• 전자공학회논문지A
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• 제31A권5호
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• pp.126-133
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• 1994

Doping effects and semiconductor behaviors of the dispersed p- and n-Si, p- and n- GaAs particles in the aqueous electrolyte have been studied using microelectrophoretic, voltammetric and chronoamperometric techniques. The cations (K$^{+}$) are adsorbed on both the p- and n- Si particle surfaces regardless of the sign of space charges in the depletion layers, i.e. doping profiles. The surface states are negatively charged acceptor states. On the other hand, the anions (CI$^{-}$) are adsorbed on both the p- and n- GaAs particle surfaces regardless of the sign of space charges in the depletion layers, i.e. doping profiles. The surface states are positively charged donor states. Under the same conditions, electrophoretic mobilities, electrochemical processes, doping effects and related semiconductor behaviors of the Si and the GaAs particles are similar regardless of the doping profiles, i. e. dopants and doping concentrations. The doping effects and related semiconductor behaviors of the dispersed p- and n- type semiconductor particles are gradually lost with decreasing dimensions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.535-536
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• 2010

• 한국전기전자재료학회논문지
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• 제29권12호
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• pp.750-758
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• 2016

For the channel doping of shallow junction and retrograde well formation in CMOS, indium can be implanted in silicon. The retrograde doping profiles can serve the needs of channel engineering in deep MOS devices for punch-through suppression and threshold voltage control. Indium is heavier element than B, $BF_2$ and Ga ions. It also has low coefficient of diffusion at high temperatures. Indium ions can be cause the erode of wafer surface during the implantation process due to sputtering. For the ultra shallow junction, indium ions can be implanted for p-doping in silicon. UT-MARLOWE and SRIM as Monte carlo ion-implant models have been developed for indium implantation into single crystal and amorphous silicon, respectively. An analytical tool was used to carry out for the annealing process from the extracted simulation data. For the 1D (one-dimensional) and 2D (two-dimensional) diffused profiles, the analytical model is also developed a simulation program with $C^{{+}{+}}$ code. It is very useful to simulate the indium profiles in implanted and annealed silicon autonomously. The fundamental ion-solid interactions and sputtering effects of ion implantation are discussed and explained using SRIM and T-dyn programs. The exact control of indium doping profiles can be suggested as a future technology for the extreme shallow junction in the fabrication process of integrated circuits.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3319-3325
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• 2014

Eu(III)-doped $CeO_2$ nanorods were prepared by a co-precipitation method at room temperature, and their photoluminescence profiles were examined with different Eu(III)-doping concentrations and thermal annealing temperatures. Scanning electron microscopy, X-ray diffraction crystallography and UV-Vis absorption spectroscopy were employed to examine the morphology, crystal structure and photon absorption profiles of the nanorods, respectively. Additionally, their 2D and 3D-photoluminescence profile maps were obtained to fully understand the photoluminescence mechanism. We found that the magnetic dipole $^5D_0{\rightarrow}^7F_1$ and the electric dipole $^5D_0{\rightarrow}^7F_2$ transitions of Eu(III) were highly dependent on the doping concentration, annealing temperature and excitation wavelength, which was explained by the presence of different Eu(III)-doping sites (with and without an inversion center) in the $CeO_2$ host with a cubic crystal structure.

• 분석과학
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• 제8권4호
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• pp.895-900
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• 1995

Urinary free and acetylated polyamine profiles have been investigated for their potential usefulness as biochemical markers of cancer in a control of group comprised of healthy volunteers (32 cases) and patients with various types of cancers(48 cases). The nine (5 free and 4 acetylated) endogeneous polyamines were simultaneously determined by a sensitive capillary gas chromatography/nitrogen-phosphorus detector (GC/NPD). The newly modified (simple and convenient) method was developed and the compounds were isolated by adsorption onto silica gel and derivatized by heptafluorobutyric anhydride to enhance their specificity on gas chromatograms. The good quality-control data were obtained through the precision and accuracy test and the recovery range of them was 48.6 ~ 101.2 %. The Korean reference values of urinary polyamines were established and significant differences were found in cancer patients compared with normal subjects. Also, to eliminate subject variations, precursors to product concentration ratios were compared between cancer patients and control group. The ratios of both putrescine to spermidine and total (free plus acetylated) putrescine to total spermidine were significantly greater in cancer patients than in normal subjects.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.475-476
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• 2006

