• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.18-19
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• 2008

Polycrystalline(poly) 3C-SiC film is a promising structural material for M/NEMS used in harsh environments, bio and fields. In order to realize poly 3C-SiC based M/NEMS devices, the electrical properties of poly 3C-SiC film have to be optimized. The n-type poly 3C-SiC thin film is deposited by APCVD using HMDS$(Si_2(CH_3)_6)$ as single precursor and are in-situ doped using N2. Resistivity values as low as 0.014 $\Omega$cm were achieved. The carrier concentration increased with doping from $3.0819\times10^{17}$ to $2.2994\times10^{19}cm^{-3}$ and electronicmobility increased from 2.433 to 29.299 $cm^2/V{\cdot}s$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.492-496
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• 2001

Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e,g. As, Cl). In this paper, We investigated dopants(As, Cl) composition rate to improve dark resistivity and transport properties of charge carrier in amorphous selenium using by direct X-ray conversion material. Alloying a-Se with As inhibits the recrystallization of a-Se but introduces undesirable deep hole traps. then doping with Cl(in the ppm range) compensates for the deep hole traps. We investigated their composition rate in various doping conditions and then obtained optimum dopant composition rate. The result was Se-As 0.3%-Cl 30 ppm and X-ray Sensitivity was 0.57 pc/pixel$.$mR at 137 $\mu\textrm{m}$ x 137 $\mu\textrm{m}$ Pixel area.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.156-157
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• 2007

For tens of years many advantages of Phase-Change Random Access Memory(PRAM) were introduced. Although the performance improved gradually, there are some portions which must be improved. So, we studied new constitution of $Ge_1Se_1Te_2$ chalcogenide material to improve phase transition characteristic. Actually, the performance properties have been improved surprisingly. However, crystallization time was as long as ever for amorphization time. We conducted this experiment in order to solve that problem by doping-Sb.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.424-425
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• 2006

Zinc sulfide is a well-known host material of phosphor emitting different radiations dependent on different doping impurities of metallic ion. It emits green, blue, orange-yellow or white colors by doping with activators such as copper, silver, manganese and so on. In this study, manganese, copper and chlorine doped ZnS phosphor (ZnS:Mn,Cu,Cl) was synthesized by solid-state reaction method. The optical properties were investigated according to different concentrations of sulfur and activators used during the synthesis process.

• Transactions on Electrical and Electronic Materials
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• 제14권5호
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• pp.246-249
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• 2013

Graphene was obtained on Cu foil by thermal decomposition method. A gas mixture of $H_2$ and $CH_4$ and an ambient annealing temperature of $1,000^{\circ}C$ were used during the deposition for 30 Min., and for the transfer onto $SiO_2/Si$ and Si substrates. The physical properties of graphene were investigated with regard to the effect ofnitrogen atom doping and the various substrates used. The G/2D ratio decreased when the graphene became monolayer graphene. The graphene grown on $SiO_2/Si$ substrate showed a low intensity of the G/2D ratio, because the polarity of the $SiO_2$ layer improved the quality of graphene. The intensity of the G/2D ratio of graphene doped with nitrogen atoms increased with the doping time. The quality of graphene depended on the concentration of the nitrogen doping and chemical properties of substrates. High-quality monolayer graphene was obtained with a low G/2D ratio. The increase in the intensity of the G/2D ratios corresponded to a blue shift in the 2D peaks.

• Transactions on Electrical and Electronic Materials
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• 제8권6호
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• pp.234-240
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• 2007

The electrical properties and dc aging behavior for specified stress state of system, which is composed of quaternary Zn-Pr-Co-Cr, were investigated for different $Dy_2O_3$ addition doping level. As $Dy_2O_3$ doping level increased, the density decreased in the range of 5.51-4.90 $g/cm^3$, reaching maximum at 0.5 mol% and the average ZnO grain size decreased in the range of 17.7-6.0 ${\mu}m$. The incorporation of $Dy_2O_3$ significantly improved the non-ohmic properties, above 30 in non-ohmic coefficient, compared with that of undoped samples. The samples with the best performance of non-ohmic properties were obtained for $Dy_2O_3$ doping level of 1.0 mol%, with 49 in non-ohmic coefficient and 2.6 ${\mu}A/cm^2$ in leakage current. The samples with the highest stability were obtained for $Dy_2O_3$ doping level of 0.5 mol%.

