• Journal of Korea Water Resources Association
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• v.37 no.9
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• pp.781-787
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• 2004

The variation of channel bed which shows the complex hydraulic characteristics at channel junction was investigated by variation of discharge ratio and location of pier. As discharge ratio increase, the depth and width of erosion region become bigger to point of 63% of channel width in case of 1:0.5 discharge ratio. It was observed that the maximum scour depth at the point of 0.5 times of the channel width in the channel junction as 2.5 times bigger than straight channel. It means that the maximum scour depth at the channel junction is 2 times greater than by experimental formulas which are widely used in practical engineering, location of pier should be determined when it is installed in channel junction.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.1
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• pp.13-20
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• 2000

In this paper, we demonstrated an analytical description method of forward votage drop and reverse leakage current of the junction barrier controlled schottky rectifier with linearly graded junction and abrupt junction models. In this case, the vertical depths of device are 1[${\mu}{\textrm}{m}$] and 2[${\mu}{\textrm}{m}$], respectively. Through ion implantation and annealing process, we obtain the data of lateral and depth from implanted 2-dimensional profiles. Also we applied these data to models that indicate the change of depletion each on linearly-graded and abrupt juction as the forward and revers bias. After applied depletion changes to electric characteristics of JBS rectifiers, we calculated the forward I-V, the reverse leakage current and temperatures vs. power dissipations according to each junction. When we compared the rectifier with calculated and measured data, from the calculated results, forward votage drop with linearly graded junction is lower than that of abrupt junction and reverse leakage current with linearly graded junction is lower(≒1$\times$10\ulcorner times) than that of abrupt junction. Also, the power dissipations according to different juction depth(1[${\mu}{\textrm}{m}$], 2[${\mu}{\textrm}{m}$]) of device are calculated. Seeing the calculated results, we confirmed it from analytic model that the rectifier with linearly graded junction retained a low power dissipation up to 600[$^{\circ}C$] in comparison with the rectifier with abrupt junction.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.171-171
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• 2000

차세대 반도체 제조에서 Design rule 이 점점 더 shrink 됨에 따라 shallow junction 분석의 중요성이 강조되고 있다. 이러한 shallow junction에 대한 분석방법중의 하나인 SIMS 분석에 있어서 depth resolution을 향상시키는 것이 중요하며, 일차이온의 에너지를 낮추어 줌으로써 이러한 효과를 달성할 수 있다. 그러나 최근의 연구에 따르면 O2+를 이용한 low energy SIMS 분석 시에 non-zero incidence angle로 분석할 경우 surface roughness가 발생한다는 사실이 보고되었으며, surface roughness를 줄이고 분석 초기의 transient region을 줄이기 위한 방법으로 oxygen flooding을 사용하는 경우 특정 각도에서 surface roughness가 여전히 존재할 뿐 아니라 분석 초기영역에서의 sputter rate이 변화하는 문제가 있음이 보고된바 있다. 본 연구에서는 2keV O2+ 일차이온을 이용하여 oxygen flooding 하에서 기존 조건인 60도 incidence로 분석하는 방법의 문제점을 파악하고 incidence angle을 45도로 바꾸어 분석하는 방법을 검토하였다. 그 결과 기존의 분석조건에서는 분석도중 표면부근에서 sputter rate이 변화하고 surface roughness가 증가하는 것을 확인하였고, 그로 인하여 oxygen flooding을 하지 않은 경우와 많은 차이가 발생하는 것을 발견하였다. Incidence angle을 45도로 바꾼 결과 이러한 문제가 해결되는 것을 확인하였으며, 특히 GaAs $\delta$layer 분석을 통하여 이 분석조건이 기존의 분석조건에 비하여 획기적으로 향상되는 것을 확인 할 수 있었다. 또한 여러 가지 shallow junction 분석을 통하여 이 분석방법이 상당히 신뢰성이 있음을 알 수 있었다. 그러나 여전히 oxygen flooding을 하지 않은 경우에 비하여 다소간의 차이가 있는 것이 발견되었는데, 이는 주로 표면에 잔존하는 산화막에 의한 효과와 oxygen flooding에서 보다 더 depth resolution이 좋음으로 인하여 발생하는 것으로 추정되었으며 그 밖에 다른 가능성도 제기되었다. 따라서 이 방법은 표면 산화막이 거의 없는 시료에 대하여 적용한다면 oxygen flooding을 하지 않은 경웨 비하여 transient region이 거의 없고 junction depth를 보다 신뢰성 있게 측정할 수 잇는 장점이 있는 것으로 판단되었다. As, P의 저 에너지이온 주입시료에 대해 이 분석방법을 적용할 경우 C+s 분석법에 비하여 depth resolution을 비교적 쉽게 향상시킬 수 있었고, oxygen follding을 쓰지 않은 경우에 비해서는 검출한도를 약 100배 정도 향상시킬 수 있었다. 그러나 2.5keV Cs+ 분석법에 비하면 아직 depth resolution이 불충분하여 실제로 shallow As 분석에 적용하기에는 다소 문제점이 있었다.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.2
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• pp.68-76
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• 1992

Concurrent Junction process (simultaneous formation of a silicide and a junction on the implanted substrate) by Rapid Thermal Annealig has been investigated. Electrical and material properties of CoSi$_2$ films were analyzed with Alpha Step, 4-point probe, X-ray diffraction(XRD) and Scanning Electron Microscope(SEM). And CoSi$_2$ junctions were examined with Spreading Resistance probe in order to see the redistribution of electrically activated dopants and determined the junction depth. Two step annealing process, which was 80$0^{\circ}C$ for 30sec and 100$0^{\circ}C$ for 30sec in NS12T ambient was employed to form CoSi$_2$ and shallow junctions. Resistivity of CoSi$_2$ was turned out to be 11-15${\mu}$cm and shallow junctions less than 0.1$\mu$m were successfully formed by the process. It was found that the dopant concentration at CoSi$_2$/Si interface increased as decreasing the thickness of Co films in case of $p^{+}/n$ and $n^{+}/p$ junctions while the junction depth decreased as increasing CoSiS12T thickness in case of $p^{+}/n$ junction.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.2
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• pp.89-95
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• 1995