Recently, the demand for high density MOSFET arrays are increasing. In implementing 3-D devices to this end, it is inevitable to ion-implant vertically in order to avoid screening effects caused by high silicon fins. In this study, the dependency of drain current characteristics on doping profiles is investigated by 3-D numerical analysis. The position of concentration peak (PCP) and the doping gradient are varied to look into the effects on primary current characteristics. Through these analyses, criteria of ion-implantation for 3-D devices are established.

• 반도체디스플레이기술학회지
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• 제10권4호
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• pp.61-64
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• 2011

In order to grow the crystalline solar cells industry continuously, development of alternate low-cost manufacturing processes is required. Plasma doping system is the technique for introducing dopants into semiconductor wafers in CMOS devices. In photovoltaics, plasma doping system could be an interesting alternative to thermal furnace diffusion processes. In this paper, plasma doping system was applied for phosphorus doping in crystalline solar cells. The Plasma doping was carried out in 1~4 KV bias voltages for four minutes. For removing surface damage and formation of pn junction, annealing steps were carried out in the range of $800{\sim}900^{\circ}C$ with $O_2$ ambient using thermal furnace. The junction depth in about $0.35{\sim}0.6{\mu}m$ range have been achieved and the doping profiles were very similar to emitter by thermal diffusion. So, It could be confirmed that plasma doping technique can be used for emitter formation in crystalline solar cells.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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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.

• 한국정보통신학회논문지
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• 제19권11호
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• pp.2643-2648
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• 2015

본 연구에서는 비대칭 이중게이트 MOSFET의 채널 내 도핑농도분포에 대한 드레인유도장벽감소(Drain Induced Barrier Lowering; DIBL)에 대하여 분석하고자한다. DIBL은 드레인 전압에 의하여 소스 측 전위장벽이 낮아지는 효과로서 중요한 단채널 효과이다. 이를 분석하기 위하여 포아송방정식을 이용하여 해석학적 전위분포를 구하였으며 전위분포에 영향을 미치는 채널도핑농도의 분포함수변화에 대하여 DIBL을 관찰하였다. 채널길이, 채널두께, 상하단 게이트 산화막 두께, 하단 게이트 전압 등을 파라미터로 하여 DIBL을 관찰하였다. 결과적으로 DIBL은 채널도핑 농도분포함수의 변수인 이온주입범위 및 분포편차에 변화를 나타냈다. 특히 두 변수에 대한 DIBL의 변화는 최대채널도핑농도가 $10^{18}/cm^3$ 정도로 고도핑 되었을 경우 더욱 현저히 나타나고 있었다. 채널길이가 감소할수록 그리고 채널두께가 증가할수록 DIBL은 증가하였으며 하단 게이트 전압과 상하단게이트 산화막 두께가 증가할수록 DIBL은 증가하였다.

• 한국표면공학회지
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• 제54권6호
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• pp.348-356
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• 2021

In this study, optical diagnosis of plasma was performed for nitrogen doping in graphene using a horizontal inductively coupled plasma (ICP) system. Graphene was prepared by mechanical exfoliation and the ICP system using nitrogen gas was ignited for plasma-induced and defect-suppressed nitrogen doping. In order to derive the optimum condition for the doping, plasma power, working pressure, and treatment time were changed. Optical emission spectroscopy (OES) was used as plasma diagnosis method. The Boltzmann plot method was adopted to estimate the electron excitation temperature using obtained OES spectra. Ar ion peaks were interpreted as a reference peak. As a result, the change in the concentration of nitrogen active species and electron excitation temperature depending on process parameters were confirmed. Doping characteristics of graphene were quantitatively evaluated by comparison of intensity ratio of graphite (G)-band to 2-D band, peak position, and shape of G-band in Raman profiles. X-ray photoelectron spectroscopy also revealed the nitrogen doping in graphene.