• 한국전기전자재료학회논문지
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• 제20권6호
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• pp.520-526
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• 2007

In order to acquire fundamental informations to fabricate high precision thin film resistors, NiCr/NiCrSi alloy films were prepared using Ni and Cr targets. Effect of composition on the electrical properties of the NiCr/NiCrSi alloy film were then investigated. Considering the effect of Si doping on the electrical and material characteristics, the lower TCR (temperature coefficient of resistance) values could be achieved for samples with Ni/Cr ratio of $0.8{\sim}1.5$ (in a range of relative higher specific resistivity and Cr composition of $40\;wt%{\sim}55\;wt%$) and with Si doping. Consequently, the sample prepared using a DC power showed a good TCR of $-25\;ppm/^{\circ}C$, which implies that increase of specific resistivity and decrease of TCR would be achieved more efficiently not for Ni-Cr binary material but for Si doped Ni-Cr ternary material, and not using RF power but using DC power in the sputtering process.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.50-50
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• 2009

In this paper, the plasma doping is performed on p-type wafers using $PH_3$ gas(10 %) diluted with He gas(90 %). The wafer is placed in the plasma generated with 200 W and a negative DC bias (1 kV) is applied to the substrate for 60 sec under no substrate heating. the flow rate of the diluted $PH_3$ gas and the process pressure are 100 sccm and 10 mTorr, respectively. In order to diffuse and activate the dopant, annealing process such as rapid thermal annealing (RTA) is performed. RTA process is performed either in $N_2$, $O_2$ or $O_2+N_2$ ambient at $900{\sim}950^{\circ}C$ for 10 sec. The sheet resistance is measured using four point probe. The shallow n+/p doping profiles are investigated using secondary ion mass spectromtry (SIMS). The analysis of crystalline defect is also done using transmission electron microscopy (TEM) and double crystal X-ray diffraction (DXRD).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.199-200
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• 2009

This paper describes the electrical properties of polycrystalline (poly) 3C-SiC thin films with different nitrogen doping concentrations. The in-situ-doped poly 3C-SiC thin films were deposited by using atmospheric-pressure chemical vapor deposition (APCVD) at $1200^{\circ}C$ with hexamethyldisilane (HMDS: $Si_2$ $(CH_3)_6)$ as a single precursor and 0 ~ 100 sccm of $N_2$ as the dopant source gas. The peaks of the SiC (111) and the Si-C bonding were observed for the poly 3C-SiC thin films grown on $SiO_2/Si$ substrates by using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) analyses, respectively. The resistivity of the poly 3C-SiC thin films decreased from $8.35\;{\Omega}{\cdot}cm$ for $N_2$ of 0 sccm to $0.014\;{\Omega}{\cdot}cm$ with $N_2$ of 100 sccm. The carrier concentration of the poly 3C-SiC films increased with doping from $3.0819\;{\times}\;10^{17}$ to $2.2994\;{\times}\;10^{19}\;cm^{-3}$, and their electronic mobilities increased from 2.433 to $29.299\;cm^2/V{\cdot}S$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.63-63
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• 2009

In this work, we demonstrate 800V 4H-SiC power DMOSFETs with several structural alterations to observe static DC characteristics, such as a threshold voltage ($V_{TH}$) and a figure of merit ($V_B^2/R_{SP,ON}$). To optimize the static DC characteristics, we consider four design parameters; (a) the doping concentration ($N_{CSL}$) of current spreading layer (CSL) beneath the p-base region, (b) the thickness of p-base ($t_{BASE}$), (c) the doping concentration ($N_J$) and width ($W_J$) of a JFET region, (d) the doping concentration ($N_{EPI}$) and thickness ($t_{EPI}$) of epi-layer. Design parameters are optimized using 2D numerical simulations and the 4H-SiC DMOSFET structure results in high figure of merit ($V_B^2/R_{SP,ON}$>~$340MW/cm^2$) for a power MOSFET in $V_B{\sim}1200V$ range.