• Proceedings of the Korean Vacuum Society Conference
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• 2006.08a
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• pp.151-151
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• 2006

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.85-85
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• 2003

최근 양자구속 구조 중에서 Stranski-Krastanow 모드에 의해 형성된 양자점에 관한 연구가 활발히 진행되고 있다 양자점은 단전자소자, 고밀도메모리, 발광소자와 같은 양자기능성 소자 제작을 위한 가장 유력한 후보로서 각광받고 있다. 그러나 평탄한 기판 위에서 양자점은 무질서한 형태로 성장되어 양자점의 정확한 위치 조절이 어렵다. 또한 양자점의 위치 조절을 위해서는 정밀한 리소그라피와 정밀한 성장조건이 요구된다. 본 연구에서는 최초로 저압 MOCVD를 사용하여 일차원 InAs 양자점을 GaAs 기판에 새겨진 V 홈 바닥을 따라 위치 조절하여 형성하였다.

• Proceedings of the Korean Statistical Society Conference
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• 2003.10a
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• pp.91-95
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• 2003

본 논문에서는 정보 전달 능력이 향상된 변형된 축차확률비검정을 소개한다. 새로운 검정은기존의 검정과 수학적인 면에서 공동된 점들을 갖고 있으나, 이상치의 영향을 덜 받고 더욱이 그 존재에 대하여 시각적으로 보여주며, 또한 자료의 변화에 보다 민감하게 반응하는 특성이 있다. 새롭게 제안된 로버스트 축차확률비검정 시스템을 Microsoft사의 Visual Basic 6.0 언어로 구현하여 본 연구에서 제안한 모델과 기존의 검정모델을 비교한 결과 제안된 검정 모델의 우수성과 실용가능성을 실증적으로 확인하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.11a
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• pp.170-170
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• 2001

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2005.09a
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• pp.129-132
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• 2005

투명전극용 AZO 박막을 RF 마그네트론 스퍼터로 낮은 온도에서 제조하였다. Al을 도핑한 ZnO 박막을 유리위에 증착하였고, AZO의 구조적, 전기적 그리고 광학적 특성을 조사하였다. 증착된 박막은 hexagonal wurtzite 구조를 가진 다결정계이다. 이 박막은 가시광선 영역에서 $90.7\%$ 이상의 투과율을 보였고, 가장 낮은 비저항 값은 $5.86{\times}10^{-4}{\Omega}{\cdot}cm$이었다.

• Korean Journal of Materials Research
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• v.13 no.11
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• pp.708-710
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• 2003

One-dimensional array of InAs quantum dots (QDs) have been grown on V-grooved GaAs substrates by low-pressure metalorganic chemical vapor deposition. Atomic force microscope images show that InAs QDs are aligned in one-dimensional rows along the ［011］oriented bottom of V-grooves and no QDs are formed on the sidewalls and the surface of mesa top. Capability to grow one-dimensional InAs QDs array would feasible for the single electron tunneling devices and other novel quantum-confined devices.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.207-207
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• 2003

Uncooled infrared(IR) detectors that use a microbolometer with a large focal-plane array(FPA) have been developed with surface micromachining technology. There are many materials for microbolometers, such as metals, vanadium oxide, semiconductors and superconductors. Among theses, vanadium oxide is a promising material for uncooled microbolometers due to it high temperature coefficient of resistance(TCR) at room temperature. It is, however, is very difficult to deposit vanadium oxide thin films having a high TCR and low resistance because of the process limits in microbolometer fabrication. In general, vanadium oxides have been applied to microbolometer in mixed phases formed by ion beam deposition methods at low temperature with TCR in the range from -1.5 to -2.0%K.

• 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.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.461-464
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• 1998

Self-aligned AlGaAs/GaAs HBTs with the emitter area of 1.5*10.mu.$m^{2}$ were fabricated usng $WN_{x}$ as emitter metal. Their DC and RF characteristics were investigated. The common emitter current gain was 45 at $J_{c}$ = 6*$10^{4}$A/$cm^{2}$. From the Gummel plot, the ideality factors of $I_{c}$ and $I_{B}$ were 1.18 and 1.70, respectively. Emitter and base resistance were extracted from voltage drop region in gummel plot, and their values were 5.3.ohm. and 38.2.ohm.. The extrapolated $f_{T}$ = 72GHz and $f_{max}$ = 81GHz were obtained at $V_{CE}$ = 2V.

• Journal of the Korean Vacuum Society
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• v.8 no.2
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• pp.153-157
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• 1999

The dependence of the absorption edge of wurtzite $Al_xGa_{1-x}N$ on alN mole fraction has been studied. The AlN mole fraction was varied from 0 to 1. The absorption coefficients at room temperature were determined by transmission and photothermal deflection spectroscopy. Photothermal deflection spectroscopy can be applied to determine the low absorbance values. From the results, the effective bandgaps of $Al_xGa_{1-x}N$ alloys were determined by choosing corresponding photon energies of the positions of the absorption coefficient of $6.3\times10^4\textrm{cm}^{-1}$ at the absorption curves of the $Al_xGa_{1-x}N$ alloys. From the energy position of the absorption coefficient versus AlN mole fraction, a bowing parameter of 1.3eV was determined. The bowing parameter agreed quite well with the measured effective bandgaps of AlGaN alloys.