• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.96.2-96.2
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• 2010

The surface morphology and structural properties of polycrystalline silicon (poly-Si) films made in-situ aluminum induced crystallization at various substrate temperature (300~600) was investigated. Silicon films were deposited by hot-wire chemical vapor deposition (HWCVD), as the catalytic or pyrolytic decomposition of precursor gases SiH4 occurs only on the surface of the heated wire. Aluminum films were deposited by DC magnetron sputtering at room temperature. continuous poly-Si films were achieved at low temperature. from cross-section TEM analyses, It was confirmed that poly-Si above $450^{\circ}C$ was successfully grown on and poly-Si films had (111) preferred orientation. As substrate temperature increases, Si(111)/Si(220) ratio was decreased. The electrical properties of poly-Si film were investigated by Hall effect measurement. Poly-Si film was p-type by Al and resistivity and hall effect mobility was affected by substrate temperature.

• Journal of the Korean Ceramic Society
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• v.39 no.12
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• pp.1149-1152
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• 2002

Indentation was used to analyze high pressure phases of silicon. Phase transformations on both loading time and loading rate were studied. Micro-raman spectroscopy was used to observe the indentation-induced transformations. As the loading time increased, Si-III and Si-XII disappeared and only a-Si was observed in (111) samples. As the loading time increased, the residual stress was removed by creation of cracks or dislocations. At 0.1 mm/min loading rate, pop-in . At 5 mm/min loading rate pop-in was observed in force/displacement curve of (111) sample, but pop-in was not observed in force/displacement curve of (100) sample. This result indicates that the loading rate affects the volume of phase transformation in silicon.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.153-153
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• 2000

Si 산화는 반도체 공정상 필요한 과정으로 산업적으로나 학문적으로 중요하고 많이 연구되었다. 이중에서 Si(1110-7x7표면에서 초기 흡착된 산소는 준안정적 상태로 존재하며 표면온도, 산소의 노출량 그리고 진공도에 따라 그 수명이 제한된다. 이러한 준안정적 상태의 산소의 화학적 성질은 여러 표면분석장비가 동원되어 연구되었으나 아직까지 논쟁이 되고 있다. 이 경우 산소가 어떤 상태로 존재하는가는 표면화학종을 검출함으로서 해결될 수 있다. 저에너지 Cs+ 이온 반응성 산란은 이러한 요구를 충족시킬수 있는 가장 적합한 실험 방법중의 하나이다. 저에너지 Cs+ 이온 산란의 특징 중의 하나는 입사된 Cs+ 이온이 표면에 흡착된 화학종과 충돌후 탈착되면서 반응을 하여 송이 이온을 형성한다는 것이다. 이 송이 이온을 관측함으로서 표면에 존재하는 화학종을 알아 낼 수 있다. 이에 산소가 흡착된 Si(111)-7x7 표면에서의 산소의 준안정적 상태가 저에너지 Cs+ 이온 산란 실험을 통하여 연구되었다. 실험은 0.2-2L(1Langmuir = 10-6 Torr x 1 sec) 산소 노출량과 -15$0^{\circ}C$ - $25^{\circ}C$의 표면온도 그리고 5eV - 20eV의 Cs+ 이온 충돌에너지에서 CsSiO+ 이온이 유일한 생산물로서 검출되었다. CsSiO+ 이온은 입사된 Cs+ 이온과 표면에 존재하는 SiO 분자가 충돌 후 반응하여 탈착된 것으로 생각된다. 이것은 낮은 산소 노출량 즉, 초기 산화 단계에서 SiO가 표면에 존재한다는 것을 의미한다. 즉, 산소 분자는 산화단계의 초기에 해리되어 표면에 흡착되고 선구물질인 SiO를 형성함을 제시한다. 최근의 이론적 계산인 density functional calculation에서도 산소분자가 Si(111)-7$\times$7 표면의 준안정적 산화상태의 선구물질일 가능성을 배제한다. 이는 본 저에너지 Cs+ 이온 반응성 산란실험을 뒷받침하는 계산 결과이다. 높은 Cs+ 이온 충돌에너지에서 CsSi+, Si+, SiO+, Si2+, Si2O+ 등이 추가로 검출되었다. 이는 CsSi 이온을 제외하고 수 keV의 충돌에너지를 사용하는 이차 이온 질량 분석법과 비슷한 결과이다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.115-115
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• 2009

