• Title/Summary/Keyword: semiconductors

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Application of Neural Inverse Modeling Scheme to Optimal Parameter Tuning of Filter Test Equipment

  • Kim, Sung-Ho;Han, Yun-Jong;Bae, Geum-Dong
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.4 no.2
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    • pp.172-175
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    • 2004
  • Generally, the yield rate of semiconductors is the major factor that affects directly the price of semiconductors. For a high yield rate of semiconductors, the air inside clean room is needed to be purified and high efficient filters are used for this. The filter are made of super-fine fiber and certain pinholes can be easily produced on the filter's surface by inadvertent manufacturing. As these pinholes are not easily detected with the bare sight, these pinholes exert a negative impact to filtration performance of the filter. In this research, not only the automatic test equipment for detecting pinholes is proposed, but also inverse modeling scheme based on artificial neural network is applied for tuning of its important parameters.

Fabrication of Organic-Inorganic Nanohybrid Semiconductors for Flexible Electronic Device

  • Han, Gyu-Seok;Jeong, Hui-Chan;Gwon, Deok-Hyeon;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.114-114
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    • 2011
  • We report a high-performance and air-stable flexible and invisible semiconductor which can be substitute for the n-type organic semiconductors. N-type organic-inorganic nanohybrid superlattices were developed for active semiconducting channel layers of thin film transistors at low temperature of $150^{\circ}C$ by using molecular layer deposition with atomic layer deposition. In these nanohybrid superlattices, self-assembled organic layers (SAOLs) offer structural flexibility, whereas ZnO inorganic layers provide the potential for semiconducting properties, and thermal and mechanical stability. The prepared SAOLs-ZnO nanohybrid thin films exhibited good flexibility, transparent in the visible range, and excellent field effect mobility (> 7cm2/$V{\cdot}s$) under low voltage operation (from -1 to 3V). The nanohybrid semiconductor is also compatible with pentacene in p-n junction diodes.

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The theory of non-Markovian optical gain in excited semiconductors

  • Ahn, Doyeol
    • Proceedings of the Optical Society of Korea Conference
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    • 1995.06a
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    • pp.138-148
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    • 1995
  • A reduced description of the dynamics of carriers in excited semiconductors is presented. Fristly, a time-convolutionless equation of motion for the reduced density operator is derved from the microscopic Liouville wquation operator method. Secondly, the quantum kinetic equations for intercting electron-hole parirs near band-edge in semiconductors under an extermal optical field are obtained from the equation of motion for the reduced density operator. The non-Markovian optical gain of a driven semiconductor is derived including the many-body effects. plasma screening and excitinic effects are taken into account using as effective Hamiltonian in the time-dependent Hartree-Fock approximation. it is shown that the line shape of optical-gain spectra gain is enhanced by the exicitonic effects caused by the attrative electron-hole Coulomb interaction and the interference effects (renormalized memory effects) between the extermal driving filed and the intermal driving Filed and the stochastic reservoir of the system.

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High performance organic gate dielectrics for solution processible organic and inorganic thin-film transitors

  • Ga, Jae-Won;Jang, Gwang-Seok;Lee, Mi-Hye
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.64.1-64.1
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    • 2012
  • Next generation displays such as high performance LCD, AMOLED, flexible display and transparent display require specific TFT back-planes. For high performance TFT back-planes, low temperature poly silicon (LTPS), and metal-oxide semiconductors are studied. Flexible TFT backplanes require low temperature processible organic semiconductors. Not only development of active semiconducting materials but also design and synthesis of semiconductor corresponding gate dielectric materials are important issues in those display back-planes. In this study, we investigate the high heat resistant polymeric gate dielectric materials for organic TFT and inorganic TFT with good insulating properties and processing chemical resistance. We also controlled and optimized surface energy and morphology of gate dielectric layers for direct printing process with solution processible organic and inorganic semiconductors.

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Samsung Austin Semiconductors: Its Adaptation, Survival and Growth (삼성반도체의 현지화 전략)

  • Noh, Jeon-Pyo
    • Korean Business Review
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    • v.15
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    • pp.47-58
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    • 2002
  • Samsung Electronics has 25 production bases, 36 marketing subsidiaries and 23 overseas offices in 46 countries around the world. Samsung Electronics global strategy involves seven main regions: North America, Europe, Southeast Asia, Central Asia, China, the CIS and Latin America. Samsung Electronics is dedicated to helping the local communities where it does business, helping to advance local economies and develop products that best suit local needs. This case attempts to introduce the localization strategies of Samsung Austin Semiconductors especially with respect to the community service programs. Samsung Austin Semiconductors develops a framework for a firm to adapt in a foreign environment creating corporate citizenship. This model surely helps the firm to adapt, survive and grow even in a hostile foreign environment.

