• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.3
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• pp.264-275
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• 2008

Electron mobility has been investigated theoretically in undoped double-gate (DG) MOSFETs of different channel architectures: a relaxed-Si DG SOI, a strained-Si (sSi) DG SSOI (strained-Si-on-insulator, containing no SiGe layer), and a strained-Si DG SGOI (strained-Si-on-SiGe-on-insulator, containing a SiGe layer) at 300K. Electron mobility in the DG SSOI device exhibits high enhancement relative to the DG SOI. In the DG SGOI devices the mobility is strongly suppressed by the confinement of electrons in much narrower strained-Si layers, as well as by the alloy scattering within the SiGe layer. As a consequence, in the DG SGOI devices with thinnest strained-Si layers the electron mobility may drop below the level of the relaxed DG SOI and the mobility enhancement expected from the strained-Si devices may be lost.

• Transactions on Electrical and Electronic Materials
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• v.12 no.1
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• pp.7-10
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• 2011

High voltage (HV) integrated circuits are viable alternatives to discrete circuits in a wide variety of applications. A HV device generally used in these circuits is a lateral double diffused metal oxide semiconductor (LDMOS) transistor. Attempts to model LDMOS devices are complicated by the existence of the lightly doped drain and by the extension of the poly-silicon and the gate oxide. Several physically based investigations of the bias-dependent drift resistance of HV devices have been conducted, but a complete physical model has not been reported. We propose a new technique to model HV devices using both the BSIM3 SPICE model and a bias dependent resistor model (sub-circuit macro model).

• Journal of Applied Reliability
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• v.10 no.1
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• pp.65-71
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• 2010

NAND-type SONOS with a separated double-gate FinFET structure (SDF-Fin SONOS) flash memory devices are proposed to reduce the unit cell size of the memory device and increase the memory density in comparison with conventional non volatile memory devices. The proposed memory device consists of a pair of control gates separated along the direction of the Fin width. There are two unique alternative technologies in this study. One is a channel doping method and the other is an oxide thickness variation method, which are used to operate the SDF-Fin SONOS memory device as two-bit. The fabrication processes and the device characteristics are simulated by using technology comuter-adided(TCAD). The simulation results indicate that the charge trap probability depends on the different channel doping concentration and the tunneling oxide thickness. The proposed SDG-Fin SONOS memory devices hold promise for potential application.

• Journal of the Korean Ceramic Society
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• v.32 no.7
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• pp.761-768
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• 1995

Double layered BaTiO3 thin films with high dielectric constant as well as good insulating property were prepared for the application to low voltage driving thin film electroluminescent (TFEL) device. BaTiO3 thin films were formed by rf-magnetron sputtering technique. Amorphous and polycrystalline BaTiO3 thin films were deposited at the substrate temperatures of room temperature and 55$0^{\circ}C$, respectively. Two kinds of films prepared under these conditions showed high resistivity and high dielectric constant. The figure of merit (=$\varepsilon$r$\times$Eb.d) of polycrystalline BaTiO3 thin film was very high (8.43$\mu$C/$\textrm{cm}^2$). The polycrystalline BaTiO3 showed a substantial amount of leakage current (I), under the high electric field above 0.5 MV/cm. The double layered BaTiO3 thin film, i.e., amorphous BaTiO3 layer coated polycrystalline BaTiO3 thin film, was prepared by the new stacking method and showed very good dielectric and insulating properties. It showed a high dielectric constant fo 95 and leakage current density of 25 nA/$\textrm{cm}^2$ (0.3MV/cm) with the figure of merit of 20$\mu$C/$\textrm{cm}^2$. The leakage current density in the double layered BaTiO3 was much smaller than that in polycrystalline BaTiO3 under the high electric field. The saturated brightness of the devices using double layered BaTiO3 was about 220cd/$m^2$. Threshold voltage of TFEL devices fabricated on double layered BaTiO3 decreased by 50V compared to the EL devices fabricated on amorphous BaTiO3.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.457-458
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• 2014

In this paper, quantum mechanical simulations of the double-gate ultra-thin body (DG-UTB) MOSFETs are performed according to the International Technology Roadmap of Semiconductors (ITRS) specifications planned for 2020, to devise the way for on-current ($I_{on}$) improvement. We have employed non-equilibrium Green's function (NEGF) approach and solved the self-consistent equations based on the parabolic effective mass theory [1]. Our study shows that the [100]/<001> Ge and GaSb channel devices have higher $I_{on}$ than Si channel devices under the body thickness ($T_{bd}$) <5nm condition.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.287.2-287.2
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• 2013

We synthesized a new composite of poly sodium 4-styrenesulfonate intercalated graphene oxide for energy storage devices by controlling oxidation time in the synthesis of graphite oxide. Specific capacitance was improved from 20 F/g of the previous composites to 88 F/g of the new composite at the current density of 0.3 A/g. The capacitance retention was 94% after 3000 cycles, indicating that the new composites of high cyclic stability, prominent performance as electric double layer capacitor, and even low resistance could be an excellent carbon based electrode for further energy storage devices.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.110-114
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• 1990

Double Injection Switching Devices consist of $P^+$ and $n^+$ contact separated by a near intrinsic Semiconductor region containing deep trap. A V-Groove Double Injection Switching Devices were proposed for high voltage performance and Optical gating scheme. The experimental result to demonstrate the feasibility of these devices (Planar type, V-Groove type, Injection Gate mode, Optical Gate mode) for practical application are described.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.246.2-246.2
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• 2014

Green-light emitting OLED with single layer of Alq3 and orange-light emitting OLED with double layer of rubrene/Alq3 as EML were fabricated and characterized comparatively. The two OLED devices were based on an anode of ITO, HTL of TPD, and cathode of Al, respectively. The green light emitting OLED was then prepared with Alq3 as both ETL and EML, while the orange-light emitting OLED was prepared with rubrene deposited on Alq3. All the component layers of the OLED devices were deposited by a thermal evaporation technique in vacuum. Photoluminescence characteristics of the EML layers were investigated. Electrolumiscence characteristics of the OLED devices were comparatively investigated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.180-183
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• 2000

Beginning with a brief introduction on near 100 nm or below CMOS devices, this paper addresses novel devices for future sub-100 nm CMOS. First, key issues such as gate materials, gate dielectric, source/drain, and channel in Si bulk CMOS devices are considered. CMOS devices with different channel doping and structure are introduced by explaining a figure of merit. Finally, novel device structures such as SOI, SiGe, and double-gate devices will be discussed for possible candidates for sub-100 nm CMOS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.840-845
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• 2013

In this paper, the broadband frequency double down-converter based on LC filter technologies has been designed and implemented, and its performances are introduced. The Designed frequency double down-converter is consisted with a low-noise amplifier, mixer, IF amplifier, LC filter, DC-block capacitor and RF-bypass capacitor. Especially, instead of active devices of a typical converter, the suggested converter designed using passive devices to provide both low-power consumption and low-cost model. As results of the measurement, the implemented frequency double down-converter realizes the broadband performance with the bandwidth of 100MHz (13~113MHz) at the center frequency of 63MHz, and its gain is approximately 40dB.