• Journal of Periodontal and Implant Science
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• 제33권3호
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• pp.499-518
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• 2003

The surface characteristics of titanium have been shown to have an important role in contact ossseointegration around the implant. Anodizing at high voltage produces microporous structure and increases thickness of surface titanium dioxide layer. The aim of present study was to analyse the response of rat calvarial osteoblast cell to commercially pure titanium and Ti-6A1-4V anodized in 0.06 mol/l ${\beta}$-glycerophosphate and 0.03 mol/l sodium acetate. In this study, rat calvarial osteoblasts were used to assay for cell viability and cell proliferation on the implant surface at 1,2,4,7 days. 1. Surface roughness was 1.256${\mu}m$ at 200V, and 1.745${\mu}m$ at 300V. 2. The thickness of titanium oxide layer was increased 1 ${\mu}m$ with the increase of 50V. 3. The proliferation rate of osteoblastic cells was increased with the increase of the surface roughness and the thickness of titanium oxide layer. 4. There was no difference in cell viability and cell proliferation between commercially pure titanium and Ti-6A1-4V anodized at the same condition. In conclusion, the titanium surface modified by anodizing was biocompatible, produced enhanced osteoblastic response. The reasons of enhanced osteoblast response might be due to reduced metal ion release by thickened and stabilized titanium dioxide layer and microporous rough structures.

• 열처리공학회지
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• 제13권4호
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• pp.259-264
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• 2000

In this study, we quantitatively measure the ion ranges of arsenic with energies ranging from 10 KeV to 100 KeV, implanted at $3^{\circ}$, $9^{\circ}$ $15^{\circ}$ the (100) plane, and the damage created during ion implantation. To obtain detailed information of ion range and damage distributions in low energy region where elastic collisions dominate the slowing down process, molecular dynamics computer simulation was performed and compared to the existing results. The effects of implant energy and degree on damage generation are present. The number of vacancy were calculated from the deposited energy using Kinchin-Pease equation. In the energy range 10 keV-100 keV, simulations show that the number of Frenckel pairs produced by As-ion bimbardment is 9 and incident angle dependence of the vacancy was the same but defects were distributed at different depth.

• 한국전기전자재료학회논문지
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• 제31권2호
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• pp.74-79
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• 2018

In this report, the results of a systematic study on the effects of polycrystalline silicon gate depletion on the reliability characteristics of metal-oxide semiconductor field-effect transistor (MOSFET) devices were discussed. The devices were fabricated using standard complimentary metal-oxide semiconductor (CMOS) processes, wherein phosphorus ion implantation with implant doses varying from $10^{13}$ to $5{\times}10^{15}cm^{-2}$ was performed to dope the polycrystalline silicon gate layer. For implant doses of $10^{14}/cm^2$ or less, the threshold voltage was increased with the formation of a depletion layer in the polycrystalline silicon gate layer. The gate-depletion effect was more pronounced for shorter channel lengths, like the narrow-width effect, which indicated that the gate-depletion effect could be used to solve the short-channel effect. In addition, the hot-carrier effects were significantly reduced for implant doses of $10^{14}/cm^2$ or less, which was attributed to the decreased gate current under the gate-depletion effects.

• 한국위성정보통신학회논문지
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• 제11권4호
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• pp.21-26
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• 2016

PPS 소자가 삽입된 N형 실리콘 제어 정류기(NSCR_PPS) 소자에서 채널차단영역의 이온주입 변화가 정전기 보호 성능에 미치는 영향을 연구하였다. 종래의 NSCR 표준소자는 on 저항, 스냅백 홀딩 전압 및 열적 브레이크다운 전압이 너무 낮아 마이크로칩의 정전기보호소자로 적용이 어려웠다. 그러나 본 연구에서 제안하는 채널 차단 영역의 이온주입 조건을 변화시켜 각각 변형설계된 소자에서는 채널 차단 이온주입이 정전기 보호성능의 향상에 영향을 주는 중요한 파라미터였으며, CPS_PDr+HNF 구조의 변형소자는 정전기보호소자의 설계창을 만족시키는 향상된 정전기보호성능을 나타내어 고전압 동작용 마이크로 칩의 정전기보호 소자로 적용 가능함을 확인하였다.

