가와 높은 직렬저항(series resistance) 등의 문제가 발생한다. CMOS 소자의 구동전류(drive current)를 높이고, 단채널 효과를 줄이기 위한 가장 효율적인 방법은 소스 및 드레인의 얕은 접합(shallow junction) 형성과 직렬 저항을 줄이는 것이다. 플라즈마 도핑 방법은 플라즈마 밀도 컨트롤, 주입 바이어스 전압 조절 등을 통해 저 에너지 이온주입법보다 기판 손상 및 표면 결함의 생성을 억제하면서 고농도로 얕은 접합을 형성할 수 있다. 그리고 얕은 접합을 형성하기 위해 주입된 불순물의 활성화와 확산을 위해 후속 열처리 공정은 높은 온도에서 짧은 시간 열처리하여 불순물 물질의 활성화를 높여주면서 열처리로 인한 접합 깊이를 얕게 해야 한다. 그러나 접합의 깊이가 줄어듦에 따라서 소스 및 드레인의 표면 저항(sheet resistance)과 접촉저항(contact resistance)이 급격하게 증가하는 문제점이 있다. 이러한 표면저항과 접촉저항을 줄이기 위한 방안으로 실리사이드 박막(silicide thin film)을 형성하는 방법이 사용되고 있다. 본 논문에서는 (100) p-type 웨이퍼 He(90 %) 가스로 희석된 $PH_3$(10 %) 가스를 사용하여 플라즈마 도핑을 실시하였다. 10 mTorr의 압력에서 200 W RF 파워를 인가하여 플라즈마를 생성하였고 도핑은 바이어스 전압 -1 kV에서 60 초 동안 실시하였다. 얕은 접합을 형성하기 위한 불순물의 활성화는 ArF(193 nm) excimer laser를 통해 $460\;mJ/cm^2$의 에니지로 열처리를 실시하였다. 그리고 낮은 접촉비저항과 표면저항을 얻기 위해 metal sputter를 통해 TiN/Ti를 $800/400\;{\AA}$ 증착하고 metal RTP를 사용하여 실리사이드 형성 온도를 $650{\sim}800^{\circ}C$까지 60 초 동안 열처리를 실시하여 $TiSi_2$ 박막을 형성하였다. 그리고 $TiSi_2$의 두께를 측정하기 위해 TEM(Transmission Electron Microscopy)을 측정하였다. 화학적 결합상태를 분석하기 위해 XPS(X-ray photoelectronic)와 XRD(X-ray diffraction)를 측정하였다. 접촉비저항, 접촉저항과 표면저항을 분석하기 위해 TLM(Transfer Length Method) 패턴을 제작하여 I-V 특성을 측정하였다. TEM 측정결과 $TiSi_2$의 두께는 약 $580{\AA}$ 정도이고 morphology는 안정적이고 실리사이드 집괴 현상은 발견되지 않았다. XPS와 XRD 분석결과 실리사이드 형성 온도가 $700^{\circ}C$에서 C54 형태의 $TiSi_2$ 박막이 형성되었고 가장 낮은 접촉비저항과 접촉저항 값을 가진다.