• Journal of the Korean Vacuum Society
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• v.7 no.s1
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• pp.85-99
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• 1998

A ultrahigh vacuum chemical vapor deposition(UHVCVD)/metalorganic chemical vapor deposition(MOMBE) system equipped with a radio frequency(RF)-plasma cell was employed to grow GaN layer on the sapphire at a low temperature. The x-ray photoelectron spectroscopy analysis of nitrogen composition on the nitridated sapphite surface indicated that a nitridation process is mostly affected by the RF power at low temperature. Atomic force microscope images of nitridated surface the protrusion density on the nitridated sapphire is dependent on the nitridation temperature. The crystallinity of GaN grown at $450^{\circ}C$ was found to be much improved when the sapphire was nitridated at low temperature prior to the GaN layer growth. Moreover, a strong photoluminescence spectrum of GaN grown by UHVCVD/MOMBE with a rf-nitrogen plasma was observed for the first time at room temperature.

• Transactions on Electrical and Electronic Materials
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• v.8 no.2
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• pp.58-66
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• 2007

In this paper, the process effect on the RMS roughness of the $HfO_2$ thin films grown by metal organic molecular beam epitaxy was investigated. The measured RMS roughness is examined to characterize the surface morphology. In order to analyze the factor effects, the significant factors of both the main and the interaction effects were extracted through the effect analysis. In order to compare the regression model with the variable transformation, the effect of each factor and the model efficiency are calculated. The methodology can allow us to analyze the effects between the process parameters related to the process variability.

• Journal of the Korean Vacuum Society
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• v.4 no.3
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• pp.275-282
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• 1995

III족 원료 가스로 triethylgallium(TEGa)과 trimethylindium(TMIn)을 사용하고 V족 원료 가스로 사전 열 분해하지 않은 arsine(AsH3)과 monoethylarsine(MEAs)을 사용하여 ultrahigh vacuum chemical vapor deposition(UHVCVD)법으로 Si3N4로 패턴된 GaAs(100)기판 위에 GaAs와 InGaAsqkr막을 선택적으로 에피택시 성장을 하였다. V족 원료 가스를 사전 열 분해하지 않으므로 넓은 성장 온도 구간과 V/lll 비율에서도 선택적으로 박막이 성장되었다. 또한 선택 에피택시의 성장 메카니즘을 규명하기 위하여 다양한 filling factor(전체면적중 opening된 면적의 비율)를 가지는 기판을 제작하여 성장에 사용하였다. UHVCVD법에서는 마스크에 면적중 opening된 면적의 비율)를 가지는 기판을 제작하여 성장에 사용하였다. UHVCVD법에서는 마스크에 입사된 분자 상태의 원료 기체가 탈착된 후 표면 이동이나 가스 상태의 확산과정 없이 마스크로부터 제거되므로 패턴의 크기와 모양에 따른 성장 속도의 변화나 조성의 변화가 없을 뿐만 아니라 chemical beam epitaxy(CBE)/metalorganic molecular beam epitaxy(MOMBE)법에서 알려진 한계 성장온도 이하에서 선택 에피택시 성장이 이루어졌다.

• Electronics and Telecommunications Trends
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• v.3 no.4
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• pp.3-12
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• 1988

Epilayer growing process has been recognized as a key technology for successful GaAs based devices and integrations. These may include HEMT, multiple quantum well structures, band gap engineering, and quantum confinement heterostructures. The fabrication of epilayers in these devices must meet very stringent requirements in terms of crystallinity, composition, film thickness and interface quality. In particular, the quality of interfaces is getting more important because the film thickness, and flatness, roughness and stability at interface of ultrathin films cause critical effects on the device performance. This article reviews the current status of modern epitaxial techniques which have been developed in the last few years. First, the new techniques PLE, GI, MEE, TSL based on MBE technique will be reviewed and their technical importance will be stressed. Secondly, MOMBE, GSMBE, CBE which combine the advantages of MBE and MOCVD will also be discussed. Thirdly, the new sophisticated epitaxial technique, ALE, of which mechanism is totally different from others, will also be reviewed. Finally, areas which should be exploited more extensively to accomplish these techniques will be addressed.