• Title/Summary/Keyword: InAs

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Reactive Ion Etching of InP, InGaAs and InAIAs by SiCl$_4$ and Cl$_2$ Gases: Effects of Gas Flow Rate, rf Power, Process Pressure and Ar Addition (SiCl$_4$와 Cl$_2$가스에 의한 InP, InGaAs 및 InAIAs의 반응성 이온 식각: 가스유량, rf 전력, 공정압력, Ar 첨가의 영향)

  • 유재수;송진동;배성주;정지훈;이용탁
    • Proceedings of the IEEK Conference
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    • 2001.06b
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    • pp.25-28
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    • 2001
  • In this paper, we have investigated the effects of gas flow rate, rf power, process pressure and Ar addition on reactive ion etching of InP, InGaAs and InAlAs using Sic14 and Cl$_2$ gases. The etch rates were measured by using a surface profiler. The etched profiles, sidewall roughness, and surface morphology were observed by scanning electron microscopy and by atomic force microscopy. The selective etching of InGaAs to InP and InAlAs was studied by varying the etching parameters. It was found that Cl$_2$ gas is more efficient for the selective etching of InGaAs to InAlAs than SiCl$_4$ gas. The etch selectivity of InGaAs to InAlAs is strongly dependent on the rf power and the process pressure.

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A Study on the Yang Taeg in Traditional Korean Housing. (전통주거건축의 양택적 원리에 관한 연구)

  • HyunJangPak
    • Journal of the Korean housing association
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    • v.4 no.2
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    • pp.63-71
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    • 1993
  • This study is to find mental element and principle for building as the side of tranditional ideas and to understand dwelling from and style by this wag. So we can understand yang taeg theory as a part of feng shui that controls the mental, field of traditional architecture. The results may besummarised as follows. 1. Mentalprinciple of traditional architecfure being understood as a "역" is to result is not the concept of shape as materials and in but that of phase as a spririt. 2. In yang taeg theory, architectural behavior (as selecting site, building and the day for building) is made form the base of that, a human being as a part of universe. 3. Geomantic aspect, to being, laid in an fying a human being and nature as spatial, time concept. 4. The concept of domain in feng-shui is found in village as well as in house.

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A study on surface photovoltage characteristics of $IN_{0.03}Ga_{0.97}AS/GaAs$ epilayer ($IN_{0.03}Ga_{0.97}AS/GaAs$에피층의 표면 광전압 특성에 관한 연구)

  • 최상수;김기홍;배인호
    • Journal of the Korean Vacuum Society
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    • v.10 no.1
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    • pp.81-86
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    • 2001
  • We have investigated surface photovoltage characteristics of InGaAs grown by metalorganic chemical vapor deposition (MOCVD) method on semi-insulating GaAs. The splitted SPV signals from the substrate and epilayer were observed. The band gap energy of InGaAs was about 1.376 eV, The In composition(x) was determined by Pan's composition formula. The photovoltage gradually decreases with increasing frequency. This is because the transfer of charge from the surface states reduces. From the temperature dependent SPV measurement, we obtained Varshni and temperature coefficients. In spectrum of etched sample at 300 K, the 'A' peak below $E_o(GaAs)$ is related with residual impurity during sample growth.

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Movpe Growth of InP/GaAs and GalnAs/GaAs from EDMln, TBP and TBAs (EDMln, TBP와 TBAs를 이용한 InP/GaAs와 GalnAs/GaAs의 MOVPE 성장)

  • 유충현
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.1
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    • pp.12-17
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    • 1998
  • The heteroepitaxial growth of InP and GaInAs on GaAs substrates has been studied by using a new combination of source materials: ethyldimethylindium (EDMIn) and trimethylgallium (TMGa) as group III sources, and tertiarybutylarsine (TBAs) and tertiarybutylphosphine (TBP) as group V sources. Device quality InP heteroepitaxial layers were obtained by using a two-step growth process under atmospheric pressure, involving a growth of an initial nucleation layer at low temperature followed by high temperature annealing and the deposition of epitaxial layer at a growth temperature. The continuity and thickness of nucleation layer were important parameters. The InP layers deposited at 500$^{\circ}$- 55$0^{\circ}C$ are all n-type, and the electron concentration decreases with decreasing TBP/EDMIn molar ratio. The excellent optical quality was revealed by the 4.4 K photoluminescence (PL) measurement with the full width at half maximum (FWHM) of 4.94 meV. Epitaxial Ga\ulcorner\ulcorner\ulcornerIn\ulcorner\ulcorner\ulcornerAs layers have been deposited on GaAs substrates at 500$^{\circ}$ - 55$0^{\circ}C$ by using InP buffer layers. The composition of GaInAs was determined by optical absorption measurements.

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A study of interfacial characteristics for $In_{0.1}Ga_{0.9}As/GaAs$ by photoreflectance measurement (Photoreflectance 측정에 의한 $In_{0.1}Ga_{0.9}As/GaAs$ 계면의 특성 조사)

  • 이철욱;김인수;손정식;김동렬;임재영;배인호
    • Journal of the Korean Vacuum Society
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    • v.6 no.3
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    • pp.263-266
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    • 1997
  • We studied an interfacial characteristics of $In_{0.1}Ga_{0.9}As$/ GaAs by photoreflectance (PR) measurement at room temperature. With increasing thickness of epitaxial layer, Franz-Keldysh oscillation (FKO) periods of PR signals were decreased, and interfacial electric field was decreased. This can be explained by the increases of defects due to lattice mismatch near the heterointerface between InGaAs and GaAs. For the thickness of epitaxial layer thinner than the 300$\AA$, InGaAs epitazial layer closed to critical thickness and increased strain, and then the bandgap energy shifted high greatly.

