• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.363-367
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• 1988

A simple analytical model for the lateral channel electric field in gate - offset structured Lightly Doped Drain MOSFET has been developed. The model's results agree well with two dimensional device simulations. Due to its simplicity, our model gives a better understanding of the mechanisms involved in reducing the electric field in the LDD MOSFET. The model shows clearly the dependencies of the lateral channel electric field as function of drain and gate bias conditions and process, design parameters. Advantages of analytical model over costly 2-D device simulations is to identify the effects of various parameters, such as oxide thickness, junction depth, gate / drain bias, the length and doping concentration of the lightly doped region, on the peak electric field that causes hot - electron phenomena, individually. We are able to find the optimum doping concentration of LDD minimizing the peak electric field and hot - electron effects.

• Transactions on Electrical and Electronic Materials
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• v.11 no.1
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• pp.15-19
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• 2010

In this paper, we discuss design considerations for an n-channel metal-oxide-semiconductor field-effect transistor (MOSFET) with a lateral asymmetric channel (LAC) doping profile. We employed a $0.35\;{\mu}m$ standard complementary MOSFET process for fabrication of the devices. The gates to the LAC doping overlap lengths were 0.5, 1.0, and $1.5\;{\mu}m$. The drain current ($I_{ON}$), transconductance ($g_m$), substrate current ($i_{SUB}$), drain to source leakage current ($i_{OFF}$), and channel-hot-electron (CHE) reliability characteristics were taken into account for optimum device design. The LAC devices with shorter overlap lengths demonstrated improved $I_{ON}$ and $g_m$ characteristics. On the other hand, the LAC devices with longer overlap lengths demonstrated improved CHE degradation and $I_{OFF}$ characteristics.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.1
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• pp.116-127
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• 1996

This paper dealt with FEM analysis of foundation improved with pack drain. The theory on pack drain was scrutinized and observed values in the field were compared with numerical results. Work site of Kwangyang container pier was selected as a ease study in which measurement of settlement and pore water pressure was accurately carried out. Biot's consolidation equation was selected as governing One, coupled with modified Camclay model as constitutive one. Christian and Boehmer's numerical technique was adopted. Behavior of foundation with pack drain is not simple but very complicated. Discontinuity resulted from rigidity difference between adjacent materials, smear effect and complicated boundary conditions should be considered in the behavior analysis of foundation behavior. The results of numerical analysis were influenced by smear zone. In relevant to this effect, finite element analysis was carried out using the reduced horizontal coefficient of permeability in the smear zone; The numerical results were compared with observed values in surface settlement. including pore water pressure. However only lateral di5plaoement by numerical ana1Ysis was shown since its measurement was not performed in the field. The predication of settlement to be developed later can be effectively employed for the obtimization of construction. The predication of residual settlement using the data measured in the field was made by Hoshino, Asaoka and hyperbolic method. Among them, the hyperbolic method proved best one. Settlements accorded well between numsrical and observed values while pore pressure showed a slight difference. Lateral displacement showed largest values at constant distance from ground surface. The validation of foundation analysis improved with pack drain by computer program employed in this study selecting modified Cam-clay model was satisfactorily secured.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.2
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• pp.170-177
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• 2008

In the present work a methodology to minimize short channel effects (SCEs) by modulating the effective channel length is proposed to design 25 nm single and double gate-source/drain underlap MOSFETs. The analysis is based on the evaluation of the ratio of effective channel length to natural/ characteristic length. Our results show that for this ratio to be greater than 2, steeper source/drain doping gradients along with wider source/drain roll-off widths will be required for both devices. In order to enhance short channel immunity, the ratio of source/drain roll-off width to lateral straggle should be greater than 2 for a wide range of source/drain doping gradients.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1165-1172
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• 2006

In this study, an aspect of settlement, developed from different ground improvement method like suction drain method using vacuum pressure and vertical drain method using overburden pressure, was compared each other. In order to analyze settlement tendency of each method exactly, the finite element analysis program was used. The analyses of vertical settlement and lateral displacement for suction drain method and vertical drain method were conducted independently during the solving stage. The initial condition of drainage zone was fixed with 25m depth and 21m width. After the program analyses, the settlement condition had a different tendency with the ground improvement method. Especially, in the results of vertical drain method, the disparity of settlement between the middle of improved zone and unimproved zone. In the case of suction drain method, however, the difference of settlement was smaller than that of vertical drain method.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.10
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• pp.1-6
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• 2008