Epitaxial ZnO film was grown on Si(111) substrate with oxidazed CrN buffer by plasma-assisted molecular beam epitaxy (PAMBE). The growth and structural properties are investigated. The single crystalline growth was revealed by in-situ RHEED analysis. Crystalline quality of ZnO film grown on oxidized CrN buffer was investigated by the X-ray rocking curves. The FWHMs of (0002) XRCs was $1.379^{\circ}$. This value was smaller than the ZnO film grown directly on (111) Si substrate.

• Journal of the Korean Vacuum Society
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• v.2 no.4
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• pp.399-403
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• 1993

Si(111)7 $\times$ 7 위에 Mg를 흡착시켜 표면구조의 변화를 RHEED(Reflection High Energy Electron diffraction) 와 XPS(X-ray PhotoelectronSpectroscopy)를 이용하여 연구하였다. RT ~20$0^{\circ}C$까지의 기판온도에서 증착량의 증가에 따라 표면구조는 (7$\times$7)에서 diffused (1$\times$1) 그리고 (2 3 3 $\times$2√3√3-R30$^{\circ}$) 구조로 변화하였다. 또한, 기판온도를 증가시킴에 따라 (1$\times$1), three domain(3$\times$1) 등의 구조를 볼 수 있었고, 특히 , $450^{\circ}C$의 기판온도에서는 single domain (3$\times$1) 구조를 최초로 관측하였다. 이렇게 형성된 각 구조에 대한 Mg KLL과 Si2p의 XPS peak intensity ratio를 증착량의 증가에 따라 측정하여 각기 다른 온도에서의 Mg 성장에 대한 메카니즘을 제시하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.231-231
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• 2005

• Proceedings of the Materials Research Society of Korea Conference
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• 2000.11a
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• pp.99-99
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• 2000

• Proceedings of the Korean Magnestics Society Conference
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• 1999.10a
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• pp.98-99
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• 1999

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.395-402
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• 1997

The $SiO_2$ films were prepared by ECR(electron cyclotron resonance) plasma diffusion method, Deal-Grove model and Wolters-Zegers-van Duynhoven model were used to estimate the oxidation rate which was correlated with surface morphology for different orientation of Si(100) and Si(111). It was seen the $SiO_2$ thickness increased linearly with initial oxidation time. But oxidation rate slightly decrease with oxidation time. It was also shown that the oxidation process was controlled by the diffusion of the reactive species through the oxide layer rather than by the reaction rate at the oxide interface. The similar time dependency has been observed for thermal and plasma oxidation of silicon. From D-G model and W-Z model, the oxidation rate of Si(111) was 1.13 times greater than Si(100) because Si(111) had higher diffusion and reaction rate, these models more closely fits the experimental data. The $SiO_2$ surface roughness was found to be uniform at experimental conditions without etching although oxidation rate was increased, and to be nonuniform due to etching at experimental condition with higher microwave power and closer substrate distance.

• Journal of the Korean Vacuum Society
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• v.7 no.3
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• pp.237-241
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• 1998

The growth orientation and the surface roughness of AIN/Si(111) films grown by radio frequency (RF) reactive magnetron sputtering were investigated using in-situ x-ray scattering technique and atomic force microscopy (AFM). AIN films were initially grown with the <001> preferred growth orientation under most growth conditions. As the film gets thicker, however, the growth orientation changes significantly, especially at high substrate temperature and high RF powers. We attribute the observed behavior to the competition between the surface energy that prefers the <001> growth orientation and the strain energy that randomizes the growth orientation. In addition, we investigated the evolution of the surface morphology during the growth using the x-ray reflectivity measurement.