• 한국표면공학회지
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• 제48권6호
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• pp.283-291
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• 2015

The purpose of this study was to investigate effects of TiN coating on the fatigue fracture of dental implant system with various cyclic loads. TiN coated abutment screw, the fixture, and abutment of internal hex type were prepared for fatigue test. The fatigue test was carried out according to ISO 14801:2003(E) using tensile and compression tester with repeated load from 30% to 80% of static fracture force. Morphology and fractured surface was observed by field emission scanning electron microscope(FE-SEM) and energy dispersive X-ray spectroscope(EDS). The fracture cycle drastically decreased as repeated load increased. Especially, in the case of TiN-coated abutment screw, fracture cycle increased compared to non-coated abutment screw. The fatigue crack was propagated fast as repeated load increased. The plastic deformation region decreased, whereas, cleavage fracture region increased as repeated load increased.

• 대한전자공학회논문지SD
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• 제41권8호
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• pp.45-50
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• 2004

전류집속을 위하여 Vertical Cavity Surface Emitting Laser(VCSEL)에 임플랜트 공정으로 만들어지는 반 절연층의 깊이는 VCSEL의 특성 및 신뢰도에 많은 영향을 준다. 이 연구에서는 낮은 문턱전류와 높은 신뢰도의 관점에서 최적화된 임플랜트 깊이를 정하고, 전기적 미분특성을 사용하여 최적화된 임플랜트 깊이를 판정하는 간단한 방법을 제시하였다. 최적화된 임플랜트 깊이는 임플랜트 선단을 1 - λ cavity에서 p-DBR mirror 약 2 주기 위에 위치시키는 것이다. 이 최적화된 임플랜트 깊이는 임플랜트 영역 밑을 옆 방향으로 흐르는 누설전류의 크기로부터 구할 수 있다. 전기적 미분특성은 이 누설전류를 찾아내는 좋은 방법인데, 이 전기적 미분특성을 이용하면 임플랜트 깊이를 간단하고 빠르게 알아낼 수 있기 때문이다.

• Journal of Korean Vacuum Science & Technology
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• 제3권1호
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• pp.1-9
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• 1999

This paper presents a newly enhanced damage model in Monte Carlo (MC) simulation for the accurate prediction of 3-Dimensional (3D) as-implanted impurity and point defect profiles induced by ion implantation in (100) crystal silicon. An empirical electronic energy loss model for B, BF2, As, P and Si self implant over the wide energy range has been proposed for the ULSI device technology and development. Our model shows very good agreement with the SIMS data over the wide energy range. In the damage accumulation, we considered the self-annealing effects by introducing our proposed non-linear recomvination probability function of each point defect for the computational efficiency. For the damage profiles, we compared the published RBS/channeling data with our results of phosphorus implants. Our damage model shows very reasonable agreement with the experiments for phosphorus implants.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.585-588
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• 1998

We investigated the ultra-low energy B, P, and As ion implantation using ungraded MDRANGE code to form nanometer junction depths. Even at the ultra-low energies that were simulated in paper, it was found that channeling cases must be carefully considered. In the cases of B, channeling occurred above 500 eV, in the cases of P, channeling occurred above 1 keV, and in the cases of As, channeling occurred above 2 keV. Comparing 2D dopant profiles of 1 keV B, 2 keV P, and 5 keV As with tilts, we demonstrated that most channeling cases occurred not lateral directions but depth directions. Through thus results, even below 5 keV energy ion implant considered here, it is estimated that channeling effects are important in the formation of nanometer junction depths.

• 한국진공학회지
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• 제2권4호
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• pp.468-473
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• 1993

Damages on Si substrate induced by Ar ion implantation and it annealing behavior during rapid thermal annealing were investigated by the cross-sectional TEM (transmissin electron microscopy), RB(Rutherfordbackscattering) spectra an dthermal wave (TW) modulation reflectance methods. Continuous amorphous layer extending to the surface were generated by Ar ion implantation for higher doses than 1 $\times$1015cm-2. The recrystallization of the amorphous layer prodeeded as the annealing temperature increased . However the amorphous /crystal interfacial undulations caused the micro twins and damage clusters. Damage clusters generated by lower doses than 1 $\times$1015 cm-2 disappeared slowly as the annealing temperature increased, but even at 110$0^{\circ}C$ a few damage clusters still remained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1270-1273
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• 1997

We have investigated the latchup characteristics of BL/BILLI retrograde twin well CMOS that has the high energy ion implanted buried layer to intend for more improvement of latchup compare to conventional retrograde well and BILLI structures. We explored the dependence of various latchup characteristics such as n+ trigger latchup and p+ trigger latchup on the buried layer implant doses. We show various DC latchup characteristics that allow us to evaluate each technology and suggest guidelines for the reduction of latchup susceptibility.