The holding voltage of the high-voltage MOSFETs in snapback condition is much smaller than the power supply voltage. Such characteristics may cause the latcup-like problems in the Smart Power ICs if these devices are directly used in the ESD (Electrostatic Discharge) power clamp. In this work, a latchup-free design based on the Drain-Extended PMOS (DEPMOS) adopting gate VDD structure is proposed. The operation region of the proposed gate-VDD DEPMOS ESD power clamp is below the onset of the snapback to avoid the danger of latch-up. From the measurement on the devices fabricated using a $0.35\;{\mu}m$ BCD (Bipolar-CMOS-DMOS) Process (60V), it was observed that the proposed ESD power clamp can provide 500% higher ESD robustness per silicon area as compared to the conventional clamps with gate-driven LDMOS (lateral double-diffused MOS).

• Transactions on Electrical and Electronic Materials
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• v.12 no.3
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• pp.93-97
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• 2011

In this paper, we discuss design considerations for an n-channel metal-oxide-semiconductor field-effect transistor (MOSFET) with a lateral asymmetric channel (LAC) doping profile. We employed a 0.35 ${\mu}M$ standard complementary MOSFET process for fabrication of the devices. The gates to the LAC doping overlap lengths were 0.5, 1.0, and 1.5 ${\mu}M$. The drain current ($I_{ON}$), transconductance ($g_m$), substrate current ($I_{SUB}$), drain to source leakage current ($I_{OFF}$), and channel-hot-electron (CHE) reliability characteristics were taken into account for optimum device design. The LAC devices with shorter overlap lengths demonstrated improved $I_{ON}$ and $g_m$ characteristics. On the other hand, the LAC devices with longer overlap lengths demonstrated improved CHE degradation and $I_{OFF}$ characteristics.

• Geotechnical Engineering
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• v.1 no.2
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• pp.17-26
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• 1985

This study was carried out for the purpose of comparing in reference to sand drain in the next three different cases. First, The case of drain material (sand pile) has some rigidity during embankment and consolidation. Second, In usual case of no rigidity as a paper drain without permeability during embankment and consolidation Third, Check up clay behavior when above the two cases carried out respectively. This FEM analysis is consisted with Biot's consolidation equation when it is used for Christian Boehmer's numerical technique. The main results are obtained from above the Analysis When sand drain has some rigidity, the lateral and vertical deformation of clay foundation is restrained considerable amount and .exhibited bearing capacity of load as a pile According to the foundation in drained condition and untrained condition, the results are much variable in this analysis method. Also, The behaviors of stress path and pore water pressure met our expectation during , consolidation. This analysis should be considered to put into use of sand drain and design in future.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.5
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• pp.48-53
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• 1998

Poly-Si TFT's could be fabricated on glass substrates by metal induced lateral crystallization (MILC) method at 450.deg. C. Channel area of the poly-Si TFT's was laterally crystallized from source and drain areas, where a thn nickel film was deposited. Dopants activation for the formation of source and drain region could be achieved by thermal annealing at 450.deg. C after the ion mass doping of phosphorus. The field effect mobility of thus formed N-channel poly-Si TFT's was 76cm$^{2}$/Vs, and the on/off current ratio was higher than 7E6.

• Computational Structural Engineering
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• v.2 no.4
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• pp.79-88
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• 1989

The behavior of composite beams in steel building structures subjected to lateral loading is studied. Mathematical models for the stiffness of composite beams and the strength at the connections, which are dependent on details of the connections are developed based on the previous experimental results and the results from numerical analyses. Analytical models for the skeleton and hysteresis curves of cantilever composite beams are also presented. A single component model for the composite beam, consisting of elastic beam and the end springs at which all the inelstic deformations within a member are lumped, is implemented into the computer program, DRAIN-2D. And a comparison of analytical results is made with the experimental results.