• Proceedings of the KSME Conference
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• 2007.05a
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• pp.518-520
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• 2007

Since all essential property of semiconductor materials are structure-sensitive, the understanding of the deformation mechanism and the deformed structure which can be formed in the nanometer-scale devices is very crucial. To investigate the deformation mechanism and the corresponding structures, nanometer-scale contact loading simulations are carried out using molecular dynamics in silicon and gallium-arsenide.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.05a
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• pp.56-59
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• 1988

Electron transport properties of gallium arsenide in an electric field are simulated the drift velocity, Mn.energy, electron occupation, mobility in the temperature range $77^{\circ}K-500^{\circ}K$ using a Monte Carlo Method. Therefore it can be used for a GaAs MESFET design.

• The Magazine of the IEIE
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• v.14 no.1
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• pp.47-55
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• 1987

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.10
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• pp.1209-1215
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• 1988

A space charge effect at the doped silicon semiconductor/organic solvent ($C_6H_6$, $CH_3OH$, $C_2H_5OH$) interfaces and a mechanism for two reversals of zeta potentials at the undoped polycrystalline gallium arsenide semiconductor/electrolyte (NaCl, KCl, KI solution) interfaces has been qualitatively analyzed using microelectrophoresis measurements. It has been found that the space charge effect in the organic solvents can be neglected and the two reversals of zeta potentials depend on surface states, specific adsorption, electronegativity and size of specifically adsorbed ions at the undoped polycrystalline gallium arsenide/electrolyte interfaces. The position of shear plane of colloidal semiconductors is a fixed distance from the surface and is almost or exactly coincides with the outer Helmholtz plane (OHP).

• Journal of Mechanical Science and Technology
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• v.20 no.8
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• pp.1292-1301
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• 2006

This article investigates numerically the carrier-phonon interactions in thin gallium arsenide (GaAs) film structures irradiated by subpicosecond laser pulses to figure out the role of several recombination processes on the energy transport during laser pulses and to examine the effects of laser fluences and pulses on non-equilibrium energy transfer characteristics in thin film structures. The self-consistent hydrodynamic equations derived from the Boltzmann transport equations are established for carriers and two different types of phonons, i.e., acoustic phonons and longitudinal optical (LO) phonons. From the results, it is found that the two-peak structure of carrier temperatures depends mainly on the pulse durations, laser fluences, and nonradiative recombination processes, two different phonons are in nonequilibrium state within such lagging times, and this lagging effect can be neglected for longer pulses. Finally, at the initial stage of laser irradiation, SRH recombination rates increases sufficiently because the abrupt increase in carrier number density no longer permits Auger recombination to be activated. For thin GaAs film structures, it is thus seen that Auger recombination is negligible even at high temperature during laser irradiation.

• ETRI Journal
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• v.43 no.5
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• pp.909-915
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• 2021

GaAs on Si grown via metalorganic chemical vapor deposition is demonstrated using various Si substrate thicknesses and three types of dislocation filter layers (DFLs). The bowing was used to measure wafer-scale characteristics. The surface morphology and electron channeling contrast imaging (ECCI) were used to analyze the material quality of GaAs films. Only 3-㎛ bowing was observed using the 725-㎛-thick Si substrate. The bowing shows similar levels among the samples with DFLs, indicating that the Si substrate thickness mostly determines the bowing. According to the surface morphology and ECCI results, the compressive strained indium gallium arsenide/GaAs DFLs show an atomically flat surface with a root mean square value of 1.288 nm and minimum threading dislocation density (TDD) value of 2.4×10⁷ cm^-2. For lattice-matched DFLs, the indium gallium phosphide/GaAs DFLs are more effective in reducing the TDD than aluminum gallium arsenide/GaAs DFLs. Finally, we found that the strained DFLs can block propagate TDD effectively. The strained DFLs on the 725-㎛-thick Si substrate can be used for the large-scale integration of GaAs on Si with less bowing and low TDD.

• Journal of Magnetics
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• v.11 no.1
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• pp.5-7
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• 2006

The magnetotransport properties at room temperature of the 250-nm-thick MnAs(-1100) film grown on GaAs(001) substrate by molecular beam epitaxy was investigated. The results measured with various magnetic field directions were reported. They show the negative magnetoresistive effect for all field directions. The difference in the magnetoresistance curves for different field directions is in agreement with the magnetic anisotropy of the film.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.8
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• pp.959-965
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• 1988

Zinc diffusion characteristics and its applicabilities have been studied using an open-tube system. Thermal decomposition of arsenide(As) at gallium arsenide(GaAs) wafer surface was well inhibited by using Ga: poly-GaAs: Zn compositon as a diffusion source. Junction depth was obtained as 4.6x10**7\ulcorner exp)-1.25/kT) where activation energy of diffusion was 1.25eV. From Boltzmann-matano analysis, it could be identified that concentration dependencies of Zn diffusivity well consisted with those of kick-out model. The ideality factor of p+-n junction formed by Zn diffusion was about 1.6 and infrared light intensity was linearly varied in the range of sixty folds. It is concluded frodm these results that Zn diffuses according to kick-out model, and open-tube method is applicable to compound semiconductor devices.

• 전기의세계
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• v.11
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• pp.14-17
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• 1963

정확하게 control된 pulse의 용도는 과학과 공업이 발달될수록 날로 많아져 가고 있는데 그의 일부는 대전력을 취급하는 경우로서, Radar에 대한 응용을 들 수 있다. 한편, 요지음 gallium-arsenide등 반도체 diode를 사용해서 Laser action을 일으킬 수 있다는것이 발견되어 G.E. 및 IBM등에서 개발되고 있다. 이 경우에, continuous emission도 가능하지만 흔히, intermittent operation을 시켜야 할 때가 많기 때문에 timed pulse source가 필요하게 된다. 또 한편, spot welding의 경우에도 이러한 pulse source가 필요하게 된다. 이들을 크게 나누어 source를 AC로 할 경우와 DC로 할 경우가 있는데, 전자의 경우는 thyratron을 사용할 경우가 많게 될 것이다. DC의 경우나 AC의 경우에나 잘 shape되고 time된 pulse source를 만들어 놓으면 진공관이나 thyratron이나 같은 모양으로 drive할 수 (thyratron의 경우는 trigger)있을 것이기 때문에, 이러한 pulse source를 만들 필요가 있게 된다.

• Solar Energy
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• v.8 no.2
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• pp.73-76
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• 1988

Thick films based on the mature crystalline silicon technology are expected to exhibit eversmaller cost reduction. The thin-film-based technology is, however, expected to exhibit a much sharper drop in cost as it develops. In this report, technology and recent R & D of thin film solar cell, such as amorphous silicon, cadnium telluride, copper indium diselenide and gallium arsenide, are described. Perspectives of world photovoltaic market and solar cell price are also described.