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Symbolic Values of Fur in Fashion Since 1990s - An Analysis under the Theories of Fetishism -

  • Hahn, Soo-Yeon;Yang, Sook-Hi
    • Journal of Fashion Business
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    • v.5 no.5
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    • pp.49-64
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    • 2001
  • Fur is conceived as a material signifier, not only with its commodity value as luxury goods but also as its symbolic value as objects invested by one's libidinal desire. In this study, complex meanings of fur as multi-layered signs of political and sexual power focusing on fetishism shall be explored, especially on the spectacle fetishism acted by mass media during the anti-fur movement in the 1980s. In conjuction herewith, a highlight shall also be made to the symbolic value in fashion design since 1990s. In this study, first, as a theoretical investigation, fetishism, that has been traditionally considered only as sexual fetishism in fashion discourse will be explored in socio-economic level. Second, in historical context, how the meanings and values of fur have become realized in various cultural spaces, such as literature, art, film and finally, fashion will be viewed. In fashion, fur is a product of desire and power influenced by commodity fetishism as well as sexual fetishism. During the anti-fur movement, mass media has developed the concept of spectacle fetishism. Fur is a sign of animal-victim, and fur-clad women is viewed with images full of imperialsm, sexism and racism, thus act as derisive spectacles of consumerism. Since 1990s as a reflection on anti-fur movement, fetishistic characteristics, which challenge traditional operation method, are expressed by disguise, parody, and returning to the nature. First, fur as disguise is intended to hide sexually perverse, decadent characteristics and expensiveness of fur by texturing or patterning techniques. Second, fur as parody uses fake fur or dyed fur in order to satirize erotically and ethnographically fetishized meanings of fur. Third, aboriginal design of fur is adapted to use symbolic values outside the West, which can potentially mobilize antagonistic oppositions out of their fetishistic regimes. In conclusion, fur as sign of female sexuality and its libidinal profits of exchange, has significant symbolic values expressed in fashion.

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Literature as a Strange Body: Modernity, Literariness and Dislocation

  • Lee, Alex Taek-Gwang
    • Journal of English Language & Literature
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    • v.64 no.4
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    • pp.617-628
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    • 2018
  • The aim of this essay is to discuss the relationship between Korean literature and Korean intellectual scenes. Since its first introduction to the local context, literature as a genre has served as a field in which colonial and post-colonial intellectuals have attempted to win the accreditation of Western enlightenment. Literature has been regarded as a crucial instrument of liberal arts and education in Korea. Literature has functioned as a social movement in Korea since its inception. During the colonial period, radical intellectuals and literary writers published essays and articles in literary journals. This status as a social movement is still a distinctive characteristic of Korean literature. From the outset, Korean literature has functioned as an enlightenment project for cultural development. As such, Korean literature retains a political meaning of "literariness," which reshuffles the hierarchy of the sensible and creates novelty against given aesthetic regimes. As a result, in the process these regimes are thereby de-purified of their status as purely aesthetic movements; their perspectives thereby come into contact with other discourses and practices outside the art world. This essay argues that as a genre, Korean literature always functions as "world literature" in Korean intellectual scenes.

Photoluminescence Up-conversion in GaAs/AlGaAs Heterostructures

  • Cheong, Hyeonsik M.
    • Journal of Korean Vacuum Science & Technology
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    • v.6 no.2
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    • pp.58-61
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    • 2002
  • Photoluminescence up-conversion in semiconductor heterostructures is a phenomenon in which luminescence occurs at energies higher than that of the excitation photons. It has been observed in many semiconductor heterostructure systems, including InP/AnALAs, CdTe/CdMgTe, GaAs/ordered-(Al)GalnP, GaAs/AIGaAs, and InAs/GaAs. In this wort, GaAs/AIGaAs heterostructures are used as a model system to study the mechanism of the up-conversion process. This system is ideal for testing different models because the band offsets are quite well documented. Different heterostructures are designed to study the effect of disorder on the up-converted luminescence efficiency. In order to study the roles of different types of carriers, the effect of doping was investigated. It was found that the up-converted luminescence is significantly enhanced by p-type doping of the higher-band-gap material.

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Monte Carlo Study of Hot-Electron Transport in AlInAs/GaInAs Modulation-Doped Structure (Monte Carlo 모의실험에 의한 AlInAs/GaInAs 변조 도핑 구조에서의 Hot-Electron Transport에 관한 연구)

  • Kim, Choong-Won;Park, Seong-Ho;Kim, Koung-Suk;Han, Baik-Hyung
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.3
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    • pp.79-85
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    • 1990
  • Monte Carlo simulation of hot-electron transport in $Al_{0.48}In_{0.52}As/Ga_{0.47}In_{0.53}$ As modulation-doped structure has been performed in which the nonparabolicity in $\Gamma$ valley is taken into account. The calculated results show that the inclusion of the nonparabolicty effect results in a huge decrease in drift velocity.

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Effects of barrier height on electron scattering mechanisms in $\delta-doped$ InAlAs/InGaAs/InAlAs Heterostructures

  • Park, H.S.;Vang, S.J.;Kim, J.I.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.955-959
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    • 2004
  • The effects of conduction band offset on 2 dimensional electron gas (2DEG) in N-InAlAs(AlAsSb)/InGaAs/InAlAs (AlAsSb) metamorphic heterostructures (MMHS) are studied. A combination of the Shubnikov-deHaas oscillations and the Hall measurements is used to investigate the electron transport properties of these structures. The mobility in the second subband is higher than that in the first subband in all heterostructures. This is attributed to the fact that electrons in the first subband we, on average, closer to the interface and are therefore scattered more strongly by ionized impurities. The results suggest that intersubband scattering rate is more dominant in structures with higher conduction band offset whereas alloy scattering is found to be more dominant in the higher band offset system.

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