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New Approach to Reduce Radiated Emissions from Semiconductor by Using Absorbent Materials

  • Kim, Soo-Hyung;Moon, Kyoung-Sik
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.1
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    • pp.34-41
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    • 2001
  • Semiconductors performing digital clocking are a main source of radiated emission noise. Therefore, the most secure method of reducing emission noise is to reduce emission radiated from semiconductors; an application of an absorber to the surface of semiconductors is one of these methods, too. However, in reality, it is difficult to achieve as much effect of noise reduction as expected by using only absorber. It is confirmed by experiment in this paper that a loop area within chip has no correlation with radiated emission noise and it is clarified why the existing absorber fails to achieve a satisfactory effect of emission noise reduction. Besides, a new type of chip coating absorber has been developed which can cover up to semiconductor out lead by using ferrite coating material of ferrite/epoxy acrylate substance using only permeability loss out of electromagnetic wave reduction characteristics of materials. As a result of evaluating radiated emission noise by applying this coating absorber to semiconductor device, it could be confirmed that emission noise decreased from about 3 ㏈ up to 20㏈ depending on frequency.

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Study of the Non-polar Optical Phonon Scattering According to the Size of Unit Cell in an Alloy Semiconductor (혼합물반도체에서 단위격자 크기 설정에 따른 비극성 Optical 포논산란에 대한 연구)

  • Chun, Dae-Myung;Kim, Tae-Hyun;Chun, Sang-Kook
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.10
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    • pp.784-789
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    • 2011
  • A linear spring model, where the interactions among atoms are assumed to be isotropic and elastic, is employed for the study of non-polar optical phonon scattering in the valence band of alloy semiconductors. The force equations of n atoms are used in the spring model for the consideration of the random distribution of constituent atoms in an alloy semiconductor. When the number of atoms in a unit cell is assumed to be two based on the experimental result, the optical deformation potent is valid for compound semiconductors as well as alloy semiconductors.

Study on Operating Characteristics of a Water Cooling System for cooling Power Conversion Semiconductors (전력변환반도체 냉각용 수냉각장치의 작동특성에 관한 연구)

  • Ryoo, Seong-Ryoul;Kim, Sung-Dae;Yim, Kwang-Bin;Kim, Chul-Ju
    • Proceedings of the KSR Conference
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    • 2009.05b
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    • pp.249-256
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    • 2009
  • The cooling technology of power conversion semiconductors in the propulsion system for the HEMU(High Electrical Multi Unit) are applied in water cooling method and phase change method such as the immersed type and the heat pipe type. This research designs and manufactures the water cooling system that could cool about heat load Q=2kW and performance tests to apply it by an electric power conversion semiconductors(IGBT) cooling technology. Experimental condition made change of a flow rate, an air velocity and a heat load to confirm operation characteristics of water cooling device, and when is heat load 2kW, air velocity 20 m/s, and water flow rate 7kg/s, it is about $80^{\circ}C$ to temperature of cooling plate.

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ROOM TEMPERATURE FERROMAGNETISM IN TRANSITION METAL DOPED OXIDE SEMICONDUCTORS, $TiO_2$ and ZnO

  • Y. H. Jeong;S-J. Han;Park, J.H.
    • Proceedings of the Korean Magnestics Society Conference
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    • 2003.06a
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    • pp.17-17
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    • 2003
  • Semiconductors with ferromagnetism at room temperature has been actively searched for in recent years; a prospect of devices using both charge and spin continuously gives impetus to the activities. Transition metal doped oxide materials have been of particular interest. Co substituted ZnO [1] and TiO$_2$ [2] thin films, for example, were reported to show ferromagnetic properties at room temperature. However, various studies do not seem to converge on a definite picture [3,4,5]. The issue is rather fundamental: whether a system shows ferromagnetic properties at all, and in case it does, whether the system possesses a close coupling between magnetism and transport properties. In this talk, we shall assess the current status of transition metal doped oxide materials as room temperature ferromagnetic semiconductors.

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Apple's Semiconductor Internalization Strategy (애플의 반도체 내재화 전략)

  • H.S. Chun;S.M. Kim
    • Electronics and Telecommunications Trends
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    • v.38 no.3
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    • pp.86-97
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    • 2023
  • The outbreak of the novel coronavirus disease in 2020 caused a global semiconductor supply shortage and disruption in the production of devices such as iPhones owing to China's quarantine lockdown. Thus, Apple is diversifying its production bases from China to countries like India and Vietnam. The company is also accelerating semiconductor development to guarantee a stable supply, reduce design costs, and customize semiconductors with high quality and outstanding specifications for their products to outperform devices that use general-purpose semiconductors. Following the mobile application processor, Apple is releasing world-class semiconductors, such as the M1 and M2 chips that play the role of central processing units.