The structure of boron ion-implanted pn junctio in the vacancy-doped p-type HgCdTe was investigated with the differential Hall measurement. The as-implanted junction showed the electron concentration as high as 1${\times}10^{18}/cm^{3}$ and the junction depth of 0.6.mu.m. When the HgCdTe junction was heated in oven, the electron concentration near the junction decreased and the junction depth increased as the annealing temperature and time increased. The junction structure after the thermal annealing was n$^{+}$/n$^{-}$/p. For the 200.deg. C 20min annealed sample, the electron mobility was 10$^{4}cm^{2}/V{\cdot}$s near the surface(n$^{+}$), and was larger thatn 10$^{5}cm^{2}/V{\cdot}$s near the junction(n$^{+}$). The junction formation mechanism is conjectured as follows. When HgCdTe is ion-implanted, the ion energy generates crystal defecis and displaced Hg atoms HgCdTe is ion-implanted, the ion energy generates crystal defecis and displaced Hg atoms near the surface. The displaced Hg vacancies diffuse in easily by the thernal treatment and a fill the Hg vacancies in the p-HgCdTe substrate. With the Hg vacancies filled completely, the GfCdTe substrate becomes n-type because of the residual n-type impurity which was added during the wafer growing. Therefore, the n$^{+}$/n$^{-}$/p regions are formed by crystal defects, residual impurities, and Hg vacancies, respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1328-1332
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• 2006

As the city is developed, Sewerage outlet is installed for the discharge of rainfall special at new town or modified the existed sewerage network. But the sewerage outlet is influenced to the cannel flow. In this paper, for analyzing variation of flow properties by installing sewerage outlet, it was experimented a with $120^{\circ}$ channel junction. The water depth is rapidly increasing at the just before sewerage installed position, but the velocity is represented increasing at the just after sewerage installed position. In addition, the biggest increment of water depth and velocity is represented $3.0m^3/hr{\sim}4.0.m^3/hr$. At the position of the sewerage outlet installation, separate install at up and downstream is rather than only one position at up or down stream. If it was not install both installation, the upstream installation is better than downstream installation.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.2
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• pp.260-264
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• 1987

We examine the effect of junction depth on the charge density solving numerically the general form of Poisson's equation for Gaussian $n^{+}$-p junctions. We also present an analytical model for the charge diopole due to the variation of the dielectric constant with doping.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.5
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• pp.87-92
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• 1998

Ultr shallow p$^{+}$-n junction with Co/Ti bilayer silicidde contact was formed by ion implantation of BF$_{2}$ [energy : (30, 50)keV, dose:($5{\times}10^{14}$, $5{\times}10^{15}$/$\textrm{cm}^2$] onto the n-well Si(100) region and by RTA-silicidation and post annealing of the evaporated Co(120.angs., 170.angs.)/Ti(40~50.angs.) double layer. The sheet resistance of the silicided p$^{+}$ region of the p$^{+}$-n junction formed by BF2 implantation with energy of 30keV and dose of $5{\times}10^{15}$/$\textrm{cm}^2$ and Co/Ti thickness of $120{\AA}$/(40~$50{\AA}$) was about $8{\Omega}$/${\box}$. The junction depth including silicide thickness of about $500{\AA}$ was 0.14${\mu}$. The fabricated p$^{+}$ -n ultra shallow junction depth including silicide thickness of about $500{\AA}$ was 0.14${\mu}$. The fabricated p$^{+}$-n ultra shallow junction with Co/Ti bilayer silicide contact did not show any agglomeration or variation of sheet resistance value after post annealing at $850^{\circ}C$ for 30 minutes. The boron concentration at the epitaxial CoSi$_{2}$/Si interface of the fabricated junction was about 6*10$6{\times}10^{19}$ / $\textrm{cm}^2$./TEX>.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.149-153
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• 2011

The PC1D is widely used for modeling the properties of crystalline silicon solar cell. Optimized doping profile in crystalline silicon solar cell fabrication is necessary to obtain high conversion efficiency. Doping profile in the forms of a uniform, gaussian, exponential and erfc function can be simulated using the PC1D program. In this paper, the doping profiles including junction depth, dopant concentration on surface and the form of doping profile (gaussian, gaussian+erfc function) were changed to study its effect on electrical properties of solar cell. As decreasing junction depth and doping concentration on surface, electrical properties of solar cell were improved. The characteristics for the solar cells with doping profile using the combination of gaussian and erfc function showed better open-circuit voltage, short-circuit current and conversion efficiency.

• Journal of Korea Water Resources Association
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• v.31 no.5
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• pp.529-538
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• 1998

The flow configurations at open channel junctions are analyzed by 2-D depth averaged mathematical model. The governing factors of the flow at the junction are found to be discharge ratio between tributary flow and the post confluence combined flow, and confluence angle. Analyzed by these two factors are flow patterns and flow depth variation at the confluence, discharge ratio above which the flow upstresm from the junction is affected by the tributary flow and the geometries of a recirculation region. Further, the flow contraction in the downstream region and the deflection of the tributary flow in the main channel were investigated. The numerical results are compared with the existing experimental data fairly well.